{"gene":"NHERF1","run_date":"2026-06-10T05:19:52","timeline":{"discoveries":[{"year":1997,"finding":"EBP50/NHERF1 was identified as a PDZ-containing phosphoprotein that directly binds the N-terminal domains of ezrin and moesin (N-ERMADs) via affinity chromatography. It colocalizes with actin and ezrin in apical microvilli of epithelial cells and can be co-immunoprecipitated with ezrin from human placental microvilli, establishing it as a physiologically relevant ezrin-binding protein that links membrane proteins to the actin cytoskeleton through its PDZ domains.","method":"Affinity chromatography, co-immunoprecipitation, immunofluorescence microscopy, immunoelectron microscopy, recombinant protein binding assays","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — multiple orthogonal methods (affinity chromatography, Co-IP, direct binding assay, immunolocalization) in a single foundational study, widely replicated","pmids":["9314537"],"is_preprint":false},{"year":1998,"finding":"The C-terminal 30 residues of EBP50 are sufficient to bind ezrin residues 1-286, but EBP50 does not bind full-length ezrin because the EBP50-binding site is masked by intramolecular N/C-ERMAD association. Binding of EBP50 and the C-ERMAD to the ezrin N-terminal domain is mutually exclusive, with C-ERMAD having higher affinity, establishing a model of regulated ezrin activation to expose the EBP50 binding site.","method":"Blot overlays, in-solution binding assays, truncation/deletion mutagenesis of EBP50 and ezrin","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro reconstitution with mutagenesis, multiple binding assays, mechanistic model validated by competition experiments","pmids":["9660814"],"is_preprint":false},{"year":1998,"finding":"NHERF/EBP50 and the related E3KARP function as scaffold adapters that bind both NHE3 and ezrin simultaneously, linking NHE3 to ezrin to localize PKA type II near NHE3 and enable PKA-mediated phosphorylation and inhibition of NHE3. NHERF is a phosphoprotein under basal conditions but does not change phosphorylation state after cAMP treatment; E3KARP is not phosphorylated.","method":"Co-immunoprecipitation, in vivo phosphorylation studies, intracellular pH measurement of Na+/H+ exchange activity, cAMP analog pharmacology","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP plus functional activity assays, replicated in subsequent studies","pmids":["9792717"],"is_preprint":false},{"year":1999,"finding":"EBP50 PDZ domain 1 binds CFTR and PDZ domain 2 binds YAP65, localizing YAP65 to the apical membrane of airway epithelial cells. The EBP50-YAP65 interaction recruits the nonreceptor tyrosine kinase c-Yes into apical EBP50 protein complexes. Mutant YAP65 lacking the EBP50-interaction motif is mislocalized when expressed in airway epithelial cells.","method":"Co-immunoprecipitation, immunofluorescence, expression of mutant proteins, confocal microscopy","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — Co-IP in cells, functional mislocalization with domain-deletion mutants, multiple orthogonal methods","pmids":["10562288"],"is_preprint":false},{"year":2000,"finding":"NHERF1 PDZ domain 1 interacts with murine Trp4, Trp5, and phospholipase C-β1 and β2. Co-immunoprecipitation confirmed the Trp4-NHERF1 and PLC-β1-NHERF1 association in HEK293 cells expressing Trp4 and in adult mouse brain, establishing that NHERF1 scaffolds store-operated channels with PLC isozymes and links them to the actin cytoskeleton via ERM proteins.","method":"Yeast two-hybrid, GST pulldown, co-immunoprecipitation from HEK293 cells and mouse brain lysates","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP in two distinct cellular contexts, multiple binding partners confirmed","pmids":["10980202"],"is_preprint":false},{"year":2000,"finding":"NHERF associations with both NHE3 (via PDZ domains) and ezrin (via C-terminal ERM-binding domain) are both required for cAMP-mediated phosphorylation and inhibition of NHE3. Truncated NHERF lacking the ezrin-binding domain (NHERF 1-325) bound NHE3 but failed to support cAMP-mediated NHE3 inhibition or NHE3 phosphorylation, demonstrating that the NHERF-ezrin scaffold is essential for PKA access to NHE3.","method":"Stable transfection of truncated NHERF constructs in PS120/NHE3 cells, co-immunoprecipitation, Na+/H+ exchange activity assays, in vivo phosphorylation","journal":"Biochemistry","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — domain-deletion mutagenesis combined with functional assays and phosphorylation measurements, mechanistically decisive","pmids":["10821685"],"is_preprint":false},{"year":2001,"finding":"NHERF-1 PDZ domains can oligomerize; oligomerization of NHERF-1 (but not NHERF-2) is facilitated by ligand binding to its PDZ domains (e.g., β2-adrenergic receptor or PDGFR C-termini). Phosphomimetic mutation S289D enhances NHERF-1 homo- and hetero-oligomerization, while S289A reduces it. NHERF-1 and NHERF-2 form homo- and hetero-oligomers in cells.","method":"Purified PDZ domain association assays, co-immunoprecipitation with differentially tagged constructs, phosphomimetic/phosphodeficient mutagenesis","journal":"Biochemistry","confidence":"High","confidence_rationale":"Tier 1-2 / Moderate — in vitro reconstitution with purified domains plus cellular Co-IP, mutagenesis, single lab","pmids":["11456497"],"is_preprint":false},{"year":2002,"finding":"Targeted disruption of NHERF-1 in mice causes internalization of the renal sodium-phosphate cotransporter Npt2 away from the brush-border membrane, resulting in renal phosphate wasting. NHE3 localization at the apical surface is unaffected, demonstrating a unique and specific role for NHERF-1 in apical targeting/retention of Npt2 that is not shared by NHERF-2.","method":"Gene knockout mouse model, immunocytochemistry, brush-border membrane fractionation, urine electrolyte analysis","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic loss-of-function with defined molecular and physiological phenotype, replicated in subsequent studies","pmids":["12169661"],"is_preprint":false},{"year":2002,"finding":"EBP50/NHERF1 PDZ domain 1 binds the human kappa opioid receptor (hKOR) C-terminus; agonist treatment enhances this association. NHERF1 expression (requiring its ERM-binding domain) blocks U50,488H-induced hKOR down-regulation by increasing receptor recycling rate, without affecting agonist binding, G-protein signaling, desensitization, or internalization. C-terminal mutations in hKOR that prevent NHERF1 binding abolish this protective effect.","method":"Co-immunoprecipitation in CHO cells, radioligand binding, flow cytometry, mutagenesis of receptor C-terminus and NHERF1 domains","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — Co-IP, functional receptor trafficking assays, domain mutagenesis of both interacting proteins","pmids":["12004055"],"is_preprint":false},{"year":2003,"finding":"NHERF-1 uniquely transduces cAMP signals that inhibit NHE3 in mouse renal brush-border membranes. In NHERF-1(-/-) BBMs, cAMP-activated PKA failed to inhibit NHE3 activity and failed to phosphorylate NHE3, despite normal levels of NHE3, NHERF-2, PKA, and ezrin, demonstrating that NHERF-2 cannot compensate for NHERF-1 in this signaling context.","method":"Isolated brush-border membrane vesicles from NHERF-1 knockout mice, Na+/H+ exchange activity assays, NHE3 phosphorylation by immunoprecipitation","journal":"FEBS letters","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic KO with biochemical and functional assays on native membranes, unambiguous phenotype","pmids":["12586353"],"is_preprint":false},{"year":2003,"finding":"NHERF1 (EBP50) inhibits activation-independent, arrestin-independent PTH1R internalization. In cells lacking NHERF1, PTH antagonists (PTH 7-34, PTH 7-84) induce dynamin-dependent but β-arrestin-independent PTH1R endocytosis. NHERF1 expression blocked this endocytosis; dominant-negative NHERF1 conferred internalization sensitivity to cells normally expressing NHERF1. Both the PTH1R PDZ-binding motif and NHERF1 ERM domain are required; actin polymerization is necessary for NHERF1-mediated retention.","method":"Radioligand binding, live-cell confocal microscopy of fluorescent PTH1R, dominant-negative constructs, PDZ-binding motif mutagenesis, actin depolymerization experiments","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal approaches including live imaging, mutagenesis, dominant-negatives, and pharmacological perturbation","pmids":["12920119"],"is_preprint":false},{"year":2003,"finding":"EBP50 interacts with β-catenin through its C-terminal PDZ domain both in vitro and in vivo. Over-expression of EBP50 enhances β-catenin/TCF-dependent transcription in a dose-dependent manner in hepatocellular carcinoma and colorectal cancer cells, but only when β-catenin is already stabilized.","method":"Protein interaction screening, GST pulldown, co-immunoprecipitation, luciferase reporter assays, Northern/RT-PCR, immunohistochemistry","journal":"Hepatology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP and in vitro binding confirmed, functional transcription assays, single lab","pmids":["12830000"],"is_preprint":false},{"year":2003,"finding":"NHERF-1 is required for PTH regulation of Na-K ATPase in renal proximal tubule cells. Wild-type NHERF-1 supported PTH-induced inhibition of Na-K ATPase and increased serine phosphorylation of its α-subunit; NHERF-1 lacking the ezrin-binding domain (1-325) blunted α-subunit phosphorylation and reversed the response to stimulation. Basal sodium-dependent phosphate transport was lower in cells expressing the truncation.","method":"Stable transfection of NHERF-1 truncation mutants in opossum kidney cells, ouabain-sensitive ATPase activity assays, phosphorylation assays","journal":"Journal of the American Society of Nephrology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — domain truncation mutagenesis with functional assays, single lab, limited replication","pmids":["12819230"],"is_preprint":false},{"year":2004,"finding":"Podocalyxin activates RhoA and induces apical actin redistribution through NHERF (NHERF2) and ezrin in MDCK cells. Full-length podocalyxin, but not a mutant lacking the NHERF binding site, connects to actin, activates RhoA, and redistributes actin apically. Ezrin was found to bind directly to the juxtamembrane cytoplasmic region of podocalyxin.","method":"Stable cell lines expressing full-length or PDZ-binding-deficient podocalyxin, pulldown assays, RhoA activity assays, immunofluorescence","journal":"Journal of the American Society of Nephrology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss-of-binding mutant, RhoA activity assay, pulldown mapping, single lab","pmids":["15339978"],"is_preprint":false},{"year":2004,"finding":"NHERF-1/EBP50 PDZ domain 1 directly binds the hKOR C-tail (but not μ or δ opioid receptor C-tails), and this interaction enhances NHERF-1 oligomerization. In OK cells expressing endogenous NHERF-1, kappa opioid receptor stimulation increases Na+/H+ exchange in a pertussis toxin-independent manner; in OKH cells (NHERF-1-deficient), this effect is absent and restored by NHERF-1 transfection, establishing that NHERF-1 mediates KOR-stimulated NHE3 activity.","method":"GST pulldown with purified proteins, co-immunoprecipitation, intracellular pH/Na+/H+ exchange assays, NHERF-1 stable transfection in OKH cells","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — direct GST pulldown with purified proteins, Co-IP, loss-of-function/gain-of-function functional assays","pmids":["15070904"],"is_preprint":false},{"year":2005,"finding":"NHERF-1 inhibits agonist-induced internalization of the adrenomedullin AM2 receptor complex (CRLR/RAMP3) by tethering it to the actin cytoskeleton via the ERM-binding domain of NHERF-1. NHERF-1 interaction is RAMP3-isoform specific (not RAMP1 or RAMP2). RAMP3 and NHERF-1 interact via a PDZ type I domain on NHERF-1. siRNA knockdown of RAMP3 or NHERF-1 in human proximal tubule cells enabled agonist-induced internalization.","method":"Co-immunoprecipitation, overlay assays, mutational analysis, siRNA knockdown, internalization assays in HEK293T and primary proximal tubule cells","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — endogenous and overexpression models, siRNA knockdown, mutagenesis of ERM domain, RAMP isoform specificity established","pmids":["15805108"],"is_preprint":false},{"year":2007,"finding":"NHERF1 adopts a head-to-tail autoinhibited conformation in which the C-terminal EB region binds the PDZ2 domain, masking both PDZ domains from interacting with ligands such as PTEN and β-catenin. Prior association of ezrin with the EB region disrupts this intramolecular interaction, releasing PDZ domain accessibility. NHERF2 does not exhibit this regulatory conformation.","method":"In vitro binding assays, mutagenesis, co-immunoprecipitation, confocal microscopy in polarized epithelial cells","journal":"Molecular and cellular biology","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — in vitro binding reconstitution, mutagenesis, and cellular functional validation in a single study","pmids":["17242191"],"is_preprint":false},{"year":2007,"finding":"Phosphorylation of NHERF-1 PDZ1 domain at serine 77 attenuates its binding to physiological targets including β2-adrenergic receptor, PDGFR, CFTR, and Npt2a. Phosphatase inhibitors enhance NHERF-1 phosphorylation and inhibit its dimerization. S77A mutation abolishes PDZ1 phosphorylation and increases NHERF-1 localization at the cell periphery; S77D reduces colocalization with cortical actin.","method":"Metabolic labeling, phosphatase inhibitor treatment, mutagenesis (S77A/S77D), co-immunoprecipitation, confocal microscopy","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — site-specific mutagenesis with functional binding assays and localization studies, phosphorylation site mapped","pmids":["17895247"],"is_preprint":false},{"year":2007,"finding":"NHERF-1 and the actin cytoskeleton regulate the distribution and trafficking of GPCRs. NHERF-1 expression reduces diffusion of β2AR and PTH1R, forms receptor bundles along stress fibers for β2AR, and reduces ligand-induced internalization rate of PTH1R by slowing arrestin recruitment. CaSR does not interact with the cytoskeleton via NHERF-1.","method":"FRAP, TIRF microscopy, image correlation spectroscopy, live-cell confocal imaging of fluorescent receptors","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple live-cell imaging modalities, receptor-specific effects documented, mechanistic conclusions supported by quantitative biophysics","pmids":["17599914"],"is_preprint":false},{"year":2007,"finding":"NHERF1 inhibits PTH1R endocytosis and delays PTH1R recycling. Both the PDZ-binding domain and MERM domain of NHERF1, as well as the PTH1R C-terminal PDZ recognition motif, are required for inhibition of endocytosis. NHERF1-mediated effects involve β-arrestin and dynamin. shRNA knockdown of NHERF1 in HEK-293 cells augmented PTH1R endocytosis.","method":"Radioligand binding, confocal microscopy of fluorescent PTH1R, tetracycline-inducible NHERF1 expression, PDZ-domain mutagenesis, shRNA knockdown","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — inducible expression, shRNA knockdown, domain mutagenesis, functional trafficking assays","pmids":["17884816"],"is_preprint":false},{"year":2009,"finding":"NHERF1 is an obligatory linker for β2-adrenergic receptor stimulation of CFTR-dependent HCO3- secretion in mouse duodenum. NHERF1 ablation strongly reduced basal and FSK-stimulated HCO3- secretion and blocked β2-AR stimulation; colocalization of β2-AR and CFTR was reduced in NHERF1-null mice. NHERF2 confers inhibitory signals by coupling LPA receptor to CFTR.","method":"Knockout mouse models (Nherf1-/-, Nherf2-/-, Pdzk1-/-), HCO3- secretion measurements, laser microdissection/qPCR, immunofluorescence colocalization","journal":"The Journal of clinical investigation","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple genetic KO models with defined physiological phenotypes and molecular colocalization data","pmids":["19221439"],"is_preprint":false},{"year":2009,"finding":"NHERF1 inhibits PTH1R desensitization by blocking β-arrestin2 binding to the receptor. NHERF1 prevents PTH-induced dissociation of PTH1R from Gαs. Both PDZ-binding and MERM domains of NHERF1 are required. NHERF1 forms a ternary complex with PTH1R and β-arrestin2 in cells; NHERF1 modulates the kinetics of β-arrestin2 recruitment to the PTH1R.","method":"Adenylyl cyclase activity assays, tetracycline-inducible NHERF1, shRNA knockdown, mutagenesis, co-immunoprecipitation, FRET imaging","journal":"Molecular pharmacology","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple assays (AC activity, co-IP, FRET), gain and loss of function, domain mutagenesis","pmids":["19188335"],"is_preprint":false},{"year":2009,"finding":"The NMR structure of the NHERF1 PDZ2-CT domain reveals weak intramolecular interactions between the disordered CT domain and the PDZ ligand binding site, and a novel helix-turn-helix subdomain allosterically coupled to PDZ2. Binding of ezrin releases these intramolecular domain-domain interactions as demonstrated by NMR and SANS. Disease-causing mutations R153Q and E225K in PDZ2 significantly reduce protein stability.","method":"High-resolution NMR, small-angle X-ray scattering (SAXS), small-angle neutron scattering (SANS), mutagenesis of disease variants","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Strong — high-resolution NMR