{"gene":"AP1M1","run_date":"2026-06-09T22:02:43","timeline":{"discoveries":[{"year":2000,"finding":"Targeted disruption of mouse mu1A-adaptin (AP1M1) causes embryonic lethality at day 13.5. In mu1A-deficient cells, the remaining AP-1 adaptins (gamma-adaptin) fail to bind to the TGN, demonstrating that mu1A is required for AP-1 membrane recruitment. Mannose 6-phosphate receptors (MPR46 and MPR300) are rerouted to endosomes at the expense of the TGN, and MPR46 fails to recycle back from endosomes to the TGN, establishing AP-1/mu1A as required for retrograde endosome-to-TGN transport.","method":"Gene knockout (targeted disruption), cell fractionation, immunofluorescence microscopy, receptor trafficking assays","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic KO with defined molecular and cellular phenotypes, multiple orthogonal readouts (membrane binding, receptor localization, recycling), replicated across developmental and cell biology contexts","pmids":["10811610"],"is_preprint":false},{"year":1999,"finding":"mu1A (AP1M1) is the ubiquitous mu1 subunit of the AP-1 clathrin adaptor complex (AP-1A), whereas the epithelial-specific isoform mu1B forms a distinct AP-1B complex. Stable expression of mu1B (not mu1A) in LLC-PK1 cells selectively restores basolateral targeting of membrane proteins, demonstrating that mu1A-containing AP-1A does not mediate basolateral sorting in epithelial cells.","method":"Stable transfection, immunofluorescence, domain-specific protein targeting assays in polarized epithelial cells","journal":"Cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — functional complementation in defined cell system, multiple basolateral cargo readouts, independently confirmed in companion FEBS Letters paper","pmids":["10535737","10338135"],"is_preprint":false},{"year":2001,"finding":"AP-1A (mu1A-containing complex) localizes to the TGN and colocalizes with furin, whereas AP-1B localizes to recycling endosomes, as determined by immunofluorescence and immunoelectron microscopy of epitope-tagged mu1 subunits. AP-1A and AP-1B occupy distinct subdomains of the perinuclear region and interact differentially with clathrin-coated buds.","method":"Immunofluorescence microscopy, immunoelectron microscopy, subcellular fractionation, epitope-tagged subunit expression","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — dual orthogonal imaging methods (IF + IEM), functional cargo-interaction assays, independently replicated in follow-up study","pmids":["11157985"],"is_preprint":false},{"year":2003,"finding":"AP-1A (mu1A) and AP-1B define physically distinct membrane domains; AP-1B (but not AP-1A) enhances recruitment of exocyst subunits Sec8 and Exo70 to recycling endosome-proximal membranes, linking mu1A-containing AP-1A specifically to TGN/endosomal transport rather than basolateral exocytic delivery.","method":"Immunofluorescence, cell fractionation, co-localization analysis with exocyst subunit markers","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (IF, fractionation), clear functional distinction between AP-1A and AP-1B, single lab","pmids":["14581457"],"is_preprint":false},{"year":2001,"finding":"In mu1A-adaptin-deficient fibroblasts, the internalization rate of MPR300 is increased 7-fold without an increase in steady-state plasma membrane levels. More MPR300 is found in clathrin-coated pits at the plasma membrane, while all intracellular receptors reside in endosomes in equilibrium with the plasma membrane, indicating that AP-1-mediated transport from endosomes to TGN indirectly controls MPR300 recycling between plasma membrane and endosomes.","method":"Radioligand internalization assays, immunoelectron microscopy, receptor trafficking in mu1A-KO fibroblasts","journal":"Journal of cell science","confidence":"High","confidence_rationale":"Tier 2 / Moderate — quantitative trafficking assays in defined KO cells, multiple readouts (rate measurement, EM localization)","pmids":["11792812"],"is_preprint":false},{"year":2012,"finding":"The mu1A subunit of AP-1 mediates somatodendritic sorting of transmembrane receptors in rat hippocampal neurons by recognizing sorting signals within the cytosolic domains of the proteins. AP-1/mu1A functions in conjunction with clathrin in the neuronal soma to exclude somatodendritic proteins from axonal transport carriers. Perturbation of this process reduces dendritic spine morphology and synapse number.","method":"shRNA knockdown, live-cell imaging, immunofluorescence, spine/synapse morphology assays in primary hippocampal neurons","journal":"Neuron","confidence":"High","confidence_rationale":"Tier 2 / Moderate — loss-of-function with specific neuronal polarity phenotype, multiple cargo readouts, functional consequence (spine/synapse loss)","pmids":["22958822"],"is_preprint":false},{"year":2012,"finding":"The YxxΦ motif of the coxsackie and adenovirus receptor (CAR) directly interacts with a conserved pocket in mu1A of AP-1A, and this interaction is required for biosynthetic sorting of CAR to the basolateral surface. Knockdown of AP-1A (mu1A) impairs biosynthetic sorting of CAR, complementary to the role of AP-1B in basolateral recycling.","method":"Mutational analysis of YxxΦ motif, co-immunoprecipitation, siRNA knockdown, domain-specific trafficking assays in polarized MDCK cells","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 / Moderate — mutagenesis of both cargo and adaptor binding pocket, multiple orthogonal assays (co-IP, functional sorting, KD)","pmids":["22343291"],"is_preprint":false},{"year":2013,"finding":"mu1A and mu1B largely colocalize with both TGN and recycling endosome markers, and with basolateral cargoes in both biosynthetic and endocytic-recycling routes. The two isoforms differ in signal-recognition specificity: mu1B preferentially binds a subset of basolateral sorting signals not recognized by mu1A, expanding the repertoire of AP-1 cargo recognition.","method":"Improved immunofluorescence colocalization, co-immunoprecipitation of cargo-adaptor interactions, mutagenesis of sorting signals","journal":"Developmental cell","confidence":"High","confidence_rationale":"Tier 2 / Moderate — improved quantitative imaging combined with direct cargo-binding assays and functional sorting experiments, single lab","pmids":["24229647"],"is_preprint":false},{"year":2007,"finding":"The N-terminal 70 amino acids of mu1A regulate AP-1 membrane-to-cytoplasm recycling. Chimeric AP-1* complexes containing a mu2/mu1A N-terminal domain showed slowed recycling kinetics and missorting of mannose-6-phosphate receptors, demonstrating that the mu1A N-terminal domain controls AP-1 recycling between membranes and cytoplasm independently of clathrin.","method":"Domain chimera construction, FRAP/live-cell imaging of AP-1 recycling kinetics, MPR trafficking assays in cells expressing chimeric adaptins","journal":"Traffic (Copenhagen, Denmark)","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — domain chimera approach with functional readout, single lab, single study","pmids":["17988225"],"is_preprint":false},{"year":2013,"finding":"The cytoplasmic prolyl-oligopeptidase-like protein PREPL interacts with the N-terminal domain of mu1A identified by yeast two-hybrid screen. PREPL overexpression reduces AP-1 membrane binding; reduced PREPL expression increases membrane binding and impairs AP-1 recycling. PREPL-deficient cells have an expanded TGN rescued by PREPL re-expression, defining PREPL as an AP-1 effector that regulates mu1A-dependent membrane binding.","method":"Yeast two-hybrid, AP-1 membrane-binding assays, TGN morphology quantification in patient cell lines and PREPL overexpression/knockdown cells","journal":"Journal of cell science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — yeast two-hybrid plus multiple functional assays (membrane binding, recycling, organelle morphology), patient cell lines validate physiological relevance, single lab","pmids":["23321636"],"is_preprint":false},{"year":1995,"finding":"Subunit interactions within AP-1 were mapped: gamma-adaptin and AP47 (mu1A) interact; the NH2-terminal region of gamma-adaptin (aa ~130–330/350) determines membrane targeting and co-assembly with AP47 and AP19. Beta/beta'-adaptins interact with AP50/AP47, but beta/beta'-adaptins are not involved in targeting. These results establish that AP47 subunit interactions contribute to AP-1 complex assembly and TGN targeting.","method":"Yeast two-hybrid system, chimeric adaptin constructs, immunoprecipitation","journal":"The