{"gene":"COMMD5","run_date":"2026-06-09T22:57:19","timeline":{"discoveries":[{"year":2000,"finding":"HCaRG (COMMD5) protein localizes to the nucleus, contains a mutated EF-hand calcium-binding motif, four putative leucine zipper motifs, and a nuclear receptor-binding domain. Stable overexpression in HEK293 cells significantly reduced cell proliferation as measured by cell count and [3H]thymidine incorporation.","method":"Subcellular localization by nuclear fractionation/immunostaining; functional overexpression with proliferation assays ([3H]thymidine incorporation, cell count); sequence/domain analysis","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — direct localization and functional overexpression with two readouts, single lab","pmids":["10918053"],"is_preprint":false},{"year":2002,"finding":"COMMD5/HCaRG overexpression in renal epithelial HEK293 cells causes G2/M cell cycle arrest associated with upregulation of p21(Cip1/WAF1) and downregulation of p27(Kip1), and promotes a more differentiated phenotype (larger cell size, enhanced junctions, increased ANP-like immunoreactivity release).","method":"Stable transfection; cell cycle analysis by flow cytometry; Western blot for p21 and p27; [3H]thymidine incorporation; ANP immunoreactivity assay; electron microscopy for junctions","journal":"American journal of physiology. Renal physiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (flow cytometry, Western blot, functional assays), single lab","pmids":["12620924"],"is_preprint":false},{"year":2005,"finding":"COMMD5/HCaRG overexpression increases renal cell migration via an autocrine TGF-alpha/EGF receptor signaling loop: HCaRG-expressing cells show elevated TGF-alpha synthesis and secretion, and conditioned medium from these cells stimulates migration and morphological changes in control cells, partially through EGF receptor activation.","method":"Stable transfection in HEK293 and MDCK-C7 cells; wound-healing/migration assays; expression microarrays; ELISA/Western blot for TGF-alpha; conditioned medium transfer experiments with EGF receptor pathway blockade","journal":"American journal of physiology. Renal physiology","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — conditioned medium transfer with receptor-level blockade, microarray plus functional assays, single lab","pmids":["16033922"],"is_preprint":false},{"year":2011,"finding":"COMMD5/HCaRG overexpression in transgenic mice accelerates renal repair after ischemia/reperfusion injury: it reduces proximal tubular cell proliferation, hastens recovery of E-cadherin expression, attenuates vimentin induction, and reduces macrophage infiltration, consistent with facilitation of re-differentiation of tubular epithelial cells.","method":"Transgenic mouse model (human HCaRG overexpression); survival analysis; immunohistochemistry for E-cadherin, vimentin, Ki67; macrophage infiltration assays; renal function measurements","journal":"Journal of the American Society of Nephrology : JASN","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo transgenic model with multiple cellular/molecular readouts, single lab","pmids":["21921141"],"is_preprint":false},{"year":2014,"finding":"COMMD5/HCaRG facilitates p21 transactivation through a p53-independent signaling pathway in renal proximal tubular cells, contributing to cell cycle regulation during repair.","method":"Cell culture overexpression with p21 promoter assays; transgenic mouse model showing p53-independent p21 induction after ischemia/reperfusion injury","journal":"Journal of nephrology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — described in a review/summary paper citing prior work, single lab, limited methodological detail in abstract","pmids":["24515317"],"is_preprint":false},{"year":2017,"finding":"COMMD5/HCaRG promotes de-phosphorylation of ErbB2/HER2 and causes epigenetic silencing (promoter methylation) of EGFR and ErbB3 gene expression, leading to inactivation of downstream ERK, AKT, and mTOR signaling in renal cell carcinoma cells.","method":"Overexpression in RCC cells and mouse homograft tumor model; Western blot for pErbB2, ERK, AKT, mTOR; bisulfite sequencing/methylation-specific PCR for EGFR and ErbB3 promoters; tumor size measurement in vivo","journal":"Oncotarget","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — multiple orthogonal methods (phospho-Western, methylation assays, in vivo), single lab","pmids":["29050225"],"is_preprint":false},{"year":2018,"finding":"COMMD5 acts as an adaptor protein linking endosomes to the cytoskeleton: its N-terminal domain binds the endosomal GTPase Rab5, while its C-terminal COMMD domain binds cytoskeletal scaffolding components. COMMD5 is required