{"gene":"CGRRF1","run_date":"2026-04-28T17:28:52","timeline":{"discoveries":[{"year":1996,"finding":"CGR19 (CGRRF1) is transcriptionally induced by functional p53 and contains a RING-finger domain; overexpression of CGR19 inhibits the growth of several cell lines, identifying it as a p53-regulated growth suppressor.","method":"Differential RT-PCR in rat embryo fibroblasts with temperature-sensitive p53; growth inhibition assays in multiple cell lines","journal":"Cancer research","confidence":"Medium","confidence_rationale":"Tier 2 — clean gain-of-function with defined phenotype, but single lab and limited mechanistic follow-up","pmids":["8968090"],"is_preprint":false},{"year":2018,"finding":"CGRRF1 acts as an ER-resident E3 ubiquitin ligase that ubiquitinates the Wnt cargo receptor Evi (Wls/GPR177), targeting it for ERAD in a VCP-dependent manner; this regulatory mechanism controls the abundance of Evi and thereby modulates the scale of Wnt protein secretion. The E2-conjugating enzyme UBE2J2 partners with CGRRF1 in this ubiquitination event.","method":"RNAi knockdown, co-immunoprecipitation, ubiquitination assays, VCP inhibition, epistasis with Porcn","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 2 — reciprocal Co-IP, in vivo ubiquitination assay, genetic epistasis, multiple orthogonal methods in one study","pmids":["29378775"],"is_preprint":false},{"year":2019,"finding":"CGRRF1 functions as a RING-domain E3 ubiquitin ligase localized to the ER that ubiquitinates EGFR via K48-linked chains, leading to proteasomal degradation of EGFR; the RING-finger domain is required for this activity and for growth suppression. Knockout of CGRRF1 enhances AKT phosphorylation after EGF stimulation.","method":"Co-immunoprecipitation, in vivo ubiquitination assays, subcellular fractionation, MTT assay, xenograft experiment, RING-domain mutant analysis, RPPA","journal":"Breast cancer research : BCR","confidence":"High","confidence_rationale":"Tier 1-2 — in vivo ubiquitination assay with domain mutagenesis, Co-IP, subcellular fractionation, in vitro and in vivo growth assays, multiple orthogonal methods","pmids":["31801577"],"is_preprint":false},{"year":2024,"finding":"CGRRF1 functions as an E3 ubiquitin ligase for KRAS, mediating K48-linked ubiquitination and proteasomal degradation of KRAS, thereby suppressing the KRAS/ERK signaling pathway. MSI2 promotes chemoresistance by recruiting miR-30a-3p onto AGO2, which suppresses CGRRF1 expression and consequently elevates KRAS/ERK signaling.","method":"miRNA pulldown/AGO2 interaction assays, ubiquitination assays, Western blot for KRAS protein stability, luciferase reporter for miR-30a-3p/CGRRF1 axis, pharmacological inhibition","journal":"Neoplasia (New York, N.Y.)","confidence":"Medium","confidence_rationale":"Tier 2 — ubiquitination assay and protein stability data with pathway epistasis, single lab","pmids":["39522321"],"is_preprint":false},{"year":2014,"finding":"Overexpression of CGRRF1 inhibits endometrial cancer cell proliferation, and CGRRF1 expression is induced by metformin in obese rat endometrium, placing it downstream of metabolic/insulin signaling in endometrial tissue.","method":"MTT proliferation assay, RT-qPCR, Western blot, genetic overexpression in endometrial cancer cells","journal":"Gynecologic oncology","confidence":"Low","confidence_rationale":"Tier 3 — single lab, overexpression phenotype without defined molecular mechanism beyond growth inhibition","pmids":["24680596"],"is_preprint":false}],"current_model":"CGRRF1 is a p53-inducible, ER-localized RING-domain E3 ubiquitin ligase that targets multiple substrates—including Evi/Wls, EGFR, and KRAS—for K48-linked ubiquitination and proteasomal degradation, thereby suppressing Wnt secretion, EGFR/AKT signaling, and KRAS/ERK signaling; in ERAD, it cooperates with the E2 enzyme UBE2J2 and VCP to clear ER-resident clients."