structure with SAXS/SANS constraints, mutagenesis, and functional validation in a single rigorous study","pmids":["20042604"],"is_preprint":false},{"year":2009,"finding":"EBP50/NHERF1, as part of the ezrin-EBP50-PAG scaffold in T cells, positions PKA type I near its substrate Csk at the TCR. The ezrin-EBP50 interaction has a KD of 58 nM. Disruption of the ezrin-EBP50 interaction by a competing peptide (EBP50pep) delocalizes ezrin, and reverses cAMP-mediated inhibition of IL-2 production, demonstrating a required role for EBP50 in cAMP immunomodulation in T cells.","method":"Binding kinetics (KD determination), peptide competition assays, T-cell loading with competing peptide, IL-2 production assays","journal":"The Biochemical journal","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — quantitative binding assay, peptide competition with defined KD, functional immune readout","pmids":["19857202"],"is_preprint":false},{"year":2010,"finding":"EBP50/NHERF1 is necessary for microvillar assembly in epithelial cells. RNAi depletion of EBP50 reduces microvilli. This requires both a functional PDZ1 domain and the ezrin-binding site. Phosphomimetic mutations at Cdc2 or PKC phosphorylation sites render EBP50 nonfunctional in microvillar assembly. PKC activation causes EBP50 phosphorylation-dependent loss of microvillar organization.","method":"RNAi knockdown, expression of phosphomimetic/phosphodeficient EBP50 mutants, biochemical analysis of PDZ domain accessibility","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — RNAi with rescue by RNAi-resistant mutants, systematic domain analysis, PKC pharmacology, multiple orthogonal readouts","pmids":["20937695"],"is_preprint":false},{"year":2010,"finding":"NHERF1 directly interacts with a subset of Frizzled (Fzd) receptors via one of its PDZ domains, maintaining low Wnt/β-catenin signaling. Loss of NHERF1 in breast cancer cell lines enhances canonical Wnt signaling and Wnt-dependent proliferation. NHERF1-knockout mouse mammary glands exhibit increased duct density, proliferation, and β-catenin activity.","method":"Co-immunoprecipitation, reporter assays, NHERF1 knockout mice, cell proliferation assays","journal":"Oncogene","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP, functional reporter assays, KO mouse model, single lab","pmids":["20802536"],"is_preprint":false},{"year":2010,"finding":"NHERF-1 binds to Mrp2 (via Mrp2's PDZ-binding motif) in co-transfected HEK293 cells and in mouse liver. In NHERF-1(-/-) mice, Mrp2 protein is reduced ~50% in whole cell lysates and ~70% in membrane fractions (post-transcriptional regulation), bile flow is reduced ~30%, and glutathione excretion is reduced ~50%, demonstrating a critical role for NHERF-1 in canalicular Mrp2 expression and glutathione-dependent bile flow.","method":"Co-immunoprecipitation, NHERF-1 knockout mice, Western blotting, membrane fractionation, bile collection/bile flow measurement, GS-MF fluorescence assay","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — Co-IP with PDZ-motif mutagenesis, genetic KO with multiple functional endpoints","pmids":["20404332"],"is_preprint":false},{"year":2010,"finding":"NHERF-1 transduces dopamine inhibition of renal phosphate transport. NHERF-1 associates with D1-like receptors (Co-IP). Dopamine stimulated cAMP and PKC activity in wild-type proximal tubule cells but not in NHERF-1 null cells; adenoviral re-expression of NHERF-1 rescued these responses. Dopamine increased NHERF-1 phosphorylation at Ser77 (PDZ1), attenuating Npt2a binding.","method":"Co-immunoprecipitation, phosphate transport assays in WT and KO cells, cAMP/PKC activity assays, adenoviral rescue, 32P metabolic labeling","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — loss-of-function KO, adenoviral rescue, biochemical signaling assays, phosphorylation site identified","pmids":["20200151"],"is_preprint":false},{"year":2010,"finding":"NHERF-1 controls the amplitude and duration of PKD1/PKD2 signaling at the membrane scaffold. The first PDZ domain of NHERF-1 interacts with PDZ-binding motifs of PKD1 and PKD2. FRET-based live-cell imaging reveals that PKD activation at the NHERF-1 scaffold is rapid and sustained but blunted in magnitude compared with cytosolic or bulk membrane PKD activity.","method":"PDZ domain proteomic array, FRET-based PKD activity reporter, FRET translocation assay in live cells","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — PDZ array identification followed by live-cell FRET kinase activity reporter, single lab","pmids":["19581308"],"is_preprint":false},{"year":2010,"finding":"NHERF-1 forms a ternary complex with β-arrestin2 and PTH1R. NHERF1 binds constitutively to PTH1R while β-arrestin2 binding is agonist-promoted. NHERF1 interacts directly with β-arrestin2 without using PTH1R as an interface. NHERF1 modulates the kinetics of PTH1R/β-arrestin2 interactions as shown by FRET.","method":"Co-immunoprecipitation, BRET/FRET imaging, confocal microscopy, biochemical binding assays","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple biophysical methods (FRET, BRET, Co-IP) defining ternary complex formation and interaction kinetics","pmids":["20656684"],"is_preprint":false},{"year":2010,"finding":"PDZK1 and EBP50 form a regulated ternary complex with ezrin in apical microvilli. Ezrin positively influences the PDZK1/EBP50 interaction (cooperativity). PDZK1 shuttles from nucleus to microvilli upon cell confluence, regulating complex formation. Knockdown of EBP50 reduces microvilli; this phenotype can be rescued by a PDZK1 chimera targeted directly to ezrin.","method":"In vitro binding assays, co-immunoprecipitation, RNAi knockdown, confocal microscopy of PDZK1 redistribution","journal":"Molecular biology of the cell","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — in vitro reconstitution of ternary complex, cooperative binding demonstrated, RNAi rescue experiment","pmids":["20237154"],"is_preprint":false},{"year":2010,"finding":"Arrestin scaffolds NHERF1 to the P2Y12 receptor to regulate internalization. Prior to agonist stimulation, NHERF1 interacts directly with the P2Y12R C-tail via the intact PDZ-binding motif. Upon receptor stimulation, NHERF1 no longer binds the receptor directly but instead is recruited via arrestin as an adaptor, facilitating NHERF1-dependent P2Y12R internalization.","method":"Co-immunoprecipitation in vitro and in cells, PDZ-binding motif mutagenesis, internalization assays","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP with mutagenesis, functional internalization assay, novel mechanism in a single lab","pmids":["22610101"],"is_preprint":false},{"year":2011,"finding":"EBP50 depletion in biliary cancer cells increases EGFR surface expression and causes sustained EGFR activation (ERK1/2, STAT3) under basal and EGF-stimulated conditions. Loss of EBP50 induces epithelial-mesenchymal transition features (loss of E-cadherin/CK19, induction of S100A4/Slug, loss of polarity, lamellipodia formation). These effects are reversed by EGFR tyrosine kinase inhibition with gefitinib.","method":"siRNA knockdown of EBP50, Western blotting for signaling proteins, cell migration/invasion assays, immunofluorescence for junction proteins, gefitinib rescue","journal":"Oncogene","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — siRNA loss-of-function with multiple molecular readouts and pharmacological rescue, single lab","pmids":["21822312"],"is_preprint":false},{"year":2012,"finding":"NHERF1 forms an obligate ternary complex with Npt2a and the PKA-anchoring protein ezrin to facilitate PTH-responsive phosphate transport. Ezrin-anchored PKA phosphorylates NHERF1 to disassemble this complex and release Npt2a, thereby inhibiting phosphate transport. Loss-of-function NHERF1 mutations stabilize an inactive conformation refractory to PKA phosphorylation and impair ternary complex assembly.","method":"Co-immunoprecipitation, in vitro kinase assays, mutagenesis of disease-associated NHERF1 variants, phosphate transport assays, compensatory mutagenesis rescue","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — biochemical reconstitution, in vitro kinase assay, disease mutation analysis, compensatory mutagenesis rescue","pmids":["22628548"],"is_preprint":false},{"year":2012,"finding":"NHERF-1 mediates P2Y12 receptor internalization via the PDZ binding motif of the receptor prior to agonist stimulation, and via arrestin scaffolding upon agonist activation. Additionally, PDZ2 of NHERF1 binds megalin directly and via an internal (non-C-terminal) PDZ binding motif in megalin; NHERF1 silencing increases megalin expression in proximal tubule cells.","method":"Immunoprecipitation from rat kidney lysate, GST fusion protein binding, peptide studies, confocal colocalization, siRNA knockdown","journal":"Cellular physiology and biochemistry","confidence":"Medium","confidence_rationale":"Tier 2-3 / Moderate — in vivo Co-IP, GST pulldown with peptide competition mapping, siRNA functional consequence","pmids":["21325834"],"is_preprint":false},{"year":2012,"finding":"NHERF1 PDZ1 domain is required for ANG II-mediated forward trafficking and activation of NHE3. NHERF1 mediates ANG II-induced increase in NHERF1-NHE3 and NHERF1-IRBIT interactions. IRBIT is indispensable for ANG II-provoked NHERF1-NHE3 interactions; phosphorylation of IRBIT at Ser68 is necessary for assembly of the NHERF1-IRBIT-NHE3 complex.","method":"Co-immunoprecipitation, dominant-negative PDZ1 construct, adenoviral YFP-NHERF1 expression, NHE3 apical membrane trafficking assays, IRBIT siRNA","journal":"American journal of physiology. Renal physiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP, domain-deletion constructs, loss-of-function siRNA, functional trafficking assay, single lab","pmids":["27279487"],"is_preprint":false},{"year":2013,"finding":"EBP50 targets iNOS to peroxisomes in hepatocytes. siRNA knockdown of PEX7 reduced iNOS colocalization with the peroxisomal marker PMP70. Proteomic/MALDI-MS identified iNOS association with EBP50; confocal and immunoelectron microscopy confirmed co-localization. EBP50 associates with peroxisomes in a PEX5/PEX7-dependent manner, and iNOS peroxisomal localization was contingent on EBP50 expression in LPS-treated mice.","method":"siRNA knockdown, MALDI-MS proteomics, confocal microscopy, immunoelectron microscopy, in vivo LPS model","journal":"Nitric oxide : biology and chemistry","confidence":"Medium","confidence_rationale":"Tier 2-3 / Moderate — multiple microscopy methods, proteomic identification, in vivo mouse model, single lab","pmids":["23474170"],"is_preprint":false},{"year":2013,"finding":"EBP50 phosphorylation by Cdc2/CyclinB at Ser279 and Ser301 regulates actin cytoskeleton reorganization. Phosphodeficient (S279A/S301A) EBP50 significantly increased F-actin content, enhanced cell-matrix adhesion, caused cytokinesis defects (multinucleation, heteroploid DNA, giant cells), and had weaker actin binding. Phosphomimetic (S279D/S301D) did not cause these defects. Knockdown of EBP50 in AA cells rescued cytokinesis failure.","method":"Stable transfection of phosphodeficient/phosphomimetic mutants in MDA-MB-231, F-actin staining, DNA content analysis, cell adhesion assays, EBP50 knockdown rescue","journal":"Molecules and cells","confidence":"Medium","confidence_rationale":"Tier 1-2 / Moderate — phosphorylation site mutagenesis with functional cellular assays, rescue experiment, single lab","pmids":["23775624"],"is_preprint":false},{"year":2014,"finding":"NHERF1 depletion in human intestinal epithelial cells in 3D culture disrupts apical-basal polarity and prevents lumen formation. NHERF1 concentrates at the apical membrane from the two-cell stage. NHERF1 depletion displaces PTEN from the membrane and causes nuclear β-catenin translocation. Moesin (but not ezrin) depletion reproduces the NHERF1 loss phenotype. NHERF1 ERM-binding and PDZ-domain mutants fail to localize apically and impair gland formation.","method":"3D gland morphogenesis assay, siRNA knockdown, confocal microscopy, domain-mutant expression","journal":"Neoplasia","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss-of-function in 3D morphogenesis model with domain-mutant rescue analysis, single lab","pmids":["24862762"],"is_preprint":false},{"year":2015,"finding":"NHERF1 interaction with TRPC4 and TRPC5 (via their C-terminal PDZ-binding motif) regulates channel gating: dynamic dissociation of NHERF1/2 from the TRPC5 C-terminus upon PIP2 depletion is a prerequisite for DAG sensitivity. PKC inhibition or mutation of the PDZ-binding motif in TRPC4/5 conferred DAG sensitivity to the channel. PIP2 depletion evokes a C-terminal conformational change in TRPC5 leading to NHERF dissociation.","method":"PDZ-binding motif mutagenesis, PKC inhibition, electrophysiology, Co-immunoprecipitation, conformational change assays","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — PDZ motif mutagenesis, electrophysiological channel activity assays, dynamic Co-IP, PKC pharmacology, mechanistic model validated by multiple approaches","pmids":["27994151"],"is_preprint":false},{"year":2015,"finding":"NHERF1 interacts with α-actinin-4 via NHERF1's PDZ domain and the α-actinin-4 C-terminal region. The NHERF1/α-actinin-4 interaction increases α-actinin-4 ubiquitination and decreases its expression, resulting in actin cytoskeleton disassembly. NHERF1 loss-of-function/gain-of-function experiments show that NHERF1 disorganizes polymerized F-actin in HeLa cells.","method":"2D-DIGE proteomics/MALDI-TOF identification, GST pulldown, co-immunoprecipitation, siRNA/overexpression, ubiquitination assay, F-actin staining","journal":"FASEB journal","confidence":"Medium","confidence_rationale":"Tier 2-3 / Moderate — GST pulldown plus Co-IP, ubiquitination assay, functional F-actin readout, single lab","pmids":["26432781"],"is_preprint":false},{"year":2015,"finding":"NHERF1 binds BECN1 via its C-terminal domain, blocks ubiquitin-dependent BECN1 degradation, and thereby stabilizes BECN1 to stimulate autophagy. NHERF1 attenuates the BECN1-BCL2 interaction. Deletion of the NHERF1 C-terminal domain abolishes BECN1 binding, reduces BECN1 levels, and prevents autophagy induction.","method":"Co-immunoprecipitation, ubiquitination assay, autophagy flux assays, C-terminal domain deletion mutagenesis","journal":"Autophagy","confidence":"Medium","confidence_rationale":"Tier 2-3 / Moderate — Co-IP, domain deletion mutagenesis, ubiquitination assay, functional autophagy readout, single lab","pmids":["26218645"],"is_preprint":false},{"year":2016,"finding":"NHERF1 interacts with GPER via NHERF1's PDZ2 domain and the GPER C-terminal PDZ binding motif in breast cancer cells. NHERF1 stabilizes GPER protein by inhibiting its degradation through the ubiquitin-proteasome pathway in an interaction-dependent manner.","method":"Co-immunoprecipitation, domain mutagenesis (PDZ2), ubiquitin-proteasome inhibitor experiments, protein stability assays","journal":"Oncotarget","confidence":"Medium","confidence_rationale":"Tier 2-3 / Moderate — Co-IP with domain mutagenesis and functional stability assay, single lab","pmids":["27448983"],"is_preprint":false},{"year":2019,"finding":"HPV E6 proteins (both high- and low-risk) degrade NHERF1 in an E6AP ubiquitin ligase-dependent manner, independent of PDZ interactions. E6 binding requires a novel structural domain of E6 (independent of the p53-recognition domain) and the NHERF1 EB domain. NHERF1 degradation by E6 activates canonical Wnt/β-catenin signaling.","method":"E6AP mutagenesis, NHERF1 domain deletion constructs, proteasome inhibitor experiments, Wnt/β-catenin reporter assays","journal":"PLoS pathogens","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — domain mutagenesis of both E6 and NHERF1, E6AP dependence established, functional Wnt reporter assay, single lab","pmids":["31002735"],"is_preprint":false},{"year":2019,"finding":"PTH initiates dynamic NHERF1 phosphorylation cycling at Ser290: Ser290 is rapidly dephosphorylated by protein phosphatase 1α (PP1α, which binds NHERF1 via a VPF PP1-docking motif at residues 257-259) and then rephosphorylated by a GRK6A-containing kinase cascade. S290A substitution abolishes PTH-dependent phosphate transport. PP1α inhibition or mutation of the VPF motif blocks dephosphorylation and abrogates PTH-sensitive phosphate transport. Hydrogen-deuterium exchange MS reveals PTH-induced conformational changes in NHERF1 PDZ domains.","method":"Tandem MS phosphorylation site mapping, Ala-substitution mutagenesis, tautomycetin (PP1 inhibitor), FLIM, hydrogen-deuterium exchange MS, PP1α binding domain mutagenesis (VPF→Ala)","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Strong — MS site mapping, mutagenesis, structural HDX-MS, FLIM, pharmacological PP1 inhibition, and functional phosphate transport assay in a single rigorous study","pmids":["30696771"],"is_preprint":false}],"current_model":"NHERF1/EBP50 is a two-PDZ-domain scaffolding phosphoprotein that localizes to apical microvilli of polarized epithelia by binding activated ERM proteins (ezrin/moesin) via its C-terminal EB domain, assembling multiprotein complexes that tether transporters (NHE3, Npt2a/NaPi-2a, CFTR, Mrp2), GPCRs (β2-AR, PTH1R, kappa-opioid receptor), ion channels (TRPC4/5), and signaling enzymes (PKA, PKC, PLC-β) to the actin cytoskeleton; it adopts an autoinhibited head-to-tail conformation in which its EB region occludes PDZ2, released by ezrin binding; phosphorylation of PDZ1 Ser77 (by PKC/dopamine signaling) and PDZ domain Ser290 (cycled by anchored PKA and PP1α in response to PTH) dynamically regulates binding of PDZ ligands and controls transporter trafficking and hormonal signal transduction, while Cdc2/CyclinB phosphorylation at Ser279/Ser301 governs actin reorganization and cytokinesis."