for long-range endosomal transport, EGFR recycling, and assists vesicle scission into sorting endosomes. Silencing COMMD5 causes major reorganization of actin and microtubule networks.","method":"Co-immunoprecipitation/pulldown of N-terminus with Rab5 and C-terminus/COMMD domain with cytoskeletal proteins; domain deletion mapping; live-cell imaging of endosomal trafficking; EGFR recycling assays; siRNA silencing with cytoskeletal imaging","journal":"Cell reports","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal domain-mapping pulldowns, live imaging, functional trafficking assays, multiple orthogonal methods in single rigorous study","pmids":["30021164"],"is_preprint":false},{"year":2023,"finding":"Extracellular COMMD5 protein inhibits vasoconstriction in vascular rings with intact endothelium (but not in endothelium-denuded rings), and stimulates upregulation of ANP and eNOS expression in human umbilical vein endothelial cells, indicating a vasodilatory function dependent on endothelial signaling.","method":"Ex vivo vascular ring tension assays with intact vs. denuded endothelium; siRNA knockdown and COMMD5 stimulation in HUVECs; Western blot/qPCR for ANP and eNOS","journal":"European journal of pharmacology","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — ex vivo functional assay with endothelium-denuded controls plus cell-based siRNA knockdown, two orthogonal approaches, single lab","pmids":["36804542"],"is_preprint":false},{"year":2024,"finding":"COMMD5 protects renal proximal tubular epithelial cells from cisplatin-induced oxidative stress by maintaining tubular epithelial integrity, reducing intracellular ROS and mitochondrial dysfunction, increasing autophagy flux through the autophagy/lysosome pathway, and decreasing JNK/caspase-3-dependent apoptosis. siRNA knockdown of COMMD5 reduced TEC resistance to cisplatin cytotoxicity.","method":"Transgenic mouse model (PT-specific COMMD5 overexpression) with cisplatin nephrotoxicity; siRNA knockdown in TECs; ROS measurement; mitochondrial function assays; autophagy flux assays (LC3, p62); Western blot for JNK and caspase-3; cell viability assays","journal":"American journal of physiology. Renal physiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo transgenic plus siRNA loss-of-function with multiple molecular readouts, single lab","pmids":["39298552"],"is_preprint":false}],"current_model":"COMMD5 (HCaRG) is an intracellular adaptor protein that, via its N-terminal domain, binds the endosomal GTPase Rab5 and, via its C-terminal COMMD domain, anchors endosomes to the cytoskeleton to coordinate long-range endosomal trafficking and EGFR recycling; it also promotes G2/M cell cycle arrest through p53-independent p21 upregulation, suppresses ErbB receptor signaling via ErbB2 dephosphorylation and epigenetic silencing of EGFR/ErbB3, drives renal epithelial re-differentiation, promotes TGF-alpha-dependent cell migration, maintains tubular epithelial integrity and autophagy flux to limit oxidative stress-induced apoptosis, and extracellularly induces ANP/eNOS in endothelial cells to promote vasodilation."},"narrative":{"mechanistic_narrative":"COMMD5 (HCaRG) is an intracellular adaptor protein that couples endosomal trafficking to growth-factor receptor regulation and renal epithelial homeostasis [PMID:30021164]. Mechanistically, its N-terminal domain binds the endosomal GTPase Rab5 while its C-terminal COMMD domain engages cytoskeletal scaffolding, enabling long-range endosomal transport, vesicle scission into sorting endosomes, and EGFR recycling; loss of COMMD5 reorganizes the actin and microtubule networks [PMID:30021164]. Consistent with a role in restraining receptor signaling, COMMD5 drives dephosphorylation of ErbB2 and promoter methylation–dependent silencing of EGFR and ErbB3, inactivating downstream ERK, AKT, and mTOR signaling [PMID:29050225]. At the cellular level it imposes G2/M arrest with p53-independent upregulation of p21 and downregulation of p27, and promotes a differentiated epithelial phenotype [PMID:12620924, PMID:24515317]. In the kidney, COMMD5 accelerates re-differentiation and repair of proximal tubular epithelium after ischemia/reperfusion injury and protects tubular cells from cisplatin-induced oxidative stress by sustaining autophagy flux and limiting JNK/caspase-3–dependent apoptosis [PMID:21921141, PMID:39298552]. An extracellular form of COMMD5 additionally induces ANP and eNOS in endothelial cells to promote endothelium-dependent vasodilation [PMID:36804542].","teleology":[{"year":2000,"claim":"Established COMMD5/HCaRG as a nuclear protein that restrains cell proliferation, framing it as a candidate growth regulator.","evidence":"Nuclear