},"narrative":{"teleology":[{"year":1996,"claim":"The discovery that CGR19 (CGRRF1) is transcriptionally induced by p53 and contains a RING-finger domain established it as a candidate growth suppressor, but its molecular mechanism was unknown.","evidence":"Differential RT-PCR in rat embryo fibroblasts with temperature-sensitive p53; overexpression growth inhibition assays in multiple cell lines","pmids":["8968090"],"confidence":"Medium","gaps":["No enzymatic activity demonstrated","No substrates identified","Subcellular localization not defined"]},{"year":2014,"claim":"Confirmation that CGRRF1 overexpression inhibits cancer cell proliferation and is induced by metformin linked it to metabolic signaling, but the molecular targets remained unidentified.","evidence":"MTT assay, RT-qPCR, and Western blot in endometrial cancer cells and obese rat endometrium","pmids":["24680596"],"confidence":"Low","gaps":["No defined molecular mechanism beyond growth inhibition","Single lab; not independently confirmed","Causal relationship between metformin and CGRRF1 induction not mechanistically resolved"]},{"year":2018,"claim":"Demonstration that CGRRF1 is an ER-resident E3 ligase that ubiquitinates Evi/Wls with UBE2J2 for VCP-dependent ERAD provided the first defined substrate and placed CGRRF1 within the ERAD quality-control pathway controlling Wnt secretion.","evidence":"RNAi knockdown, reciprocal co-immunoprecipitation, in vivo ubiquitination assays, VCP inhibition, genetic epistasis with Porcn","pmids":["29378775"],"confidence":"High","gaps":["Whether CGRRF1-mediated Evi degradation operates in all Wnt-secreting tissues in vivo","Structural basis of CGRRF1–Evi recognition unknown","Extent of CGRRF1 substrate repertoire beyond Evi not yet explored"]},{"year":2019,"claim":"Identification of EGFR as a second CGRRF1 substrate, degraded via RING-domain-dependent K48-linked ubiquitination, broadened CGRRF1's role from Wnt regulation to EGFR/AKT signaling suppression and validated its tumor-suppressive function in vivo.","evidence":"Co-immunoprecipitation, in vivo ubiquitination assays with RING-domain mutants, subcellular fractionation, MTT assay, xenograft experiments, RPPA","pmids":["31801577"],"confidence":"High","gaps":["Whether EGFR ubiquitination by CGRRF1 occurs on newly synthesized ER-resident EGFR versus mature receptor","No structural model of CGRRF1 RING domain–E2 interaction","E2 partner for EGFR ubiquitination not confirmed"]},{"year":2024,"claim":"Discovery that CGRRF1 mediates K48-linked ubiquitination and degradation of KRAS, suppressing KRAS/ERK signaling, revealed a third major oncogenic substrate and connected CGRRF1 loss to chemoresistance via the MSI2/miR-30a-3p axis.","evidence":"Ubiquitination assays, KRAS protein stability measurements, AGO2 interaction assays, luciferase reporter for miR-30a-3p/CGRRF1 3′UTR","pmids":["39522321"],"confidence":"Medium","gaps":["Independent replication of CGRRF1-KRAS direct ubiquitination needed","Whether KRAS ubiquitination is RING-domain dependent not tested with domain mutants","In vivo relevance of the MSI2/miR-30a-3p/CGRRF1/KRAS axis not demonstrated in animal models"]},{"year":null,"claim":"Key unresolved questions include the full substrate repertoire of CGRRF1 in ERAD, its structural basis for substrate recognition, and whether its tumor-suppressive functions are tissue-specific.","evidence":"","pmids":[],"confidence":"Low","gaps":["No structural model of CGRRF1","No systematic substrate identification (e.g., ubiquitin remnant proteomics)","In vivo phenotype of CGRRF1 knockout in mammalian models not reported"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[1,2,3]}],"localization":[{"term_id":"GO:0005783","term_label":"endoplasmic reticulum","supporting_discovery_ids":[1,2]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[1,2,3]},{"term_id":"R-HSA-392499","term_label":"Metabolism of proteins","supporting_discovery_ids":[1,2,3]}],"complexes":[],"partners":["UBE2J2","EGFR","WLS","KRAS","VCP"],"other_free_text":[]},"mechanistic_narrative":"CGRRF1 is a p53-inducible, ER-localized RING-domain E3 ubiquitin ligase that suppresses cell growth by targeting multiple oncogenic substrates for K48-linked ubiquitination and proteasomal degradation. It ubiquitinates the Wnt cargo receptor Evi/Wls in partnership with the E2 enzyme UBE2J2, directing Evi to VCP-dependent ERAD and thereby limiting Wnt secretion [PMID:29378775]. CGRRF1 also ubiquitinates EGFR via its RING-finger domain, promoting EGFR degradation and attenuating AKT signaling [PMID:31801577], and mediates K48-linked ubiquitination of KRAS to suppress KRAS/ERK signaling [PMID:39522321]. Originally identified as a p53-responsive growth suppressor [PMID:8968090], its broad substrate repertoire positions it as a tumor-suppressive E3 ligase operating at the intersection of Wnt, EGFR, and RAS signaling pathways."