{"gene":"DCAF12","run_date":"2026-06-09T22:57:19","timeline":{"discoveries":[{"year":2019,"finding":"CRL4-DCAF12 E3 ubiquitin ligase mediates proteasome-dependent degradation of MAGE-A3/6 proteins in response to nutrient deprivation, and this degradation is required for starvation-induced autophagy.","method":"Proteomic analysis of MAGE-A3/6 interactors, proteasome inhibitor assays, CRL4-DCAF12 complex identification, functional autophagy assays","journal":"EMBO reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — proteomic identification of E3 ligase complex plus functional autophagy readout, single lab","pmids":["31267705"],"is_preprint":false},{"year":2021,"finding":"CRL4-DCAF12 recognizes a C-terminal acidic amino acid degron on MOV10 (an RNA helicase) and promotes its proteasome- and CRL-dependent degradation; loss of Dcaf12 in mice elevates MOV10 levels, impairs spermatogenesis, and disrupts T cell activation.","method":"Affinity purification of CRL4-DCAF12 complexes, proteasome inhibitor assays, Dcaf12 knockout mice, analysis of MOV10 protein levels, spermatogenesis and T cell phenotyping","journal":"International journal of molecular sciences","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal complex purification, CRL dependence assay, and in vivo KO mouse with defined cellular phenotypes across two biological contexts","pmids":["34065512"],"is_preprint":false},{"year":2019,"finding":"Drosophila DCAF12 acts as a cofactor of Cullin4 (Cul4) ubiquitin ligase at synapses: presynaptically it promotes evoked neurotransmitter release and synaptic homeostatic potentiation; postsynaptically (in muscle nuclei) it down-regulates glutamate receptor subunits GluRIIA, GluRIIC, and GluRIID in a Cul4-dependent manner.","method":"Genetic deletion in Drosophila, presynaptic vs postsynaptic rescue experiments, electrophysiology at larval NMJs, genetic epistasis with Cul4","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic epistasis, tissue-specific rescue, electrophysiological readouts, multiple independent functions dissected","pmids":["30670470"],"is_preprint":false},{"year":2023,"finding":"Cryo-EM structure of DDB1-DCAF12-CCT5 complex at 2.8 Å shows DCAF12 acts as a WD40 β-propeller substrate receptor that binds the C-terminal di-Glu (double glutamate) motif of CCT5 via a positively charged central pocket; DCAF12 ubiquitinates monomeric CCT5 but not CCT5 assembled into the TRiC complex, indicating CRL4DCAF12 functions in Assembly Quality Control.","method":"Cryo-EM structure determination, biochemical ubiquitination assays with monomeric vs. assembled CCT5, mutagenesis of degron contacts","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 1 / Strong — near-atomic cryo-EM structure plus reconstituted in vitro ubiquitination assay with functional validation of assembly state dependence","pmids":["36715408"],"is_preprint":false},{"year":2016,"finding":"Drosophila DCAF12 is required for Diap1 (Drosophila IAP1) cleavage in response to pro-apoptotic signals and is necessary and sufficient for RHG (Reaper, Hid, Grim)-mediated apoptosis; loss of DCAF12 impairs elimination of supernumerary cells and enhances tumor growth caused by loss of neoplastic tumor suppressors.","method":"Drosophila genetic loss-of-function, apoptosis assays, genetic epistasis with pro-apoptotic and tumor suppressor genes","journal":"Developmental biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Drosophila KO with defined apoptotic phenotype and epistasis, single lab","pmids":["26972874"],"is_preprint":false},{"year":2022,"finding":"Human DCAF12 binds multiple IAP family members (XIAP, cIAP1, cIAP2, BRUCE) via their BIR domains; in response to apoptotic stimuli DCAF12 translocates from the nucleus to the cytoplasm where it blocks XIAP–caspase interactions to facilitate caspase activation; DCAF12 also suppresses NF-κB activation in an IAP-binding-dependent manner.","method":"Co-immunoprecipitation of DCAF12 with IAPs, subcellular fractionation/localization upon apoptotic stimuli, domain-mapping (BIR domain binding), caspase activation assays, NF-κB reporter assays","journal":"Oncogene","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP with multiple IAPs, translocation experiments, functional caspase and NF-κB assays; single lab","pmids":["35459779"],"is_preprint":false},{"year":2024,"finding":"Cryo-EM structure of DDB1-DCAF12-MAGEA3 complex at 3.17 Å identifies key DCAF12 WD40-domain residues responsible for recognizing the C-terminal di-Glu degron of MAGEA3; biophysical and NanoBRET assays show nanomolar-affinity interactions between DCAF12 and C-terminal degron peptides of both MAGEA3 and CCT5 in vitro and in cells.","method":"Cryo-EM structure determination, NanoBRET proximity assays, biophysical