fractionation/immunostaining and overexpression proliferation assays in HEK293 cells","pmids":["10918053"],"confidence":"Medium","gaps":["No molecular partner or mechanism for proliferation control identified","Functional domains assigned by sequence only, not validated"]},{"year":2002,"claim":"Linked the anti-proliferative effect to a defined cell-cycle checkpoint by showing G2/M arrest with p21 up- and p27 downregulation and an epithelial differentiation program.","evidence":"Stable transfection with flow cytometry, Western blot, and differentiation/junction readouts in renal epithelial cells","pmids":["12620924"],"confidence":"Medium","gaps":["Did not establish how COMMD5 transactivates p21","Mechanism connecting cell-cycle arrest to differentiation unresolved"]},{"year":2005,"claim":"Connected COMMD5 to growth-factor signaling by showing it drives an autocrine TGF-alpha/EGFR loop that promotes migration.","evidence":"Conditioned-medium transfer with EGFR pathway blockade, microarray, and migration assays in HEK293/MDCK-C7","pmids":["16033922"],"confidence":"Medium","gaps":["Direct molecular link between COMMD5 and TGF-alpha induction not defined","Receptor-level effects only partially blocked"]},{"year":2011,"claim":"Demonstrated physiological relevance in vivo by showing COMMD5 overexpression accelerates tubular re-differentiation and repair after ischemic injury.","evidence":"Transgenic mouse ischemia/reperfusion model with E-cadherin, vimentin, Ki67 and macrophage readouts","pmids":["21921141"],"confidence":"Medium","gaps":["Molecular mechanism of accelerated re-differentiation not dissected","Single transgenic gain-of-function model"]},{"year":2014,"claim":"Specified that COMMD5-driven p21 induction operates through a p53-independent pathway during repair.","evidence":"p21 promoter assays and transgenic ischemia/reperfusion model","pmids":["24515317"],"confidence":"Low","gaps":["Reported in a review/summary with limited methodological detail","p53-independent effector linking COMMD5 to p21 unidentified"]},{"year":2017,"claim":"Revealed COMMD5 as a suppressor of ErbB receptor signaling through ErbB2 dephosphorylation and epigenetic silencing of EGFR/ErbB3.","evidence":"Overexpression in RCC cells and homograft model with phospho-Western, methylation assays, and tumor measurement","pmids":["29050225"],"confidence":"Medium","gaps":["Phosphatase and methyltransferase machinery recruited by COMMD5 not identified","Single lab"]},{"year":2018,"claim":"Defined the core molecular mechanism: COMMD5 is a bipartite adaptor linking Rab5-positive endosomes to the cytoskeleton, governing long-range trafficking and EGFR recycling.","evidence":"Reciprocal domain-mapping pulldowns, live-cell trafficking imaging, EGFR recycling and siRNA cytoskeletal imaging","pmids":["30021164"],"confidence":"High","gaps":["Specific cytoskeletal scaffolding partner(s) of the COMMD domain not fully named","Link between endosomal adaptor function and nuclear/cell-cycle roles unresolved"]},{"year":2023,"claim":"Uncovered an extracellular, endothelium-dependent vasodilatory activity of COMMD5 acting through ANP and eNOS.","evidence":"Ex vivo vascular ring assays with denuded controls and HUVEC siRNA/stimulation with ANP/eNOS readouts","pmids":["36804542"],"confidence":"Medium","gaps":["Receptor or surface mechanism for extracellular COMMD5 unknown","Relationship between intracellular adaptor role and secreted activity unclear"]},{"year":2024,"claim":"Showed COMMD5 protects tubular epithelium from oxidative injury by sustaining autophagy flux and suppressing JNK/caspase-3 apoptosis.","evidence":"PT-specific transgenic mouse cisplatin model plus TEC siRNA with ROS, mitochondrial, autophagy and apoptosis readouts","pmids":["39298552"],"confidence":"Medium","gaps":["Mechanism by which COMMD5 enhances autophagy flux not defined","Direct effector linking COMMD5 to JNK regulation unknown"]},{"year":null,"claim":"How the endosomal/cytoskeletal adaptor function mechanistically integrates with the nuclear cell-cycle, epigenetic ErbB-silencing, and extracellular vasodilatory roles remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No unifying mechanism connecting trafficking, transcriptional, and secreted activities","Cytoskeletal binding partner and putative phosphatase/methyltransferase effectors unidentified","No structural model of the bipartite domain architecture"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[6]},{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[6]}],"localization":[{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[0]},{"term_id":"GO:0005768","term_label":"endosome","supporting_discovery_ids":[6]},{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[6]}],"pathway":[{"term_id":"R-HSA-5653656","term_label":"Vesicle-mediated