{"gene":"RBP1","run_date":"2026-06-10T06:43:36","timeline":{"discoveries":[{"year":1993,"finding":"Apo-CRBP1 stimulates a bile salt-independent microsomal retinyl ester hydrolase to release retinol from retinyl ester stores, generating holo-CRBP1; holo-CRBP1 then serves as a direct substrate for an NADP-dependent microsomal retinol dehydrogenase to produce retinal, which is further converted to retinoic acid by a cytosolic NAD-dependent retinal dehydrogenase. Thus CRBP1 channels retinol through the retinoic acid biosynthesis pathway via a series of protein-protein interactions.","method":"In vitro enzyme assays with purified apo- and holo-CRBP, microsomal fractions, cofactor specificity studies, substrate competition","journal":"The Journal of nutrition","confidence":"High","confidence_rationale":"Tier 1 / Strong — multiple in vitro enzymatic assays with defined substrates and cofactors, replicated across multiple publications from the same group and independently corroborated","pmids":["8381481","1932598"],"is_preprint":false},{"year":1992,"finding":"Holo-CRBP1 (retinol-bound CRBP) is specifically recognized as substrate by an NADP-dependent microsomal retinol dehydrogenase for retinal synthesis; NADPH does not support significant retinal synthesis from holo-CRBP1 or physiological concentrations of free retinol when an NADPH-regenerating system prevents NADP formation, establishing cofactor specificity.","method":"Microsomal enzyme assays with holo-CRBP vs. free retinol, varying cofactors (NADP, NAD, NADPH) with and without regenerating systems; Km and Vmax determinations","journal":"Biochimica et biophysica acta","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro reconstitution with purified components, quantitative kinetics, cofactor specificity rigorously established","pmids":["1562584"],"is_preprint":false},{"year":1995,"finding":"A microsomal retinol dehydrogenase (RoDH) from rat liver, identified as a short-chain alcohol dehydrogenase (SCAD, 34 kDa active subunit), directly cross-links to and uses holo-CRBP1 as substrate (Km ~0.4–0.6 µM), catalyzing retinal synthesis with NADP as cofactor via an ordered bisubstrate mechanism. The enzyme discriminates against CRBP1-bound didehydroretinol and 9-cis-retinol, demonstrating substrate specificity conferred by the CRBP1 complex.","method":"Affinity chromatography, Triton X-114 phase partitioning, covalent cross-linking of holo-CRBP1 to the 34 kDa subunit, phenylarsine oxide inactivation, Km determination, SCAD inhibitor profiling (carbenoxolone, ethanol), cofactor studies","journal":"Biochemistry","confidence":"High","confidence_rationale":"Tier 1 / Strong — direct biochemical reconstitution with cross-linking, active-site labeling, and kinetic characterization in a single rigorous study","pmids":["7766612"],"is_preprint":false},{"year":1992,"finding":"The rat CRBP1 (rCRBPI) promoter contains a retinoic acid response element (RARE) ~1 kb upstream of the transcription start, consisting of a direct repeat with a two-nucleotide spacer. This RARE is activated by RARα and RARβ (but not RARγ1) and requires RAR/RXR heterodimers for efficient binding and transcriptional activation; RARs or RXR alone do not interact effectively with the element.","method":"Promoter deletion and sequence analysis, transient transfection reporter assays, gel-shift binding assays with RAR and RXR combinations","journal":"Biochemical and biophysical research communications","confidence":"High","confidence_rationale":"Tier 1 / Moderate — reporter assay plus gel-shift binding, multiple receptor combinations tested, single lab but orthogonal methods","pmids":["1339275"],"is_preprint":false},{"year":2003,"finding":"Human microsomal RoDH-4 (SDR family) recognizes cytosolic holo-CRBP1 as a substrate with Km close to liver holo-CRBP1 concentration (~59 min⁻¹ mM⁻¹ catalytic efficiency); apo-CRBP1 acts as a strong competitive inhibitor (Ki ~0.2 µM) of holo-CRBP1 oxidation, indicating that the apo/holo-CRBP1 ratio regulates retinol flux to retinoic acid. RoDH-4 faces the cytosolic side of the membrane (established by immunoprecipitation and glycosylation scanning), consistent with its access to cytosolic holo-CRBP1.","method":"Purified RoDH-4 reconstituted in proteoliposomes; kinetic assays with holo-CRBP1 vs. free retinol; competitive inhibition by apo-CRBP1; membrane topology by immunoprecipitation and glycosylation scanning mutagenesis","journal":"Biochemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro reconstitution, kinetics, topology mapping, multiple orthogonal methods in one study","pmids":["12534290"],"is_preprint":false},{"year":2005,"finding":"CRBP1 restricts the oxidation of all-trans-retinol by RDH12 but has little effect on reduction of all-trans-retinaldehyde, because CRBP1 binds all-trans-retinol with much higher affinity than all-trans-retinaldehyde; RDH12 utilizes only the unbound (free) forms of retinoids, not holo-CRBP1 complexes.","method":"In vitro RDH12 activity assays with retinoids in the presence or absence of CRBP1 or CRALBP; kinetic analysis (Km, kcat)","journal":"Biochemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — direct in vitro enzyme assays with purified proteins, quantitative kinetics, single lab with multiple substrate combinations","pmids":["15865448"],"is_preprint":false},{"year":2011,"finding":"CRBP1 and CRBP2 bind 9-cis-retinol (Kd ~11 nM and ~68 nM, respectively) and 9-cis-retinal (Kd ~8 nM and ~5 nM, respectively) with high affinity, but neither protein shows significant binding to 9-cis-retinoic acid. This supports a model in which CRBP1 chaperones 9-cis-retinoids to enzymes for 9-cis-retinoic acid biosynthesis.","method":"Fluorescence spectroscopy binding assays with non-linear regression to determine apparent dissociation constants for multiple retinoid ligands","journal":"Biochimica et biophysica acta","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — rigorous fluorescence binding assay, but single lab and single method","pmids":["21382444"],"is_preprint":false},{"year":2002,"finding":"CRBP1 knockout mice (CRBPI⁻/⁻) accumulate all-trans-retinol transiently in the neural retina after a light flash (instead of converting it to retinyl ester as in wild-type), and have ~67% reduction in retinyl ester stores in the RPE, indicating that CRBP1 participates in driving diffusion of all-trans-retinol from photoreceptors to RPE and in delivering retinol to LRAT for esterification in the visual cycle. Dark adaptation was delayed approximately 2-fold but rhodopsin regeneration rate was not majorly impaired.","method":"Retinoid analysis by HPLC in dark-adapted and flash-recovered eyes of CRBPI⁻/⁻ vs. wild-type mice; electroretinography (ERG) for dark adaptation rates","journal":"Investigative ophthalmology & visual science","confidence":"High","confidence_rationale":"Tier 2 / Moderate — clean genetic knockout with quantitative retinoid biochemistry and electrophysiological readout, multiple orthogonal methods","pmids":["12036972"],"is_preprint":false},{"year":1994,"finding":"Retinol transfers rapidly and nearly completely (>100%) from IRBP to CRBP1 in vitro with a half-time of ~4 seconds, driven by CRBP1's ~100-fold higher affinity for retinol compared to IRBP. No transfer from CRBP1 back to IRBP was detected, establishing a thermodynamic gradient that drives retinol flow toward the RPE during the visual cycle.","method":"UV absorbance spectroscopy (shift from 330 to 350 nm upon transfer), size-exclusion HPLC separation of IRBP and CRBP1 followed by retinoid quantification with diode-array detection","journal":"Experimental eye research","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — clean biophysical transfer assay with two orthogonal detection methods, but single lab","pmids":["7835405"],"is_preprint":false},{"year":2010,"finding":"CRBP1 (CRBP-I) regulates adipocyte differentiation: CRBP-I is specifically expressed in preadipocytes in white adipose tissue, and its absence in knockout mice leads to increased adiposity. CRBP-I–deficient 3T3-L1 cells and MEFs show increased adipogenesis and triglyceride accumulation due to increased PPARγ expression and activity, while CRBP-I overexpression decreases triglyceride accumulation. The effect is PPARγ-dependent with other early and late adipogenic transcription factor pathways unaffected.","method":"CRBP-I knockout mice, 3T3-L1 cells with shRNA knockdown, MEFs from knockout mice, overexpression in 3T3-L1; PPARγ activity assays, Oil Red O staining, triglyceride quantification, qPCR for transcription factors","journal":"Molecular and cellular biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic knockout mouse plus cell-based gain- and loss-of-function with defined pathway (PPARγ) and multiple orthogonal readouts","pmids":["20498279"],"is_preprint":false},{"year":2011,"finding":"CrbpI (encoded by Rbp1) modulates pancreatic 9-cis-retinoic acid (9cRA) levels and glucose homeostasis: Rbp1⁻/⁻ mice have abnormally elevated pancreatic 9cRA that resists postprandial decrease, associated with defective islet gene expression for glucose sensing and insulin secretion, reduced glucose-stimulated insulin secretion, high glucagon, increased gluconeogenesis, and hyperglycemia. Ectopic CrbpII expression in Rbp1⁻/⁻ pancreas contributes to elevated 9cRA biosynthesis. Rbp1⁻/⁻ mice also show increased fatty acid oxidation and obesity resistance on high-fat diet.","method":"Rbp1 knockout mice; retinoid quantification by LC-MS; islet gene expression by qPCR; glucose tolerance tests; insulin and glucagon secretion assays; measurement of gluconeogenesis rates","journal":"Molecular and cellular biology","confidence":"High","confidence_rationale":"Tier 2 / Moderate — clean genetic knockout with quantitative metabolomics and multiple functional metabolic readouts, single lab","pmids":["21670153"],"is_preprint":false},{"year":2013,"finding":"CrbpI loss in mouse mammary tissue disrupts retinoic acid (atRA) homeostasis, resulting in 40% depleted endogenous atRA. Rbp1⁻/⁻ mammary subcellular fractions show 24–42% less atRA production due to altered retinol dehydrogenase/reductase enzyme activity. CrbpIII cannot functionally replace CrbpI as a retinoid chaperone. Loss of CrbpI precedes defects in atRA biosynthesis enzyme expression and causes epithelial hyperplasia, stromal hypercellularity, increased collagen, and oxidative stress consistent with atRA deficiency.","method":"Rbp1⁻/⁻ mouse mammary tissue; retinoid quantification by LC-MS; subcellular fractionation with Rdh enzyme activity assays; histological analysis; qPCR for biosynthesis enzymes","journal":"FASEB journal","confidence":"High","confidence_rationale":"Tier 2 / Moderate — clean genetic knockout with retinoid biochemistry, enzyme activity assays, and histopathology, multiple orthogonal methods","pmids":["23362116"],"is_preprint":false},{"year":2016,"finding":"Crystal structures of human CRBP1 in apo (ligand-free) and holo (retinol-bound or retinylamine-bound) forms reveal that ligand binding induces conformational changes in α-helix II, hairpin turns between β-strands βC-βD and βE-βF, and side chains Phe-57, Tyr-60, and Ile-77 surrounding the entrance to the retinoid-binding pocket. The apoprotein has greater backbone mobility in these regions (higher B-factors) that facilitates induced-fit ligand uptake; the rigid holoprotein structure protects the retinoid during transport.","method":"X-ray crystallography of apo-CRBP1 and holo-CRBP1 bound to all-trans-retinol or retinylamine at atomic/ultra-high resolution; B-factor analysis; hydrogen bond network mapping","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — atomic resolution crystal structures of apo and holo forms with functional interpretation; single lab but multiple structures and orthogonal analyses","pmids":["26900151"],"is_preprint":false},{"year":2017,"finding":"Mutational analysis of human CRBP1 identified Gln108 and Lys40 as key polar residues for high-affinity retinol binding (Kd ~4.5 nM for wild-type; ~65 nM for Q108L; ~70 nM for K40L; ~250 nM for Q108L/K40L double mutant). Extensive apolar interactions in the binding cavity are sufficient to maintain ligand positioning, but polar interactions of the retinol hydroxyl with Gln108 and Lys40 are required for high affinity and selectivity. The putative portal region (α-helix-II, Arg58, E-F loop) is the most flexible region in both apo- and holo-CRBP1.","method":"X-ray crystallography of wild-type and mutant CRBP1 forms; fluorometric titration for Kd determination of wild-type and point mutants (Q108L, K40L, Q108L/K40L); B-factor analysis","journal":"Journal of structural biology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — crystal structures plus active-site mutagenesis with quantitative binding measurements, multiple orthogonal methods in single study","pmids":["28057518"],"is_preprint":false},{"year":2019,"finding":"Abnormal cannabidiol (abn-CBD) is a nonretinoid competitive inhibitor of CRBP1. X-ray crystal structures of CRBP1 in complex with abn-CBD and derivatives reveal a distinctive binding mode in the retinol-binding pocket. Abn-CBD modulates retinoid flux through the visual cycle in vivo and protects against light-induced retinal damage in mice.","method":"X-ray crystallography of CRBP1–abn-CBD complexes; competitive binding assays; in vivo mouse retinal damage model (light exposure); retinoid cycle flux measurements","journal":"ACS chemical biology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — crystal structures with in vivo functional validation, multiple orthogonal methods","pmids":["30721022"],"is_preprint":false},{"year":2023,"finding":"High-throughput screening identified new nonretinoid competitive inhibitors of CRBP1. Crystal structures of CRBP1 with six inhibitors revealed their binding modes within the retinol-binding pocket. Hydrogen/deuterium exchange mass spectrometry quantified inhibitor-induced conformational changes and correlated their magnitude with binding affinity. Molecular dynamics simulations demonstrated that the 'closed' conformation of CRBP1 retains ligands within the binding pocket, providing mechanistic insight into high-affinity binding.","method":"High-throughput screening; X-ray crystallography (6 inhibitor complexes); hydrogen/deuterium exchange mass spectrometry (HDX-MS); molecular dynamics simulations","journal":"ACS chemical biology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — crystal structures combined with HDX-MS and MD simulations, four orthogonal methods in single study","pmids":["37713257"],"is_preprint":false},{"year":2001,"finding":"Ectopic CRBP1 expression in CRBP-null human breast epithelial cells suppresses anchorage-independent growth and colony formation by inhibiting cell survival (not proliferation of adherent cells). This was mechanistically linked to inhibition of protein kinase B/Akt activation specifically in suspension conditions, and mimicked by PI3K inhibitor LY294002. CRBP1-mediated effects were independent of retinoic acid receptor activity; CRBP1 enhanced retinyl ester formation rather than retinoic acid synthesis.","method":"Ectopic expression of CRBP1 in MTSV1-7 and T47D breast cells; soft-agar colony assay; TUNEL and viability assays; Western blot for phospho-Akt; pharmacological inhibition with LY294002; RA receptor activity assays; retinyl ester quantification","journal":"Oncogene","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — gain-of-function in two cell lines with defined PI3K/Akt pathway readout and multiple orthogonal assays, single lab","pmids":["11704871"],"is_preprint":false},{"year":2012,"finding":"CRBP1 overexpression in bone marrow mesenchymal stem cells (MSCs) promotes osteogenic and inhibits adipogenic differentiation. The mechanism involves CRBP1 inhibiting RXRα-induced β-catenin degradation, maintaining higher levels of β-catenin and phospho-ERK1/2, thereby activating Wnt/β-catenin signaling to favor osteogenesis over adipogenesis.","method":"CRBP1 overexpression in MSCs; in vitro and in vivo osteogenic/adipogenic differentiation assays; Western blot for β-catenin, RXRα, pERK1/2; Alizarin Red staining for mineralization","journal":"The international journal of biochemistry & cell biology","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — gain-of-function with defined pathway (RXRα/β-catenin) and in vivo validation, but single lab and mechanistic link relies on correlative Western blots","pmids":["22230368"],"is_preprint":false},{"year":1989,"finding":"The human RBP1 (CRBP1) gene was mapped to chromosomal region 3q21–q22 by somatic cell hybrid panel analysis and in situ hybridization.","method":"Somatic cell hybrid panel Southern blotting; in situ hybridization","journal":"Somatic cell and molecular genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — two independent mapping methods (somatic cell hybrids and in situ hybridization) concordant for chromosomal localization","pmids":["2928844"],"is_preprint":false},{"year":2024,"finding":"In IDH-mutant gliomas, RBP1 (CRBP1) is epigenetically silenced, impairing retinoic acid pathway signaling. This silencing contributes to immunosuppression by reducing inflammatory cell states and promoting suppressive myeloid phenotypes. Restoration of RA signaling (ATRA treatment) in murine IDHm glioma models promotes clonal CD4+ T cell expansion and tumor regression, specifically in IDHm but not IDH-wildtype tumors.","method":"Murine IDHm glioma models; ATRA treatment; flow cytometry for T cell and myeloid phenotyping; scRNA-seq for immune cell state analysis; epigenetic analysis of RBP1 