},"prefetch_data":{"uniprot":{"accession":"Q99675","full_name":"Cell growth regulator with RING finger domain protein 1","aliases":["Cell growth regulatory gene 19 protein","RING finger protein 197"],"length_aa":332,"mass_kda":38.2,"function":"Able to inhibit growth in several cell lines","subcellular_location":"Nucleus; Endoplasmic reticulum","url":"https://www.uniprot.org/uniprotkb/Q99675/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/CGRRF1","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":1208,"dependency_fraction":0.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/CGRRF1","total_profiled":1310},"omim":[{"mim_id":"606138","title":"CELL GROWTH REGULATOR WITH RING FINGER DOMAIN 1; CGRRF1","url":"https://www.omim.org/entry/606138"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Nucleoplasm","reliability":"Supported"},{"location":"Vesicles","reliability":"Additional"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/CGRRF1"},"hgnc":{"alias_symbol":["CGR19","RNF197"],"prev_symbol":[]},"alphafold":{"accession":"Q99675","domains":[{"cath_id":"-","chopping":"71-225","consensus_level":"high","plddt":93.7095,"start":71,"end":225},{"cath_id":"3.30.40.10","chopping":"228-233_272-321","consensus_level":"medium","plddt":88.0909,"start":228,"end":321}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q99675","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q99675-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q99675-F1-predicted_aligned_error_v6.png","plddt_mean":80.19},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=CGRRF1","jax_strain_url":"https://www.jax.org/strain/search?query=CGRRF1"},"sequence":{"accession":"Q99675","fasta_url":"https://rest.uniprot.org/uniprotkb/Q99675.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q99675/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q99675"}},"corpus_meta":[{"pmid":"17029216","id":"PMC_17029216","title":"Novel epigenetically deregulated genes in testicular cancer include homeobox genes and SCGB3A1 (HIN-1).","date":"2006","source":"The Journal of pathology","url":"https://pubmed.ncbi.nlm.nih.gov/17029216","citation_count":76,"is_preprint":false},{"pmid":"8968090","id":"PMC_8968090","title":"Induction of cell growth regulatory genes by p53.","date":"1996","source":"Cancer research","url":"https://pubmed.ncbi.nlm.nih.gov/8968090","citation_count":71,"is_preprint":false},{"pmid":"11352657","id":"PMC_11352657","title":"Molecular cloning and characterization of RNF26 on human chromosome 11q23 region, encoding a novel RING finger protein with leucine zipper.","date":"2001","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/11352657","citation_count":63,"is_preprint":false},{"pmid":"29378775","id":"PMC_29378775","title":"ERAD-dependent control of the Wnt secretory factor Evi.","date":"2018","source":"The EMBO journal","url":"https://pubmed.ncbi.nlm.nih.gov/29378775","citation_count":44,"is_preprint":false},{"pmid":"35702180","id":"PMC_35702180","title":"Dysregulation of MiR-144-5p/RNF187 Axis Contributes To the Progression of Colorectal Cancer.","date":"2022","source":"Journal of translational internal medicine","url":"https://pubmed.ncbi.nlm.nih.gov/35702180","citation_count":35,"is_preprint":false},{"pmid":"12070015","id":"PMC_12070015","title":"Novel transcription factors in human CD34 antigen-positive hematopoietic cells.","date":"2002","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/12070015","citation_count":28,"is_preprint":false},{"pmid":"17485552","id":"PMC_17485552","title":"Gene-expression