transport","supporting_discovery_ids":[6]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[1]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[5]}],"complexes":[],"partners":["RAB5","EGFR","ERBB2","ERBB3"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9GZQ3","full_name":"COMM domain-containing protein 5","aliases":["Hypertension-related calcium-regulated gene protein","HCaRG"],"length_aa":224,"mass_kda":24.7,"function":"Scaffold protein in the commander complex that is essential for endosomal recycling of transmembrane cargos; the commander complex is composed of the CCC subcomplex and the retriever subcomplex (PubMed:37172566, PubMed:38459129). May modulate activity of cullin-RING E3 ubiquitin ligase (CRL) complexes (PubMed:21778237). Negatively regulates cell proliferation (By similarity). Negatively regulates cell cycle G2/M phase transition probably by transactivating p21/CDKN1A through the p53/TP53-independent signaling pathway (By similarity). Involved in kidney proximal tubule morphogenesis (By similarity). Down-regulates activation of NF-kappa-B (PubMed:15799966)","subcellular_location":"Cytoplasm; Nucleus","url":"https://www.uniprot.org/uniprotkb/Q9GZQ3/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/COMMD5","classification":"Not Classified","n_dependent_lines":43,"n_total_lines":1208,"dependency_fraction":0.03559602649006623},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"CCDC22","stoichiometry":10.0},{"gene":"CCDC93","stoichiometry":10.0},{"gene":"COMMD1","stoichiometry":10.0},{"gene":"COMMD2","stoichiometry":10.0},{"gene":"COMMD4","stoichiometry":10.0},{"gene":"SRPK2","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/COMMD5","total_profiled":1310},"omim":[{"mim_id":"616704","title":"COMM DOMAIN-CONTAINING PROTEIN 10; COMMD10","url":"https://www.omim.org/entry/616704"},{"mim_id":"616700","title":"COMM DOMAIN-CONTAINING PROTEIN 3; COMMD3","url":"https://www.omim.org/entry/616700"},{"mim_id":"612299","title":"COMM DOMAIN-CONTAINING PROTEIN 9; COMMD9","url":"https://www.omim.org/entry/612299"},{"mim_id":"608216","title":"COMM DOMAIN-CONTAINING PROTEIN 5; COMMD5","url":"https://www.omim.org/entry/608216"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Nucleoplasm","reliability":"Supported"},{"location":"Cytosol","reliability":"Supported"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/COMMD5"},"hgnc":{"alias_symbol":["HT002","FLJ13008","HCaRG"],"prev_symbol":[]},"alphafold":{"accession":"Q9GZQ3","domains":[{"cath_id":"-","chopping":"32-146","consensus_level":"high","plddt":90.9685,"start":32,"end":146},{"cath_id":"-","chopping":"149-193","consensus_level":"medium","plddt":85.5344,"start":149,"end":193},{"cath_id":"1.20.5","chopping":"199-224","consensus_level":"medium","plddt":86.2869,"start":199,"end":224}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9GZQ3","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9GZQ3-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9GZQ3-F1-predicted_aligned_error_v6.png","plddt_mean":84.0},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=COMMD5","jax_strain_url":"https://www.jax.org/strain/search?query=COMMD5"},"sequence":{"accession":"Q9GZQ3","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9GZQ3.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9GZQ3/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9GZQ3"}},"corpus_meta":[{"pmid":"10918053","id":"PMC_10918053","title":"HCaRG, a novel calcium-regulated gene coding for a nuclear protein, is potentially involved in the regulation of cell proliferation.","date":"2000","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/10918053","citation_count":38,"is_preprint":false},{"pmid":"12620924","id":"PMC_12620924","title":"HCaRG is a novel regulator of renal epithelial cell growth and differentiation causing G2M arrest.","date":"2002","source":"American journal of physiology. Renal physiology","url":"https://pubmed.ncbi.nlm.nih.gov/12620924","citation_count":23,"is_preprint":false},{"pmid":"30021164","id":"PMC_30021164","title":"COMMD5/HCaRG Hooks Endosomes on Cytoskeleton and Coordinates EGFR Trafficking.","date":"2018","source":"Cell reports","url":"https://pubmed.ncbi.nlm.nih.gov/30021164","citation_count":21,"is_preprint":false},{"pmid":"16033922","id":"PMC_16033922","title":"HCaRG increases renal cell migration by a TGF-alpha autocrine loop mechanism.","date":"2005","source":"American journal of physiology. Renal physiology","url":"https://pubmed.ncbi.nlm.nih.gov/16033922","citation_count":18,"is_preprint":false},{"pmid":"29050225","id":"PMC_29050225","title":"HCaRG/COMMD5 