promoter","journal":"bioRxiv","confidence":"Low","confidence_rationale":"Tier 2 / Weak — preprint, murine model with immune phenotyping, mechanistic link via epigenetic silencing established but not yet peer-reviewed","pmids":["38645178"],"is_preprint":true}],"current_model":"CRBP1 (RBP1/hCRBP1) is a small (~15 kDa) cytosolic retinol-binding protein that acts as a chaperone to channel vitamin A (retinol) through the retinoic acid biosynthetic pathway: the apo form stimulates retinyl ester hydrolysis to mobilize retinol stores, while the holo form delivers retinol directly to specific NADP-dependent microsomal retinol dehydrogenases (e.g., RoDH-4) via protein-protein interaction, with apo-CRBP1 serving as a competitive inhibitor to regulate flux; structural studies reveal an induced-fit mechanism whereby ligand binding closes a portal region (α-helix II, βC-βD and βE-βF hairpins) around the retinoid; in vivo knockout models demonstrate roles in visual cycle retinoid trafficking (driving retinol transfer from photoreceptors to RPE for LRAT-mediated esterification), pancreatic 9-cis-retinoic acid homeostasis and glucose-stimulated insulin secretion, mammary gland retinoic acid production, regulation of adipogenesis (suppressing PPARγ activity and fat accumulation), and suppression of anchorage-independent cell survival via inhibition of PI3K/Akt signaling."},"narrative":{"mechanistic_narrative":"RBP1 (CRBP1) is a small cytosolic retinol-binding protein that channels vitamin A through the retinoic acid biosynthetic pathway via a series of regulated protein-protein interactions [PMID:8381481, PMID:1932598]. In its retinol-bound (holo) form, CRBP1 is specifically recognized as substrate by NADP-dependent microsomal retinol dehydrogenases (RoDH/RoDH-4, short-chain dehydrogenase family) that oxidize it to retinal, with strict cofactor specificity for NADP over NADPH and direct enzyme cross-linking to the holoprotein [PMID:1562584, PMID:7766612, PMID:12534290]; the apo form conversely stimulates microsomal retinyl ester hydrolysis to mobilize stored retinol and acts as a potent competitive inhibitor of holo-CRBP1 oxidation, so the apo/holo ratio sets the flux of retinol toward retinoic acid [PMID:8381481, PMID:1932598, PMID:12534290]. Substrate selectivity is intrinsic to the complex: CRBP1 sequesters retinol from enzymes that act only on free retinoids (e.g. RDH12) while delivering it to those that accept the bound form [PMID:7766612, PMID:15865448]. Crystallographic and mutational studies define an induced-fit mechanism in which a flexible portal region (α-helix II, β-hairpin turns βC–βD and βE–βF) closes around the ligand, with polar contacts from Gln108 and Lys40 conferring high-affinity, selective retinol binding while the rigid holo conformation protects the retinoid during transport [PMID:26900151, PMID:28057518, PMID:37713257]. Physiologically, CRBP1 drives retinol trafficking from photoreceptors to the RPE and delivery to LRAT in the visual cycle [PMID:12036972, PMID:7835405], maintains tissue retinoic acid homeostasis in mammary gland and pancreas where its loss perturbs islet gene expression and glucose-stimulated insulin secretion [PMID:21670153, PMID:23362116], and restrains adipogenesis by suppressing PPARγ expression and activity [PMID:20498279]. Beyond retinoid metabolism, CRBP1 suppresses anchorage-independent survival of breast epithelial cells through inhibition of PI3K/Akt signaling independently of retinoic acid receptors [PMID:11704871].","teleology":[{"year":1992,"claim":"Established the core enzymatic logic of the pathway by showing that retinol-bound CRBP1, not free retinol, is the recognized substrate for retinal synthesis, defining CRBP1 as an obligate carrier rather than a passive solubilizer.","evidence":"Microsomal enzyme assays comparing holo-CRBP vs free retinol with defined cofactors and a NADPH-regenerating system","pmids":["1562584"],"confidence":"High","gaps":["Identity of the responsible dehydrogenase not yet defined","Did not address how the apo form regulates flux"]},{"year":1992,"claim":"Showed CRBP1 expression is itself retinoic-acid-responsive, linking the protein into a feedback loop of vitamin A signaling via a RARE in its promoter.","evidence":"Promoter deletion, reporter assays, and gel-shift binding with RAR/RXR combinations on the rat Rbp1 promoter","pmids":["1339275"],"confidence":"High","gaps":["Done in rat promoter; human regulatory element not characterized here","Physiological consequence of feedback regulation untested"]},{"year":1993,"claim":"Unified the apo and holo states into a directional channeling model: apo-CRBP1 mobilizes retinol from ester stores and holo-CRBP1 feeds it forward to dehydrogenases, casting CRBP1 as a flux-controlling chaperone.","evidence":"In vitro enzyme assays with purified apo/holo-CRBP, microsomal fractions, and substrate competition","pmids":["8381481","1932598"],"confidence":"High","gaps":["Quantitative regulation by apo/holo ratio not yet measured","Specific dehydrogenase still unidentified"]},{"year":1994,"claim":"Provided the thermodynamic basis for directional retinol movement in the eye by showing irreversible transfer from IRBP to CRBP1 driven by a ~100-fold affinity difference.","evidence":"UV absorbance shift and size-exclusion HPLC transfer assays between IRBP and CRBP1","pmids":["7835405"],"confidence":"Medium","gaps":["Single lab, in vitro only","Whether transfer occurs at membrane interfaces in vivo not addressed"]},{"year":1995,"claim":"Identified the dehydrogenase as a short-chain alcohol dehydrogenase that physically cross-links to holo-CRBP1, providing direct biochemical proof of the protein-protein channeling interaction and substrate discrimination.","evidence":"Affinity purification, covalent cross-linking, active-site labeling, and kinetics of rat liver RoDH","pmids":["7766612"],"confidence":"High","gaps":["Human ortholog not yet characterized","Membrane topology of the interaction surface unresolved"]},{"year":2001,"claim":"Uncovered a retinoid-independent role: CRBP1 suppresses anchorage-independent cell survival via PI3K/Akt inhibition, broadening its function beyond metabolic chaperoning.","evidence":"Ectopic CRBP1 expression in breast epithelial cell lines with soft-agar, TUNEL, phospho-Akt, and pharmacological PI3K inhibition","pmids":["11704871"],"confidence":"Medium","gaps":["Molecular link between CRBP1 and Akt not defined","Gain-of-function only; endogenous loss not tested"]},{"year":2002,"claim":"Genetic knockout placed CRBP1 in the visual cycle, demonstrating it drives retinol movement from photoreceptors to RPE and delivery to LRAT for esterification.","evidence":"HPLC retinoid analysis and ERG in CRBP1-null vs wild-type mouse eyes","pmids":["12036972"],"confidence":"High","gaps":["Rhodopsin regeneration largely intact, indicating redundancy","Molecular mechanism of retinol hand-off to LRAT not resolved"]},{"year":2003,"claim":"Defined the human enzyme partner and the regulatory switch: RoDH-4 oxidizes holo-CRBP1 from the cytosolic membrane face, and apo-CRBP1 is a strong competitive inhibitor, establishing the apo/holo ratio as the flux regulator.","evidence":"Reconstituted RoDH-4 proteoliposome kinetics, apo-CRBP1 inhibition, and membrane topology mapping","pmids":["12534290"],"confidence":"High","gaps":["In vivo demonstration of apo/holo flux control not provided","Whether other SDR enzymes share this mechanism untested"]},{"year":2005,"claim":"Clarified CRBP1's selectivity logic by showing it withholds retinol from enzymes (RDH12) that use only free retinoid, sharpening the concept of substrate channeling versus sequestration.","evidence":"In vitro RDH12 kinetics with and without CRBP1 or CRALBP","pmids":["15865448"],"confidence":"High","gaps":["Physiological balance between channeling and sequestration in cells not quantified"]},{"year":2010,"claim":"Linked CRBP1 to metabolic control by showing it restrains adipogenesis through suppression of PPARγ, identifying a discrete transcriptional pathway under its influence.","evidence":"Knockout mice, 3T3-L1 knockdown/overexpression, MEFs with PPARγ activity and lipid readouts","pmids":["20498279"],"confidence":"High","gaps":["Whether the PPARγ effect is retinoid-ligand mediated not fully dissected","Direct molecular connection to PPARγ regulation unresolved"]},{"year":2011,"claim":"Extended the chaperone role to 9-cis-retinoid biosynthesis and demonstrated in vivo control of pancreatic 9-cis-retinoic acid, glucose sensing, and insulin secretion.","evidence":"Fluorescence binding assays for 9-cis retinoids and Rbp1-knockout metabolic/retinoid phenotyping by LC-MS","pmids":["21382444","21670153"],"confidence":"Medium","gaps":["Binding study single-lab/single-method","Identity of 9cRA-synthesizing enzymes downstream of CRBP1 not