binding assays (in vitro and cellular)","journal":"PNAS nexus","confidence":"High","confidence_rationale":"Tier 1 / Moderate — atomic-resolution cryo-EM structure plus orthogonal biophysical and cell-based binding assays; single lab but multiple methods","pmids":["38665159"],"is_preprint":false},{"year":2025,"finding":"CRL4DCAF12 facilitates proteasomal degradation of MCMBP (MCM-binding protein), thereby enabling incorporation of MCM2 into MCM3-7 subcomplexes and assembly of nascent MCM2-7 complexes; loss of CRL4DCAF12 reduces chromatin-bound nascent MCMs, causes accelerated replication forks, and induces replication stress.","method":"Identification of MCMBP as CRL4DCAF12 substrate, CRL4DCAF12 KO cells, chromatin fractionation, DNA fiber assays, replication stress markers","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 2 / Strong — substrate identification with KO phenotype, multiple orthogonal methods (fractionation, DNA fiber, replication stress assays), peer-reviewed","pmids":["41145411"],"is_preprint":false},{"year":2025,"finding":"DCAF12 catalyzes non-degradative ubiquitination of TRiC/CCT subunits, which enhances chaperonin assembly and folding of cytoskeletal clients (β-actin, tubulin) and oncogenic clients (STAT3, Raptor, mLST8), thereby activating YAP, STAT3, and mTOR pathways to promote lung cancer metastasis.","method":"DCAF12 knockdown in vitro and in vivo metastasis assays, ubiquitination assays of TRiC/CCT subunits, proteostasis/chaperonin assembly assays, pathway activation (YAP/STAT3/mTOR) readouts, pharmacological inhibition with HSF1A","journal":"Advanced science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — KD with in vitro and in vivo phenotypes plus ubiquitination and pathway assays; single lab, relatively new findings","pmids":["41047465"],"is_preprint":false},{"year":2008,"finding":"TCC52 (DCAF12) localizes to the centrosome, as identified by subcellular localization studies in a cancer-testis antigen characterization study.","method":"Subcellular localization/immunostaining identifying centrosomal localization","journal":"Cancer science","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single localization observation without functional follow-up, single lab","pmids":["18957058"],"is_preprint":false}],"current_model":"DCAF12 is the substrate receptor subunit of the CUL4-RBX1-DDB1-DCAF12 (CRL4DCAF12) E3 ubiquitin ligase complex; it uses a WD40 β-propeller domain with a positively charged central pocket to recognize C-terminal di-Glu (double glutamate) degrons on substrates including MAGE-A3/6, MOV10, CCT5 (preferentially in its monomeric, unassembled form), and MCMBP, driving their proteasomal degradation to regulate autophagy, RNA silencing, chaperonin assembly quality control, and MCM complex biogenesis/DNA replication licensing; additionally, DCAF12 can catalyze non-degradative ubiquitination of TRiC/CCT subunits to enhance chaperonin function and downstream oncogenic signaling, and it acts as an IAP antagonist by translocating from nucleus to cytoplasm upon apoptotic stimuli to block XIAP–caspase interactions and facilitate caspase activation."},"narrative":{"mechanistic_narrative":"DCAF12 is the substrate-receptor subunit of a CUL4-DDB1 (CRL4) E3 ubiquitin ligase that recognizes substrates through a C-terminal acidic di-glutamate degron and directs their proteasomal degradation to regulate diverse cellular processes [PMID:34065512, PMID:36715408]. Structurally, DCAF12 uses a WD40 β-propeller with a positively charged central pocket to engage the C-terminal di-Glu motif, binding degron peptides of CCT5 and MAGEA3 with nanomolar affinity [PMID:36715408, PMID:38665159]. Through this degron-recognition mechanism CRL4DCAF12 degrades MAGE-A3/6 in response to nutrient deprivation to enable starvation-induced autophagy [PMID:31267705], degrades the RNA helicase MOV10 — a function required in mice for normal spermatogenesis and T cell activation [PMID:34065512], degrades monomeric (but not TRiC-assembled) CCT5 as a chaperonin assembly quality-control step [PMID:36715408], and degrades MCMBP to license incorporation of MCM2 into MCM2-7 complexes, preventing replication stress [PMID:41145411]. Beyond canonical degradation, DCAF12 catalyzes non-degradative ubiquitination of TRiC/CCT subunits that enhances chaperonin folding of cytoskeletal and oncogenic clients and activates YAP, STAT3, and mTOR signaling to promote lung cancer metastasis [PMID:41047465]. Independently of its ligase role, DCAF12 acts as an IAP antagonist: it binds the BIR domains of XIAP, cIAP1/2, and BRUCE and, upon apoptotic stimuli, translocates from nucleus to cytoplasm to block XIAP–caspase interactions and facilitate caspase activation, a function conserved in Drosophila where DCAF12 