inhibits ErbB receptor-driven renal cell carcinoma.","date":"2017","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/29050225","citation_count":17,"is_preprint":false},{"pmid":"18949406","id":"PMC_18949406","title":"Rosiglitazone suppresses gastric carcinogenesis by up-regulating HCaRG expression.","date":"2008","source":"Oncology reports","url":"https://pubmed.ncbi.nlm.nih.gov/18949406","citation_count":11,"is_preprint":false},{"pmid":"21921141","id":"PMC_21921141","title":"HCaRG accelerates tubular repair after ischemic kidney injury.","date":"2011","source":"Journal of the American Society of Nephrology : JASN","url":"https://pubmed.ncbi.nlm.nih.gov/21921141","citation_count":10,"is_preprint":false},{"pmid":"11871861","id":"PMC_11871861","title":"Chromosomal mapping of HCaRG, a novel hypertension-related, calcium-regulated gene.","date":"2002","source":"Folia biologica","url":"https://pubmed.ncbi.nlm.nih.gov/11871861","citation_count":7,"is_preprint":false},{"pmid":"24515317","id":"PMC_24515317","title":"Hypertension-related, calcium-regulated gene (HCaRG/COMMD5) and kidney diseases: HCaRG accelerates tubular repair.","date":"2014","source":"Journal of nephrology","url":"https://pubmed.ncbi.nlm.nih.gov/24515317","citation_count":6,"is_preprint":false},{"pmid":"39298552","id":"PMC_39298552","title":"COMMD5 counteracts cisplatin-induced nephrotoxicity by maintaining tubular epithelial integrity and autophagy flux.","date":"2024","source":"American journal of physiology. Renal physiology","url":"https://pubmed.ncbi.nlm.nih.gov/39298552","citation_count":6,"is_preprint":false},{"pmid":"34083270","id":"PMC_34083270","title":"COMMD5 Inhibits Malignant Behavior of Renal Cancer Cells.","date":"2021","source":"Anticancer research","url":"https://pubmed.ncbi.nlm.nih.gov/34083270","citation_count":4,"is_preprint":false},{"pmid":"33768002","id":"PMC_33768002","title":"Does Subtelomeric Position of COMMD5 Influence Cancer Progression?","date":"2021","source":"Frontiers in oncology","url":"https://pubmed.ncbi.nlm.nih.gov/33768002","citation_count":3,"is_preprint":false},{"pmid":"36804542","id":"PMC_36804542","title":"COMMD5 is involved in the mechanisms of hypotension after parathyroidectomy in patients receiving hemodialysis.","date":"2023","source":"European journal of pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/36804542","citation_count":3,"is_preprint":false},{"pmid":"40155026","id":"PMC_40155026","title":"Contrasting Role of COMMD5 in Renal Cell Carcinoma: Tumor Suppression and Metastatic Enhancement.","date":"2025","source":"Anticancer research","url":"https://pubmed.ncbi.nlm.nih.gov/40155026","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.11.14.688543","title":"Study on  <i>Dianthus superbus</i>  L. against Acute Liver Injury via the Gut–Liver Axis — Regulation of Gut Microbiota and Tryptophan Metabolism to Activate AhR Signaling","date":"2025-11-15","source":"bioRxiv","url":"https://doi.org/10.1101/2025.11.14.688543","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":9769,"output_tokens":2545,"usd":0.033741,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":9693,"output_tokens":3013,"usd":0.061895,"stage2_stop_reason":"end_turn"},"total_usd":0.095636,"stage1_batch_id":"msgbatch_01ACAxJQabDsht39JXeWG22d","stage2_batch_id":"msgbatch_01QEU22A9U5sbPTgsMzTmvSf","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2000,\n      \"finding\": \"HCaRG (COMMD5) protein localizes to the nucleus, contains a mutated EF-hand calcium-binding motif, four putative leucine zipper motifs, and a nuclear receptor-binding domain. Stable overexpression in HEK293 cells significantly reduced cell proliferation as measured by cell count and [3H]thymidine incorporation.\",\n      \"method\": \"Subcellular localization by nuclear fractionation/immunostaining; functional overexpression with proliferation assays ([3H]thymidine incorporation, cell count); sequence/domain analysis\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — direct localization and functional overexpression with two readouts, single lab\",\n      \"pmids\": [\"10918053\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"COMMD5/HCaRG overexpression in renal epithelial HEK293 cells causes G2/M cell cycle arrest associated with upregulation of p21(Cip1/WAF1) and downregulation of p27(Kip1), and promotes a more differentiated phenotype (larger cell size, enhanced junctions, increased ANP-like immunoreactivity release).