Journal of cell biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — yeast two-hybrid plus co-immunoprecipitation of chimeric constructs, two orthogonal methods, single lab","pmids":["7593184"],"is_preprint":false},{"year":1994,"finding":"The C. elegans unc-101 gene encodes a homolog of mammalian AP47 (mu1A). Mouse AP47 and nematode UNC-101 are functionally equivalent as demonstrated in transgenic nematodes, establishing cross-species conservation of the mu1A clathrin-adaptor function. Loss of unc-101/mu1A function causes pleiotropic developmental defects including misregulation of vulval differentiation.","method":"Genetic analysis, cDNA cloning, transgenic rescue assay in C. elegans","journal":"Genes & development","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — transgenic rescue demonstrates functional equivalence, genetic epistasis places unc-101/mu1A in vulval signaling pathway, single lab","pmids":["8288128"],"is_preprint":false},{"year":2010,"finding":"AP-1 mu1A directly interacts with the C-terminal cytoplasmic domain of kidney anion exchanger 1 (kAE1) via the YXXØ motif Y904DEV907. siRNA-mediated knockdown of AP-1 mu1A in HEK293T cells decreases membrane localization of kAE1 and increases its intracellular accumulation, demonstrating that AP-1 mu1A is required for kAE1 trafficking to the plasma membrane.","method":"Yeast two-hybrid, co-immunoprecipitation, affinity co-purification, GST pulldown, YFP-based protein fragment complementation assay, siRNA knockdown with localization readout","journal":"Biochemical and biophysical research communications","confidence":"High","confidence_rationale":"Tier 2 / Strong — five independent binding assays plus functional siRNA knockdown, multiple orthogonal methods in single study","pmids":["20833140"],"is_preprint":false},{"year":2012,"finding":"mu1A (and to a lesser extent mu1B) are required for kAE1 trafficking to the basolateral plasma membrane; knockdown of mu1A causes kAE1 to fail to reach the plasma membrane and undergo lysosomal degradation. Reciprocal co-immunoprecipitation confirmed mu1A–kAE1 interaction in epithelial cells and in mouse kidney extracts in vivo. Newly synthesized kAE1 does not traffic through recycling endosomes, suggesting AP-1A (not AP-1B) is the primary mediator of newly synthesized kAE1 delivery.","method":"Reciprocal co-immunoprecipitation in epithelial cells and mouse kidney extract, siRNA knockdown, immunofluorescence trafficking assays","journal":"American journal of physiology. Cell physiology","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP in cells and in vivo tissue, loss-of-function with specific trafficking phenotype, pathway placement relative to AP-1B","pmids":["22744004"],"is_preprint":false},{"year":2014,"finding":"AP-1 mu1A (AP-1A) is required for kAE1 sorting from the TGN to the basolateral membrane; RNA interference of AP-1 mu1A (but not mu1B, PKD1, or PKD2) blocks kAE1 intracellular sorting and trafficking. AP-3 mu1 and AP-4 mu1 and clathrin are also required, placing AP-1A/mu1A in the TGN-to-basolateral trafficking pathway for kAE1.","method":"siRNA knockdown, co-immunoprecipitation, YFP-PCA, immunofluorescence in polarized and non-polarized kidney cells and human kidney tissue","journal":"Traffic (Copenhagen, Denmark)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple adaptor KDs with pathway specificity, co-IP confirmation, two cell systems, single lab","pmids":["24698155"],"is_preprint":false},{"year":2014,"finding":"AP-1A (mu1A subunit) is required for normal secretory granule (SG) biogenesis in AtT-20 corticotrope cells. Twofold reduction of mu1A decreases TGN cisternae and immature SGs, misroutes carboxypeptidase D (CPD) and peptidylglycine alpha-amidating monooxygenase-1 (PAM-1) from their normal immature SG pathway, and halves stimulated secretion. Yeast two-hybrid and co-immunoprecipitation demonstrated direct interaction between PAM-1 cytosolic domain and AP-1A (mu1A).","method":"shRNA knockdown, secretion assays, morphological analysis (TEM), yeast two-hybrid, co-immunoprecipitation, metabolic labeling","journal":"Traffic (Copenhagen, Denmark)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal approaches (Y2H, co-IP, KD + multiple phenotypic readouts), single lab","pmids":["25040637"],"is_preprint":false},{"year":2013,"finding":"IRS-1 associates with mu1A of AP-1A via three YXXØ motifs. Wild-type IRS-1 localizes to peripheral vesicular structures dependent on AP-1; IRS-1 mutants lacking YXXØ motifs are mislocalized to mannose-6-phosphate receptor-positive structures, impairing IGF-I-induced tyrosine phosphorylation, PI3-kinase association, and cell proliferation.","method":"Co-immunoprecipitation, mutagenesis of YXXØ motifs, immunofluorescence localization, siRNA knockdown, IGF-I signaling assays (phosphorylation, PI3K association), proliferation assays","journal":"Molecular and cellular biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — mutagenesis of binding motif plus functional signaling and proliferation readouts, multiple orthogonal methods, single lab","pmids":["23478262"],"is_preprint":false},{"year":2016,"finding":"mu1A (AP1M1) subunit depletion, but not gamma1 (AP1G1) depletion, prevents HIV-1 Nef-mediated lysosomal degradation of CD4, causing internalized CD4 to accumulate in early endosomes. This places mu1A in the AP-1 variant containing gamma2 (AP1G2) that routes endosomal cargo to lysosomes, distinct from the gamma1-containing AP-1 complex.","method":"siRNA knockdown, immunofluorescence, CD4 surface/intracellular trafficking assays in Nef-expressing cells","journal":"Journal of cell science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — selective subunit depletion with clear trafficking phenotype, epistatic distinction between gamma1 and gamma2/mu1A complexes, single lab","pmids":["27909244"],"is_preprint":false},{"year":2017,"finding":"The cytoplasmic tail of L-selectin directly binds the C-terminal domain of mu1A via a novel basic motif (three dibasic residue clusters: 356RR357, 359KK360, 362KK363) and a distal 369DD370 element. Phosphorylation of the L-selectin tail abrogates mu1A binding. L-selectin colocalizes with AP-1 at the TGN, suggesting constitutive AP-1/mu1A-mediated retrograde transport of L-selectin.","method":"Peptide pulldown with mass spectrometry, GST-pulldown with domain mapping, co-immunoprecipitation, immunofluorescence colocalization, molecular docking","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple binding assays (pulldown + co-IP) with domain mapping, phosphorylation regulatory mechanism, molecular modeling support, single lab","pmids":["28235798"],"is_preprint":false},{"year":2018,"finding":"VZV ORF9p (tegument protein) interacts with AP1M1 (mu1 subunit of AP-1). Disruption of the ORF9p dileucine motif (L231A) abolishes AP-1 binding and strongly impairs viral growth by preventing efficient secondary envelopment, demonstrating that AP-1/mu1A interaction with ORF9p is required for VZV secondary envelopment.","method":"Yeast two-hybrid screen, co-immunoprecipitation from infected cells, viral mutant generation and growth assays","journal":"Journal of virology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Y2H confirmed by Co-IP in infected cells, viral mutant rescue experiment, functional viral replication readout, single lab","pmids":["29793951"],"is_preprint":false},{"year":2012,"finding":"A noncanonical tripartite hydrophobic motif (Trp13/Val16/Met20) in the N-terminus of HIV-1 Nef functions as a mu1A-binding motif, interacting with the tyrosine motif-binding site of mu1A, and is required for Nef-mediated MHC-I downregulation in T lymphocytes.","method":"Mutagenesis of Nef N-terminal motif, co-immunoprecipitation/binding assays with mu1A, functional MHC-I downregulation assays","journal":"Journal of virology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — mutagenesis maps binding motif with functional readout (MHC-I surface levels), single lab","pmids":["22301137"],"is_preprint":false},{"year":2014,"finding":"Basolateral sorting of the Mg2+ transporter CNNM4 requires both AP-1A (mu1A) and AP-1B; single knockdown of mu1B alone does not affect basolateral localization, but simultaneous knockdown of mu1A abrogates it. Three dileucine motifs in CNNM4 are required for basolateral sorting and for interaction with mu1A and mu1B.","method":"siRNA knockdown (single and double), mutational analysis of dileucine motifs, immunofluorescence localization