defined"]},{"year":2013,"claim":"Showed CRBP1 is non-redundant for tissue retinoic acid homeostasis, as its loss depletes mammary atRA and causes tissue pathology that paralogs cannot rescue.","evidence":"Rbp1-null mammary LC-MS retinoid quantification, subcellular Rdh activity assays, and histology","pmids":["23362116"],"confidence":"High","gaps":["Mechanism of altered Rdh enzyme activity in absence of CRBP1 unclear","Why CrbpIII cannot substitute not structurally explained"]},{"year":2012,"claim":"Identified an additional differentiation role in mesenchymal stem cells, where CRBP1 favors osteogenesis over adipogenesis by stabilizing β-catenin and Wnt signaling.","evidence":"CRBP1 overexpression in MSCs with differentiation assays and Western blots for β-catenin/RXRα/pERK","pmids":["22230368"],"confidence":"Medium","gaps":["Mechanistic link relies on correlative Westerns","Loss-of-function not tested in this system"]},{"year":2017,"claim":"Resolved the structural mechanism of ligand binding, defining an induced-fit portal closure and the polar residues (Gln108, Lys40) that confer high-affinity retinol recognition and protective enclosure.","evidence":"X-ray structures of apo/holo and mutant CRBP1, B-factor analysis, and fluorometric Kd determinations (consolidating the 2016 structural work)","pmids":["26900151","28057518"],"confidence":"High","gaps":["Structures of CRBP1 in complex with its enzyme partners not determined","Dynamics of ligand release to dehydrogenases not visualized"]},{"year":2023,"claim":"Established CRBP1 as a druggable target by characterizing nonretinoid competitive inhibitors that modulate visual-cycle flux and protect against retinal damage, with structures and dynamics explaining closed-state ligand retention.","evidence":"Crystallography of CRBP1-inhibitor complexes, HTS, HDX-MS, MD simulations, and in vivo light-damage models (consolidating 2019 and 2023 work)","pmids":["30721022","37713257"],"confidence":"High","gaps":["Therapeutic window and selectivity over other retinoid-binding proteins not addressed","Long-term in vivo consequences of CRBP1 inhibition unknown"]},{"year":2024,"claim":"Implicated CRBP1 silencing in tumor immunosuppression, suggesting restoration of its retinoic acid pathway could reprogram the glioma immune microenvironment.","evidence":"Murine IDH-mutant glioma models, ATRA treatment, scRNA-seq, and RBP1 promoter epigenetic analysis (preprint)","pmids":["38645178"],"confidence":"Low","gaps":["Preprint, not peer-reviewed","Causal role of RBP1 silencing versus broader RA pathway loss not isolated","Human relevance beyond murine models untested"]},{"year":null,"claim":"How CRBP1 physically docks onto its partner dehydrogenases and hydrolases at the microsomal membrane, and how the apo/holo conformational switch is coordinated with these enzymes in vivo, remains structurally and mechanistically undefined.","evidence":"","pmids":[],"confidence":"High","gaps":["No co-structure of CRBP1 with any partner enzyme","Spatial organization of CRBP1-enzyme interactions at the ER membrane unknown","Mechanism coupling Akt suppression and β-catenin stabilization to retinoid chaperoning not established"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0008289","term_label":"lipid binding","supporting_discovery_ids":[0,1,6,12,13]},{"term_id":"GO:0140313","term_label":"molecular sequestering activity","supporting_discovery_ids":[0,4,5]},{"term_id":"GO:0140104","term_label":"molecular carrier activity","supporting_discovery_ids":[0,8]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[4,9]}],"localization":[{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[0,4]}],"pathway":[{"term_id":"R-HSA-1430728","term_label":"Metabolism","supporting_discovery_ids":[0,1,10,11]},{"term_id":"R-HSA-9709957","term_label":"Sensory Perception","supporting_discovery_ids":[7,14]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[16,17]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[9,17]}],"complexes":[],"partners":["RDH12","IRBP"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"O95153","full_name":"Peripheral-type benzodiazepine receptor-associated protein 1","aliases":["Peripheral benzodiazepine receptor-interacting protein","PBR-IP","RIMS-binding protein 1","RIM-BP1","TSPO-associated protein 1"],"length_aa":1857,"mass_kda":200.1,"function":"Required for synaptic transmission regulation (PubMed:33539324). 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biology","url":"https://pubmed.ncbi.nlm.nih.gov/37713257","citation_count":6,"is_preprint":false},{"pmid":"37233959","id":"PMC_37233959","title":"CRBP-HFEF: Prediction of RBP-Binding Sites on circRNAs Based on Hierarchical Feature Expansion and Fusion.","date":"2023","source":"Interdisciplinary sciences, computational life sciences","url":"https://pubmed.ncbi.nlm.nih.gov/37233959","citation_count":6,"is_preprint":false},{"pmid":"10496363","id":"PMC_10496363","title":"Cytotoxic T lymphocytes that recognize decameric peptide sequences of retinoblastoma binding protein 1 (RBP-1) associated with human breast cancer.","date":"1999","source":"British journal of cancer","url":"https://pubmed.ncbi.nlm.nih.gov/10496363","citation_count":6,"is_preprint":false},{"pmid":"36970364","id":"PMC_36970364","title":"Coronary artery disease-associated immune gene RBP1 and its pan-cancer analysis.","date":"2023","source":"Frontiers in cardiovascular medicine","url":"https://pubmed.ncbi.nlm.nih.gov/36970364","citation_count":5,"is_preprint":false},{"pmid":"18503097","id":"PMC_18503097","title":"CRBP-I in the renal tubulointerstitial compartment of healthy rats and rats with renal fibrosis.","date":"2008","source":"Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association","url":"https://pubmed.ncbi.nlm.nih.gov/18503097","citation_count":5,"is_preprint":false},{"pmid":"21067480","id":"PMC_21067480","title":"Screening genes of the visual cycle RGR, RBP1 and RBP3 identifies rare sequence variations.","date":"2010","source":"Ophthalmic genetics","url":"https://pubmed.ncbi.nlm.nih.gov/21067480","citation_count":5,"is_preprint":false},{"pmid":"37694492","id":"PMC_37694492","title":"ELOA promotes tumor growth and metastasis by activating RBP1 in gastric cancer.","date":"2023","source":"Cancer medicine","url":"https://pubmed.ncbi.nlm.nih.gov/37694492","citation_count":4,"is_preprint":false},{"pmid":"41035422","id":"PMC_41035422","title":"CircSPINT2 confers sensitivity to osimertinib via hsa-miR-1296-3p/RBP1 axis and inhibits NSCLC progression.","date":"2025","source":"Molecular therapy. Oncology","url":"https://pubmed.ncbi.nlm.nih.gov/41035422","citation_count":2,"is_preprint":false},{"pmid":"18689151","id":"PMC_18689151","title":"[Retinoid expression (RARbeta and CRBP1) in non-small-cell lung carcinoma].","date":"2008","source":"Medicina","url":"https://pubmed.ncbi.nlm.nih.gov/18689151","citation_count":2,"is_preprint":false},{"pmid":"27449001","id":"PMC_27449001","title":"The 5' untranslated region of the rbp1 mRNA is required for translation of its mRNA under low temperatures in the cyanobacterium Synechococcus elongatus.","date":"2016","source":"Archives of microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/27449001","citation_count":2,"is_preprint":false},{"pmid":"3015290","id":"PMC_3015290","title":"[Presence of free retinol receptor (cRBP) and retinoic acid receptor (cRABP) in human skin tumors].","date":"1986","source":"Bulletin du cancer","url":"https://pubmed.ncbi.nlm.nih.gov/3015290","citation_count":2,"is_preprint":false},{"pmid":"38891976","id":"PMC_38891976","title":"Prediction of Pesticide Interactions with Proteins Involved in Human Reproduction by Using a Virtual Screening Approach: A Case Study of Famoxadone Binding CRBP-III and Izumo.","date":"2024","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/38891976","citation_count":2,"is_preprint":false},{"pmid":"2901072","id":"PMC_2901072","title":"Taq I RFLP in the human cellular retinol-binding protein (CRBP) gene.","date":"1988","source":"Nucleic acids research","url":"https://pubmed.ncbi.nlm.nih.gov/2901072","citation_count":2,"is_preprint":false},{"pmid":"3102874","id":"PMC_3102874","title":"Isolation and purification of cellular retinol binding protein (CRBP) from goat mammary gland.","date":"1987","source":"Life sciences","url":"https://pubmed.ncbi.nlm.nih.gov/3102874","citation_count":1,"is_preprint":false},{"pmid":"41514095","id":"PMC_41514095","title":"Knockdown of the fly spliceosome component Rbp1 (orthologue of SRSF1) extends lifespan.","date":"2026","source":"GeroScience","url":"https://pubmed.ncbi.nlm.nih.gov/41514095","citation_count":1,"is_preprint":false},{"pmid":"8643038","id":"PMC_8643038","title":"[Use of polymerase chain reaction for detecting the RBPC gene in natural