},"narrative":{"mechanistic_narrative":"NHERF1 (EBP50) is a two-PDZ-domain scaffolding phosphoprotein that organizes apical membrane signaling and transport complexes in polarized epithelia by physically coupling membrane proteins to the actin cytoskeleton through activated ERM proteins [PMID:9314537, PMID:9660814]. Its C-terminal EB region binds the N-terminal domains of ezrin and moesin, an interaction that is mutually exclusive with the ezrin intramolecular N/C-ERMAD clamp and therefore requires prior ezrin activation to expose the binding site [PMID:9660814], and that is required for microvillar assembly together with a functional PDZ1 domain [PMID:20937695, PMID:20237154]. NHERF1 adopts an autoinhibited head-to-tail conformation in which the EB region occludes PDZ2 and masks ligand binding; ezrin association relieves this intramolecular block to license PDZ-mediated interactions [PMID:17242191, PMID:20042604]. Through its PDZ domains NHERF1 assembles complexes containing the Na+/H+ exchanger NHE3, the renal sodium-phosphate cotransporter Npt2a, CFTR, Mrp2, and store-operated TRPC4/5 channels, and tethers them to ezrin-anchored kinases to control transporter trafficking and activity [PMID:9792717, PMID:10821685, PMID:12169661, PMID:20404332, PMID:27994151]. A central function is hormonal signal transduction: NHERF1 is obligatory for cAMP/PKA-mediated and dopamine-mediated regulation of NHE3 and Npt2a, and forms an obligate Npt2a-NHERF1-ezrin ternary complex in which ezrin-anchored PKA phosphorylates NHERF1 to release Npt2a and inhibit phosphate transport [PMID:12586353, PMID:20200151, PMID:22628548]. Reversible phosphorylation tunes this scaffolding: phosphorylation of PDZ1 Ser77 (by PKC/dopamine signaling) attenuates binding to β2-AR, PDGFR, CFTR, and Npt2a [PMID:17895247, PMID:20200151], while PTH drives dynamic Ser290 cycling between PP1α-mediated dephosphorylation and GRK6A-dependent rephosphorylation that is essential for PTH-sensitive phosphate transport [PMID:30696771], and Cdc2/CyclinB phosphorylation at Ser279/Ser301 governs actin reorganization and cytokinesis [PMID:23775624]. NHERF1 also restrains GPCR internalization and desensitization, blocking β-arrestin2 binding and slowing arrestin recruitment to PTH1R and stabilizing receptors such as the kappa-opioid receptor [PMID:12920119, PMID:17884816, PMID:19188335, PMID:12004055]. Beyond epithelial transport, NHERF1 modulates Wnt/β-catenin signaling and EGFR-driven epithelial-mesenchymal transition, and stabilizes partner proteins including BECN1 and GPER against ubiquitin-dependent degradation [PMID:12830000, PMID:20802536, PMID:21822312, PMID:26218645, PMID:27448983].","teleology":[{"year":1997,"claim":"Established NHERF1/EBP50 as a physiological ezrin-binding PDZ protein, defining its core role as a physical link between membrane proteins and the apical actin cytoskeleton.","evidence":"Affinity chromatography, Co-IP from placental microvilli, and immunolocalization with actin/ezrin","pmids":["9314537"],"confidence":"High","gaps":["Did not define which membrane cargoes the PDZ domains bind","Did not establish regulation of the ezrin interaction"]},{"year":1998,"claim":"Showed that NHERF1 binds only the activated (open) form of ezrin, establishing regulated ERM activation as a gate controlling scaffold assembly.","evidence":"Blot overlay and in-solution binding with ezrin/EBP50 truncation mutants and competition assays","pmids":["9660814"],"confidence":"High","gaps":["Did not show the physiological trigger that opens ezrin in cells"]},{"year":1998,"claim":"Demonstrated NHERF1 simultaneously binds NHE3 and ezrin to position PKA near NHE3, defining its function in hormonally regulated transporter inhibition.","evidence":"Reciprocal Co-IP, in vivo phosphorylation, and intracellular pH Na+/H+ exchange assays","pmids":["9792717"],"confidence":"High","gaps":["Did not separate the contributions of the PDZ versus ERM-binding regions to PKA-mediated inhibition"]},{"year":2000,"claim":"Established that both the NHE3-PDZ and the ezrin-ERM interactions are jointly required for cAMP-dependent NHE3 inhibition, proving the scaffold itself enables kinase access to substrate.","evidence":"Truncated NHERF (1-325) lacking the ezrin-binding domain in PS120/NHE3 cells with phosphorylation and activity assays","pmids":["10821685"],"confidence":"High","gaps":["Did not address whether other transporters use the same dual-requirement logic"]},{"year":2000,"claim":"Extended the scaffolding repertoire to store-operated channels by showing PDZ1 binds Trp4/Trp5 and PLC-β isozymes, linking signaling enzymes to the cytoskeleton.","evidence":"Yeast two-hybrid, GST pulldown, and Co-IP from HEK293 and mouse brain","pmids":["10980202"],"confidence":"High","gaps":["Did not define functional consequences on channel gating at this stage"]},{"year":2002,"claim":"Genetic knockout established a non-redundant, cargo-specific role: NHERF1 is required for apical retention of Npt2a but not NHE3, explaining renal phosphate wasting.","evidence":"Nherf1 knockout mouse with brush-border fractionation, immunocytochemistry, and urine electrolytes","pmids":["12169661"],"confidence":"High","gaps":["Did not explain the molecular basis of selectivity over NHERF2"]},{"year":2002,"claim":"Showed NHERF1 controls GPCR trafficking, protecting the kappa-opioid receptor from agonist-induced downregulation by promoting recycling.","evidence":"Co-IP in CHO cells, radioligand binding, flow cytometry, and receptor/NHERF1 domain mutagenesis","pmids":["12004055"],"confidence":"High","gaps":["Did not generalize the recycling mechanism to other GPCRs"]},{"year":2003,"claim":"Defined NHERF1 as the non-redundant transducer of cAMP/PKA signals to NHE3 in native renal membranes, showing NHERF2 cannot compensate.","evidence":"Brush-border vesicles from Nherf1-/- mice with Na+/H+ exchange and NHE3 phosphorylation assays","pmids":["12586353"],"confidence":"High","gaps":["Did not map the NHERF1 phosphosites driving this isoform specificity"]},{"year":2003,"claim":"Extended GPCR regulation to PTH1R, showing NHERF1 blocks arrestin-independent receptor internalization in an actin- and ERM-dependent manner.","evidence":"Live-cell confocal imaging of fluorescent PTH1R, dominant-negatives, and actin depolymerization","pmids":["12920119"],"confidence":"High","gaps":["Did not resolve how NHERF1 selects between endocytic pathways"]},{"year":2007,"claim":"Provided the regulatory mechanism for cargo binding: NHERF1 is autoinhibited by an EB-PDZ2 head-to-tail interaction that ezrin binding relieves, distinguishing it from NHERF2.","evidence":"In vitro binding, mutagenesis, and Co-IP in polarized epithelial cells with PTEN/β-catenin ligands","pmids":["17242191"],"confidence":"High","gaps":["Did not provide atomic structural detail of the autoinhibited state"]},{"year":2007,"claim":"Mapped Ser77 in PDZ1 as a phosphorylation switch that attenuates binding to β2-AR, PDGFR, CFTR, and Npt2a, linking kinase signaling to scaffold disassembly.","evidence":"Metabolic labeling, S77A/S77D mutagenesis, Co-IP, and confocal localization","pmids":["17895247"],"confidence":"High","gaps":["Did not identify the physiological kinase acting on Ser77 at this stage"]},{"year":2007,"claim":"Quantified NHERF1 control of GPCR membrane dynamics, showing it reduces receptor diffusion and slows arrestin-dependent PTH1R internalization.","evidence":"FRAP, TIRF, image correlation spectroscopy, and live-cell imaging of β2AR/PTH1R","pmids":["17599914","17884816"],"confidence":"High","gaps":["Did not establish the structural interface with arrestin"]},{"year":2009,"claim":"Determined the NMR structure of PDZ2-CT, revealing a helix-turn-helix subdomain allosterically coupled to PDZ2 and ezrin-released intramolecular contacts, and linked PDZ2 disease mutations to destabilization.","evidence":"NMR with SAXS/SANS constraints and R153Q/E225K mutagenesis","pmids":["20042604"],"confidence":"High","gaps":["Did not capture the full-length autoinhibited conformation structurally"]},{"year":2009,"claim":"Generalized the scaffold-to-secretion paradigm, establishing NHERF1 as the obligatory linker for β2-AR stimulation of CFTR-dependent bicarbonate secretion in vivo.","evidence":"Nherf1-/-, Nherf2-/-, Pdzk1-/- mice with HCO3- secretion and colocalization measurements","pmids":["19221439"],"confidence":"High","gaps":["Did not define the phosphoregulation of the β2-AR/CFTR complex"]},{"year":2009,"claim":"Defined NHERF1 as a desensitization brake forming a ternary complex with PTH1R and β-arrestin2 and preventing PTH-induced Gαs dissociation.","evidence":"Adenylyl cyclase assays, inducible NHERF1, shRNA, Co-IP, and FRET","pmids":["19188335"],"confidence":"High","gaps":["Did not resolve the kinetic basis of arrestin exclusion"]},{"year":2009,"claim":"Extended scaffold function to immune signaling, showing the ezrin-EBP50-PAG complex positions PKA near Csk to mediate cAMP inhibition of IL-2 production in T cells.","evidence":"KD determination (58 nM), peptide competition (EBP50pep) in T cells, and IL-2 assays","pmids":["19857202"],"confidence":"High","gaps":["Did not test whether other ERM-anchored kinase complexes share this architecture"]},{"year":2010,"claim":"Established a structural cell-biology role: NHERF1 is necessary for microvillar assembly, requiring functional PDZ1 and the ezrin-binding site, and is inactivated by Cdc2/PKC phosphomimetics.","evidence":"RNAi with rescue by phospho-mutant EBP50 and microvilli quantification","pmids":["20937695","20237154"],"confidence":"High","gaps":["Did not fully separate the microvillar and transport-scaffolding functions"]},{"year":2010,"claim":"Connected NHERF1 to oncogenic signaling, showing it restrains Wnt/β-catenin via Frizzled binding and that loss enhances Wnt-dependent mammary proliferation.","evidence":"Co-IP, reporter assays, and NHERF1 knockout mouse mammary gland analysis","pmids":["20802536"],"confidence":"Medium","gaps":["Single lab; did not define which Frizzled receptors are bound","Mechanism connecting Frizzled binding to β-catenin levels not resolved"]},{"year":2010,"claim":"Demonstrated post-transcriptional control of canalicular transport, showing NHERF1 binds Mrp2 and is required for its membrane expression and glutathione-dependent bile flow.","evidence":"Co-IP with PDZ-motif mutagenesis and Nherf1-/- mice with bile flow/glutathione assays","pmids":["20404332"],"confidence":"High","gaps":["Did not define the degradation pathway stabilized by NHERF1"]},{"year":2010,"claim":"Identified the kinase context for Ser77, showing dopamine signaling phosphorylates PDZ1 Ser77 to release Npt2a and inhibit renal phosphate transport.","evidence":"Co-IP, phosphate transport in WT/KO cells, cAMP/PKC assays, adenoviral rescue, and 32P labeling","pmids":["20200151"],"confidence":"High","gaps":["Did not integrate dopamine and PTH phosphoregulation of the same scaffold"]},{"year":2010,"claim":"Documented dynamic, arrestin-dependent recruitment, showing NHERF1 switches from direct P2Y12R binding to arrestin-scaffolded recruitment upon agonist stimulation.","evidence":"Co-IP, PDZ-motif mutagenesis, and internalization assays","pmids":["22610101","20656684","21325834"],"confidence":"Medium","gaps":["Single lab for P2Y12R; mechanism of the binding mode switch not structurally defined"]},{"year":2012,"claim":"Resolved the core phosphate-regulatory mechanism: NHERF1 forms an obligate Npt2a-ezrin ternary complex in which ezrin-anchored PKA phosphorylates NHERF1 to release Npt2a, and disease mutations stabilize an inactive PKA-refractory conformation.","evidence":"In vitro kinase assays, disease-variant mutagenesis, compensatory mutagenesis rescue, and phosphate transport assays","pmids":["22628548"],"confidence":"High","gaps":["Did not identify the specific NHERF1 residue phosphorylated to disassemble the complex"]},{"year":2013,"claim":"Defined cell-cycle control of the cytoskeletal function, showing Cdc2/CyclinB phosphorylation of Ser279/Ser301 regulates actin reorganization and cytokinesis.","evidence":"Phosphodeficient/phosphomimetic mutants in MDA-MB-231 with F-actin, DNA content, and adhesion assays plus knockdown rescue","pmids":["23775624"],"confidence":"Medium","gaps":["Single lab; direct Cdc2 phosphorylation of these sites in vivo not fully established"]},{"year":2014,"claim":"Established NHERF1 as a determinant of epithelial polarity and lumen formation, anchoring PTEN at the membrane and restraining nuclear β-catenin, via a moesin-dependent mechanism.","evidence":"3D gland morphogenesis with siRNA and domain-mutant expression","pmids":["24862762"],"confidence":"Medium","gaps":["Single lab; did not reconcile the moesin versus ezrin dependence with earlier ezrin-centric data"]},{"year":2015,"claim":"Defined a gating role at TRPC4/5 channels, showing PIP2-triggered NHERF dissociation from the channel C-terminus is a prerequisite for DAG sensitivity.","evidence":"PDZ-motif mutagenesis, PKC inhibition, electrophysiology, and dynamic Co-IP","pmids":["27994151"],"confidence":"High","gaps":["Did not define the upstream signal coordinating NHERF dissociation in vivo"]},{"year":2015,"claim":"Expanded NHERF1 function to controlling partner protein stability, showing it stabilizes BECN1 against ubiquitin-dependent degradation to promote autophagy and binds α-actinin-4 to promote its ubiquitination.","evidence":"Co-IP, ubiquitination assays, domain-deletion mutagenesis, and autophagy/F-actin readouts","pmids":["26218645","26432781"],"confidence":"Medium","gaps":["Single-lab findings; the opposing stabilizing/destabilizing logic across partners not mechanistically unified"]},{"year":2019,"claim":"Resolved the full PTH phosphocycle, showing Ser290 is dephosphorylated by NHERF1-docked PP1α and rephosphorylated by a GRK6A cascade to drive PTH-sensitive phosphate transport.","evidence":"MS phosphosite mapping, Ala mutagenesis, PP1 inhibition, FLIM, and HDX-MS conformational analysis","pmids":["30696771"],"confidence":"High","gaps":["Did not define the full GRK6A kinase cascade composition"]},{"year":2019,"claim":"Identified NHERF1 as a viral oncoprotein target, showing HPV E6 directs its E6AP-dependent degradation via the EB domain to activate Wnt/β-catenin signaling.","evidence":"E6AP and NHERF1 domain mutagenesis, proteasome inhibition, and Wnt reporter assays","pmids":["31002735"],"confidence":"Medium","gaps":["Single lab; in vivo relevance during HPV-driven transformation not established"]},{"year":null,"claim":"How the multiple phosphorylation switches (Ser77, Ser290, Ser279/Ser301), the autoinhibited conformation, and ERM activation are integrated to coordinate distinct cargoes in a single cell remains unresolved.","evidence":"No single study reconciles the combinatorial phosphoregulation across all known NHERF1 functions","pmids":[],"confidence":"Low","gaps":["No unified model of combinatorial phosphocode-to-cargo selectivity","No full-length structure of NHERF1 in its autoinhibited versus ezrin-activated states","Mechanism distinguishing stabilizing versus destabilizing effects on partner proteins unknown"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,2,5,16,30,33]},{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[0,24,37,40]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[8,10,19,21,39]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0,7,17,18,20]},{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[0,24,30,37,40]},{"term_id":"GO:0005777","term_label":"peroxisome","supporting_discovery_ids":[36]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[2,9,19,21,27,33,44]},{"term_id":"R-HSA-382551","term_label":"Transport of small molecules","supporting_discovery_ids":[5,7,26,33,35]},{"term_id":"R-HSA-9609507","term_label":"Protein localization","supporting_discovery_ids":[7,10,19,24,38]}],"complexes":["Npt2a-NHERF1-ezrin ternary complex","PTH1R-NHERF1-β-arrestin2 ternary complex","PDZK1-EBP50-ezrin microvillar complex","ezrin-EBP50-PAG T-cell scaffold"],"partners":["EZR","NHE3","NPT2A","CFTR","PTH1R","TRPC5","MRP2","PP1Α"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"O14745","full_name":"Na(+)/H(+) exchange regulatory cofactor NHE-RF1","aliases":["Ezrin-radixin-moesin-binding phosphoprotein 50","EBP50","Regulatory cofactor of Na(+)/H(+) exchanger","Sodium-hydrogen exchanger regulatory factor 1","Solute carrier family 9 isoform A3 regulatory factor 1"],"length_aa":358,"mass_kda":38.9,"function":"Scaffold protein that connects plasma membrane proteins with members of the ezrin/moesin/radixin family and thereby helps to link them to the actin cytoskeleton and to regulate their surface expression. Necessary for recycling of internalized ADRB2. Was first known to play a role in the regulation of the activity and subcellular location of SLC9A3. Necessary for cAMP-mediated phosphorylation and inhibition of SLC9A3. May enhance Wnt signaling. May participate in HTR4 targeting to microvilli (By similarity). Involved in the regulation of phosphate reabsorption in the renal proximal tubules. Involved in sperm capacitation. May participate in the regulation of the chloride and bicarbonate homeostasis in spermatozoa","subcellular_location":"Cytoplasm; Apical cell membrane; Endomembrane system; Cell