in MDCK cells","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic epistasis by double KD, mutagenesis of cargo binding motifs, single lab","pmids":["25449265"],"is_preprint":false},{"year":1991,"finding":"Mouse brain AP47 (mu1A) was cloned and sequenced. It is closely related to AP50 (mu2), and a yeast homolog (YAP54) was identified with striking homology to AP47, suggesting AP47/mu1A is the medium chain subunit of AP-1 in both mammals and yeast, with a conserved domain organization.","method":"cDNA cloning, sequence analysis, comparative genomics, domain modeling","journal":"European journal of biochemistry","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — foundational cloning and sequence characterization replicated across species, establishes identity of AP47 as mu1A of AP-1","pmids":["1761056"],"is_preprint":false},{"year":2025,"finding":"CRISPR/Cas9 knockout of AP1M1 strongly increases anti-sense oligonucleotide (ASO) activity by delaying endosome-to-lysosome transport both in vitro and in vivo, prolonging ASO residence time in the endosomal system and increasing likelihood of ASO endosomal escape. This places AP1M1 mechanistically at the endosome-to-lysosome transport step.","method":"Unbiased CRISPR/Cas9 knockout screen, ASO splice reporter assay, endosomal trafficking assays in vitro and in vivo","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 2 / Moderate — genome-scale unbiased screen validated with functional trafficking assays in both in vitro and in vivo systems, peer-reviewed","pmids":["40588516"],"is_preprint":false},{"year":2019,"finding":"HBV infection upregulates AP1M1 expression in HepG2.215 liver cancer cells via the JNK signaling pathway. Silencing AP1M1 suppresses proliferation of HBV-expressing cells while overexpression promotes proliferation. Increased AP1M1 enhances phosphorylation of AKT (protein kinase B), placing AP1M1 downstream of JNK and upstream of AKT in HBV-driven proliferation.","method":"siRNA knockdown, overexpression, JNK pathway inhibition, Western blot for AKT phosphorylation, cell proliferation assays","journal":"Oncology letters","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, no direct biochemical interaction between AP1M1 and AKT established, proliferation assay alone with pathway inference","pmids":["31289517"],"is_preprint":false},{"year":2006,"finding":"Both mu1A and mu1B isoforms of AP-1 are co-expressed in melanocytes and keratinocytes. Expression of mu1B (but not mu1A) restores sorting of the melanosome structural protein Pmel17 to the plasma membrane in cells lacking mu1B, indicating that mu1A-containing AP-1A and mu1B-containing AP-1B define distinct sorting routes for melanosome cargo.","method":"Real-time PCR, immunolabeling, in situ hybridization, transfection with mu1A or mu1B isoforms, Pmel17 trafficking assays","journal":"Journal of cell science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — isoform-specific functional complementation assay, multiple detection methods for expression and localization, single lab","pmids":["16492709"],"is_preprint":false},{"year":2015,"finding":"Reduced AP-1 function (via mu1A subunit knockdown) alters endocytic trafficking of PAM-1 (peptidylglycine alpha-amidating monooxygenase), causing PAM-1 accumulation on the cell surface. Co-immunoprecipitation demonstrates that a small fraction of PAM and Atp7a interact, suggesting copper transfer between the two proteins in shared subcellular compartments is disrupted when AP-1/mu1A levels are reduced.","method":"shRNA knockdown of mu1A, immunofluorescence, surface biotinylation, co-immunoprecipitation","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — multiple readouts but single lab, co-IP of small fraction interpreted cautiously","pmids":["26170456"],"is_preprint":false}],"current_model":"AP1M1 (mu1A) is the ubiquitous medium-chain subunit of the AP-1A clathrin adaptor complex; it is essential for AP-1 membrane recruitment at the TGN and is required for clathrin-coated vesicle-mediated retrograde transport of mannose-6-phosphate receptors from endosomes to the TGN, for somatodendritic sorting of transmembrane receptors in neurons via recognition of YxxΦ and related cytosolic sorting signals, for basolateral sorting of select cargo (including kAE1, CAR, CNNM4, L-selectin) through direct recognition of tyrosine- and dileucine-based motifs, for secretory granule biogenesis in neuroendocrine cells, and for endosome-to-lysosome transport; its N-terminal domain regulates AP-1 membrane-cytoplasm recycling through interaction with PREPL, and it is exploited by viral proteins (HIV-1 Nef, VZV ORF9p) and by pathogens to manipulate intracellular trafficking."},"narrative":{"mechanistic_narrative":"AP1M1 (mu1A/AP47) is the ubiquitously expressed medium-chain subunit of the AP-1A clathrin adaptor complex and is essential for AP-1 recruitment to the trans-Golgi network: in its absence the remaining gamma-adaptin fails to bind the TGN, mannose-6-phosphate receptors are rerouted to endosomes, and embryos die at midgestation [PMID:10811610]. Within the assembled complex mu1A co-assembles with gamma-adaptin and the beta/beta' chains, and gamma-adaptin's N-terminal region directs membrane targeting and co-assembly with mu1A [PMID:7593184]. mu1A executes cargo selection by binding tyrosine-based YxxΦ motifs, dileucine motifs, and even noncanonical basic motifs in the cytosolic tails of transmembrane cargo, thereby sorting kAE1 [PMID:20833140, PMID:22744004], CAR [PMID:22343291], CNNM4 [PMID:25449265], L-selectin [PMID:28235798], IRS-1 [PMID:23478262], and secretory-granule enzymes such as PAM-1 [PMID:25040637]. Functionally it drives retrograde endosome-to-TGN recycling of MPRs [PMID:10811610, PMID:11792812], somatodendritic sorting of receptors in neurons where its loss reduces dendritic spines and synapses [PMID:22958822], biosynthetic basolateral delivery of select cargo (complementary to the epithelial-specific mu1B/AP-1B isoform that governs basolateral recycling) [PMID:10535737, PMID:10338135, PMID:22343291, PMID:22744004], secretory granule biogenesis in neuroendocrine cells [PMID:25040637], and endosome-to-lysosome transport, a step whose disruption prolongs endosomal residence of antisense oligonucleotides [PMID:40588516]. The N-terminal ~70 residues of mu1A control AP-1 membrane-to-cytoplasm recycling independently of clathrin [PMID:17988225], regulated by the effector PREPL whose loss expands the TGN and impairs AP-1 recycling [PMID:23321636]. mu1A is also hijacked by pathogens: HIV-1 Nef engages the mu1A tyrosine-binding site to downregulate MHC-I and to route CD4 to lysosomes via a gamma2/mu1A complex [PMID:22301137, PMID:27909244], and VZV ORF9p binds mu1A through a dileucine motif required for viral secondary envelopment [PMID:29793951]. The function is deeply conserved, with the C. elegans ortholog unc-101 functionally interchangeable with mouse mu1A [PMID:8288128].","teleology":[{"year":1991,"claim":"Establishing the molecular identity of mu1A was the prerequisite for assigning it to the AP-1 adaptor; cloning AP47 defined it as the conserved medium-chain subunit.","evidence":"cDNA cloning and comparative sequence analysis of mouse brain AP47 with a yeast homolog","pmids":["1761056"],"confidence":"Medium","gaps":["Sequence identity alone did not establish the in vivo function","No cargo-recognition role demonstrated"]},{"year":1994,"claim":"Whether the adaptor function was conserved and physiologically important was tested genetically, showing the nematode ortholog unc-101 is functionally equivalent to mammalian mu1A.","evidence":"Genetic analysis and transgenic rescue in C. elegans","pmids":["8288128"],"confidence":"Medium","gaps":["Did not define the molecular cargo or trafficking step","Vulval phenotype is pleiotropic"]},{"year":1995,"claim":"How mu1A is incorporated into AP-1 was mapped, showing gamma-adaptin's N-terminus drives membrane targeting and co-assembly with mu1A.","evidence":"Yeast two-hybrid and immunoprecipitation of chimeric adaptin constructs","pmids":["7593184"],"confidence":"Medium","gaps":["Did not resolve which subunit recognizes cargo motifs","Assembly mapped in vitro, not in intact cells"]},{"year":2000,"claim":"The central question of whether mu1A is required for AP-1 function in vivo was answered: knockout abolished AP-1 membrane recruitment and disrupted MPR retrograde transport, making mu1A essential for development.","evidence":"Mouse gene knockout with cell