\",\n      \"method\": \"Stable transfection; cell cycle analysis by flow cytometry; Western blot for p21 and p27; [3H]thymidine incorporation; ANP immunoreactivity assay; electron microscopy for junctions\",\n      \"journal\": \"American journal of physiology. Renal physiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (flow cytometry, Western blot, functional assays), single lab\",\n      \"pmids\": [\"12620924\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"COMMD5/HCaRG overexpression increases renal cell migration via an autocrine TGF-alpha/EGF receptor signaling loop: HCaRG-expressing cells show elevated TGF-alpha synthesis and secretion, and conditioned medium from these cells stimulates migration and morphological changes in control cells, partially through EGF receptor activation.\",\n      \"method\": \"Stable transfection in HEK293 and MDCK-C7 cells; wound-healing/migration assays; expression microarrays; ELISA/Western blot for TGF-alpha; conditioned medium transfer experiments with EGF receptor pathway blockade\",\n      \"journal\": \"American journal of physiology. Renal physiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — conditioned medium transfer with receptor-level blockade, microarray plus functional assays, single lab\",\n      \"pmids\": [\"16033922\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"COMMD5/HCaRG overexpression in transgenic mice accelerates renal repair after ischemia/reperfusion injury: it reduces proximal tubular cell proliferation, hastens recovery of E-cadherin expression, attenuates vimentin induction, and reduces macrophage infiltration, consistent with facilitation of re-differentiation of tubular epithelial cells.\",\n      \"method\": \"Transgenic mouse model (human HCaRG overexpression); survival analysis; immunohistochemistry for E-cadherin, vimentin, Ki67; macrophage infiltration assays; renal function measurements\",\n      \"journal\": \"Journal of the American Society of Nephrology : JASN\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo transgenic model with multiple cellular/molecular readouts, single lab\",\n      \"pmids\": [\"21921141\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"COMMD5/HCaRG facilitates p21 transactivation through a p53-independent signaling pathway in renal proximal tubular cells, contributing to cell cycle regulation during repair.\",\n      \"method\": \"Cell culture overexpression with p21 promoter assays; transgenic mouse model showing p53-independent p21 induction after ischemia/reperfusion injury\",\n      \"journal\": \"Journal of nephrology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — described in a review/summary paper citing prior work, single lab, limited methodological detail in abstract\",\n      \"pmids\": [\"24515317\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"COMMD5/HCaRG promotes de-phosphorylation of ErbB2/HER2 and causes epigenetic silencing (promoter methylation) of EGFR and ErbB3 gene expression, leading to inactivation of downstream ERK, AKT, and mTOR signaling in renal cell carcinoma cells.\",\n      \"method\": \"Overexpression in RCC cells and mouse homograft tumor model; Western blot for pErbB2, ERK, AKT, mTOR; bisulfite sequencing/methylation-specific PCR for EGFR and ErbB3 promoters; tumor size measurement in vivo\",\n      \"journal\": \"Oncotarget\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — multiple orthogonal methods (phospho-Western, methylation assays, in vivo), single lab\",\n      \"pmids\": [\"29050225\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"COMMD5 acts as an adaptor protein linking endosomes to the cytoskeleton: its N-terminal domain binds the endosomal GTPase Rab5, while its C-terminal COMMD domain binds cytoskeletal scaffolding components. COMMD5 is required for long-range endosomal transport, EGFR recycling, and assists vesicle scission into sorting endosomes. Silencing COMMD5 causes major reorganization of actin and microtubule networks.\",\n      \"method\": \"Co-immunoprecipitation/pulldown of N-terminus with Rab5 and C-terminus/COMMD domain with cytoskeletal proteins; domain deletion mapping; live-cell imaging of endosomal trafficking; EGFR recycling assays; siRNA silencing with cytoskeletal imaging\",\n      \"journal\": \"Cell reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal domain-mapping pulldowns, live imaging, functional trafficking assays, multiple orthogonal methods in single rigorous study\",\n      \"pmids\": [\"30021164\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"Extracellular COMMD5 protein inhibits vasoconstriction in vascular rings with intact endothelium (but not in endothelium-denuded rings), and stimulates upregulation of ANP and eNOS expression in human umbilical vein endothelial cells, indicating a vasodilatory function dependent on endothelial signaling.