projection, filopodium; Cell projection, ruffle; Cell projection, microvillus","url":"https://www.uniprot.org/uniprotkb/O14745/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/NHERF1","classification":"Not Classified","n_dependent_lines":3,"n_total_lines":1208,"dependency_fraction":0.0024834437086092716},"opencell":{"profiled":true,"resolved_as":"SLC9A3R1","ensg_id":"ENSG00000109062","cell_line_id":"CID001375","localizations":[{"compartment":"vesicles","grade":3},{"compartment":"centrosome","grade":2},{"compartment":"golgi","grade":1}],"interactors":[{"gene":"HEXIM1","stoichiometry":0.2},{"gene":"SRSF1","stoichiometry":0.2},{"gene":"CDKN1B","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/target/CID001375","total_profiled":1310},"omim":[{"mim_id":"612287","title":"NEPHROLITHIASIS/OSTEOPOROSIS, HYPOPHOSPHATEMIC, 2; NPHLOP2","url":"https://www.omim.org/entry/612287"},{"mim_id":"609396","title":"PH DOMAIN AND LEUCINE-RICH REPEAT PROTEIN PHOSPHATASE 1; PHLPP1","url":"https://www.omim.org/entry/609396"},{"mim_id":"606553","title":"SOLUTE CARRIER FAMILY 9, MEMBER 3, REGULATOR 2; SLC9A3R2","url":"https://www.omim.org/entry/606553"},{"mim_id":"604990","title":"SOLUTE CARRIER FAMILY 9, MEMBER 3, REGULATOR 1; SLC9A3R1","url":"https://www.omim.org/entry/604990"},{"mim_id":"601728","title":"PHOSPHATASE AND TENSIN HOMOLOG; PTEN","url":"https://www.omim.org/entry/601728"}],"hpa":{"profiled":true,"resolved_as":"SLC9A3R1","reliability":"Approved","locations":[{"location":"Plasma membrane","reliability":"Approved"},{"location":"Centriolar satellite","reliability":"Approved"},{"location":"Vesicles","reliability":"Additional"},{"location":"Centrosome","reliability":"Additional"},{"location":"Basal body","reliability":"Additional"},{"location":"Cytosol","reliability":"Additional"},{"location":"Calyx","reliability":"Additional"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in all","driving_tissues":[{"tissue":"esophagus","ntpm":348.1}],"url":"https://www.proteinatlas.org/search/SLC9A3R1"},"hgnc":{"alias_symbol":["NHERF","EBP50","NHERF-1","NHE-RF"],"prev_symbol":["SLC9A3R1"]},"alphafold":{"accession":"O14745","domains":[{"cath_id":"2.30.42.10","chopping":"14-108","consensus_level":"high","plddt":81.0267,"start":14,"end":108},{"cath_id":"2.30.42.10","chopping":"154-251","consensus_level":"high","plddt":86.7538,"start":154,"end":251}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/O14745","model_url":"https://alphafold.ebi.ac.uk/files/AF-O14745-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-O14745-F1-predicted_aligned_error_v6.png","plddt_mean":72.81},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=NHERF1","jax_strain_url":"https://www.jax.org/strain/search?query=NHERF1"},"sequence":{"accession":"O14745","fasta_url":"https://rest.uniprot.org/uniprotkb/O14745.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/O14745/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/O14745"}},"corpus_meta":[{"pmid":"9314537","id":"PMC_9314537","title":"Identification of EBP50: A PDZ-containing phosphoprotein that associates with members of the ezrin-radixin-moesin family.","date":"1997","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/9314537","citation_count":513,"is_preprint":false},{"pmid":"11031232","id":"PMC_11031232","title":"ERM-Merlin and EBP50 protein families in plasma membrane organization and function.","date":"2000","source":"Annual review of cell and developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/11031232","citation_count":319,"is_preprint":false},{"pmid":"19221439","id":"PMC_19221439","title":"Differential roles of NHERF1, NHERF2, and PDZK1 in regulating CFTR-mediated intestinal anion secretion in mice.","date":"2009","source":"The Journal of clinical investigation","url":"https://pubmed.ncbi.nlm.nih.gov/19221439","citation_count":303,"is_preprint":false},{"pmid":"12169661","id":"PMC_12169661","title":"Targeted disruption of the mouse NHERF-1 gene promotes internalization of proximal tubule sodium-phosphate cotransporter type IIa and renal phosphate wasting.","date":"2002","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/12169661","citation_count":256,"is_preprint":false},{"pmid":"14608357","id":"PMC_14608357","title":"A putative RUNX1 binding site variant between SLC9A3R1 and NAT9 is associated with susceptibility to psoriasis.","date":"2003","source":"Nature genetics","url":"https://pubmed.ncbi.nlm.nih.gov/14608357","citation_count":234,"is_preprint":false},{"pmid":"10980202","id":"PMC_10980202","title":"Association of mammalian trp4 and phospholipase C isozymes with a PDZ domain-containing protein, NHERF.","date":"2000","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/10980202","citation_count":195,"is_preprint":false},{"pmid":"9792717","id":"PMC_9792717","title":"The role of NHERF and E3KARP in the cAMP-mediated inhibition of NHE3.","date":"1998","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/9792717","citation_count":178,"is_preprint":false},{"pmid":"9660814","id":"PMC_9660814","title":"The carboxyl-terminal region of EBP50 binds to a site in the amino-terminal domain of ezrin that is masked in the dormant molecule.","date":"1998","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/9660814","citation_count":176,"is_preprint":false},{"pmid":"10562288","id":"PMC_10562288","title":"Yes-associated protein 65 localizes p62(c-Yes) to the apical compartment of airway epithelia by association with EBP50.","date":"1999","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/10562288","citation_count":163,"is_preprint":false},{"pmid":"16460281","id":"PMC_16460281","title":"The association of NHERF adaptor proteins with g protein-coupled receptors and receptor tyrosine kinases.","date":"2006","source":"Annual review of physiology","url":"https://pubmed.ncbi.nlm.nih.gov/16460281","citation_count":146,"is_preprint":false},{"pmid":"11181400","id":"PMC_11181400","title":"NHERF: targeting and trafficking membrane proteins.","date":"2001","source":"American journal of physiology. Renal physiology","url":"https://pubmed.ncbi.nlm.nih.gov/11181400","citation_count":143,"is_preprint":false},{"pmid":"11607833","id":"PMC_11607833","title":"Expanding the role of NHERF, a PDZ-domain containing protein adapter, to growth regulation.","date":"2001","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/11607833","citation_count":143,"is_preprint":false},{"pmid":"12830000","id":"PMC_12830000","title":"EBP50, a beta-catenin-associating protein, enhances Wnt signaling and is over-expressed in hepatocellular carcinoma.","date":"2003","source":"Hepatology (Baltimore, Md.)","url":"https://pubmed.ncbi.nlm.nih.gov/12830000","citation_count":131,"is_preprint":false},{"pmid":"12920119","id":"PMC_12920119","title":"Activation-independent parathyroid hormone receptor internalization is regulated by NHERF1 (EBP50).","date":"2003","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/12920119","citation_count":131,"is_preprint":false},{"pmid":"10821685","id":"PMC_10821685","title":"NHERF associations with sodium-hydrogen exchanger isoform 3 (NHE3) and ezrin are essential for cAMP-mediated phosphorylation and inhibition of NHE3.","date":"2000","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/10821685","citation_count":118,"is_preprint":false},{"pmid":"11121391","id":"PMC_11121391","title":"Differential renal distribution of NHERF isoforms and their colocalization with NHE3, ezrin, and ROMK.","date":"2001","source":"American journal of physiology. Cell physiology","url":"https://pubmed.ncbi.nlm.nih.gov/11121391","citation_count":115,"is_preprint":false},{"pmid":"15339978","id":"PMC_15339978","title":"Podocalyxin activates RhoA and induces actin reorganization through NHERF1 and Ezrin in MDCK cells.","date":"2004","source":"Journal of the American Society of Nephrology : JASN","url":"https://pubmed.ncbi.nlm.nih.gov/15339978","citation_count":107,"is_preprint":false},{"pmid":"11456497","id":"PMC_11456497","title":"Oligomerization of NHERF-1 and NHERF-2 PDZ domains: differential regulation by association with receptor carboxyl-termini and by phosphorylation.","date":"2001","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/11456497","citation_count":100,"is_preprint":false},{"pmid":"12004055","id":"PMC_12004055","title":"Ezrin-radixin-moesin-binding phosphoprotein-50/Na+/H+ exchanger regulatory factor (EBP50/NHERF) blocks U50,488H-induced down-regulation of the human kappa opioid receptor by enhancing its recycling rate.","date":"2002","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/12004055","citation_count":100,"is_preprint":false},{"pmid":"10966919","id":"PMC_10966919","title":"Signal complex regulation of renal transport proteins: NHERF and regulation of NHE3 by PKA.","date":"2000","source":"American journal of physiology. Renal physiology","url":"https://pubmed.ncbi.nlm.nih.gov/10966919","citation_count":100,"is_preprint":false},{"pmid":"18942765","id":"PMC_18942765","title":"Downregulation of sodium transporters and NHERF proteins in IBD patients and mouse colitis models: potential contributors to IBD-associated diarrhea.","date":"2009","source":"Inflammatory bowel diseases","url":"https://pubmed.ncbi.nlm.nih.gov/18942765","citation_count":100,"is_preprint":false},{"pmid":"27994151","id":"PMC_27994151","title":"Dynamic NHERF interaction with TRPC4/5 proteins is required for channel gating by diacylglycerol.","date":"2016","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/27994151","citation_count":96,"is_preprint":false},{"pmid":"12917102","id":"PMC_12917102","title":"Localization and interaction of NHERF isoforms in the renal proximal tubule of the mouse.","date":"2003","source":"American journal of physiology. Cell physiology","url":"https://pubmed.ncbi.nlm.nih.gov/12917102","citation_count":90,"is_preprint":false},{"pmid":"18781953","id":"PMC_18781953","title":"Roles of NHERF1/EBP50 in cancer.","date":"2008","source":"Current molecular medicine","url":"https://pubmed.ncbi.nlm.nih.gov/18781953","citation_count":87,"is_preprint":false},{"pmid":"17242191","id":"PMC_17242191","title":"NHERF1/EBP50 head-to-tail intramolecular interaction masks association with PDZ domain ligands.","date":"2007","source":"Molecular and cellular biology","url":"https://pubmed.ncbi.nlm.nih.gov/17242191","citation_count":86,"is_preprint":false},{"pmid":"15901899","id":"PMC_15901899","title":"P2Y1 receptor signaling is controlled by interaction with the PDZ scaffold NHERF-2.","date":"2005","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/15901899","citation_count":79,"is_preprint":false},{"pmid":"17884816","id":"PMC_17884816","title":"NHERF1 regulates parathyroid hormone receptor membrane retention without affecting recycling.","date":"2007","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/17884816","citation_count":76,"is_preprint":false},{"pmid":"21170265","id":"PMC_21170265","title":"NHERF1/EBP50 is a new marker in colorectal cancer.","date":"2010","source":"Neoplasia (New York, N.Y.)","url":"https://pubmed.ncbi.nlm.nih.gov/21170265","citation_count":73,"is_preprint":false},{"pmid":"15467753","id":"PMC_15467753","title":"NHERF (Na+/H+ exchanger regulatory factor) gene mutations in human breast cancer.","date":"2004","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/15467753","citation_count":73,"is_preprint":false},{"pmid":"28068322","id":"PMC_28068322","title":"Role of the PDZ-scaffold protein NHERF1/EBP50 in cancer biology: from signaling regulation to clinical relevance.","date":"2017","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/28068322","citation_count":71,"is_preprint":false},{"pmid":"19538313","id":"PMC_19538313","title":"The role of the NHERF family of PDZ scaffolding proteins in the regulation of salt and water transport.","date":"2009","source":"Annals of the New York Academy of Sciences","url":"https://pubmed.ncbi.nlm.nih.gov/19538313","citation_count":70,"is_preprint":false},{"pmid":"21976599","id":"PMC_21976599","title":"Participation of the Cl-/HCO(3)- exchangers SLC26A3 and SLC26A6, the Cl- channel CFTR, and the regulatory factor SLC9A3R1 in mouse sperm capacitation.","date":"2012","source":"Biology of reproduction","url":"https://pubmed.ncbi.nlm.nih.gov/21976599","citation_count":69,"is_preprint":false},{"pmid":"11893083","id":"PMC_11893083","title":"Distinct cell type-specific expression of scaffolding proteins EBP50 and E3KARP: EBP50 is generally expressed with ezrin in specific epithelia, whereas E3KARP is not.","date":"2002","source":"European journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/11893083","citation_count":68,"is_preprint":false},{"pmid":"25756512","id":"PMC_25756512","title":"PTEN inhibits macrophage polarization from M1 to M2 through CCL2 and VEGF-A reduction and NHERF-1 synergism.","date":"2015","source":"Cancer biology & therapy","url":"https://pubmed.ncbi.nlm.nih.gov/25756512","citation_count":67,"is_preprint":false},{"pmid":"17599914","id":"PMC_17599914","title":"NHERF-1 and the cytoskeleton regulate the traffic and membrane dynamics of G protein-coupled receptors.","date":"2007","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/17599914","citation_count":65,"is_preprint":false},{"pmid":"17895247","id":"PMC_17895247","title":"Phosphorylation of PDZ1 domain attenuates NHERF-1 binding to cellular targets.","date":"2007","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/17895247","citation_count":62,"is_preprint":false},{"pmid":"12586353","id":"PMC_12586353","title":"NHERF-1 uniquely transduces the cAMP signals that inhibit sodium-hydrogen exchange in mouse renal apical membranes.","date":"2003","source":"FEBS letters","url":"https://pubmed.ncbi.nlm.nih.gov/12586353","citation_count":61,"is_preprint":false},{"pmid":"19308292","id":"PMC_19308292","title":"NHERF-1: modulator of glioblastoma cell migration and invasion.","date":"2009","source":"Neoplasia (New York, N.Y.)","url":"https://pubmed.ncbi.nlm.nih.gov/19308292","citation_count":60,"is_preprint":false},{"pmid":"20937695","id":"PMC_20937695","title":"The scaffolding protein EBP50 regulates microvillar assembly in a phosphorylation-dependent manner.","date":"2010","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/20937695","citation_count":59,"is_preprint":false},{"pmid":"19188335","id":"PMC_19188335","title":"NHERF1 regulates parathyroid hormone receptor desensitization: interference with beta-arrestin binding.","date":"2009","source":"Molecular pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/19188335","citation_count":57,"is_preprint":false},{"pmid":"15805108","id":"PMC_15805108","title":"Receptor activity-modifying protein (RAMP) isoform-specific regulation of adrenomedullin receptor trafficking by NHERF-1.","date":"2005","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/15805108","citation_count":56,"is_preprint":false},{"pmid":"21134377","id":"PMC_21134377","title":"MAGI-3 competes with NHERF-2 to negatively regulate LPA2 receptor signaling in colon cancer cells.","date":"2010","source":"Gastroenterology","url":"https://pubmed.ncbi.nlm.nih.gov/21134377","citation_count":53,"is_preprint":false},{"pmid":"21822312","id":"PMC_21822312","title":"Loss of EBP50 stimulates EGFR activity to induce EMT phenotypic features in biliary cancer cells.","date":"2011","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/21822312","citation_count":51,"is_preprint":false},{"pmid":"20237154","id":"PMC_20237154","title":"A regulated complex of the scaffolding proteins PDZK1 and EBP50 with ezrin contribute to microvillar organization.","date":"2010","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/20237154","citation_count":51,"is_preprint":false},{"pmid":"16891310","id":"PMC_16891310","title":"The PDZ scaffold NHERF-2 interacts with mGluR5 and regulates receptor activity.","date":"2006","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/16891310","citation_count":50,"is_preprint":false},{"pmid":"31002735","id":"PMC_31002735","title":"E6 proteins from high-risk HPV, low-risk HPV, and animal papillomaviruses activate the Wnt/β-catenin pathway through E6AP-dependent degradation of NHERF1.","date":"2019","source":"PLoS pathogens","url":"https://pubmed.ncbi.nlm.nih.gov/31002735","citation_count":50,"is_preprint":false},{"pmid":"21191106","id":"PMC_21191106","title":"NHERF1 and NHERF2 are necessary for multiple but usually separate aspects of basal and acute regulation of NHE3 activity.","date":"2010","source":"American journal of physiology. Cell physiology","url":"https://pubmed.ncbi.nlm.nih.gov/21191106","citation_count":49,"is_preprint":false},{"pmid":"20042604","id":"PMC_20042604","title":"A conformational switch in the scaffolding protein NHERF1 controls autoinhibition and complex formation.","date":"2009","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/20042604","citation_count":47,"is_preprint":false},{"pmid":"12819230","id":"PMC_12819230","title":"Role of NHERF-1 in regulation of the activity of Na-K ATPase and sodium-phosphate co-transport in epithelial cells.","date":"2003","source":"Journal of the American Society of Nephrology : JASN","url":"https://pubmed.ncbi.nlm.nih.gov/12819230","citation_count":46,"is_preprint":false},{"pmid":"20404332","id":"PMC_20404332","title":"NHERF-1 binds to Mrp2 and regulates hepatic Mrp2 expression and function.","date":"2010","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/20404332","citation_count":45,"is_preprint":false},{"pmid":"12952857","id":"PMC_12952857","title":"NHERF-1 is required for renal adaptation to a low-phosphate