fractionation, immunofluorescence and receptor trafficking assays","pmids":["10811610"],"confidence":"High","gaps":["Did not identify the cargo-binding motifs directly","Embryonic lethality limited tissue-specific analysis"]},{"year":2001,"claim":"The distinct sub-cellular niches of mu1A versus the epithelial mu1B isoform were resolved, localizing mu1A-containing AP-1A to the TGN with furin and AP-1B to recycling endosomes.","evidence":"Immunofluorescence and immunoelectron microscopy of epitope-tagged subunits plus fractionation; quantitative MPR300 internalization assays in KO fibroblasts","pmids":["11157985","11792812"],"confidence":"High","gaps":["Mechanism coupling AP-1A endosome-TGN transport to plasma-membrane recycling was indirect","Cargo-motif specificity not yet defined"]},{"year":2003,"claim":"The functional divergence of the two isoforms was sharpened by showing AP-1B, not mu1A-containing AP-1A, recruits exocyst subunits, tying mu1A to TGN/endosomal rather than exocytic delivery.","evidence":"Immunofluorescence, fractionation and co-localization with exocyst markers","pmids":["14581457"],"confidence":"High","gaps":["Did not address how mu1A selects its own cargo","Single-lab observation"]},{"year":2007,"claim":"The basis of AP-1 cycling on and off membranes was localized to the mu1A N-terminal domain, which controls membrane-cytoplasm recycling independently of clathrin.","evidence":"mu2/mu1A domain chimeras with FRAP/live imaging and MPR trafficking readouts","pmids":["17988225"],"confidence":"Medium","gaps":["Chimera approach, not endogenous mutation","Effector controlling N-terminal recycling unidentified at the time"]},{"year":2010,"claim":"Direct cargo recognition by mu1A was demonstrated biochemically for kAE1 via its YxxO motif, establishing mu1A as the motif-reading subunit for plasma-membrane delivery of this cargo.","evidence":"Yeast two-hybrid, co-IP, GST pulldown, affinity co-purification and PCA with siRNA localization readout","pmids":["20833140"],"confidence":"High","gaps":["Polarized sorting route not yet placed","Performed largely in non-polarized HEK293T cells"]},{"year":2012,"claim":"Multiple studies converged to define mu1A as a YxxΦ/motif reader directing biosynthetic basolateral and neuronal somatodendritic sorting, and as a target of HIV-1 Nef for MHC-I downregulation.","evidence":"Motif mutagenesis, co-IP and knockdown for CAR (MDCK) and Nef (T cells); shRNA, live imaging and synapse morphology in hippocampal neurons; reciprocal Co-IP and in vivo tissue for kAE1","pmids":["22343291","22301137","22958822","22744004"],"confidence":"High","gaps":["Structural basis of motif recognition not resolved in these studies","Functional partition between AP-1A and AP-1B cargo sets still being delineated"]},{"year":2013,"claim":"The regulatory and signal-recognition layer of mu1A was expanded: PREPL was identified as an N-terminal effector controlling AP-1 membrane binding, while mu1A/mu1B were shown to differ in sorting-signal specificity and mu1A to bind IRS-1 to control its localization and IGF signaling.","evidence":"Yeast two-hybrid, membrane-binding and TGN morphology assays in patient cells (PREPL); colocalization and cargo co-IP/mutagenesis (mu1A vs mu1B); motif mutagenesis with signaling/proliferation readouts (IRS-1)","pmids":["23321636","24229647","23478262"],"confidence":"Medium","gaps":["Structural detail of PREPL-mu1A interface unresolved","Precise rule distinguishing mu1A vs mu1B signal preference incomplete"]},{"year":2014,"claim":"mu1A's role in TGN-to-basolateral cargo delivery and secretory-granule biogenesis was established, including isoform redundancy with mu1B for some cargo and direct binding to granule enzymes.","evidence":"Single/double siRNA knockdown and dileucine-motif mutagenesis (kAE1, CNNM4); shRNA, TEM, secretion assays and Y2H/co-IP for PAM-1 (AtT-20 cells)","pmids":["24698155","25449265","25040637"],"confidence":"Medium","gaps":["Quantitative contribution of each adaptor in TGN-to-basolateral step not fully partitioned","Granule cargo selectivity mechanism incomplete"]},{"year":2016,"claim":"mu1A was assigned to a specific AP-1 variant (gamma2-containing) routing endosomal CD4 to lysosomes during Nef action, distinguishing it from the gamma1 complex.","evidence":"Selective siRNA depletion of mu1A vs gamma1 with CD4 trafficking assays in Nef-expressing cells","pmids":["27909244"],"confidence":"Medium","gaps":["Endogenous (non-Nef) cargo of the gamma2/mu1A complex not defined","Single-lab epistasis"]},{"year":2017,"claim":"The cargo-recognition repertoire of mu1A was broadened beyond tyrosine/dileucine motifs by defining a novel basic motif in L-selectin bound by the mu1A C-terminal domain and switched off by phosphorylation.","evidence":"Peptide pulldown-MS, GST pulldown with domain mapping, co-IP, colocalization and molecular docking","pmids":["28235798"],"confidence":"Medium","gaps":["No structure of the basic-motif/mu1A complex","Physiological retrograde route inferred from colocalization"]},{"year":2018,"claim":"Pathogen exploitation of mu1A was extended to VZV, where ORF9p binds mu1A via a dileucine motif required for viral secondary envelopment.","evidence":"Yeast two-hybrid, co-IP from infected cells and dileucine-mutant viral growth assays","pmids":["29793951"],"confidence":"Medium","gaps":["Structural basis of ORF9p-mu1A binding unresolved","Host membrane source for envelopment not pinpointed"]},{"year":2025,"claim":"An unbiased screen placed mu1A at the endosome-to-lysosome transport step, with its loss prolonging endosomal residence and enhancing antisense-oligonucleotide activity.","evidence":"Genome-scale CRISPR/Cas9 knockout screen with ASO splice reporter and endosomal trafficking assays in vitro and in vivo","pmids":["40588516"],"confidence":"High","gaps":["Molecular cargo mediating this lysosomal step not identified","Relationship to the gamma2/mu1A lysosomal route not directly tested"]},{"year":null,"claim":"How distinct mu1A-containing AP-1 variants (gamma1 vs gamma2) and cargo-motif classes are selected at each trafficking step, and the structural basis of noncanonical motif recognition, remain to be resolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structure of mu1A bound to dileucine or basic cargo motifs in the corpus","Endogenous cargo set of the gamma2/mu1A lysosomal complex undefined","Mechanistic integration of PREPL-regulated recycling with cargo selection unresolved"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[6,12,16,18,21]},{"term_id":"GO:0008289","term_label":"lipid binding","supporting_discovery_ids":[0]}],"localization":[{"term_id":"GO:0005794","term_label":"Golgi apparatus","supporting_discovery_ids":[2,15,18]},{"term_id":"GO:0005768","term_label":"endosome","supporting_discovery_ids":[0,4,17,23]},{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[8,9]},{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[12,13]}],"pathway":[{"term_id":"R-HSA-5653656","term_label":"Vesicle-mediated transport","supporting_discovery_ids":[0,2,4,23]},{"term_id":"R-HSA-9609507","term_label":"Protein localization","supporting_discovery_ids":[5,6,13,21]},{"term_id":"R-HSA-1643685","term_label":"Disease","supporting_discovery_ids":[17,19,20]}],"complexes":["AP-1A clathrin adaptor complex"],"partners":["AP1G1","PREPL","SLC4A1","CXADR","SELL","IRS1","PAM"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9BXS5","full_name":"AP-1 complex subunit mu-1","aliases":["AP-mu chain family member mu1A","Adaptor protein complex AP-1 subunit mu-1","Adaptor-related protein complex 1 subunit mu-1","Clathrin assembly protein complex 1 mu-1 medium chain 1","Clathrin coat assembly protein AP47","Clathrin coat-associated protein AP47","Golgi adaptor HA1/AP1 adaptin mu-1 subunit","Mu-adaptin 1","Mu1A-adaptin"],"length_aa":423,"mass_kda":48.6,"function":"Subunit of clathrin-associated adaptor protein complex 1 that plays a role in protein sorting in the trans-Golgi network (TGN) and endosomes. 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In mu1A-deficient cells, the remaining AP-1 adaptins (gamma-adaptin) fail to bind to the TGN, demonstrating that mu1A is required for AP-1 membrane recruitment. Mannose 6-phosphate receptors (MPR46 and MPR300) are rerouted to endosomes at the expense of the TGN, and MPR46 fails to recycle back from endosomes to the TGN, establishing AP-1/mu1A as required for retrograde endosome-to-TGN transport.