analysis identifies novel RBL2/p130 target genes in endemic Burkitt lymphoma cell lines and primary tumors.","date":"2007","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/17485552","citation_count":27,"is_preprint":false},{"pmid":"31801577","id":"PMC_31801577","title":"CGRRF1, a growth suppressor, regulates EGFR ubiquitination in breast cancer.","date":"2019","source":"Breast cancer research : BCR","url":"https://pubmed.ncbi.nlm.nih.gov/31801577","citation_count":17,"is_preprint":false},{"pmid":"24680596","id":"PMC_24680596","title":"CGRRF1 as a novel biomarker of tissue response to metformin in the context of obesity.","date":"2014","source":"Gynecologic oncology","url":"https://pubmed.ncbi.nlm.nih.gov/24680596","citation_count":11,"is_preprint":false},{"pmid":"37595490","id":"PMC_37595490","title":"Identification of immunological characteristics and cuproptosis-related molecular clusters in Rheumatoid arthritis.","date":"2023","source":"International immunopharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/37595490","citation_count":11,"is_preprint":false},{"pmid":"36755350","id":"PMC_36755350","title":"Short-term in vivo testing to discriminate genotoxic carcinogens from non-genotoxic carcinogens and non-carcinogens using next-generation RNA sequencing, DNA microarray, and qPCR.","date":"2023","source":"Genes and environment : the official journal of the Japanese Environmental Mutagen Society","url":"https://pubmed.ncbi.nlm.nih.gov/36755350","citation_count":6,"is_preprint":false},{"pmid":"31367973","id":"PMC_31367973","title":"Rare variants and loci for age-related macular degeneration in the Ohio and Indiana Amish.","date":"2019","source":"Human genetics","url":"https://pubmed.ncbi.nlm.nih.gov/31367973","citation_count":5,"is_preprint":false},{"pmid":"39522321","id":"PMC_39522321","title":"A novel regulatory axis of MSI2-AGO2/miR-30a-3p-CGRRF1 drives cancer chemoresistance by upregulating the KRAS/ERK pathway.","date":"2024","source":"Neoplasia (New York, N.Y.)","url":"https://pubmed.ncbi.nlm.nih.gov/39522321","citation_count":2,"is_preprint":false},{"pmid":"39702344","id":"PMC_39702344","title":"Four functional genotoxic marker genes (Bax, Btg2, Ccng1, and Cdkn1a) discriminate genotoxic hepatocarcinogens from non-genotoxic hepatocarcinogens and non-genotoxic non-hepatocarcinogens in rat public toxicogenomics data, Open TG-GATEs.","date":"2024","source":"Genes and environment : the official journal of the Japanese Environmental Mutagen Society","url":"https://pubmed.ncbi.nlm.nih.gov/39702344","citation_count":1,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":9457,"output_tokens":1354,"usd":0.024341},"stage2":{"model":"claude-opus-4-6","input_tokens":4578,"output_tokens":1704,"usd":0.098235},"total_usd":0.122576,"stage1_batch_id":"msgbatch_011kfMfE81o6CTcyhVUqumuW","stage2_batch_id":"msgbatch_01DTputS6WNkH745x1nVSoBo","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1996,\n      \"finding\": \"CGR19 (CGRRF1) is transcriptionally induced by functional p53 and contains a RING-finger domain; overexpression of CGR19 inhibits the growth of several cell lines, identifying it as a p53-regulated growth suppressor.\",\n      \"method\": \"Differential RT-PCR in rat embryo fibroblasts with temperature-sensitive p53; growth inhibition assays in multiple cell lines\",\n      \"journal\": \"Cancer research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — clean gain-of-function with defined phenotype, but single lab and limited mechanistic follow-up\",\n      \"pmids\": [\"8968090\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"CGRRF1 acts as an ER-resident E3 ubiquitin ligase that ubiquitinates the Wnt cargo receptor Evi (Wls/GPR177), targeting it for ERAD in a VCP-dependent manner; this regulatory mechanism controls the abundance of Evi and thereby modulates the scale of Wnt protein secretion. The E2-conjugating enzyme UBE2J2 partners with CGRRF1 in this ubiquitination event.