diet.","date":"2003","source":"American journal of physiology. Renal physiology","url":"https://pubmed.ncbi.nlm.nih.gov/12952857","citation_count":44,"is_preprint":false},{"pmid":"20802536","id":"PMC_20802536","title":"Direct interaction between NHERF1 and Frizzled regulates β-catenin signaling.","date":"2010","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/20802536","citation_count":41,"is_preprint":false},{"pmid":"19581308","id":"PMC_19581308","title":"The protein scaffold NHERF-1 controls the amplitude and duration of localized protein kinase D activity.","date":"2009","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/19581308","citation_count":39,"is_preprint":false},{"pmid":"19234136","id":"PMC_19234136","title":"Ezrin-radixin-moesin-binding phosphoprotein (EBP50), an estrogen-inducible scaffold protein, contributes to biliary epithelial cell proliferation.","date":"2009","source":"The American journal of pathology","url":"https://pubmed.ncbi.nlm.nih.gov/19234136","citation_count":39,"is_preprint":false},{"pmid":"26218645","id":"PMC_26218645","title":"SLC9A3R1 stimulates autophagy via BECN1 stabilization in breast cancer cells.","date":"2015","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/26218645","citation_count":37,"is_preprint":false},{"pmid":"22628548","id":"PMC_22628548","title":"Ezrin-anchored protein kinase A coordinates phosphorylation-dependent disassembly of a NHERF1 ternary complex to regulate hormone-sensitive phosphate transport.","date":"2012","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/22628548","citation_count":36,"is_preprint":false},{"pmid":"22476347","id":"PMC_22476347","title":"EBP50 inhibits EGF-induced breast cancer cell proliferation by blocking EGFR phosphorylation.","date":"2012","source":"Amino acids","url":"https://pubmed.ncbi.nlm.nih.gov/22476347","citation_count":35,"is_preprint":false},{"pmid":"18430067","id":"PMC_18430067","title":"The epithelial brush border Na+/H+ exchanger NHE3 associates with the actin cytoskeleton by binding to ezrin directly and via PDZ domain-containing Na+/H+ exchanger regulatory factor (NHERF) proteins.","date":"2008","source":"Clinical and experimental pharmacology & physiology","url":"https://pubmed.ncbi.nlm.nih.gov/18430067","citation_count":35,"is_preprint":false},{"pmid":"24862762","id":"PMC_24862762","title":"NHERF1/EBP50 controls morphogenesis of 3D colonic glands by stabilizing PTEN and ezrin-radixin-moesin proteins at the apical membrane.","date":"2014","source":"Neoplasia (New York, N.Y.)","url":"https://pubmed.ncbi.nlm.nih.gov/24862762","citation_count":34,"is_preprint":false},{"pmid":"22904329","id":"PMC_22904329","title":"NHE3 regulatory factor 1 (NHERF1) modulates intestinal sodium-dependent phosphate transporter (NaPi-2b) expression in apical microvilli.","date":"2012","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/22904329","citation_count":34,"is_preprint":false},{"pmid":"15994182","id":"PMC_15994182","title":"Beyond the brush border: NHERF4 blazes new NHERF turf.","date":"2005","source":"The Journal of physiology","url":"https://pubmed.ncbi.nlm.nih.gov/15994182","citation_count":34,"is_preprint":false},{"pmid":"20200151","id":"PMC_20200151","title":"Sodium-hydrogen exchanger regulatory factor 1 (NHERF-1) transduces signals that mediate dopamine inhibition of sodium-phosphate co-transport in mouse kidney.","date":"2010","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/20200151","citation_count":33,"is_preprint":false},{"pmid":"30230542","id":"PMC_30230542","title":"HPV16 E6 promotes cervical cancer cell migration and invasion by downregulation of NHERF1.","date":"2018","source":"International journal of cancer","url":"https://pubmed.ncbi.nlm.nih.gov/30230542","citation_count":32,"is_preprint":false},{"pmid":"20632170","id":"PMC_20632170","title":"Role of NHERF and scaffolding proteins in proximal tubule transport.","date":"2010","source":"Urological research","url":"https://pubmed.ncbi.nlm.nih.gov/20632170","citation_count":31,"is_preprint":false},{"pmid":"22610101","id":"PMC_22610101","title":"Arrestin scaffolds NHERF1 to the P2Y12 receptor to regulate receptor internalization.","date":"2012","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/22610101","citation_count":31,"is_preprint":false},{"pmid":"21325834","id":"PMC_21325834","title":"Na+-H+ exchanger regulatory factor 1 (NHERF1) PDZ scaffold binds an internal binding site in the scavenger receptor megalin.","date":"2011","source":"Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/21325834","citation_count":30,"is_preprint":false},{"pmid":"22535796","id":"PMC_22535796","title":"NHERF-1 and the regulation of renal phosphate reabsoption: a tale of three hormones.","date":"2012","source":"American journal of physiology. Renal physiology","url":"https://pubmed.ncbi.nlm.nih.gov/22535796","citation_count":29,"is_preprint":false},{"pmid":"20656684","id":"PMC_20656684","title":"Formation of a ternary complex among NHERF1, beta-arrestin, and parathyroid hormone receptor.","date":"2010","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/20656684","citation_count":29,"is_preprint":false},{"pmid":"25530180","id":"PMC_25530180","title":"The scaffolding protein NHERF1 sensitizes EGFR-dependent tumor growth, motility and invadopodia function to gefitinib treatment in breast cancer cells.","date":"2014","source":"International journal of oncology","url":"https://pubmed.ncbi.nlm.nih.gov/25530180","citation_count":29,"is_preprint":false},{"pmid":"15590898","id":"PMC_15590898","title":"Expression of TRPC4 channel protein that interacts with NHERF-2 in rat descending vasa recta.","date":"2004","source":"American journal of physiology. Cell physiology","url":"https://pubmed.ncbi.nlm.nih.gov/15590898","citation_count":29,"is_preprint":false},{"pmid":"19857202","id":"PMC_19857202","title":"The adaptor protein EBP50 is important for localization of the protein kinase A-Ezrin complex in T-cells and the immunomodulating effect of cAMP.","date":"2009","source":"The Biochemical journal","url":"https://pubmed.ncbi.nlm.nih.gov/19857202","citation_count":29,"is_preprint":false},{"pmid":"21048827","id":"PMC_21048827","title":"NHERF1/EBP50 in Breast Cancer: Clinical Perspectives.","date":"2010","source":"Breast care (Basel, Switzerland)","url":"https://pubmed.ncbi.nlm.nih.gov/21048827","citation_count":29,"is_preprint":false},{"pmid":"25775275","id":"PMC_25775275","title":"NHERF1/EBP50 is an organizer of polarity structures and a diagnostic marker in ependymoma.","date":"2015","source":"Acta neuropathologica communications","url":"https://pubmed.ncbi.nlm.nih.gov/25775275","citation_count":28,"is_preprint":false},{"pmid":"15070904","id":"PMC_15070904","title":"kappa Opioid receptor interacts with Na(+)/H(+)-exchanger regulatory factor-1/Ezrin-radixin-moesin-binding phosphoprotein-50 (NHERF-1/EBP50) to stimulate Na(+)/H(+) exchange independent of G(i)/G(o) proteins.","date":"2004","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/15070904","citation_count":28,"is_preprint":false},{"pmid":"26432781","id":"PMC_26432781","title":"NHERF1 regulates actin cytoskeleton organization through modulation of α-actinin-4 stability.","date":"2015","source":"FASEB journal : official publication of the Federation of American Societies for Experimental Biology","url":"https://pubmed.ncbi.nlm.nih.gov/26432781","citation_count":28,"is_preprint":false},{"pmid":"23109343","id":"PMC_23109343","title":"Na+/H+ exchanger regulatory factor 1 (NHERF1) directly regulates osteogenesis.","date":"2012","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/23109343","citation_count":28,"is_preprint":false},{"pmid":"20012548","id":"PMC_20012548","title":"EBP50 exerts tumor suppressor activity by promoting cell apoptosis and retarding extracellular signal-regulated kinase activity.","date":"2009","source":"Amino acids","url":"https://pubmed.ncbi.nlm.nih.gov/20012548","citation_count":28,"is_preprint":false},{"pmid":"24728453","id":"PMC_24728453","title":"PDZK1 and NHERF1 regulate the function of human organic anion transporting polypeptide 1A2 (OATP1A2) by modulating its subcellular trafficking and stability.","date":"2014","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/24728453","citation_count":28,"is_preprint":false},{"pmid":"22466651","id":"PMC_22466651","title":"Aberrant nuclear localization of EBP50 promotes colorectal carcinogenesis in xenotransplanted mice by modulating TCF-1 and β-catenin interactions.","date":"2012","source":"The Journal of clinical investigation","url":"https://pubmed.ncbi.nlm.nih.gov/22466651","citation_count":27,"is_preprint":false},{"pmid":"15742180","id":"PMC_15742180","title":"NHERF and regulation of the renal sodium-hydrogen exchanger NHE3.","date":"2005","source":"Pflugers Archiv : European journal of physiology","url":"https://pubmed.ncbi.nlm.nih.gov/15742180","citation_count":25,"is_preprint":false},{"pmid":"16705152","id":"PMC_16705152","title":"Adenoviral expression of NHERF-1 in NHERF-1 null mouse renal proximal tubule cells restores Npt2a regulation by low phosphate media and parathyroid hormone.","date":"2006","source":"American journal of physiology. Renal physiology","url":"https://pubmed.ncbi.nlm.nih.gov/16705152","citation_count":24,"is_preprint":false},{"pmid":"24196963","id":"PMC_24196963","title":"Ezrin-radixin-moesin-binding phosphoprotein 50 (EBP50) and nuclear factor-κB (NF-κB): a feed-forward loop for systemic and vascular inflammation.","date":"2013","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/24196963","citation_count":24,"is_preprint":false},{"pmid":"29867145","id":"PMC_29867145","title":"NHERF1 inhibits beta-catenin-mediated proliferation of cervical cancer cells through suppression of alpha-actinin-4 expression.","date":"2018","source":"Cell death & disease","url":"https://pubmed.ncbi.nlm.nih.gov/29867145","citation_count":23,"is_preprint":false},{"pmid":"30696771","id":"PMC_30696771","title":"Parathyroid hormone initiates dynamic NHERF1 phosphorylation cycling and conformational changes that regulate NPT2A-dependent phosphate transport.","date":"2019","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/30696771","citation_count":23,"is_preprint":false},{"pmid":"28950951","id":"PMC_28950951","title":"Roles of NHERF Family of PDZ-Binding Proteins in Regulating GPCR Functions.","date":"2017","source":"Advances in immunology","url":"https://pubmed.ncbi.nlm.nih.gov/28950951","citation_count":22,"is_preprint":false},{"pmid":"28085111","id":"PMC_28085111","title":"NHERF1 Enhances Cisplatin Sensitivity in Human Cervical Cancer Cells.","date":"2017","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/28085111","citation_count":21,"is_preprint":false},{"pmid":"27279487","id":"PMC_27279487","title":"The NHERF1 PDZ1 domain and IRBIT interact and mediate the activation of Na+/H+ exchanger 3 by ANG II.","date":"2016","source":"American journal of physiology. Renal physiology","url":"https://pubmed.ncbi.nlm.nih.gov/27279487","citation_count":21,"is_preprint":false},{"pmid":"22766563","id":"PMC_22766563","title":"Involvement of nuclear NHERF1 in colorectal cancer progression.","date":"2012","source":"Oncology reports","url":"https://pubmed.ncbi.nlm.nih.gov/22766563","citation_count":21,"is_preprint":false},{"pmid":"23474170","id":"PMC_23474170","title":"PEX7 and EBP50 target iNOS to the peroxisome in hepatocytes.","date":"2013","source":"Nitric oxide : biology and chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/23474170","citation_count":21,"is_preprint":false},{"pmid":"20420835","id":"PMC_20420835","title":"Spatiotemporal control of cyclic AMP immunomodulation through the PKA-Csk inhibitory pathway is achieved by anchoring to an Ezrin-EBP50-PAG scaffold in effector T cells.","date":"2010","source":"FEBS letters","url":"https://pubmed.ncbi.nlm.nih.gov/20420835","citation_count":20,"is_preprint":false},{"pmid":"27448983","id":"PMC_27448983","title":"NHERF1, a novel GPER associated protein, increases stability and activation of GPER in ER-positive breast cancer.","date":"2016","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/27448983","citation_count":20,"is_preprint":false},{"pmid":"12865627","id":"PMC_12865627","title":"Expression of NHERF-1, NHERF-2, PDGFR-alpha, and PDGFR-beta in normal human kidneys and in renal transplant rejection.","date":"2002","source":"Pathobiology : journal of immunopathology, molecular and cellular biology","url":"https://pubmed.ncbi.nlm.nih.gov/12865627","citation_count":20,"is_preprint":false},{"pmid":"11918742","id":"PMC_11918742","title":"NHE3 and NHERF are targeted to the basolateral membrane in proximal tubules of colchicine-treated rats.","date":"2002","source":"Kidney international","url":"https://pubmed.ncbi.nlm.nih.gov/11918742","citation_count":20,"is_preprint":false},{"pmid":"23775624","id":"PMC_23775624","title":"EBP50 phosphorylation by Cdc2/Cyclin B kinase affects actin cytoskeleton reorganization and regulates functions of human breast cancer cell line MDA-MB-231.","date":"2013","source":"Molecules and cells","url":"https://pubmed.ncbi.nlm.nih.gov/23775624","citation_count":20,"is_preprint":false},{"pmid":"27566107","id":"PMC_27566107","title":"NHERF1/EBP50 Suppresses Wnt-β-Catenin Pathway-Driven Intestinal Neoplasia.","date":"2016","source":"Neoplasia (New York, N.Y.)","url":"https://pubmed.ncbi.nlm.nih.gov/27566107","citation_count":19,"is_preprint":false},{"pmid":"28235801","id":"PMC_28235801","title":"The scaffolding protein NHERF1 regulates the stability and activity of the tyrosine kinase HER2.","date":"2017","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/28235801","citation_count":19,"is_preprint":false},{"pmid":"29901158","id":"PMC_29901158","title":"Wnt signaling pathway upregulates DNMT1 to trigger NHERF1 promoter hypermethylation in colon cancer.","date":"2018","source":"Oncology reports","url":"https://pubmed.ncbi.nlm.nih.gov/29901158","citation_count":19,"is_preprint":false},{"pmid":"18216150","id":"PMC_18216150","title":"Novel regulatory function for NHERF-1 in Npt2a transcription.","date":"2008","source":"American journal of physiology. Renal physiology","url":"https://pubmed.ncbi.nlm.nih.gov/18216150","citation_count":19,"is_preprint":false},{"pmid":"21160026","id":"PMC_21160026","title":"Dopamine regulation of Na+-K+-ATPase requires the PDZ-2 domain of sodium hydrogen regulatory factor-1 (NHERF-1) in opossum kidney cells.","date":"2010","source":"American journal of physiology. Cell physiology","url":"https://pubmed.ncbi.nlm.nih.gov/21160026","citation_count":19,"is_preprint":false},{"pmid":"29455084","id":"PMC_29455084","title":"NHERF1 Between Promises and Hopes: Overview on Cancer and Prospective Openings.","date":"2018","source":"Translational oncology","url":"https://pubmed.ncbi.nlm.nih.gov/29455084","citation_count":18,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":54100,"output_tokens":12635,"usd":0.175912,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":23879,"output_tokens":7600,"usd":0.154697,"stage2_stop_reason":"end_turn"},"total_usd":0.330609,"stage1_batch_id":"msgbatch_013a8chtv3AWyTqv4z4sEF4C","stage2_batch_id":"msgbatch_01AHsuW63vinsvuTgzmQ3n62","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1997,\n      \"finding\": \"EBP50/NHERF1 was identified as a PDZ-containing phosphoprotein that directly binds the N-terminal domains of ezrin and moesin (N-ERMADs) via affinity chromatography. It colocalizes with actin and ezrin in apical microvilli of epithelial cells and can be co-immunoprecipitated with ezrin from human placental microvilli, establishing it as a physiologically relevant ezrin-binding protein that links membrane proteins to the actin cytoskeleton through its PDZ domains.\",\n      \"method\": \"Affinity chromatography, co-immunoprecipitation, immunofluorescence microscopy, immunoelectron microscopy, recombinant protein binding assays\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — multiple orthogonal methods (affinity chromatography, Co-IP, direct binding assay, immunolocalization) in a single foundational study, widely replicated\",\n      \"pmids\": [\"9314537\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1998,\n      \"finding\": \"The C-terminal 30 residues of EBP50 are sufficient to bind ezrin residues 1-286, but EBP50 does not bind full-length ezrin because the EBP50-binding site is masked by intramolecular N/C-ERMAD association. Binding of EBP50 and the C-ERMAD to the ezrin N-terminal domain is mutually exclusive, with C-ERMAD having higher affinity, establishing a model of regulated ezrin activation to expose the EBP50 binding site.\",\n      \"method\": \"Blot overlays, in-solution binding assays, truncation/deletion mutagenesis of EBP50 and ezrin\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro reconstitution with mutagenesis, multiple binding assays, mechanistic model validated by competition experiments\",\n      \"pmids\": [\"9660814\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1998,\n      \"finding\": \"NHERF/EBP50 and the related E3KARP function as scaffold adapters that bind both NHE3 and ezrin simultaneously, linking NHE3 to ezrin to localize PKA type II near NHE3 and enable PKA-mediated phosphorylation and inhibition of NHE3. NHERF is a phosphoprotein under basal conditions but does not change phosphorylation state after cAMP treatment; E3KARP is not phosphorylated.