\",\n      \"method\": \"Gene knockout (targeted disruption), cell fractionation, immunofluorescence microscopy, receptor trafficking assays\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic KO with defined molecular and cellular phenotypes, multiple orthogonal readouts (membrane binding, receptor localization, recycling), replicated across developmental and cell biology contexts\",\n      \"pmids\": [\"10811610\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1999,\n      \"finding\": \"mu1A (AP1M1) is the ubiquitous mu1 subunit of the AP-1 clathrin adaptor complex (AP-1A), whereas the epithelial-specific isoform mu1B forms a distinct AP-1B complex. Stable expression of mu1B (not mu1A) in LLC-PK1 cells selectively restores basolateral targeting of membrane proteins, demonstrating that mu1A-containing AP-1A does not mediate basolateral sorting in epithelial cells.\",\n      \"method\": \"Stable transfection, immunofluorescence, domain-specific protein targeting assays in polarized epithelial cells\",\n      \"journal\": \"Cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — functional complementation in defined cell system, multiple basolateral cargo readouts, independently confirmed in companion FEBS Letters paper\",\n      \"pmids\": [\"10535737\", \"10338135\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"AP-1A (mu1A-containing complex) localizes to the TGN and colocalizes with furin, whereas AP-1B localizes to recycling endosomes, as determined by immunofluorescence and immunoelectron microscopy of epitope-tagged mu1 subunits. AP-1A and AP-1B occupy distinct subdomains of the perinuclear region and interact differentially with clathrin-coated buds.\",\n      \"method\": \"Immunofluorescence microscopy, immunoelectron microscopy, subcellular fractionation, epitope-tagged subunit expression\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — dual orthogonal imaging methods (IF + IEM), functional cargo-interaction assays, independently replicated in follow-up study\",\n      \"pmids\": [\"11157985\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"AP-1A (mu1A) and AP-1B define physically distinct membrane domains; AP-1B (but not AP-1A) enhances recruitment of exocyst subunits Sec8 and Exo70 to recycling endosome-proximal membranes, linking mu1A-containing AP-1A specifically to TGN/endosomal transport rather than basolateral exocytic delivery.\",\n      \"method\": \"Immunofluorescence, cell fractionation, co-localization analysis with exocyst subunit markers\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (IF, fractionation), clear functional distinction between AP-1A and AP-1B, single lab\",\n      \"pmids\": [\"14581457\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"In mu1A-adaptin-deficient fibroblasts, the internalization rate of MPR300 is increased 7-fold without an increase in steady-state plasma membrane levels. More MPR300 is found in clathrin-coated pits at the plasma membrane, while all intracellular receptors reside in endosomes in equilibrium with the plasma membrane, indicating that AP-1-mediated transport from endosomes to TGN indirectly controls MPR300 recycling between plasma membrane and endosomes.\",\n      \"method\": \"Radioligand internalization assays, immunoelectron microscopy, receptor trafficking in mu1A-KO fibroblasts\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — quantitative trafficking assays in defined KO cells, multiple readouts (rate measurement, EM localization)\",\n      \"pmids\": [\"11792812\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"The mu1A subunit of AP-1 mediates somatodendritic sorting of transmembrane receptors in rat hippocampal neurons by recognizing sorting signals within the cytosolic domains of the proteins. AP-1/mu1A functions in conjunction with clathrin in the neuronal soma to exclude somatodendritic proteins from axonal transport carriers. Perturbation of this process reduces dendritic spine morphology and synapse number.\",\n      \"method\": \"shRNA knockdown, live-cell imaging, immunofluorescence, spine/synapse morphology assays in primary hippocampal neurons\",\n      \"journal\": \"Neuron\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss-of-function with specific neuronal polarity phenotype, multiple cargo readouts, functional consequence (spine/synapse loss)\",\n      \"pmids\": [\"22958822\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"The YxxΦ motif of the coxsackie and adenovirus receptor (CAR) directly interacts with a conserved pocket in mu1A of AP-1A, and this interaction is required for biosynthetic sorting of CAR to the basolateral surface. Knockdown of AP-1A (mu1A) impairs biosynthetic sorting of CAR, complementary to the role of AP-1B in basolateral recycling.\",\n      \"method\": \"Mutational analysis of YxxΦ motif, co-immunoprecipitation, siRNA knockdown, domain-specific trafficking assays in polarized MDCK cells\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mutagenesis of both cargo and adaptor binding pocket, multiple orthogonal assays (co-IP, functional sorting, KD)\",\n      \"pmids\": [\"22343291\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"mu1A and mu1B largely colocalize with both TGN and recycling endosome markers, and with basolateral cargoes in both biosynthetic and endocytic-recycling routes. The two isoforms differ in signal-recognition specificity: mu1B preferentially binds a subset of basolateral sorting signals not recognized by mu1A, expanding the repertoire of AP-1 cargo recognition.\",\n      \"method\": \"Improved immunofluorescence colocalization, co-immunoprecipitation of cargo-adaptor interactions, mutagenesis of sorting signals\",\n      \"journal\": \"Developmental cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — improved quantitative imaging combined with direct cargo-binding assays and functional sorting experiments, single lab\",\n      \"pmids\": [\"24229647\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"The N-terminal 70 amino acids of mu1A regulate AP-1 membrane-to-cytoplasm recycling. Chimeric AP-1* complexes containing a mu2/mu1A N-terminal domain showed slowed recycling kinetics and missorting of mannose-6-phosphate receptors, demonstrating that the mu1A N-terminal domain controls AP-1 recycling between membranes and cytoplasm independently of clathrin.\",\n      \"method\": \"Domain chimera construction, FRAP/live-cell imaging of AP-1 recycling kinetics, MPR trafficking assays in cells expressing chimeric adaptins\",\n      \"journal\": \"Traffic (Copenhagen, Denmark)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — domain chimera approach with functional readout, single lab, single study\",\n      \"pmids\": [\"17988225\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"The cytoplasmic prolyl-oligopeptidase-like protein PREPL interacts with the N-terminal domain of mu1A identified by yeast two-hybrid screen. PREPL overexpression reduces AP-1 membrane binding; reduced PREPL expression increases membrane binding and impairs AP-1 recycling. PREPL-deficient cells have an expanded TGN rescued by PREPL re-expression, defining PREPL as an AP-1 effector that regulates mu1A-dependent membrane binding.\",\n      \"method\": \"Yeast two-hybrid, AP-1 membrane-binding assays, TGN morphology quantification in patient cell lines and PREPL overexpression/knockdown cells\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — yeast two-hybrid plus multiple functional assays (membrane binding, recycling, organelle morphology), patient cell lines validate physiological relevance, single lab\",\n      \"pmids\": [\"23321636\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1995,\n      \"finding\": \"Subunit interactions within AP-1 were mapped: gamma-adaptin and AP47 (mu1A) interact; the NH2-terminal region of gamma-adaptin (aa ~130–330/350) determines membrane targeting and co-assembly with AP47 and AP19. Beta/beta'-adaptins interact with AP50/AP47, but beta/beta'-adaptins are not involved in targeting. These results establish that AP47 subunit interactions contribute to AP-1 complex assembly and TGN targeting.\",\n      \"method\": \"Yeast two-hybrid system, chimeric adaptin constructs, immunoprecipitation\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — yeast two-hybrid plus co-immunoprecipitation of chimeric constructs, two orthogonal methods, single lab\",\n      \"pmids\": [\"7593184\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1994,\n      \"finding\": \"The C. elegans unc-101 gene encodes a homolog of mammalian AP47 (mu1A). Mouse AP47 and nematode UNC-101 are functionally equivalent as demonstrated in transgenic nematodes, establishing cross-species conservation of the mu1A clathrin-adaptor function. Loss of unc-101/mu1A function causes pleiotropic developmental defects including misregulation of vulval differentiation.