\",\n      \"method\": \"RNAi knockdown, co-immunoprecipitation, ubiquitination assays, VCP inhibition, epistasis with Porcn\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal Co-IP, in vivo ubiquitination assay, genetic epistasis, multiple orthogonal methods in one study\",\n      \"pmids\": [\"29378775\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"CGRRF1 functions as a RING-domain E3 ubiquitin ligase localized to the ER that ubiquitinates EGFR via K48-linked chains, leading to proteasomal degradation of EGFR; the RING-finger domain is required for this activity and for growth suppression. Knockout of CGRRF1 enhances AKT phosphorylation after EGF stimulation.\",\n      \"method\": \"Co-immunoprecipitation, in vivo ubiquitination assays, subcellular fractionation, MTT assay, xenograft experiment, RING-domain mutant analysis, RPPA\",\n      \"journal\": \"Breast cancer research : BCR\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — in vivo ubiquitination assay with domain mutagenesis, Co-IP, subcellular fractionation, in vitro and in vivo growth assays, multiple orthogonal methods\",\n      \"pmids\": [\"31801577\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"CGRRF1 functions as an E3 ubiquitin ligase for KRAS, mediating K48-linked ubiquitination and proteasomal degradation of KRAS, thereby suppressing the KRAS/ERK signaling pathway. MSI2 promotes chemoresistance by recruiting miR-30a-3p onto AGO2, which suppresses CGRRF1 expression and consequently elevates KRAS/ERK signaling.\",\n      \"method\": \"miRNA pulldown/AGO2 interaction assays, ubiquitination assays, Western blot for KRAS protein stability, luciferase reporter for miR-30a-3p/CGRRF1 axis, pharmacological inhibition\",\n      \"journal\": \"Neoplasia (New York, N.Y.)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — ubiquitination assay and protein stability data with pathway epistasis, single lab\",\n      \"pmids\": [\"39522321\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Overexpression of CGRRF1 inhibits endometrial cancer cell proliferation, and CGRRF1 expression is induced by metformin in obese rat endometrium, placing it downstream of metabolic/insulin signaling in endometrial tissue.\",\n      \"method\": \"MTT proliferation assay, RT-qPCR, Western blot, genetic overexpression in endometrial cancer cells\",\n      \"journal\": \"Gynecologic oncology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 — single lab, overexpression phenotype without defined molecular mechanism beyond growth inhibition\",\n      \"pmids\": [\"24680596\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"CGRRF1 is a p53-inducible, ER-localized RING-domain E3 ubiquitin ligase that targets multiple substrates—including Evi/Wls, EGFR, and KRAS—for K48-linked ubiquitination and proteasomal degradation, thereby suppressing Wnt secretion, EGFR/AKT signaling, and KRAS/ERK signaling; in ERAD, it cooperates with the E2 enzyme UBE2J2 and VCP to clear ER-resident clients.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"CGRRF1 is a p53-inducible, ER-localized RING-domain E3 ubiquitin ligase that suppresses cell growth by targeting multiple oncogenic substrates for K48-linked ubiquitination and proteasomal degradation. It ubiquitinates the Wnt cargo receptor Evi/Wls in partnership with the E2 enzyme UBE2J2, directing Evi to VCP-dependent ERAD and thereby limiting Wnt secretion [PMID:29378775]. CGRRF1 also ubiquitinates EGFR via its RING-finger domain, promoting EGFR degradation and attenuating AKT signaling [PMID:31801577], and mediates K48-linked ubiquitination of KRAS to suppress KRAS/ERK signaling [PMID:39522321]. Originally identified as a p53-responsive growth suppressor [PMID:8968090], its broad substrate repertoire positions it as a tumor-suppressive E3 ligase operating at the intersection of Wnt, EGFR, and RAS signaling pathways.\",\n  \"teleology\": [\n    {\n      \"year\": 1996,\n      \"claim\": \"The discovery that CGR19 (CGRRF1) is transcriptionally induced by p53 and contains a RING-finger domain established it as a candidate growth suppressor, but its molecular mechanism was unknown.