\",\n      \"method\": \"Co-immunoprecipitation, in vivo phosphorylation studies, intracellular pH measurement of Na+/H+ exchange activity, cAMP analog pharmacology\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP plus functional activity assays, replicated in subsequent studies\",\n      \"pmids\": [\"9792717\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1999,\n      \"finding\": \"EBP50 PDZ domain 1 binds CFTR and PDZ domain 2 binds YAP65, localizing YAP65 to the apical membrane of airway epithelial cells. The EBP50-YAP65 interaction recruits the nonreceptor tyrosine kinase c-Yes into apical EBP50 protein complexes. Mutant YAP65 lacking the EBP50-interaction motif is mislocalized when expressed in airway epithelial cells.\",\n      \"method\": \"Co-immunoprecipitation, immunofluorescence, expression of mutant proteins, confocal microscopy\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — Co-IP in cells, functional mislocalization with domain-deletion mutants, multiple orthogonal methods\",\n      \"pmids\": [\"10562288\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"NHERF1 PDZ domain 1 interacts with murine Trp4, Trp5, and phospholipase C-β1 and β2. Co-immunoprecipitation confirmed the Trp4-NHERF1 and PLC-β1-NHERF1 association in HEK293 cells expressing Trp4 and in adult mouse brain, establishing that NHERF1 scaffolds store-operated channels with PLC isozymes and links them to the actin cytoskeleton via ERM proteins.\",\n      \"method\": \"Yeast two-hybrid, GST pulldown, co-immunoprecipitation from HEK293 cells and mouse brain lysates\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP in two distinct cellular contexts, multiple binding partners confirmed\",\n      \"pmids\": [\"10980202\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"NHERF associations with both NHE3 (via PDZ domains) and ezrin (via C-terminal ERM-binding domain) are both required for cAMP-mediated phosphorylation and inhibition of NHE3. Truncated NHERF lacking the ezrin-binding domain (NHERF 1-325) bound NHE3 but failed to support cAMP-mediated NHE3 inhibition or NHE3 phosphorylation, demonstrating that the NHERF-ezrin scaffold is essential for PKA access to NHE3.\",\n      \"method\": \"Stable transfection of truncated NHERF constructs in PS120/NHE3 cells, co-immunoprecipitation, Na+/H+ exchange activity assays, in vivo phosphorylation\",\n      \"journal\": \"Biochemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — domain-deletion mutagenesis combined with functional assays and phosphorylation measurements, mechanistically decisive\",\n      \"pmids\": [\"10821685\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"NHERF-1 PDZ domains can oligomerize; oligomerization of NHERF-1 (but not NHERF-2) is facilitated by ligand binding to its PDZ domains (e.g., β2-adrenergic receptor or PDGFR C-termini). Phosphomimetic mutation S289D enhances NHERF-1 homo- and hetero-oligomerization, while S289A reduces it. NHERF-1 and NHERF-2 form homo- and hetero-oligomers in cells.\",\n      \"method\": \"Purified PDZ domain association assays, co-immunoprecipitation with differentially tagged constructs, phosphomimetic/phosphodeficient mutagenesis\",\n      \"journal\": \"Biochemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — in vitro reconstitution with purified domains plus cellular Co-IP, mutagenesis, single lab\",\n      \"pmids\": [\"11456497\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"Targeted disruption of NHERF-1 in mice causes internalization of the renal sodium-phosphate cotransporter Npt2 away from the brush-border membrane, resulting in renal phosphate wasting. NHE3 localization at the apical surface is unaffected, demonstrating a unique and specific role for NHERF-1 in apical targeting/retention of Npt2 that is not shared by NHERF-2.\",\n      \"method\": \"Gene knockout mouse model, immunocytochemistry, brush-border membrane fractionation, urine electrolyte analysis\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic loss-of-function with defined molecular and physiological phenotype, replicated in subsequent studies\",\n      \"pmids\": [\"12169661\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"EBP50/NHERF1 PDZ domain 1 binds the human kappa opioid receptor (hKOR) C-terminus; agonist treatment enhances this association. NHERF1 expression (requiring its ERM-binding domain) blocks U50,488H-induced hKOR down-regulation by increasing receptor recycling rate, without affecting agonist binding, G-protein signaling, desensitization, or internalization. C-terminal mutations in hKOR that prevent NHERF1 binding abolish this protective effect.\",\n      \"method\": \"Co-immunoprecipitation in CHO cells, radioligand binding, flow cytometry, mutagenesis of receptor C-terminus and NHERF1 domains\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — Co-IP, functional receptor trafficking assays, domain mutagenesis of both interacting proteins\",\n      \"pmids\": [\"12004055\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"NHERF-1 uniquely transduces cAMP signals that inhibit NHE3 in mouse renal brush-border membranes. In NHERF-1(-/-) BBMs, cAMP-activated PKA failed to inhibit NHE3 activity and failed to phosphorylate NHE3, despite normal levels of NHE3, NHERF-2, PKA, and ezrin, demonstrating that NHERF-2 cannot compensate for NHERF-1 in this signaling context.\",\n      \"method\": \"Isolated brush-border membrane vesicles from NHERF-1 knockout mice, Na+/H+ exchange activity assays, NHE3 phosphorylation by immunoprecipitation\",\n      \"journal\": \"FEBS letters\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic KO with biochemical and functional assays on native membranes, unambiguous phenotype\",\n      \"pmids\": [\"12586353\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"NHERF1 (EBP50) inhibits activation-independent, arrestin-independent PTH1R internalization. In cells lacking NHERF1, PTH antagonists (PTH 7-34, PTH 7-84) induce dynamin-dependent but β-arrestin-independent PTH1R endocytosis. NHERF1 expression blocked this endocytosis; dominant-negative NHERF1 conferred internalization sensitivity to cells normally expressing NHERF1. Both the PTH1R PDZ-binding motif and NHERF1 ERM domain are required; actin polymerization is necessary for NHERF1-mediated retention.\",\n      \"method\": \"Radioligand binding, live-cell confocal microscopy of fluorescent PTH1R, dominant-negative constructs, PDZ-binding motif mutagenesis, actin depolymerization experiments\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal approaches including live imaging, mutagenesis, dominant-negatives, and pharmacological perturbation\",\n      \"pmids\": [\"12920119\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"EBP50 interacts with β-catenin through its C-terminal PDZ domain both in vitro and in vivo. Over-expression of EBP50 enhances β-catenin/TCF-dependent transcription in a dose-dependent manner in hepatocellular carcinoma and colorectal cancer cells, but only when β-catenin is already stabilized.\",\n      \"method\": \"Protein interaction screening, GST pulldown, co-immunoprecipitation, luciferase reporter assays, Northern/RT-PCR, immunohistochemistry\",\n      \"journal\": \"Hepatology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP and in vitro binding confirmed, functional transcription assays, single lab\",\n      \"pmids\": [\"12830000\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"NHERF-1 is required for PTH regulation of Na-K ATPase in renal proximal tubule cells. Wild-type NHERF-1 supported PTH-induced inhibition of Na-K ATPase and increased serine phosphorylation of its α-subunit; NHERF-1 lacking the ezrin-binding domain (1-325) blunted α-subunit phosphorylation and reversed the response to stimulation. Basal sodium-dependent phosphate transport was lower in cells expressing the truncation.\",\n      \"method\": \"Stable transfection of NHERF-1 truncation mutants in opossum kidney cells, ouabain-sensitive ATPase activity assays, phosphorylation assays\",\n      \"journal\": \"Journal of the American Society of Nephrology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — domain truncation mutagenesis with functional assays, single lab, limited replication\",\n      \"pmids\": [\"12819230\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"Podocalyxin activates RhoA and induces apical actin redistribution through NHERF (NHERF2) and ezrin in MDCK cells. Full-length podocalyxin, but not a mutant lacking the NHERF binding site, connects to actin, activates RhoA, and redistributes actin apically. Ezrin was found to bind directly to the juxtamembrane cytoplasmic region of podocalyxin.\",\n      \"method\": \"Stable cell lines expressing full-length or PDZ-binding-deficient podocalyxin, pulldown assays, RhoA activity assays, immunofluorescence\",\n      \"journal\": \"Journal of the American Society of Nephrology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss-of-binding mutant, RhoA activity assay, pulldown mapping, single lab\",\n      \"pmids\": [\"15339978\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"NHERF-1/EBP50 PDZ domain 1 directly binds the hKOR C-tail (but not μ or δ opioid receptor C-tails), and this interaction enhances NHERF-1 oligomerization. In OK cells expressing endogenous NHERF-1, kappa opioid receptor stimulation increases Na+/H+ exchange in a pertussis toxin-independent manner; in OKH cells (NHERF-1-deficient), this effect is absent and restored by NHERF-1 transfection, establishing that NHERF-1 mediates KOR-stimulated NHE3 activity.\",\n      \"method\": \"GST pulldown with purified proteins, co-immunoprecipitation, intracellular pH/Na+/H+ exchange assays, NHERF-1 stable transfection in OKH cells\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — direct GST pulldown with purified proteins, Co-IP, loss-of-function/gain-of-function functional assays\",\n      \"pmids\": [\"15070904\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"NHERF-1 inhibits agonist-induced internalization of the adrenomedullin AM2 receptor complex (CRLR/RAMP3) by tethering it to the actin cytoskeleton via the ERM-binding domain of NHERF-1. NHERF-1 interaction is RAMP3-isoform specific (not RAMP1 or RAMP2). RAMP3 and NHERF-1 interact via a PDZ type I domain on NHERF-1. siRNA knockdown of RAMP3 or NHERF-1 in human proximal tubule cells enabled agonist-induced internalization.\",\n      \"method\": \"Co-immunoprecipitation, overlay assays, mutational analysis, siRNA knockdown, internalization assays in HEK293T and primary proximal tubule cells\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — endogenous and overexpression models, siRNA knockdown, mutagenesis of ERM domain, RAMP isoform specificity established\",\n      \"pmids\": [\"15805108\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"NHERF1 adopts a head-to-tail autoinhibited conformation in which the C-terminal EB region binds the PDZ2 domain, masking both PDZ domains from interacting with ligands such as PTEN and β-catenin. Prior association of ezrin with the EB region disrupts this intramolecular interaction, releasing PDZ domain accessibility. NHERF2 does not exhibit this regulatory conformation.\",\n      \"method\": \"In vitro binding assays, mutagenesis, co-immunoprecipitation, confocal microscopy in polarized epithelial cells\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — in vitro binding reconstitution, mutagenesis, and cellular functional validation in a single study\",\n      \"pmids\": [\"17242191\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"Phosphorylation of NHERF-1 PDZ1 domain at serine 77 attenuates its binding to physiological targets including β2-adrenergic receptor, PDGFR, CFTR, and Npt2a. Phosphatase inhibitors enhance NHERF-1 phosphorylation and inhibit its dimerization. S77A mutation abolishes PDZ1 phosphorylation and increases NHERF-1 localization at the cell periphery; S77D reduces colocalization with cortical actin.\",\n      \"method\": \"Metabolic labeling, phosphatase inhibitor treatment, mutagenesis (S77A/S77D), co-immunoprecipitation, confocal microscopy\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — site-specific mutagenesis with functional binding assays and localization studies, phosphorylation site mapped\",\n      \"pmids\": [\"17895247\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"NHERF-1 and the actin cytoskeleton regulate the distribution and trafficking of GPCRs. NHERF-1 expression reduces diffusion of β2AR and PTH1R, forms receptor bundles along stress fibers for β2AR, and reduces ligand-induced internalization rate of PTH1R by slowing arrestin recruitment. CaSR does not interact with the cytoskeleton via NHERF-1.\",\n      \"method\": \"FRAP, TIRF microscopy, image correlation spectroscopy, live-cell confocal imaging of fluorescent receptors\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple live-cell imaging modalities, receptor-specific effects documented, mechanistic conclusions supported by quantitative biophysics\",\n      \"pmids\": [\"17599914\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"NHERF1 inhibits PTH1R endocytosis and delays PTH1R recycling. Both the PDZ-binding domain and MERM domain of NHERF1, as well as the PTH1R C-terminal PDZ recognition motif, are required for inhibition of endocytosis. NHERF1-mediated effects involve β-arrestin and dynamin. shRNA knockdown of NHERF1 in HEK-293 cells augmented PTH1R endocytosis.\",\n      \"method\": \"Radioligand binding, confocal microscopy of fluorescent PTH1R, tetracycline-inducible NHERF1 expression, PDZ-domain mutagenesis, shRNA knockdown\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — inducible expression, shRNA knockdown, domain mutagenesis, functional trafficking assays\",\n      \"pmids\": [\"17884816\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"NHERF1 is an obligatory linker for β2-adrenergic receptor stimulation of CFTR-dependent HCO3- secretion in mouse duodenum. NHERF1 ablation strongly reduced basal and FSK-stimulated HCO3- secretion and blocked β2-AR stimulation; colocalization of β2-AR and CFTR was reduced in NHERF1-null mice. NHERF2 confers inhibitory signals by coupling LPA receptor to CFTR.\",\n      \"method\": \"Knockout mouse models (Nherf1-/-, Nherf2-/-, Pdzk1-/-), HCO3- secretion measurements, laser microdissection/qPCR, immunofluorescence colocalization\",\n      \"journal\": \"The Journal of clinical investigation\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple genetic KO models with defined physiological phenotypes and molecular colocalization data\",\n      \"pmids\": [\"19221439\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"NHERF1 inhibits PTH1R desensitization by blocking β-arrestin2 binding to the receptor. NHERF1 prevents PTH-induced dissociation of PTH1R from Gαs. Both PDZ-binding and MERM domains of NHERF1 are required. NHERF1 forms a ternary complex with PTH1R and β-arrestin2 in cells; NHERF1 modulates the kinetics of β-arrestin2 recruitment to the PTH1R.\",\n      \"method\": \"Adenylyl cyclase activity assays, tetracycline-inducible NHERF1, shRNA knockdown, mutagenesis, co-immunoprecipitation, FRET imaging\",\n      \"journal\": \"Molecular pharmacology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple assays (AC activity, co-IP, FRET), gain and loss of function, domain mutagenesis\",\n      \"pmids\": [\"19188335\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"The NMR structure of the NHERF1 PDZ2-CT domain reveals weak intramolecular interactions between the disordered CT domain and the PDZ ligand binding site, and a novel helix-turn-helix subdomain allosterically coupled to PDZ2. Binding of ezrin releases these intramolecular domain-domain interactions as demonstrated by NMR and SANS. Disease-causing mutations R153Q and E225K in PDZ2 significantly reduce protein stability.\",\n      \"method\": \"High-resolution NMR, small-angle X-ray scattering (SAXS), small-angle neutron scattering (SANS), mutagenesis of disease variants\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — high-resolution NMR structure with SAXS/SANS constraints, mutagenesis, and functional validation in a single rigorous study\",\n      \"pmids\": [\"20042604\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"EBP50/NHERF1, as part of the ezrin-EBP50-PAG scaffold in T cells, positions PKA type I near its substrate Csk at the TCR. The ezrin-EBP50 interaction has a KD of 58 nM. Disruption of the ezrin-EBP50 interaction by a competing peptide (EBP50pep) delocalizes ezrin, and reverses cAMP-mediated inhibition of IL-2 production, demonstrating a required role for EBP50 in cAMP immunomodulation in T cells.\",\n      \"method\": \"Binding kinetics (KD determination), peptide competition assays, T-cell loading with competing peptide, IL-2 production assays\",\n      \"journal\": \"The Biochemical journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — quantitative binding assay, peptide competition with defined KD, functional immune readout\",\n      \"pmids\": [\"19857202\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"EBP50/NHERF1 is necessary for microvillar assembly in epithelial cells. RNAi depletion of EBP50 reduces microvilli. This requires both a functional PDZ1 domain and the ezrin-binding site. Phosphomimetic mutations at Cdc2 or PKC phosphorylation sites render EBP50 nonfunctional in microvillar assembly. PKC activation causes EBP50 phosphorylation-dependent loss of microvillar organization.