\",\n      \"method\": \"Genetic analysis, cDNA cloning, transgenic rescue assay in C. elegans\",\n      \"journal\": \"Genes & development\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — transgenic rescue demonstrates functional equivalence, genetic epistasis places unc-101/mu1A in vulval signaling pathway, single lab\",\n      \"pmids\": [\"8288128\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"AP-1 mu1A directly interacts with the C-terminal cytoplasmic domain of kidney anion exchanger 1 (kAE1) via the YXXØ motif Y904DEV907. siRNA-mediated knockdown of AP-1 mu1A in HEK293T cells decreases membrane localization of kAE1 and increases its intracellular accumulation, demonstrating that AP-1 mu1A is required for kAE1 trafficking to the plasma membrane.\",\n      \"method\": \"Yeast two-hybrid, co-immunoprecipitation, affinity co-purification, GST pulldown, YFP-based protein fragment complementation assay, siRNA knockdown with localization readout\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — five independent binding assays plus functional siRNA knockdown, multiple orthogonal methods in single study\",\n      \"pmids\": [\"20833140\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"mu1A (and to a lesser extent mu1B) are required for kAE1 trafficking to the basolateral plasma membrane; knockdown of mu1A causes kAE1 to fail to reach the plasma membrane and undergo lysosomal degradation. Reciprocal co-immunoprecipitation confirmed mu1A–kAE1 interaction in epithelial cells and in mouse kidney extracts in vivo. Newly synthesized kAE1 does not traffic through recycling endosomes, suggesting AP-1A (not AP-1B) is the primary mediator of newly synthesized kAE1 delivery.\",\n      \"method\": \"Reciprocal co-immunoprecipitation in epithelial cells and mouse kidney extract, siRNA knockdown, immunofluorescence trafficking assays\",\n      \"journal\": \"American journal of physiology. Cell physiology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP in cells and in vivo tissue, loss-of-function with specific trafficking phenotype, pathway placement relative to AP-1B\",\n      \"pmids\": [\"22744004\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"AP-1 mu1A (AP-1A) is required for kAE1 sorting from the TGN to the basolateral membrane; RNA interference of AP-1 mu1A (but not mu1B, PKD1, or PKD2) blocks kAE1 intracellular sorting and trafficking. AP-3 mu1 and AP-4 mu1 and clathrin are also required, placing AP-1A/mu1A in the TGN-to-basolateral trafficking pathway for kAE1.\",\n      \"method\": \"siRNA knockdown, co-immunoprecipitation, YFP-PCA, immunofluorescence in polarized and non-polarized kidney cells and human kidney tissue\",\n      \"journal\": \"Traffic (Copenhagen, Denmark)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple adaptor KDs with pathway specificity, co-IP confirmation, two cell systems, single lab\",\n      \"pmids\": [\"24698155\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"AP-1A (mu1A subunit) is required for normal secretory granule (SG) biogenesis in AtT-20 corticotrope cells. Twofold reduction of mu1A decreases TGN cisternae and immature SGs, misroutes carboxypeptidase D (CPD) and peptidylglycine alpha-amidating monooxygenase-1 (PAM-1) from their normal immature SG pathway, and halves stimulated secretion. Yeast two-hybrid and co-immunoprecipitation demonstrated direct interaction between PAM-1 cytosolic domain and AP-1A (mu1A).\",\n      \"method\": \"shRNA knockdown, secretion assays, morphological analysis (TEM), yeast two-hybrid, co-immunoprecipitation, metabolic labeling\",\n      \"journal\": \"Traffic (Copenhagen, Denmark)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal approaches (Y2H, co-IP, KD + multiple phenotypic readouts), single lab\",\n      \"pmids\": [\"25040637\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"IRS-1 associates with mu1A of AP-1A via three YXXØ motifs. Wild-type IRS-1 localizes to peripheral vesicular structures dependent on AP-1; IRS-1 mutants lacking YXXØ motifs are mislocalized to mannose-6-phosphate receptor-positive structures, impairing IGF-I-induced tyrosine phosphorylation, PI3-kinase association, and cell proliferation.\",\n      \"method\": \"Co-immunoprecipitation, mutagenesis of YXXØ motifs, immunofluorescence localization, siRNA knockdown, IGF-I signaling assays (phosphorylation, PI3K association), proliferation assays\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mutagenesis of binding motif plus functional signaling and proliferation readouts, multiple orthogonal methods, single lab\",\n      \"pmids\": [\"23478262\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"mu1A (AP1M1) subunit depletion, but not gamma1 (AP1G1) depletion, prevents HIV-1 Nef-mediated lysosomal degradation of CD4, causing internalized CD4 to accumulate in early endosomes. This places mu1A in the AP-1 variant containing gamma2 (AP1G2) that routes endosomal cargo to lysosomes, distinct from the gamma1-containing AP-1 complex.\",\n      \"method\": \"siRNA knockdown, immunofluorescence, CD4 surface/intracellular trafficking assays in Nef-expressing cells\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — selective subunit depletion with clear trafficking phenotype, epistatic distinction between gamma1 and gamma2/mu1A complexes, single lab\",\n      \"pmids\": [\"27909244\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"The cytoplasmic tail of L-selectin directly binds the C-terminal domain of mu1A via a novel basic motif (three dibasic residue clusters: 356RR357, 359KK360, 362KK363) and a distal 369DD370 element. Phosphorylation of the L-selectin tail abrogates mu1A binding. L-selectin colocalizes with AP-1 at the TGN, suggesting constitutive AP-1/mu1A-mediated retrograde transport of L-selectin.\",\n      \"method\": \"Peptide pulldown with mass spectrometry, GST-pulldown with domain mapping, co-immunoprecipitation, immunofluorescence colocalization, molecular docking\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple binding assays (pulldown + co-IP) with domain mapping, phosphorylation regulatory mechanism, molecular modeling support, single lab\",\n      \"pmids\": [\"28235798\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"VZV ORF9p (tegument protein) interacts with AP1M1 (mu1 subunit of AP-1). Disruption of the ORF9p dileucine motif (L231A) abolishes AP-1 binding and strongly impairs viral growth by preventing efficient secondary envelopment, demonstrating that AP-1/mu1A interaction with ORF9p is required for VZV secondary envelopment.\",\n      \"method\": \"Yeast two-hybrid screen, co-immunoprecipitation from infected cells, viral mutant generation and growth assays\",\n      \"journal\": \"Journal of virology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Y2H confirmed by Co-IP in infected cells, viral mutant rescue experiment, functional viral replication readout, single lab\",\n      \"pmids\": [\"29793951\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"A noncanonical tripartite hydrophobic motif (Trp13/Val16/Met20) in the N-terminus of HIV-1 Nef functions as a mu1A-binding motif, interacting with the tyrosine motif-binding site of mu1A, and is required for Nef-mediated MHC-I downregulation in T lymphocytes.\",\n      \"method\": \"Mutagenesis of Nef N-terminal motif, co-immunoprecipitation/binding assays with mu1A, functional MHC-I downregulation assays\",\n      \"journal\": \"Journal of virology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mutagenesis maps binding motif with functional readout (MHC-I surface levels), single lab\",\n      \"pmids\": [\"22301137\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Basolateral sorting of the Mg2+ transporter CNNM4 requires both AP-1A (mu1A) and AP-1B; single knockdown of mu1B alone does not affect basolateral localization, but simultaneous knockdown of mu1A abrogates it. Three dileucine motifs in CNNM4 are required for basolateral sorting and for interaction with mu1A and mu1B.