\",\n      \"evidence\": \"Differential RT-PCR in rat embryo fibroblasts with temperature-sensitive p53; overexpression growth inhibition assays in multiple cell lines\",\n      \"pmids\": [\"8968090\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No enzymatic activity demonstrated\", \"No substrates identified\", \"Subcellular localization not defined\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Confirmation that CGRRF1 overexpression inhibits cancer cell proliferation and is induced by metformin linked it to metabolic signaling, but the molecular targets remained unidentified.\",\n      \"evidence\": \"MTT assay, RT-qPCR, and Western blot in endometrial cancer cells and obese rat endometrium\",\n      \"pmids\": [\"24680596\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No defined molecular mechanism beyond growth inhibition\", \"Single lab; not independently confirmed\", \"Causal relationship between metformin and CGRRF1 induction not mechanistically resolved\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Demonstration that CGRRF1 is an ER-resident E3 ligase that ubiquitinates Evi/Wls with UBE2J2 for VCP-dependent ERAD provided the first defined substrate and placed CGRRF1 within the ERAD quality-control pathway controlling Wnt secretion.\",\n      \"evidence\": \"RNAi knockdown, reciprocal co-immunoprecipitation, in vivo ubiquitination assays, VCP inhibition, genetic epistasis with Porcn\",\n      \"pmids\": [\"29378775\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether CGRRF1-mediated Evi degradation operates in all Wnt-secreting tissues in vivo\", \"Structural basis of CGRRF1–Evi recognition unknown\", \"Extent of CGRRF1 substrate repertoire beyond Evi not yet explored\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Identification of EGFR as a second CGRRF1 substrate, degraded via RING-domain-dependent K48-linked ubiquitination, broadened CGRRF1's role from Wnt regulation to EGFR/AKT signaling suppression and validated its tumor-suppressive function in vivo.\",\n      \"evidence\": \"Co-immunoprecipitation, in vivo ubiquitination assays with RING-domain mutants, subcellular fractionation, MTT assay, xenograft experiments, RPPA\",\n      \"pmids\": [\"31801577\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether EGFR ubiquitination by CGRRF1 occurs on newly synthesized ER-resident EGFR versus mature receptor\", \"No structural model of CGRRF1 RING domain–E2 interaction\", \"E2 partner for EGFR ubiquitination not confirmed\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Discovery that CGRRF1 mediates K48-linked ubiquitination and degradation of KRAS, suppressing KRAS/ERK signaling, revealed a third major oncogenic substrate and connected CGRRF1 loss to chemoresistance via the MSI2/miR-30a-3p axis.\",\n      \"evidence\": \"Ubiquitination assays, KRAS protein stability measurements, AGO2 interaction assays, luciferase reporter for miR-30a-3p/CGRRF1 3′UTR\",\n      \"pmids\": [\"39522321\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Independent replication of CGRRF1-KRAS direct ubiquitination needed\", \"Whether KRAS ubiquitination is RING-domain dependent not tested with domain mutants\", \"In vivo relevance of the MSI2/miR-30a-3p/CGRRF1/KRAS axis not demonstrated in animal models\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"Key unresolved questions include the full substrate repertoire of CGRRF1 in ERAD, its structural basis for substrate recognition, and whether its tumor-suppressive functions are tissue-specific.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No structural model of CGRRF1\", \"No systematic substrate identification (e.g., ubiquitin remnant proteomics)\", \"In vivo phenotype of CGRRF1 knockout in mammalian models not reported\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [1, 2, 3]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005783\", \"supporting_discovery_ids\": [1, 2]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [1, 2, 3]},\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [1, 2, 3]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"UBE2J2\", \"EGFR\", \"WLS\", \"KRAS\", \"VCP\"],\n    \"other_free_text\": []\n  }\n}\n```"}