\",\n      \"method\": \"RNAi knockdown, expression of phosphomimetic/phosphodeficient EBP50 mutants, biochemical analysis of PDZ domain accessibility\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — RNAi with rescue by RNAi-resistant mutants, systematic domain analysis, PKC pharmacology, multiple orthogonal readouts\",\n      \"pmids\": [\"20937695\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"NHERF1 directly interacts with a subset of Frizzled (Fzd) receptors via one of its PDZ domains, maintaining low Wnt/β-catenin signaling. Loss of NHERF1 in breast cancer cell lines enhances canonical Wnt signaling and Wnt-dependent proliferation. NHERF1-knockout mouse mammary glands exhibit increased duct density, proliferation, and β-catenin activity.\",\n      \"method\": \"Co-immunoprecipitation, reporter assays, NHERF1 knockout mice, cell proliferation assays\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP, functional reporter assays, KO mouse model, single lab\",\n      \"pmids\": [\"20802536\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"NHERF-1 binds to Mrp2 (via Mrp2's PDZ-binding motif) in co-transfected HEK293 cells and in mouse liver. In NHERF-1(-/-) mice, Mrp2 protein is reduced ~50% in whole cell lysates and ~70% in membrane fractions (post-transcriptional regulation), bile flow is reduced ~30%, and glutathione excretion is reduced ~50%, demonstrating a critical role for NHERF-1 in canalicular Mrp2 expression and glutathione-dependent bile flow.\",\n      \"method\": \"Co-immunoprecipitation, NHERF-1 knockout mice, Western blotting, membrane fractionation, bile collection/bile flow measurement, GS-MF fluorescence assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — Co-IP with PDZ-motif mutagenesis, genetic KO with multiple functional endpoints\",\n      \"pmids\": [\"20404332\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"NHERF-1 transduces dopamine inhibition of renal phosphate transport. NHERF-1 associates with D1-like receptors (Co-IP). Dopamine stimulated cAMP and PKC activity in wild-type proximal tubule cells but not in NHERF-1 null cells; adenoviral re-expression of NHERF-1 rescued these responses. Dopamine increased NHERF-1 phosphorylation at Ser77 (PDZ1), attenuating Npt2a binding.\",\n      \"method\": \"Co-immunoprecipitation, phosphate transport assays in WT and KO cells, cAMP/PKC activity assays, adenoviral rescue, 32P metabolic labeling\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — loss-of-function KO, adenoviral rescue, biochemical signaling assays, phosphorylation site identified\",\n      \"pmids\": [\"20200151\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"NHERF-1 controls the amplitude and duration of PKD1/PKD2 signaling at the membrane scaffold. The first PDZ domain of NHERF-1 interacts with PDZ-binding motifs of PKD1 and PKD2. FRET-based live-cell imaging reveals that PKD activation at the NHERF-1 scaffold is rapid and sustained but blunted in magnitude compared with cytosolic or bulk membrane PKD activity.\",\n      \"method\": \"PDZ domain proteomic array, FRET-based PKD activity reporter, FRET translocation assay in live cells\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — PDZ array identification followed by live-cell FRET kinase activity reporter, single lab\",\n      \"pmids\": [\"19581308\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"NHERF-1 forms a ternary complex with β-arrestin2 and PTH1R. NHERF1 binds constitutively to PTH1R while β-arrestin2 binding is agonist-promoted. NHERF1 interacts directly with β-arrestin2 without using PTH1R as an interface. NHERF1 modulates the kinetics of PTH1R/β-arrestin2 interactions as shown by FRET.\",\n      \"method\": \"Co-immunoprecipitation, BRET/FRET imaging, confocal microscopy, biochemical binding assays\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple biophysical methods (FRET, BRET, Co-IP) defining ternary complex formation and interaction kinetics\",\n      \"pmids\": [\"20656684\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"PDZK1 and EBP50 form a regulated ternary complex with ezrin in apical microvilli. Ezrin positively influences the PDZK1/EBP50 interaction (cooperativity). PDZK1 shuttles from nucleus to microvilli upon cell confluence, regulating complex formation. Knockdown of EBP50 reduces microvilli; this phenotype can be rescued by a PDZK1 chimera targeted directly to ezrin.\",\n      \"method\": \"In vitro binding assays, co-immunoprecipitation, RNAi knockdown, confocal microscopy of PDZK1 redistribution\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — in vitro reconstitution of ternary complex, cooperative binding demonstrated, RNAi rescue experiment\",\n      \"pmids\": [\"20237154\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"Arrestin scaffolds NHERF1 to the P2Y12 receptor to regulate internalization. Prior to agonist stimulation, NHERF1 interacts directly with the P2Y12R C-tail via the intact PDZ-binding motif. Upon receptor stimulation, NHERF1 no longer binds the receptor directly but instead is recruited via arrestin as an adaptor, facilitating NHERF1-dependent P2Y12R internalization.\",\n      \"method\": \"Co-immunoprecipitation in vitro and in cells, PDZ-binding motif mutagenesis, internalization assays\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP with mutagenesis, functional internalization assay, novel mechanism in a single lab\",\n      \"pmids\": [\"22610101\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"EBP50 depletion in biliary cancer cells increases EGFR surface expression and causes sustained EGFR activation (ERK1/2, STAT3) under basal and EGF-stimulated conditions. Loss of EBP50 induces epithelial-mesenchymal transition features (loss of E-cadherin/CK19, induction of S100A4/Slug, loss of polarity, lamellipodia formation). These effects are reversed by EGFR tyrosine kinase inhibition with gefitinib.\",\n      \"method\": \"siRNA knockdown of EBP50, Western blotting for signaling proteins, cell migration/invasion assays, immunofluorescence for junction proteins, gefitinib rescue\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — siRNA loss-of-function with multiple molecular readouts and pharmacological rescue, single lab\",\n      \"pmids\": [\"21822312\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"NHERF1 forms an obligate ternary complex with Npt2a and the PKA-anchoring protein ezrin to facilitate PTH-responsive phosphate transport. Ezrin-anchored PKA phosphorylates NHERF1 to disassemble this complex and release Npt2a, thereby inhibiting phosphate transport. Loss-of-function NHERF1 mutations stabilize an inactive conformation refractory to PKA phosphorylation and impair ternary complex assembly.\",\n      \"method\": \"Co-immunoprecipitation, in vitro kinase assays, mutagenesis of disease-associated NHERF1 variants, phosphate transport assays, compensatory mutagenesis rescue\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — biochemical reconstitution, in vitro kinase assay, disease mutation analysis, compensatory mutagenesis rescue\",\n      \"pmids\": [\"22628548\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"NHERF-1 mediates P2Y12 receptor internalization via the PDZ binding motif of the receptor prior to agonist stimulation, and via arrestin scaffolding upon agonist activation. Additionally, PDZ2 of NHERF1 binds megalin directly and via an internal (non-C-terminal) PDZ binding motif in megalin; NHERF1 silencing increases megalin expression in proximal tubule cells.\",\n      \"method\": \"Immunoprecipitation from rat kidney lysate, GST fusion protein binding, peptide studies, confocal colocalization, siRNA knockdown\",\n      \"journal\": \"Cellular physiology and biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 / Moderate — in vivo Co-IP, GST pulldown with peptide competition mapping, siRNA functional consequence\",\n      \"pmids\": [\"21325834\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"NHERF1 PDZ1 domain is required for ANG II-mediated forward trafficking and activation of NHE3. NHERF1 mediates ANG II-induced increase in NHERF1-NHE3 and NHERF1-IRBIT interactions. IRBIT is indispensable for ANG II-provoked NHERF1-NHE3 interactions; phosphorylation of IRBIT at Ser68 is necessary for assembly of the NHERF1-IRBIT-NHE3 complex.\",\n      \"method\": \"Co-immunoprecipitation, dominant-negative PDZ1 construct, adenoviral YFP-NHERF1 expression, NHE3 apical membrane trafficking assays, IRBIT siRNA\",\n      \"journal\": \"American journal of physiology. Renal physiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP, domain-deletion constructs, loss-of-function siRNA, functional trafficking assay, single lab\",\n      \"pmids\": [\"27279487\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"EBP50 targets iNOS to peroxisomes in hepatocytes. siRNA knockdown of PEX7 reduced iNOS colocalization with the peroxisomal marker PMP70. Proteomic/MALDI-MS identified iNOS association with EBP50; confocal and immunoelectron microscopy confirmed co-localization. EBP50 associates with peroxisomes in a PEX5/PEX7-dependent manner, and iNOS peroxisomal localization was contingent on EBP50 expression in LPS-treated mice.\",\n      \"method\": \"siRNA knockdown, MALDI-MS proteomics, confocal microscopy, immunoelectron microscopy, in vivo LPS model\",\n      \"journal\": \"Nitric oxide : biology and chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 / Moderate — multiple microscopy methods, proteomic identification, in vivo mouse model, single lab\",\n      \"pmids\": [\"23474170\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"EBP50 phosphorylation by Cdc2/CyclinB at Ser279 and Ser301 regulates actin cytoskeleton reorganization. Phosphodeficient (S279A/S301A) EBP50 significantly increased F-actin content, enhanced cell-matrix adhesion, caused cytokinesis defects (multinucleation, heteroploid DNA, giant cells), and had weaker actin binding. Phosphomimetic (S279D/S301D) did not cause these defects. Knockdown of EBP50 in AA cells rescued cytokinesis failure.\",\n      \"method\": \"Stable transfection of phosphodeficient/phosphomimetic mutants in MDA-MB-231, F-actin staining, DNA content analysis, cell adhesion assays, EBP50 knockdown rescue\",\n      \"journal\": \"Molecules and cells\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — phosphorylation site mutagenesis with functional cellular assays, rescue experiment, single lab\",\n      \"pmids\": [\"23775624\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"NHERF1 depletion in human intestinal epithelial cells in 3D culture disrupts apical-basal polarity and prevents lumen formation. NHERF1 concentrates at the apical membrane from the two-cell stage. NHERF1 depletion displaces PTEN from the membrane and causes nuclear β-catenin translocation. Moesin (but not ezrin) depletion reproduces the NHERF1 loss phenotype. NHERF1 ERM-binding and PDZ-domain mutants fail to localize apically and impair gland formation.\",\n      \"method\": \"3D gland morphogenesis assay, siRNA knockdown, confocal microscopy, domain-mutant expression\",\n      \"journal\": \"Neoplasia\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss-of-function in 3D morphogenesis model with domain-mutant rescue analysis, single lab\",\n      \"pmids\": [\"24862762\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"NHERF1 interaction with TRPC4 and TRPC5 (via their C-terminal PDZ-binding motif) regulates channel gating: dynamic dissociation of NHERF1/2 from the TRPC5 C-terminus upon PIP2 depletion is a prerequisite for DAG sensitivity. PKC inhibition or mutation of the PDZ-binding motif in TRPC4/5 conferred DAG sensitivity to the channel. PIP2 depletion evokes a C-terminal conformational change in TRPC5 leading to NHERF dissociation.\",\n      \"method\": \"PDZ-binding motif mutagenesis, PKC inhibition, electrophysiology, Co-immunoprecipitation, conformational change assays\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — PDZ motif mutagenesis, electrophysiological channel activity assays, dynamic Co-IP, PKC pharmacology, mechanistic model validated by multiple approaches\",\n      \"pmids\": [\"27994151\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"NHERF1 interacts with α-actinin-4 via NHERF1's PDZ domain and the α-actinin-4 C-terminal region. The NHERF1/α-actinin-4 interaction increases α-actinin-4 ubiquitination and decreases its expression, resulting in actin cytoskeleton disassembly. NHERF1 loss-of-function/gain-of-function experiments show that NHERF1 disorganizes polymerized F-actin in HeLa cells.\",\n      \"method\": \"2D-DIGE proteomics/MALDI-TOF identification, GST pulldown, co-immunoprecipitation, siRNA/overexpression, ubiquitination assay, F-actin staining\",\n      \"journal\": \"FASEB journal\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 / Moderate — GST pulldown plus Co-IP, ubiquitination assay, functional F-actin readout, single lab\",\n      \"pmids\": [\"26432781\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"NHERF1 binds BECN1 via its C-terminal domain, blocks ubiquitin-dependent BECN1 degradation, and thereby stabilizes BECN1 to stimulate autophagy. NHERF1 attenuates the BECN1-BCL2 interaction. Deletion of the NHERF1 C-terminal domain abolishes BECN1 binding, reduces BECN1 levels, and prevents autophagy induction.\",\n      \"method\": \"Co-immunoprecipitation, ubiquitination assay, autophagy flux assays, C-terminal domain deletion mutagenesis\",\n      \"journal\": \"Autophagy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 / Moderate — Co-IP, domain deletion mutagenesis, ubiquitination assay, functional autophagy readout, single lab\",\n      \"pmids\": [\"26218645\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"NHERF1 interacts with GPER via NHERF1's PDZ2 domain and the GPER C-terminal PDZ binding motif in breast cancer cells. NHERF1 stabilizes GPER protein by inhibiting its degradation through the ubiquitin-proteasome pathway in an interaction-dependent manner.\",\n      \"method\": \"Co-immunoprecipitation, domain mutagenesis (PDZ2), ubiquitin-proteasome inhibitor experiments, protein stability assays\",\n      \"journal\": \"Oncotarget\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 / Moderate — Co-IP with domain mutagenesis and functional stability assay, single lab\",\n      \"pmids\": [\"27448983\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"HPV E6 proteins (both high- and low-risk) degrade NHERF1 in an E6AP ubiquitin ligase-dependent manner, independent of PDZ interactions. E6 binding requires a novel structural domain of E6 (independent of the p53-recognition domain) and the NHERF1 EB domain. NHERF1 degradation by E6 activates canonical Wnt/β-catenin signaling.\",\n      \"method\": \"E6AP mutagenesis, NHERF1 domain deletion constructs, proteasome inhibitor experiments, Wnt/β-catenin reporter assays\",\n      \"journal\": \"PLoS pathogens\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — domain mutagenesis of both E6 and NHERF1, E6AP dependence established, functional Wnt reporter assay, single lab\",\n      \"pmids\": [\"31002735\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"PTH initiates dynamic NHERF1 phosphorylation cycling at Ser290: Ser290 is rapidly dephosphorylated by protein phosphatase 1α (PP1α, which binds NHERF1 via a VPF PP1-docking motif at residues 257-259) and then rephosphorylated by a GRK6A-containing kinase cascade. S290A substitution abolishes PTH-dependent phosphate transport. PP1α inhibition or mutation of the VPF motif blocks dephosphorylation and abrogates PTH-sensitive phosphate transport. Hydrogen-deuterium exchange MS reveals PTH-induced conformational changes in NHERF1 PDZ domains.\",\n      \"method\": \"Tandem MS phosphorylation site mapping, Ala-substitution mutagenesis, tautomycetin (PP1 inhibitor), FLIM, hydrogen-deuterium exchange MS, PP1α binding domain mutagenesis (VPF→Ala)\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — MS site mapping, mutagenesis, structural HDX-MS, FLIM, pharmacological PP1 inhibition, and functional phosphate transport assay in a single rigorous study\",\n      \"pmids\": [\"30696771\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"NHERF1/EBP50 is a two-PDZ-domain scaffolding phosphoprotein that localizes to apical microvilli of polarized epithelia by binding activated ERM proteins (ezrin/moesin) via its C-terminal EB domain, assembling multiprotein complexes that tether transporters (NHE3, Npt2a/NaPi-2a, CFTR, Mrp2), GPCRs (β2-AR, PTH1R, kappa-opioid receptor), ion channels (TRPC4/5), and signaling enzymes (PKA, PKC, PLC-β) to the actin cytoskeleton; it adopts an autoinhibited head-to-tail conformation in which its EB region occludes PDZ2, released by ezrin binding; phosphorylation of PDZ1 Ser77 (by PKC/dopamine signaling) and PDZ domain Ser290 (cycled by anchored PKA and PP1α in response to PTH) dynamically regulates binding of PDZ ligands and controls transporter trafficking and hormonal signal transduction, while Cdc2/CyclinB phosphorylation at Ser279/Ser301 governs actin reorganization and cytokinesis.