\",\n      \"method\": \"Ex vivo vascular ring tension assays with intact vs. denuded endothelium; siRNA knockdown and COMMD5 stimulation in HUVECs; Western blot/qPCR for ANP and eNOS\",\n      \"journal\": \"European journal of pharmacology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — ex vivo functional assay with endothelium-denuded controls plus cell-based siRNA knockdown, two orthogonal approaches, single lab\",\n      \"pmids\": [\"36804542\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"COMMD5 protects renal proximal tubular epithelial cells from cisplatin-induced oxidative stress by maintaining tubular epithelial integrity, reducing intracellular ROS and mitochondrial dysfunction, increasing autophagy flux through the autophagy/lysosome pathway, and decreasing JNK/caspase-3-dependent apoptosis. siRNA knockdown of COMMD5 reduced TEC resistance to cisplatin cytotoxicity.\",\n      \"method\": \"Transgenic mouse model (PT-specific COMMD5 overexpression) with cisplatin nephrotoxicity; siRNA knockdown in TECs; ROS measurement; mitochondrial function assays; autophagy flux assays (LC3, p62); Western blot for JNK and caspase-3; cell viability assays\",\n      \"journal\": \"American journal of physiology. Renal physiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo transgenic plus siRNA loss-of-function with multiple molecular readouts, single lab\",\n      \"pmids\": [\"39298552\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"COMMD5 (HCaRG) is an intracellular adaptor protein that, via its N-terminal domain, binds the endosomal GTPase Rab5 and, via its C-terminal COMMD domain, anchors endosomes to the cytoskeleton to coordinate long-range endosomal trafficking and EGFR recycling; it also promotes G2/M cell cycle arrest through p53-independent p21 upregulation, suppresses ErbB receptor signaling via ErbB2 dephosphorylation and epigenetic silencing of EGFR/ErbB3, drives renal epithelial re-differentiation, promotes TGF-alpha-dependent cell migration, maintains tubular epithelial integrity and autophagy flux to limit oxidative stress-induced apoptosis, and extracellularly induces ANP/eNOS in endothelial cells to promote vasodilation.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"COMMD5 (HCaRG) is an intracellular adaptor protein that couples endosomal trafficking to growth-factor receptor regulation and renal epithelial homeostasis [#6]. Mechanistically, its N-terminal domain binds the endosomal GTPase Rab5 while its C-terminal COMMD domain engages cytoskeletal scaffolding, enabling long-range endosomal transport, vesicle scission into sorting endosomes, and EGFR recycling; loss of COMMD5 reorganizes the actin and microtubule networks [#6]. Consistent with a role in restraining receptor signaling, COMMD5 drives dephosphorylation of ErbB2 and promoter methylation–dependent silencing of EGFR and ErbB3, inactivating downstream ERK, AKT, and mTOR signaling [#5]. At the cellular level it imposes G2/M arrest with p53-independent upregulation of p21 and downregulation of p27, and promotes a differentiated epithelial phenotype [#1, #4]. In the kidney, COMMD5 accelerates re-differentiation and repair of proximal tubular epithelium after ischemia/reperfusion injury and protects tubular cells from cisplatin-induced oxidative stress by sustaining autophagy flux and limiting JNK/caspase-3–dependent apoptosis [#3, #8]. An extracellular form of COMMD5 additionally induces ANP and eNOS in endothelial cells to promote endothelium-dependent vasodilation [#7].\",\n  \"teleology\": [\n    {\n      \"year\": 2000,\n      \"claim\": \"Established COMMD5/HCaRG as a nuclear protein that restrains cell proliferation, framing it as a candidate growth regulator.\",\n      \"evidence\": \"Nuclear fractionation/immunostaining and overexpression proliferation assays in HEK293 cells\",\n      \"pmids\": [\"10918053\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No molecular partner or mechanism for proliferation control identified\", \"Functional domains assigned by sequence only, not validated\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Linked the anti-proliferative effect to a defined cell-cycle checkpoint by showing G2/M arrest with p21 up- and p27 downregulation and an epithelial differentiation program.\",\n      \"evidence\": \"Stable transfection with flow cytometry, Western blot, and differentiation/junction readouts in renal epithelial cells\",\n      \"pmids\": [\"12620924\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Did not establish how COMMD5 transactivates p21\", \"Mechanism connecting cell-cycle arrest to differentiation unresolved\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Connected COMMD5 to growth-factor signaling by showing it drives an autocrine TGF-alpha/EGFR loop that promotes migration.