samples].","date":"1995","source":"Mikrobiologiia","url":"https://pubmed.ncbi.nlm.nih.gov/8643038","citation_count":1,"is_preprint":false},{"pmid":"38645178","id":"PMC_38645178","title":"All-trans retinoic acid induces durable tumor immunity in IDH-mutant gliomas by rescuing transcriptional repression of the CRBP1-retinoic acid axis.","date":"2024","source":"bioRxiv : the preprint server for biology","url":"https://pubmed.ncbi.nlm.nih.gov/38645178","citation_count":0,"is_preprint":false},{"pmid":"9338114","id":"PMC_9338114","title":"Assignment of the cellular retinol binding protein 1 (Rbp1) and hepatic lipase (Lipc) genes to rat chromosome 8.","date":"1997","source":"Folia biologica","url":"https://pubmed.ncbi.nlm.nih.gov/9338114","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.09.18.677196","title":"Knockdown of the fly spliceosome component  <i>Rbp1</i>  (orthologue of  <i>SRSF1</i>  ) extends lifespan","date":"2025-09-21","source":"bioRxiv","url":"https://doi.org/10.1101/2025.09.18.677196","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.12.09.627542","title":"Pol II degradation activates cell death independently from the loss of transcription","date":"2024-12-10","source":"bioRxiv","url":"https://doi.org/10.1101/2024.12.09.627542","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":45963,"output_tokens":6733,"usd":0.119442,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":14954,"output_tokens":5069,"usd":0.100748,"stage2_stop_reason":"end_turn"},"total_usd":0.22019,"stage1_batch_id":"msgbatch_01CNoDbkChHEkgrJnL7BwtGJ","stage2_batch_id":"msgbatch_016Y4x9E9Wg5VQDANj9quSQD","note":"batch pricing = 50% of standard"},"stage1_raw":"Looking at the corpus, I need to identify which papers are about the canonical human/mammalian RBP1 gene (CRBP1, CRBP, hCRBP1 — the cellular retinol-binding protein 1) versus other genes that share the \"RBP1\" symbol:\n\n- Papers about CRBP1/CRBP-I (cellular retinol-binding protein 1, vitamin A chaperone): **INCLUDE** — these are the query gene\n- Papers about RBP1 as retinoblastoma-binding protein 1 (large nuclear phosphoprotein, ~200 kDa, binds pRB pocket): **INCLUDE** — this is also called RBP1 in humans (ARID4A), but checking HGNC aliases: the query gene aliases are CRBP1, CRBP, RBPC, CRBPI, CRBP-I, hCRBP1. The retinoblastoma-binding protein RBP1 (ARID4A) is a *different gene*. I must exclude those papers.\n- Drosophila RBP1 (SR splicing factor): different gene — EXCLUDE\n- Yeast RBP1 (RNA-binding/rapamycin): different gene — EXCLUDE\n- Nematode RBP-1 (SPRYSEC): different gene — EXCLUDE\n- Plasmodium RBP-1: different gene — EXCLUDE\n- Cyanobacterial Rbp1: different gene — EXCLUDE\n\nSo the query gene (CRBP1/hCRBP1) papers are those about the small (~15 kDa) cytosolic retinol-binding protein.\n\nThe retinoblastoma-binding protein RBP1 papers (PMIDs 11283269, 8414517, 10490602, 10321733, 18193082, 16479010, 21148318) are about ARID4A, NOT the query gene CRBP1. I must exclude these.\n\nNow extracting mechanistic discoveries from CRBP1-relevant papers only:\n\n```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1993,\n      \"finding\": \"Apo-CRBP1 stimulates a bile salt-independent microsomal retinyl ester hydrolase to release retinol from retinyl ester stores, generating holo-CRBP1; holo-CRBP1 then serves as a direct substrate for an NADP-dependent microsomal retinol dehydrogenase to produce retinal, which is further converted to retinoic acid by a cytosolic NAD-dependent retinal dehydrogenase. Thus CRBP1 channels retinol through the retinoic acid biosynthesis pathway via a series of protein-protein interactions.\",\n      \"method\": \"In vitro enzyme assays with purified apo- and holo-CRBP, microsomal fractions, cofactor specificity studies, substrate competition\",\n      \"journal\": \"The Journal of nutrition\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — multiple in vitro enzymatic assays with defined substrates and cofactors, replicated across multiple publications from the same group and independently corroborated\",\n      \"pmids\": [\"8381481\", \"1932598\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1992,\n      \"finding\": \"Holo-CRBP1 (retinol-bound CRBP) is specifically recognized as substrate by an NADP-dependent microsomal retinol dehydrogenase for retinal synthesis; NADPH does not support significant retinal synthesis from holo-CRBP1 or physiological concentrations of free retinol when an NADPH-regenerating system prevents NADP formation, establishing cofactor specificity.\",\n      \"method\": \"Microsomal enzyme assays with holo-CRBP vs. free retinol, varying cofactors (NADP, NAD, NADPH) with and without regenerating systems; Km and Vmax determinations\",\n      \"journal\": \"Biochimica et biophysica acta\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro reconstitution with purified components, quantitative kinetics, cofactor specificity rigorously established\",\n      \"pmids\": [\"1562584\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1995,\n      \"finding\": \"A microsomal retinol dehydrogenase (RoDH) from rat liver, identified as a short-chain alcohol dehydrogenase (SCAD, 34 kDa active subunit), directly cross-links to and uses holo-CRBP1 as substrate (Km ~0.4–0.6 µM), catalyzing retinal synthesis with NADP as cofactor via an ordered bisubstrate mechanism. The enzyme discriminates against CRBP1-bound didehydroretinol and 9-cis-retinol, demonstrating substrate specificity conferred by the CRBP1 complex.\",\n      \"method\": \"Affinity chromatography, Triton X-114 phase partitioning, covalent cross-linking of holo-CRBP1 to the 34 kDa subunit, phenylarsine oxide inactivation, Km determination, SCAD inhibitor profiling (carbenoxolone, ethanol), cofactor studies\",\n      \"journal\": \"Biochemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — direct biochemical reconstitution with cross-linking, active-site labeling, and kinetic characterization in a single rigorous study\",\n      \"pmids\": [\"7766612\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1992,\n      \"finding\": \"The rat CRBP1 (rCRBPI) promoter contains a retinoic acid response element (RARE) ~1 kb upstream of the transcription start, consisting of a direct repeat with a two-nucleotide spacer. This RARE is activated by RARα and RARβ (but not RARγ1) and requires RAR/RXR heterodimers for efficient binding and transcriptional activation; RARs or RXR alone do not interact effectively with the element.\",\n      \"method\": \"Promoter deletion and sequence analysis, transient transfection reporter assays, gel-shift binding assays with RAR and RXR combinations\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — reporter assay plus gel-shift binding, multiple receptor combinations tested, single lab but orthogonal methods\",\n      \"pmids\": [\"1339275\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"Human microsomal RoDH-4 (SDR family) recognizes cytosolic holo-CRBP1 as a substrate with Km close to liver holo-CRBP1 concentration (~59 min⁻¹ mM⁻¹ catalytic efficiency); apo-CRBP1 acts as a strong competitive inhibitor (Ki ~0.2 µM) of holo-CRBP1 oxidation, indicating that the apo/holo-CRBP1 ratio regulates retinol flux to retinoic acid. RoDH-4 faces the cytosolic side of the membrane (established by immunoprecipitation and glycosylation scanning), consistent with its access to cytosolic holo-CRBP1.\",\n      \"method\": \"Purified RoDH-4 reconstituted in proteoliposomes; kinetic assays with holo-CRBP1 vs. free retinol; competitive inhibition by apo-CRBP1; membrane topology by immunoprecipitation and glycosylation scanning mutagenesis\",\n      \"journal\": \"Biochemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro reconstitution, kinetics, topology mapping, multiple orthogonal methods in one study\",\n      \"pmids\": [\"12534290\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"CRBP1 restricts the oxidation of all-trans-retinol by RDH12 but has little effect on reduction of all-trans-retinaldehyde, because CRBP1 binds all-trans-retinol with much higher affinity than all-trans-retinaldehyde; RDH12 utilizes only the unbound (free) forms of retinoids, not holo-CRBP1 complexes.\",\n      \"method\": \"In vitro RDH12 activity assays with retinoids in the presence or absence of CRBP1 or CRALBP; kinetic analysis (Km, kcat)\",\n      \"journal\": \"Biochemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — direct in vitro enzyme assays with purified proteins, quantitative kinetics, single lab with multiple substrate combinations\",\n      \"pmids\": [\"15865448\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"CRBP1 and CRBP2 bind 9-cis-retinol (Kd ~11 nM and ~68 nM, respectively) and 9-cis-retinal (Kd ~8 nM and ~5 nM, respectively) with high affinity, but neither protein shows significant binding to 9-cis-retinoic acid. This supports a model in which CRBP1 chaperones 9-cis-retinoids to enzymes for 9-cis-retinoic acid biosynthesis.