\",\n      \"method\": \"siRNA knockdown (single and double), mutational analysis of dileucine motifs, immunofluorescence localization in MDCK cells\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic epistasis by double KD, mutagenesis of cargo binding motifs, single lab\",\n      \"pmids\": [\"25449265\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1991,\n      \"finding\": \"Mouse brain AP47 (mu1A) was cloned and sequenced. It is closely related to AP50 (mu2), and a yeast homolog (YAP54) was identified with striking homology to AP47, suggesting AP47/mu1A is the medium chain subunit of AP-1 in both mammals and yeast, with a conserved domain organization.\",\n      \"method\": \"cDNA cloning, sequence analysis, comparative genomics, domain modeling\",\n      \"journal\": \"European journal of biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — foundational cloning and sequence characterization replicated across species, establishes identity of AP47 as mu1A of AP-1\",\n      \"pmids\": [\"1761056\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"CRISPR/Cas9 knockout of AP1M1 strongly increases anti-sense oligonucleotide (ASO) activity by delaying endosome-to-lysosome transport both in vitro and in vivo, prolonging ASO residence time in the endosomal system and increasing likelihood of ASO endosomal escape. This places AP1M1 mechanistically at the endosome-to-lysosome transport step.\",\n      \"method\": \"Unbiased CRISPR/Cas9 knockout screen, ASO splice reporter assay, endosomal trafficking assays in vitro and in vivo\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genome-scale unbiased screen validated with functional trafficking assays in both in vitro and in vivo systems, peer-reviewed\",\n      \"pmids\": [\"40588516\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"HBV infection upregulates AP1M1 expression in HepG2.215 liver cancer cells via the JNK signaling pathway. Silencing AP1M1 suppresses proliferation of HBV-expressing cells while overexpression promotes proliferation. Increased AP1M1 enhances phosphorylation of AKT (protein kinase B), placing AP1M1 downstream of JNK and upstream of AKT in HBV-driven proliferation.\",\n      \"method\": \"siRNA knockdown, overexpression, JNK pathway inhibition, Western blot for AKT phosphorylation, cell proliferation assays\",\n      \"journal\": \"Oncology letters\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, no direct biochemical interaction between AP1M1 and AKT established, proliferation assay alone with pathway inference\",\n      \"pmids\": [\"31289517\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"Both mu1A and mu1B isoforms of AP-1 are co-expressed in melanocytes and keratinocytes. Expression of mu1B (but not mu1A) restores sorting of the melanosome structural protein Pmel17 to the plasma membrane in cells lacking mu1B, indicating that mu1A-containing AP-1A and mu1B-containing AP-1B define distinct sorting routes for melanosome cargo.\",\n      \"method\": \"Real-time PCR, immunolabeling, in situ hybridization, transfection with mu1A or mu1B isoforms, Pmel17 trafficking assays\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — isoform-specific functional complementation assay, multiple detection methods for expression and localization, single lab\",\n      \"pmids\": [\"16492709\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Reduced AP-1 function (via mu1A subunit knockdown) alters endocytic trafficking of PAM-1 (peptidylglycine alpha-amidating monooxygenase), causing PAM-1 accumulation on the cell surface. Co-immunoprecipitation demonstrates that a small fraction of PAM and Atp7a interact, suggesting copper transfer between the two proteins in shared subcellular compartments is disrupted when AP-1/mu1A levels are reduced.\",\n      \"method\": \"shRNA knockdown of mu1A, immunofluorescence, surface biotinylation, co-immunoprecipitation\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — multiple readouts but single lab, co-IP of small fraction interpreted cautiously\",\n      \"pmids\": [\"26170456\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"AP1M1 (mu1A) is the ubiquitous medium-chain subunit of the AP-1A clathrin adaptor complex; it is essential for AP-1 membrane recruitment at the TGN and is required for clathrin-coated vesicle-mediated retrograde transport of mannose-6-phosphate receptors from endosomes to the TGN, for somatodendritic sorting of transmembrane receptors in neurons via recognition of YxxΦ and related cytosolic sorting signals, for basolateral sorting of select cargo (including kAE1, CAR, CNNM4, L-selectin) through direct recognition of tyrosine- and dileucine-based motifs, for secretory granule biogenesis in neuroendocrine cells, and for endosome-to-lysosome transport; its N-terminal domain regulates AP-1 membrane-cytoplasm recycling through interaction with PREPL, and it is exploited by viral proteins (HIV-1 Nef, VZV ORF9p) and by pathogens to manipulate intracellular trafficking.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"AP1M1 (mu1A/AP47) is the ubiquitously expressed medium-chain subunit of the AP-1A clathrin adaptor complex and is essential for AP-1 recruitment to the trans-Golgi network: in its absence the remaining gamma-adaptin fails to bind the TGN, mannose-6-phosphate receptors are rerouted to endosomes, and embryos die at midgestation [#0]. Within the assembled complex mu1A co-assembles with gamma-adaptin and the beta/beta' chains, and gamma-adaptin's N-terminal region directs membrane targeting and co-assembly with mu1A [#10]. mu1A executes cargo selection by binding tyrosine-based Yxx\\u03a6 motifs, dileucine motifs, and even noncanonical basic motifs in the cytosolic tails of transmembrane cargo, thereby sorting kAE1 [#12, #13], CAR [#6], CNNM4 [#21], L-selectin [#18], IRS-1 [#16], and secretory-granule enzymes such as PAM-1 [#15]. Functionally it drives retrograde endosome-to-TGN recycling of MPRs [#0, #4], somatodendritic sorting of receptors in neurons where its loss reduces dendritic spines and synapses [#5], biosynthetic basolateral delivery of select cargo (complementary to the epithelial-specific mu1B/AP-1B isoform that governs basolateral recycling) [#1, #6, #13], secretory granule biogenesis in neuroendocrine cells [#15], and endosome-to-lysosome transport, a step whose disruption prolongs endosomal residence of antisense oligonucleotides [#23]. The N-terminal ~70 residues of mu1A control AP-1 membrane-to-cytoplasm recycling independently of clathrin [#8], regulated by the effector PREPL whose loss expands the TGN and impairs AP-1 recycling [#9]. mu1A is also hijacked by pathogens: HIV-1 Nef engages the mu1A tyrosine-binding site to downregulate MHC-I and to route CD4 to lysosomes via a gamma2/mu1A complex [#20, #17], and VZV ORF9p binds mu1A through a dileucine motif required for viral secondary envelopment [#19]. The function is deeply conserved, with the C. elegans ortholog unc-101 functionally interchangeable with mouse mu1A [#11].\",\n  \"teleology\": [\n    {\n      \"year\": 1991,\n      \"claim\": \"Establishing the molecular identity of mu1A was the prerequisite for assigning it to the AP-1 adaptor; cloning AP47 defined it as the conserved medium-chain subunit.\",\n      \"evidence\": \"cDNA cloning and comparative sequence analysis of mouse brain AP47 with a yeast homolog\",\n      \"pmids\": [\"1761056\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Sequence identity alone did not establish the in vivo function\", \"No cargo-recognition role demonstrated\"]\n    },\n    {\n      \"year\": 1994,\n      \"claim\": \"Whether the adaptor function was conserved and physiologically important was tested genetically, showing the nematode ortholog unc-101 is functionally equivalent to mammalian mu1A.\",\n      \"evidence\": \"Genetic analysis and transgenic rescue in C. elegans\",\n      \"pmids\": [\"8288128\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Did not define the molecular cargo or trafficking step\", \"Vulval phenotype is pleiotropic\"]\n    },\n    {\n      \"year\": 1995,\n      \"claim\": \"How mu1A is incorporated into AP-1 was mapped, showing gamma-adaptin's N-terminus drives membrane targeting and co-assembly with mu1A.\",\n      \"evidence\": \"Yeast two-hybrid and immunoprecipitation of chimeric adaptin constructs\",\n      \"pmids\": [\"7593184\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Did not resolve which subunit recognizes cargo motifs\", \"Assembly mapped in vitro, not in intact cells\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"The central question of whether mu1A is required for AP-1 function in vivo was answered: knockout abolished AP-1 membrane recruitment and disrupted MPR retrograde transport, making mu1A essential for development.