\",\n      \"evidence\": \"Conditioned-medium transfer with EGFR pathway blockade, microarray, and migration assays in HEK293/MDCK-C7\",\n      \"pmids\": [\"16033922\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct molecular link between COMMD5 and TGF-alpha induction not defined\", \"Receptor-level effects only partially blocked\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Demonstrated physiological relevance in vivo by showing COMMD5 overexpression accelerates tubular re-differentiation and repair after ischemic injury.\",\n      \"evidence\": \"Transgenic mouse ischemia/reperfusion model with E-cadherin, vimentin, Ki67 and macrophage readouts\",\n      \"pmids\": [\"21921141\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Molecular mechanism of accelerated re-differentiation not dissected\", \"Single transgenic gain-of-function model\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Specified that COMMD5-driven p21 induction operates through a p53-independent pathway during repair.\",\n      \"evidence\": \"p21 promoter assays and transgenic ischemia/reperfusion model\",\n      \"pmids\": [\"24515317\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Reported in a review/summary with limited methodological detail\", \"p53-independent effector linking COMMD5 to p21 unidentified\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Revealed COMMD5 as a suppressor of ErbB receptor signaling through ErbB2 dephosphorylation and epigenetic silencing of EGFR/ErbB3.\",\n      \"evidence\": \"Overexpression in RCC cells and homograft model with phospho-Western, methylation assays, and tumor measurement\",\n      \"pmids\": [\"29050225\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Phosphatase and methyltransferase machinery recruited by COMMD5 not identified\", \"Single lab\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Defined the core molecular mechanism: COMMD5 is a bipartite adaptor linking Rab5-positive endosomes to the cytoskeleton, governing long-range trafficking and EGFR recycling.\",\n      \"evidence\": \"Reciprocal domain-mapping pulldowns, live-cell trafficking imaging, EGFR recycling and siRNA cytoskeletal imaging\",\n      \"pmids\": [\"30021164\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Specific cytoskeletal scaffolding partner(s) of the COMMD domain not fully named\", \"Link between endosomal adaptor function and nuclear/cell-cycle roles unresolved\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Uncovered an extracellular, endothelium-dependent vasodilatory activity of COMMD5 acting through ANP and eNOS.\",\n      \"evidence\": \"Ex vivo vascular ring assays with denuded controls and HUVEC siRNA/stimulation with ANP/eNOS readouts\",\n      \"pmids\": [\"36804542\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Receptor or surface mechanism for extracellular COMMD5 unknown\", \"Relationship between intracellular adaptor role and secreted activity unclear\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Showed COMMD5 protects tubular epithelium from oxidative injury by sustaining autophagy flux and suppressing JNK/caspase-3 apoptosis.\",\n      \"evidence\": \"PT-specific transgenic mouse cisplatin model plus TEC siRNA with ROS, mitochondrial, autophagy and apoptosis readouts\",\n      \"pmids\": [\"39298552\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism by which COMMD5 enhances autophagy flux not defined\", \"Direct effector linking COMMD5 to JNK regulation unknown\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How the endosomal/cytoskeletal adaptor function mechanistically integrates with the nuclear cell-cycle, epigenetic ErbB-silencing, and extracellular vasodilatory roles remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No unifying mechanism connecting trafficking, transcriptional, and secreted activities\", \"Cytoskeletal binding partner and putative phosphatase/methyltransferase effectors unidentified\", \"No structural model of the bipartite domain architecture\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [6]},\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [6]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0005768\", \"supporting_discovery_ids\": [6]},\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [6]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-5653656\", \"supporting_discovery_ids\": [6]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [1]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [5]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"RAB5\", \"EGFR\", \"ERBB2\", \"ERBB3\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}