\",\n      \"method\": \"Fluorescence spectroscopy binding assays with non-linear regression to determine apparent dissociation constants for multiple retinoid ligands\",\n      \"journal\": \"Biochimica et biophysica acta\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — rigorous fluorescence binding assay, but single lab and single method\",\n      \"pmids\": [\"21382444\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"CRBP1 knockout mice (CRBPI⁻/⁻) accumulate all-trans-retinol transiently in the neural retina after a light flash (instead of converting it to retinyl ester as in wild-type), and have ~67% reduction in retinyl ester stores in the RPE, indicating that CRBP1 participates in driving diffusion of all-trans-retinol from photoreceptors to RPE and in delivering retinol to LRAT for esterification in the visual cycle. Dark adaptation was delayed approximately 2-fold but rhodopsin regeneration rate was not majorly impaired.\",\n      \"method\": \"Retinoid analysis by HPLC in dark-adapted and flash-recovered eyes of CRBPI⁻/⁻ vs. wild-type mice; electroretinography (ERG) for dark adaptation rates\",\n      \"journal\": \"Investigative ophthalmology & visual science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean genetic knockout with quantitative retinoid biochemistry and electrophysiological readout, multiple orthogonal methods\",\n      \"pmids\": [\"12036972\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1994,\n      \"finding\": \"Retinol transfers rapidly and nearly completely (>100%) from IRBP to CRBP1 in vitro with a half-time of ~4 seconds, driven by CRBP1's ~100-fold higher affinity for retinol compared to IRBP. No transfer from CRBP1 back to IRBP was detected, establishing a thermodynamic gradient that drives retinol flow toward the RPE during the visual cycle.\",\n      \"method\": \"UV absorbance spectroscopy (shift from 330 to 350 nm upon transfer), size-exclusion HPLC separation of IRBP and CRBP1 followed by retinoid quantification with diode-array detection\",\n      \"journal\": \"Experimental eye research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — clean biophysical transfer assay with two orthogonal detection methods, but single lab\",\n      \"pmids\": [\"7835405\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"CRBP1 (CRBP-I) regulates adipocyte differentiation: CRBP-I is specifically expressed in preadipocytes in white adipose tissue, and its absence in knockout mice leads to increased adiposity. CRBP-I–deficient 3T3-L1 cells and MEFs show increased adipogenesis and triglyceride accumulation due to increased PPARγ expression and activity, while CRBP-I overexpression decreases triglyceride accumulation. The effect is PPARγ-dependent with other early and late adipogenic transcription factor pathways unaffected.\",\n      \"method\": \"CRBP-I knockout mice, 3T3-L1 cells with shRNA knockdown, MEFs from knockout mice, overexpression in 3T3-L1; PPARγ activity assays, Oil Red O staining, triglyceride quantification, qPCR for transcription factors\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic knockout mouse plus cell-based gain- and loss-of-function with defined pathway (PPARγ) and multiple orthogonal readouts\",\n      \"pmids\": [\"20498279\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"CrbpI (encoded by Rbp1) modulates pancreatic 9-cis-retinoic acid (9cRA) levels and glucose homeostasis: Rbp1⁻/⁻ mice have abnormally elevated pancreatic 9cRA that resists postprandial decrease, associated with defective islet gene expression for glucose sensing and insulin secretion, reduced glucose-stimulated insulin secretion, high glucagon, increased gluconeogenesis, and hyperglycemia. Ectopic CrbpII expression in Rbp1⁻/⁻ pancreas contributes to elevated 9cRA biosynthesis. Rbp1⁻/⁻ mice also show increased fatty acid oxidation and obesity resistance on high-fat diet.\",\n      \"method\": \"Rbp1 knockout mice; retinoid quantification by LC-MS; islet gene expression by qPCR; glucose tolerance tests; insulin and glucagon secretion assays; measurement of gluconeogenesis rates\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean genetic knockout with quantitative metabolomics and multiple functional metabolic readouts, single lab\",\n      \"pmids\": [\"21670153\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"CrbpI loss in mouse mammary tissue disrupts retinoic acid (atRA) homeostasis, resulting in 40% depleted endogenous atRA. Rbp1⁻/⁻ mammary subcellular fractions show 24–42% less atRA production due to altered retinol dehydrogenase/reductase enzyme activity. CrbpIII cannot functionally replace CrbpI as a retinoid chaperone. Loss of CrbpI precedes defects in atRA biosynthesis enzyme expression and causes epithelial hyperplasia, stromal hypercellularity, increased collagen, and oxidative stress consistent with atRA deficiency.\",\n      \"method\": \"Rbp1⁻/⁻ mouse mammary tissue; retinoid quantification by LC-MS; subcellular fractionation with Rdh enzyme activity assays; histological analysis; qPCR for biosynthesis enzymes\",\n      \"journal\": \"FASEB journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean genetic knockout with retinoid biochemistry, enzyme activity assays, and histopathology, multiple orthogonal methods\",\n      \"pmids\": [\"23362116\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Crystal structures of human CRBP1 in apo (ligand-free) and holo (retinol-bound or retinylamine-bound) forms reveal that ligand binding induces conformational changes in α-helix II, hairpin turns between β-strands βC-βD and βE-βF, and side chains Phe-57, Tyr-60, and Ile-77 surrounding the entrance to the retinoid-binding pocket. The apoprotein has greater backbone mobility in these regions (higher B-factors) that facilitates induced-fit ligand uptake; the rigid holoprotein structure protects the retinoid during transport.\",\n      \"method\": \"X-ray crystallography of apo-CRBP1 and holo-CRBP1 bound to all-trans-retinol or retinylamine at atomic/ultra-high resolution; B-factor analysis; hydrogen bond network mapping\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — atomic resolution crystal structures of apo and holo forms with functional interpretation; single lab but multiple structures and orthogonal analyses\",\n      \"pmids\": [\"26900151\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Mutational analysis of human CRBP1 identified Gln108 and Lys40 as key polar residues for high-affinity retinol binding (Kd ~4.5 nM for wild-type; ~65 nM for Q108L; ~70 nM for K40L; ~250 nM for Q108L/K40L double mutant). Extensive apolar interactions in the binding cavity are sufficient to maintain ligand positioning, but polar interactions of the retinol hydroxyl with Gln108 and Lys40 are required for high affinity and selectivity. The putative portal region (α-helix-II, Arg58, E-F loop) is the most flexible region in both apo- and holo-CRBP1.\",\n      \"method\": \"X-ray crystallography of wild-type and mutant CRBP1 forms; fluorometric titration for Kd determination of wild-type and point mutants (Q108L, K40L, Q108L/K40L); B-factor analysis\",\n      \"journal\": \"Journal of structural biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — crystal structures plus active-site mutagenesis with quantitative binding measurements, multiple orthogonal methods in single study\",\n      \"pmids\": [\"28057518\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Abnormal cannabidiol (abn-CBD) is a nonretinoid competitive inhibitor of CRBP1. X-ray crystal structures of CRBP1 in complex with abn-CBD and derivatives reveal a distinctive binding mode in the retinol-binding pocket. Abn-CBD modulates retinoid flux through the visual cycle in vivo and protects against light-induced retinal damage in mice.\",\n      \"method\": \"X-ray crystallography of CRBP1–abn-CBD complexes; competitive binding assays; in vivo mouse retinal damage model (light exposure); retinoid cycle flux measurements\",\n      \"journal\": \"ACS chemical biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — crystal structures with in vivo functional validation, multiple orthogonal methods\",\n      \"pmids\": [\"30721022\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"High-throughput screening identified new nonretinoid competitive inhibitors of CRBP1. Crystal structures of CRBP1 with six inhibitors revealed their binding modes within the retinol-binding pocket. Hydrogen/deuterium exchange mass spectrometry quantified inhibitor-induced conformational changes and correlated their magnitude with binding affinity. Molecular dynamics simulations demonstrated that the 'closed' conformation of CRBP1 retains ligands within the binding pocket, providing mechanistic insight into high-affinity binding.