\",\n      \"evidence\": \"Mouse gene knockout with cell fractionation, immunofluorescence and receptor trafficking assays\",\n      \"pmids\": [\"10811610\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not identify the cargo-binding motifs directly\", \"Embryonic lethality limited tissue-specific analysis\"]\n    },\n    {\n      \"year\": 2001,\n      \"claim\": \"The distinct sub-cellular niches of mu1A versus the epithelial mu1B isoform were resolved, localizing mu1A-containing AP-1A to the TGN with furin and AP-1B to recycling endosomes.\",\n      \"evidence\": \"Immunofluorescence and immunoelectron microscopy of epitope-tagged subunits plus fractionation; quantitative MPR300 internalization assays in KO fibroblasts\",\n      \"pmids\": [\"11157985\", \"11792812\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism coupling AP-1A endosome-TGN transport to plasma-membrane recycling was indirect\", \"Cargo-motif specificity not yet defined\"]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"The functional divergence of the two isoforms was sharpened by showing AP-1B, not mu1A-containing AP-1A, recruits exocyst subunits, tying mu1A to TGN/endosomal rather than exocytic delivery.\",\n      \"evidence\": \"Immunofluorescence, fractionation and co-localization with exocyst markers\",\n      \"pmids\": [\"14581457\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not address how mu1A selects its own cargo\", \"Single-lab observation\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"The basis of AP-1 cycling on and off membranes was localized to the mu1A N-terminal domain, which controls membrane-cytoplasm recycling independently of clathrin.\",\n      \"evidence\": \"mu2/mu1A domain chimeras with FRAP/live imaging and MPR trafficking readouts\",\n      \"pmids\": [\"17988225\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Chimera approach, not endogenous mutation\", \"Effector controlling N-terminal recycling unidentified at the time\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Direct cargo recognition by mu1A was demonstrated biochemically for kAE1 via its YxxO motif, establishing mu1A as the motif-reading subunit for plasma-membrane delivery of this cargo.\",\n      \"evidence\": \"Yeast two-hybrid, co-IP, GST pulldown, affinity co-purification and PCA with siRNA localization readout\",\n      \"pmids\": [\"20833140\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Polarized sorting route not yet placed\", \"Performed largely in non-polarized HEK293T cells\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Multiple studies converged to define mu1A as a Yxx\\u03a6/motif reader directing biosynthetic basolateral and neuronal somatodendritic sorting, and as a target of HIV-1 Nef for MHC-I downregulation.\",\n      \"evidence\": \"Motif mutagenesis, co-IP and knockdown for CAR (MDCK) and Nef (T cells); shRNA, live imaging and synapse morphology in hippocampal neurons; reciprocal Co-IP and in vivo tissue for kAE1\",\n      \"pmids\": [\"22343291\", \"22301137\", \"22958822\", \"22744004\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of motif recognition not resolved in these studies\", \"Functional partition between AP-1A and AP-1B cargo sets still being delineated\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"The regulatory and signal-recognition layer of mu1A was expanded: PREPL was identified as an N-terminal effector controlling AP-1 membrane binding, while mu1A/mu1B were shown to differ in sorting-signal specificity and mu1A to bind IRS-1 to control its localization and IGF signaling.\",\n      \"evidence\": \"Yeast two-hybrid, membrane-binding and TGN morphology assays in patient cells (PREPL); colocalization and cargo co-IP/mutagenesis (mu1A vs mu1B); motif mutagenesis with signaling/proliferation readouts (IRS-1)\",\n      \"pmids\": [\"23321636\", \"24229647\", \"23478262\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Structural detail of PREPL-mu1A interface unresolved\", \"Precise rule distinguishing mu1A vs mu1B signal preference incomplete\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"mu1A's role in TGN-to-basolateral cargo delivery and secretory-granule biogenesis was established, including isoform redundancy with mu1B for some cargo and direct binding to granule enzymes.\",\n      \"evidence\": \"Single/double siRNA knockdown and dileucine-motif mutagenesis (kAE1, CNNM4); shRNA, TEM, secretion assays and Y2H/co-IP for PAM-1 (AtT-20 cells)\",\n      \"pmids\": [\"24698155\", \"25449265\", \"25040637\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Quantitative contribution of each adaptor in TGN-to-basolateral step not fully partitioned\", \"Granule cargo selectivity mechanism incomplete\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"mu1A was assigned to a specific AP-1 variant (gamma2-containing) routing endosomal CD4 to lysosomes during Nef action, distinguishing it from the gamma1 complex.\",\n      \"evidence\": \"Selective siRNA depletion of mu1A vs gamma1 with CD4 trafficking assays in Nef-expressing cells\",\n      \"pmids\": [\"27909244\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Endogenous (non-Nef) cargo of the gamma2/mu1A complex not defined\", \"Single-lab epistasis\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"The cargo-recognition repertoire of mu1A was broadened beyond tyrosine/dileucine motifs by defining a novel basic motif in L-selectin bound by the mu1A C-terminal domain and switched off by phosphorylation.\",\n      \"evidence\": \"Peptide pulldown-MS, GST pulldown with domain mapping, co-IP, colocalization and molecular docking\",\n      \"pmids\": [\"28235798\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structure of the basic-motif/mu1A complex\", \"Physiological retrograde route inferred from colocalization\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Pathogen exploitation of mu1A was extended to VZV, where ORF9p binds mu1A via a dileucine motif required for viral secondary envelopment.\",\n      \"evidence\": \"Yeast two-hybrid, co-IP from infected cells and dileucine-mutant viral growth assays\",\n      \"pmids\": [\"29793951\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Structural basis of ORF9p-mu1A binding unresolved\", \"Host membrane source for envelopment not pinpointed\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"An unbiased screen placed mu1A at the endosome-to-lysosome transport step, with its loss prolonging endosomal residence and enhancing antisense-oligonucleotide activity.\",\n      \"evidence\": \"Genome-scale CRISPR/Cas9 knockout screen with ASO splice reporter and endosomal trafficking assays in vitro and in vivo\",\n      \"pmids\": [\"40588516\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular cargo mediating this lysosomal step not identified\", \"Relationship to the gamma2/mu1A lysosomal route not directly tested\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How distinct mu1A-containing AP-1 variants (gamma1 vs gamma2) and cargo-motif classes are selected at each trafficking step, and the structural basis of noncanonical motif recognition, remain to be resolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structure of mu1A bound to dileucine or basic cargo motifs in the corpus\", \"Endogenous cargo set of the gamma2/mu1A lysosomal complex undefined\", \"Mechanistic integration of PREPL-regulated recycling with cargo selection unresolved\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [6, 12, 16, 18, 21]},\n      {\"term_id\": \"GO:0008289\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005794\", \"supporting_discovery_ids\": [2, 15, 18]},\n      {\"term_id\": \"GO:0005768\", \"supporting_discovery_ids\": [0, 4, 17, 23]},\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [8, 9]},\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [12, 13]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-5653656\", \"supporting_discovery_ids\": [0, 2, 4, 23]},\n      {\"term_id\": \"R-HSA-9609507\", \"supporting_discovery_ids\": [5, 6, 13, 21]},\n      {\"term_id\": \"R-HSA-1643685\", \"supporting_discovery_ids\": [17, 19, 20]}\n    ],\n    \"complexes\": [\"AP-1A clathrin adaptor complex\"],\n    \"partners\": [\"AP1G1\", \"PREPL\", \"SLC4A1\", \"CXADR\", \"SELL\", \"IRS1\", \"PAM\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}