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"NHERF1 (EBP50) is a two-PDZ-domain scaffolding phosphoprotein that organizes apical membrane signaling and transport complexes in polarized epithelia by physically coupling membrane proteins to the actin cytoskeleton through activated ERM proteins [#0, #1]. Its C-terminal EB region binds the N-terminal domains of ezrin and moesin, an interaction that is mutually exclusive with the ezrin intramolecular N/C-ERMAD clamp and therefore requires prior ezrin activation to expose the binding site [#1], and that is required for microvillar assembly together with a functional PDZ1 domain [#24, #30]. NHERF1 adopts an autoinhibited head-to-tail conformation in which the EB region occludes PDZ2 and masks ligand binding; ezrin association relieves this intramolecular block to license PDZ-mediated interactions [#16, #22]. Through its PDZ domains NHERF1 assembles complexes containing the Na+/H+ exchanger NHE3, the renal sodium-phosphate cotransporter Npt2a, CFTR, Mrp2, and store-operated TRPC4/5 channels, and tethers them to ezrin-anchored kinases to control transporter trafficking and activity [#2, #5, #7, #26, #39]. A central function is hormonal signal transduction: NHERF1 is obligatory for cAMP/PKA-mediated and dopamine-mediated regulation of NHE3 and Npt2a, and forms an obligate Npt2a-NHERF1-ezrin ternary complex in which ezrin-anchored PKA phosphorylates NHERF1 to release Npt2a and inhibit phosphate transport [#9, #27, #33]. Reversible phosphorylation tunes this scaffolding: phosphorylation of PDZ1 Ser77 (by PKC/dopamine signaling) attenuates binding to β2-AR, PDGFR, CFTR, and Npt2a [#17, #27], while PTH drives dynamic Ser290 cycling between PP1α-mediated dephosphorylation and GRK6A-dependent rephosphorylation that is essential for PTH-sensitive phosphate transport [#44], and Cdc2/CyclinB phosphorylation at Ser279/Ser301 governs actin reorganization and cytokinesis [#37]. NHERF1 also restrains GPCR internalization and desensitization, blocking β-arrestin2 binding and slowing arrestin recruitment to PTH1R and stabilizing receptors such as the kappa-opioid receptor [#10, #19, #21, #8]. Beyond epithelial transport, NHERF1 modulates Wnt/β-catenin signaling and EGFR-driven epithelial-mesenchymal transition, and stabilizes partner proteins including BECN1 and GPER against ubiquitin-dependent degradation [#11, #25, #32, #41, #42].\",\n  \"teleology\": [\n    {\n      \"year\": 1997,\n      \"claim\": \"Established NHERF1/EBP50 as a physiological ezrin-binding PDZ protein, defining its core role as a physical link between membrane proteins and the apical actin cytoskeleton.\",\n      \"evidence\": \"Affinity chromatography, Co-IP from placental microvilli, and immunolocalization with actin/ezrin\",\n      \"pmids\": [\"9314537\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define which membrane cargoes the PDZ domains bind\", \"Did not establish regulation of the ezrin interaction\"]\n    },\n    {\n      \"year\": 1998,\n      \"claim\": \"Showed that NHERF1 binds only the activated (open) form of ezrin, establishing regulated ERM activation as a gate controlling scaffold assembly.\",\n      \"evidence\": \"Blot overlay and in-solution binding with ezrin/EBP50 truncation mutants and competition assays\",\n      \"pmids\": [\"9660814\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not show the physiological trigger that opens ezrin in cells\"]\n    },\n    {\n      \"year\": 1998,\n      \"claim\": \"Demonstrated NHERF1 simultaneously binds NHE3 and ezrin to position PKA near NHE3, defining its function in hormonally regulated transporter inhibition.\",\n      \"evidence\": \"Reciprocal Co-IP, in vivo phosphorylation, and intracellular pH Na+/H+ exchange assays\",\n      \"pmids\": [\"9792717\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not separate the contributions of the PDZ versus ERM-binding regions to PKA-mediated inhibition\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Established that both the NHE3-PDZ and the ezrin-ERM interactions are jointly required for cAMP-dependent NHE3 inhibition, proving the scaffold itself enables kinase access to substrate.\",\n      \"evidence\": \"Truncated NHERF (1-325) lacking the ezrin-binding domain in PS120/NHE3 cells with phosphorylation and activity assays\",\n      \"pmids\": [\"10821685\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not address whether other transporters use the same dual-requirement logic\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Extended the scaffolding repertoire to store-operated channels by showing PDZ1 binds Trp4/Trp5 and PLC-β isozymes, linking signaling enzymes to the cytoskeleton.\",\n      \"evidence\": \"Yeast two-hybrid, GST pulldown, and Co-IP from HEK293 and mouse brain\",\n      \"pmids\": [\"10980202\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define functional consequences on channel gating at this stage\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Genetic knockout established a non-redundant, cargo-specific role: NHERF1 is required for apical retention of Npt2a but not NHE3, explaining renal phosphate wasting.\",\n      \"evidence\": \"Nherf1 knockout mouse with brush-border fractionation, immunocytochemistry, and urine electrolytes\",\n      \"pmids\": [\"12169661\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not explain the molecular basis of selectivity over NHERF2\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Showed NHERF1 controls GPCR trafficking, protecting the kappa-opioid receptor from agonist-induced downregulation by promoting recycling.\",\n      \"evidence\": \"Co-IP in CHO cells, radioligand binding, flow cytometry, and receptor/NHERF1 domain mutagenesis\",\n      \"pmids\": [\"12004055\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not generalize the recycling mechanism to other GPCRs\"]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"Defined NHERF1 as the non-redundant transducer of cAMP/PKA signals to NHE3 in native renal membranes, showing NHERF2 cannot compensate.\",\n      \"evidence\": \"Brush-border vesicles from Nherf1-/- mice with Na+/H+ exchange and NHE3 phosphorylation assays\",\n      \"pmids\": [\"12586353\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not map the NHERF1 phosphosites driving this isoform specificity\"]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"Extended GPCR regulation to PTH1R, showing NHERF1 blocks arrestin-independent receptor internalization in an actin- and ERM-dependent manner.\",\n      \"evidence\": \"Live-cell confocal imaging of fluorescent PTH1R, dominant-negatives, and actin depolymerization\",\n      \"pmids\": [\"12920119\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not resolve how NHERF1 selects between endocytic pathways\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Provided the regulatory mechanism for cargo binding: NHERF1 is autoinhibited by an EB-PDZ2 head-to-tail interaction that ezrin binding relieves, distinguishing it from NHERF2.\",\n      \"evidence\": \"In vitro binding, mutagenesis, and Co-IP in polarized epithelial cells with PTEN/β-catenin ligands\",\n      \"pmids\": [\"17242191\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not provide atomic structural detail of the autoinhibited state\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Mapped Ser77 in PDZ1 as a phosphorylation switch that attenuates binding to β2-AR, PDGFR, CFTR, and Npt2a, linking kinase signaling to scaffold disassembly.\",\n      \"evidence\": \"Metabolic labeling, S77A/S77D mutagenesis, Co-IP, and confocal localization\",\n      \"pmids\": [\"17895247\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not identify the physiological kinase acting on Ser77 at this stage\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Quantified NHERF1 control of GPCR membrane dynamics, showing it reduces receptor diffusion and slows arrestin-dependent PTH1R internalization.\",\n      \"evidence\": \"FRAP, TIRF, image correlation spectroscopy, and live-cell imaging of β2AR/PTH1R\",\n      \"pmids\": [\"17599914\", \"17884816\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not establish the structural interface with arrestin\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Determined the NMR structure of PDZ2-CT, revealing a helix-turn-helix subdomain allosterically coupled to PDZ2 and ezrin-released intramolecular contacts, and linked PDZ2 disease mutations to destabilization.\",\n      \"evidence\": \"NMR with SAXS/SANS constraints and R153Q/E225K mutagenesis\",\n      \"pmids\": [\"20042604\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not capture the full-length autoinhibited conformation structurally\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Generalized the scaffold-to-secretion paradigm, establishing NHERF1 as the obligatory linker for β2-AR stimulation of CFTR-dependent bicarbonate secretion in vivo.\",\n      \"evidence\": \"Nherf1-/-, Nherf2-/-, Pdzk1-/- mice with HCO3- secretion and colocalization measurements\",\n      \"pmids\": [\"19221439\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define the phosphoregulation of the β2-AR/CFTR complex\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Defined NHERF1 as a desensitization brake forming a ternary complex with PTH1R and β-arrestin2 and preventing PTH-induced Gαs dissociation.\",\n      \"evidence\": \"Adenylyl cyclase assays, inducible NHERF1, shRNA, Co-IP, and FRET\",\n      \"pmids\": [\"19188335\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not resolve the kinetic basis of arrestin exclusion\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Extended scaffold function to immune signaling, showing the ezrin-EBP50-PAG complex positions PKA near Csk to mediate cAMP inhibition of IL-2 production in T cells.\",\n      \"evidence\": \"KD determination (58 nM), peptide competition (EBP50pep) in T cells, and IL-2 assays\",\n      \"pmids\": [\"19857202\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not test whether other ERM-anchored kinase complexes share this architecture\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Established a structural cell-biology role: NHERF1 is necessary for microvillar assembly, requiring functional PDZ1 and the ezrin-binding site, and is inactivated by Cdc2/PKC phosphomimetics.\",\n      \"evidence\": \"RNAi with rescue by phospho-mutant EBP50 and microvilli quantification\",\n      \"pmids\": [\"20937695\", \"20237154\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not fully separate the microvillar and transport-scaffolding functions\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Connected NHERF1 to oncogenic signaling, showing it restrains Wnt/β-catenin via Frizzled binding and that loss enhances Wnt-dependent mammary proliferation.\",\n      \"evidence\": \"Co-IP, reporter assays, and NHERF1 knockout mouse mammary gland analysis\",\n      \"pmids\": [\"20802536\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab; did not define which Frizzled receptors are bound\", \"Mechanism connecting Frizzled binding to β-catenin levels not resolved\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Demonstrated post-transcriptional control of canalicular transport, showing NHERF1 binds Mrp2 and is required for its membrane expression and glutathione-dependent bile flow.\",\n      \"evidence\": \"Co-IP with PDZ-motif mutagenesis and Nherf1-/- mice with bile flow/glutathione assays\",\n      \"pmids\": [\"20404332\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define the degradation pathway stabilized by NHERF1\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Identified the kinase context for Ser77, showing dopamine signaling phosphorylates PDZ1 Ser77 to release Npt2a and inhibit renal phosphate transport.\",\n      \"evidence\": \"Co-IP, phosphate transport in WT/KO cells, cAMP/PKC assays, adenoviral rescue, and 32P labeling\",\n      \"pmids\": [\"20200151\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not integrate dopamine and PTH phosphoregulation of the same scaffold\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Documented dynamic, arrestin-dependent recruitment, showing NHERF1 switches from direct P2Y12R binding to arrestin-scaffolded recruitment upon agonist stimulation.\",\n      \"evidence\": \"Co-IP, PDZ-motif mutagenesis, and internalization assays\",\n      \"pmids\": [\"22610101\", \"20656684\", \"21325834\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab for P2Y12R; mechanism of the binding mode switch not structurally defined\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Resolved the core phosphate-regulatory mechanism: NHERF1 forms an obligate Npt2a-ezrin ternary complex in which ezrin-anchored PKA phosphorylates NHERF1 to release Npt2a, and disease mutations stabilize an inactive PKA-refractory conformation.\",\n      \"evidence\": \"In vitro kinase assays, disease-variant mutagenesis, compensatory mutagenesis rescue, and phosphate transport assays\",\n      \"pmids\": [\"22628548\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not identify the specific NHERF1 residue phosphorylated to disassemble the complex\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Defined cell-cycle control of the cytoskeletal function, showing Cdc2/CyclinB phosphorylation of Ser279/Ser301 regulates actin reorganization and cytokinesis.\",\n      \"evidence\": \"Phosphodeficient/phosphomimetic mutants in MDA-MB-231 with F-actin, DNA content, and adhesion assays plus knockdown rescue\",\n      \"pmids\": [\"23775624\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab; direct Cdc2 phosphorylation of these sites in vivo not fully established\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Established NHERF1 as a determinant of epithelial polarity and lumen formation, anchoring PTEN at the membrane and restraining nuclear β-catenin, via a moesin-dependent mechanism.\",\n      \"evidence\": \"3D gland morphogenesis with siRNA and domain-mutant expression\",\n      \"pmids\": [\"24862762\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab; did not reconcile the moesin versus ezrin dependence with earlier ezrin-centric data\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Defined a gating role at TRPC4/5 channels, showing PIP2-triggered NHERF dissociation from the channel C-terminus is a prerequisite for DAG sensitivity.\",\n      \"evidence\": \"PDZ-motif mutagenesis, PKC inhibition, electrophysiology, and dynamic Co-IP\",\n      \"pmids\": [\"27994151\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define the upstream signal coordinating NHERF dissociation in vivo\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Expanded NHERF1 function to controlling partner protein stability, showing it stabilizes BECN1 against ubiquitin-dependent degradation to promote autophagy and binds α-actinin-4 to promote its ubiquitination.\",\n      \"evidence\": \"Co-IP, ubiquitination assays, domain-deletion mutagenesis, and autophagy/F-actin readouts\",\n      \"pmids\": [\"26218645\", \"26432781\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single-lab findings; the opposing stabilizing/destabilizing logic across partners not mechanistically unified\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Resolved the full PTH phosphocycle, showing Ser290 is dephosphorylated by NHERF1-docked PP1α and rephosphorylated by a GRK6A cascade to drive PTH-sensitive phosphate transport.\",\n      \"evidence\": \"MS phosphosite mapping, Ala mutagenesis, PP1 inhibition, FLIM, and HDX-MS conformational analysis\",\n      \"pmids\": [\"30696771\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define the full GRK6A kinase cascade composition\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Identified NHERF1 as a viral oncoprotein target, showing HPV E6 directs its E6AP-dependent degradation via the EB domain to activate Wnt/β-catenin signaling.\",\n      \"evidence\": \"E6AP and NHERF1 domain mutagenesis, proteasome inhibition, and Wnt reporter assays\",\n      \"pmids\": [\"31002735\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab; in vivo relevance during HPV-driven transformation not established\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How the multiple phosphorylation switches (Ser77, Ser290, Ser279/Ser301), the autoinhibited conformation, and ERM activation are integrated to coordinate distinct cargoes in a single cell remains unresolved.\",\n      \"evidence\": \"No single study reconciles the combinatorial phosphoregulation across all known NHERF1 functions\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No unified model of combinatorial phosphocode-to-cargo selectivity\", \"No full-length structure of NHERF1 in its autoinhibited versus ezrin-activated states\", \"Mechanism distinguishing stabilizing versus destabilizing effects on partner proteins unknown\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 2, 5, 16, 30, 33]},\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [0, 24, 37, 40]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [8, 10, 19, 21, 39]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0, 7, 17, 18, 20]},\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [0, 24, 30, 37, 40]},\n      {\"term_id\": \"GO:0005777\", \"supporting_discovery_ids\": [36]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [2, 9, 19, 21, 27, 33, 44]},\n      {\"term_id\": \"R-HSA-382551\", \"supporting_discovery_ids\": [5, 7, 26, 33, 35]},\n      {\"term_id\": \"R-HSA-9609507\", \"supporting_discovery_ids\": [7, 10, 19, 24, 38]}\n    ],\n    \"complexes\": [\n      \"Npt2a-NHERF1-ezrin ternary complex\",\n      \"PTH1R-NHERF1-β-arrestin2 ternary complex\",\n      \"PDZK1-EBP50-ezrin microvillar complex\",\n      \"ezrin-EBP50-PAG T-cell scaffold\"\n    ],\n    \"partners\": [\n      \"EZR\",\n      \"NHE3\",\n      \"Npt2a\",\n      \"CFTR\",\n      \"PTH1R\",\n      \"TRPC5\",\n      \"MRP2\",\n      \"PP1α\"\n    ],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":8,"faith_total":8,"faith_pct":100.0}}