\",\n      \"method\": \"High-throughput screening; X-ray crystallography (6 inhibitor complexes); hydrogen/deuterium exchange mass spectrometry (HDX-MS); molecular dynamics simulations\",\n      \"journal\": \"ACS chemical biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — crystal structures combined with HDX-MS and MD simulations, four orthogonal methods in single study\",\n      \"pmids\": [\"37713257\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"Ectopic CRBP1 expression in CRBP-null human breast epithelial cells suppresses anchorage-independent growth and colony formation by inhibiting cell survival (not proliferation of adherent cells). This was mechanistically linked to inhibition of protein kinase B/Akt activation specifically in suspension conditions, and mimicked by PI3K inhibitor LY294002. CRBP1-mediated effects were independent of retinoic acid receptor activity; CRBP1 enhanced retinyl ester formation rather than retinoic acid synthesis.\",\n      \"method\": \"Ectopic expression of CRBP1 in MTSV1-7 and T47D breast cells; soft-agar colony assay; TUNEL and viability assays; Western blot for phospho-Akt; pharmacological inhibition with LY294002; RA receptor activity assays; retinyl ester quantification\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — gain-of-function in two cell lines with defined PI3K/Akt pathway readout and multiple orthogonal assays, single lab\",\n      \"pmids\": [\"11704871\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"CRBP1 overexpression in bone marrow mesenchymal stem cells (MSCs) promotes osteogenic and inhibits adipogenic differentiation. The mechanism involves CRBP1 inhibiting RXRα-induced β-catenin degradation, maintaining higher levels of β-catenin and phospho-ERK1/2, thereby activating Wnt/β-catenin signaling to favor osteogenesis over adipogenesis.\",\n      \"method\": \"CRBP1 overexpression in MSCs; in vitro and in vivo osteogenic/adipogenic differentiation assays; Western blot for β-catenin, RXRα, pERK1/2; Alizarin Red staining for mineralization\",\n      \"journal\": \"The international journal of biochemistry & cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — gain-of-function with defined pathway (RXRα/β-catenin) and in vivo validation, but single lab and mechanistic link relies on correlative Western blots\",\n      \"pmids\": [\"22230368\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1989,\n      \"finding\": \"The human RBP1 (CRBP1) gene was mapped to chromosomal region 3q21–q22 by somatic cell hybrid panel analysis and in situ hybridization.\",\n      \"method\": \"Somatic cell hybrid panel Southern blotting; in situ hybridization\",\n      \"journal\": \"Somatic cell and molecular genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — two independent mapping methods (somatic cell hybrids and in situ hybridization) concordant for chromosomal localization\",\n      \"pmids\": [\"2928844\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"In IDH-mutant gliomas, RBP1 (CRBP1) is epigenetically silenced, impairing retinoic acid pathway signaling. This silencing contributes to immunosuppression by reducing inflammatory cell states and promoting suppressive myeloid phenotypes. Restoration of RA signaling (ATRA treatment) in murine IDHm glioma models promotes clonal CD4+ T cell expansion and tumor regression, specifically in IDHm but not IDH-wildtype tumors.\",\n      \"method\": \"Murine IDHm glioma models; ATRA treatment; flow cytometry for T cell and myeloid phenotyping; scRNA-seq for immune cell state analysis; epigenetic analysis of RBP1 promoter\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 2 / Weak — preprint, murine model with immune phenotyping, mechanistic link via epigenetic silencing established but not yet peer-reviewed\",\n      \"pmids\": [\"38645178\"],\n      \"is_preprint\": true\n    }\n  ],\n  \"current_model\": \"CRBP1 (RBP1/hCRBP1) is a small (~15 kDa) cytosolic retinol-binding protein that acts as a chaperone to channel vitamin A (retinol) through the retinoic acid biosynthetic pathway: the apo form stimulates retinyl ester hydrolysis to mobilize retinol stores, while the holo form delivers retinol directly to specific NADP-dependent microsomal retinol dehydrogenases (e.g., RoDH-4) via protein-protein interaction, with apo-CRBP1 serving as a competitive inhibitor to regulate flux; structural studies reveal an induced-fit mechanism whereby ligand binding closes a portal region (α-helix II, βC-βD and βE-βF hairpins) around the retinoid; in vivo knockout models demonstrate roles in visual cycle retinoid trafficking (driving retinol transfer from photoreceptors to RPE for LRAT-mediated esterification), pancreatic 9-cis-retinoic acid homeostasis and glucose-stimulated insulin secretion, mammary gland retinoic acid production, regulation of adipogenesis (suppressing PPARγ activity and fat accumulation), and suppression of anchorage-independent cell survival via inhibition of PI3K/Akt signaling.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"RBP1 (CRBP1) is a small cytosolic retinol-binding protein that channels vitamin A through the retinoic acid biosynthetic pathway via a series of regulated protein-protein interactions [#0]. In its retinol-bound (holo) form, CRBP1 is specifically recognized as substrate by NADP-dependent microsomal retinol dehydrogenases (RoDH/RoDH-4, short-chain dehydrogenase family) that oxidize it to retinal, with strict cofactor specificity for NADP over NADPH and direct enzyme cross-linking to the holoprotein [#1, #2, #4]; the apo form conversely stimulates microsomal retinyl ester hydrolysis to mobilize stored retinol and acts as a potent competitive inhibitor of holo-CRBP1 oxidation, so the apo/holo ratio sets the flux of retinol toward retinoic acid [#0, #4]. Substrate selectivity is intrinsic to the complex: CRBP1 sequesters retinol from enzymes that act only on free retinoids (e.g. RDH12) while delivering it to those that accept the bound form [#2, #5]. Crystallographic and mutational studies define an induced-fit mechanism in which a flexible portal region (α-helix II, β-hairpin turns βC–βD and βE–βF) closes around the ligand, with polar contacts from Gln108 and Lys40 conferring high-affinity, selective retinol binding while the rigid holo conformation protects the retinoid during transport [#12, #13, #15]. Physiologically, CRBP1 drives retinol trafficking from photoreceptors to the RPE and delivery to LRAT in the visual cycle [#7, #8], maintains tissue retinoic acid homeostasis in mammary gland and pancreas where its loss perturbs islet gene expression and glucose-stimulated insulin secretion [#10, #11], and restrains adipogenesis by suppressing PPARγ expression and activity [#9]. Beyond retinoid metabolism, CRBP1 suppresses anchorage-independent survival of breast epithelial cells through inhibition of PI3K/Akt signaling independently of retinoic acid receptors [#16].\",\n  \"teleology\": [\n    {\n      \"year\": 1992,\n      \"claim\": \"Established the core enzymatic logic of the pathway by showing that retinol-bound CRBP1, not free retinol, is the recognized substrate for retinal synthesis, defining CRBP1 as an obligate carrier rather than a passive solubilizer.\",\n      \"evidence\": \"Microsomal enzyme assays comparing holo-CRBP vs free retinol with defined cofactors and a NADPH-regenerating system\",\n      \"pmids\": [\"1562584\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Identity of the responsible dehydrogenase not yet defined\", \"Did not address how the apo form regulates flux\"]\n    },\n    {\n      \"year\": 1992,\n      \"claim\": \"Showed CRBP1 expression is itself retinoic-acid-responsive, linking the protein into a feedback loop of vitamin A signaling via a RARE in its promoter.\",\n      \"evidence\": \"Promoter deletion, reporter assays, and gel-shift binding with RAR/RXR combinations on the rat Rbp1 promoter\",\n      \"pmids\": [\"1339275\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Done in rat promoter; human regulatory element not characterized here\", \"Physiological consequence of feedback regulation untested\"]\n    },\n    {\n      \"year\": 1993,\n      \"claim\": \"Unified the apo and holo states into a directional channeling model: apo-CRBP1 mobilizes retinol from ester stores and holo-CRBP1 feeds it forward to dehydrogenases, casting CRBP1 as a flux-controlling chaperone.\",\n      \"evidence\": \"In vitro enzyme assays with purified apo/holo-CRBP, microsomal fractions, and substrate competition\",\n      \"pmids\": [\"8381481\", \"1932598\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Quantitative regulation by apo/holo ratio not yet measured\", \"Specific dehydrogenase still unidentified\"]\n    },\n    {\n      \"year\": 1994,\n      \"claim\": \"Provided the thermodynamic basis for directional retinol movement in the eye by showing irreversible transfer from IRBP to CRBP1 driven by a ~100-fold affinity difference.\",\n      \"evidence\": \"UV absorbance shift and size-exclusion HPLC transfer assays between IRBP and CRBP1\",\n      \"pmids\": [\"7835405\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab, in vitro only\", \"Whether transfer occurs at membrane interfaces in vivo not addressed\"]\n    },\n    {\n      \"year\": 1995,\n      \"claim\": \"Identified the dehydrogenase as a short-chain alcohol dehydrogenase that physically cross-links to holo-CRBP1, providing direct biochemical proof of the protein-protein channeling interaction and substrate discrimination.\",\n      \"evidence\": \"Affinity purification, covalent cross-linking, active-site labeling, and kinetics of rat liver RoDH\",\n      \"pmids\": [\"7766612\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Human ortholog not yet characterized\", \"Membrane topology of the interaction surface unresolved\"]\n    },\n    {\n      \"year\": 2001,\n      \"claim\": \"Uncovered a retinoid-independent role: CRBP1 suppresses anchorage-independent cell survival via PI3K/Akt inhibition, broadening its function beyond metabolic chaperoning.\",\n      \"evidence\": \"Ectopic CRBP1 expression in breast epithelial cell lines with soft-agar, TUNEL, phospho-Akt, and pharmacological PI3K inhibition\",\n      \"pmids\": [\"11704871\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Molecular link between CRBP1 and Akt not defined\", \"Gain-of-function only; endogenous loss not tested\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Genetic knockout placed CRBP1 in the visual cycle, demonstrating it drives retinol movement from photoreceptors to RPE and delivery to LRAT for esterification.\",\n      \"evidence\": \"HPLC retinoid analysis and ERG in CRBP1-null vs wild-type mouse eyes\",\n      \"pmids\": [\"12036972\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Rhodopsin regeneration largely intact, indicating redundancy\", \"Molecular mechanism of retinol hand-off to LRAT not resolved\"]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"Defined the human enzyme partner and the regulatory switch: RoDH-4 oxidizes holo-CRBP1 from the cytosolic membrane face, and apo-CRBP1 is a strong competitive inhibitor, establishing the apo/holo ratio as the flux regulator.\",\n      \"evidence\": \"Reconstituted RoDH-4 proteoliposome kinetics, apo-CRBP1 inhibition, and membrane topology mapping\",\n      \"pmids\": [\"12534290\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"In vivo demonstration of apo/holo flux control not provided\", \"Whether other SDR enzymes share this mechanism untested\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Clarified CRBP1's selectivity logic by showing it withholds retinol from enzymes (RDH12) that use only free retinoid, sharpening the concept of substrate channeling versus sequestration.\",\n      \"evidence\": \"In vitro RDH12 kinetics with and without CRBP1 or CRALBP\",\n      \"pmids\": [\"15865448\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Physiological balance between channeling and sequestration in cells not quantified\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Linked CRBP1 to metabolic control by showing it restrains adipogenesis through suppression of PPARγ, identifying a discrete transcriptional pathway under its influence.\",\n      \"evidence\": \"Knockout mice, 3T3-L1 knockdown/overexpression, MEFs with PPARγ activity and lipid readouts\",\n      \"pmids\": [\"20498279\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether the PPARγ effect is retinoid-ligand mediated not fully dissected\", \"Direct molecular connection to PPARγ regulation unresolved\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Extended the chaperone role to 9-cis-retinoid biosynthesis and demonstrated in vivo control of pancreatic 9-cis-retinoic acid, glucose sensing, and insulin secretion.\",\n      \"evidence\": \"Fluorescence binding assays for 9-cis retinoids and Rbp1-knockout metabolic/retinoid phenotyping by LC-MS\",\n      \"pmids\": [\"21382444\", \"21670153\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Binding study single-lab/single-method\", \"Identity of 9cRA-synthesizing enzymes downstream of CRBP1 not defined\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Showed CRBP1 is non-redundant for tissue retinoic acid homeostasis, as its loss depletes mammary atRA and causes tissue pathology that paralogs cannot rescue.\",\n      \"evidence\": \"Rbp1-null mammary LC-MS retinoid quantification, subcellular Rdh activity assays, and histology\",\n      \"pmids\": [\"23362116\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism of altered Rdh enzyme activity in absence of CRBP1 unclear\", \"Why CrbpIII cannot substitute not structurally explained\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Identified an additional differentiation role in mesenchymal stem cells, where CRBP1 favors osteogenesis over adipogenesis by stabilizing β-catenin and Wnt signaling.\",\n      \"evidence\": \"CRBP1 overexpression in MSCs with differentiation assays and Western blots for β-catenin/RXRα/pERK\",\n      \"pmids\": [\"22230368\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanistic link relies on correlative Westerns\", \"Loss-of-function not tested in this system\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Resolved the structural mechanism of ligand binding, defining an induced-fit portal closure and the polar residues (Gln108, Lys40) that confer high-affinity retinol recognition and protective enclosure.\",\n      \"evidence\": \"X-ray structures of apo/holo and mutant CRBP1, B-factor analysis, and fluorometric Kd determinations (consolidating the 2016 structural work)\",\n      \"pmids\": [\"26900151\", \"28057518\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structures of CRBP1 in complex with its enzyme partners not determined\", \"Dynamics of ligand release to dehydrogenases not visualized\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Established CRBP1 as a druggable target by characterizing nonretinoid competitive inhibitors that modulate visual-cycle flux and protect against retinal damage, with structures and dynamics explaining closed-state ligand retention.\",\n      \"evidence\": \"Crystallography of CRBP1-inhibitor complexes, HTS, HDX-MS, MD simulations, and in vivo light-damage models (consolidating 2019 and 2023 work)\",\n      \"pmids\": [\"30721022\", \"37713257\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Therapeutic window and selectivity over other retinoid-binding proteins not addressed\", \"Long-term in vivo consequences of CRBP1 inhibition unknown\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Implicated CRBP1 silencing in tumor immunosuppression, suggesting restoration of its retinoic acid pathway could reprogram the glioma immune microenvironment.\",\n      \"evidence\": \"Murine IDH-mutant glioma models, ATRA treatment, scRNA-seq, and RBP1 promoter epigenetic analysis (preprint)\",\n      \"pmids\": [\"38645178\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Preprint, not peer-reviewed\", \"Causal role of RBP1 silencing versus broader RA pathway loss not isolated\", \"Human relevance beyond murine models untested\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How CRBP1 physically docks onto its partner dehydrogenases and hydrolases at the microsomal membrane, and how the apo/holo conformational switch is coordinated with these enzymes in vivo, remains structurally and mechanistically undefined.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No co-structure of CRBP1 with any partner enzyme\", \"Spatial organization of CRBP1-enzyme interactions at the ER membrane unknown\", \"Mechanism coupling Akt suppression and β-catenin stabilization to retinoid chaperoning not established\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0008289\", \"supporting_discovery_ids\": [0, 1, 6, 12, 13]},\n      {\"term_id\": \"GO:0140313\", \"supporting_discovery_ids\": [0, 4, 5]},\n      {\"term_id\": \"GO:0140104\", \"supporting_discovery_ids\": [0, 8]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [4, 9]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [0, 4]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1430728\", \"supporting_discovery_ids\": [0, 1, 10, 11]},\n      {\"term_id\": \"R-HSA-9709957\", \"supporting_discovery_ids\": [7, 14]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [16, 17]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [9, 17]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"RDH12\", \"IRBP\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}