is required for IAP cleavage and RHG-mediated apoptosis [PMID:26972874, PMID:35459779]. In Drosophila it also functions as a Cul4 cofactor at synapses, controlling neurotransmitter release and glutamate receptor abundance [PMID:30670470].","teleology":[{"year":2008,"claim":"Initial characterization placed the cancer-testis antigen TCC52/DCAF12 at a subcellular location, providing a first physical anchor before any biochemical function was known.","evidence":"Subcellular immunostaining in a cancer-testis antigen study","pmids":["18957058"],"confidence":"Low","gaps":["Single localization observation without functional follow-up","No link to ubiquitin ligase activity established","Centrosomal localization not corroborated by later mechanistic studies"]},{"year":2016,"claim":"Drosophila genetics established that DCAF12 is required for apoptosis, showing it is necessary and sufficient for RHG-mediated death and limits tumor growth, but left the molecular mechanism open.","evidence":"Drosophila loss-of-function, apoptosis assays, genetic epistasis with pro-apoptotic and tumor suppressor genes","pmids":["26972874"],"confidence":"Medium","gaps":["Direct biochemical mechanism for IAP cleavage not defined","Single model organism","Relationship to ubiquitin ligase activity unresolved"]},{"year":2019,"claim":"Identification of CRL4-DCAF12 as the E3 ligase degrading MAGE-A3/6 under starvation defined DCAF12 as a substrate receptor coupling protein degradation to autophagy regulation.","evidence":"Proteomic interactor analysis, proteasome inhibitor assays, complex identification, autophagy functional assays","pmids":["31267705"],"confidence":"Medium","gaps":["Degron recognition basis not yet structurally resolved","Single lab","Physiological scope beyond starvation unclear"]},{"year":2019,"claim":"Synaptic studies in Drosophila showed DCAF12 acts as a Cul4 cofactor with distinct pre- and postsynaptic roles, broadening its function beyond apoptosis to neuronal regulation.","evidence":"Genetic deletion, tissue-specific rescue, NMJ electrophysiology, epistasis with Cul4","pmids":["30670470"],"confidence":"High","gaps":["Synaptic substrates of CRL4DCAF12 not identified","Conservation in mammalian neurons untested"]},{"year":2021,"claim":"Discovery of MOV10 as a substrate recognized via a C-terminal acidic degron, combined with knockout mice, tied DCAF12-mediated degradation to RNA silencing control and in vivo phenotypes in spermatogenesis and T cell activation.","evidence":"Reciprocal complex purification, CRL dependence assays, Dcaf12 knockout mice, protein-level and phenotypic analysis","pmids":["34065512"],"confidence":"High","gaps":["Atomic basis of degron recognition not resolved here","Full substrate repertoire in vivo unknown"]},{"year":2023,"claim":"A cryo-EM structure of DDB1-DCAF12-CCT5 explained substrate selection at near-atomic resolution and revealed assembly-state-dependent ubiquitination, establishing CRL4DCAF12 in chaperonin assembly quality control.","evidence":"2.8 Å cryo-EM structure, reconstituted ubiquitination of monomeric vs. assembled CCT5, degron-contact mutagenesis","pmids":["36715408"],"confidence":"High","gaps":["How DCAF12 discriminates monomeric from assembled CCT5 mechanistically","In vivo consequences of CCT5 degradation not fully mapped"]},{"year":2024,"claim":"A second structure with MAGEA3 plus biophysical/cellular binding assays generalized the di-Glu degron recognition mechanism across substrates, defining the receptor residues and nanomolar binding affinities.","evidence":"3.17 Å cryo-EM structure, NanoBRET, in vitro and cellular biophysical binding assays","pmids":["38665159"],"confidence":"High","gaps":["Degron prediction across the full substrate space not completed","Single lab"]},{"year":2025,"claim":"Identification of MCMBP as a CRL4DCAF12 substrate connected the ligase to MCM2-7 assembly and DNA replication licensing, with loss causing replication stress.","evidence":"Substrate identification, KO cells, chromatin fractionation, DNA fiber assays, replication stress markers","pmids":["41145411"],"confidence":"High","gaps":["Whether MCMBP carries a canonical di-Glu degron not stated","Cell-cycle regulation of this activity unknown"]},{"year":2025,"claim":"Demonstration of non-degradative TRiC/CCT ubiquitination revealed a second mode of DCAF12 action that enhances chaperonin folding and drives YAP/STAT3/mTOR signaling and lung cancer metastasis.","evidence":"Knockdown with in vitro/in vivo metastasis assays, ubiquitination assays, pathway activation readouts, HSF1A inhibition","pmids":["41047465"],"confidence":"Medium","gaps":["Ubiquitin linkage type and how it avoids degradation not defined","Reconciliation with degradative CCT5 regulation unclear","Single lab"]},{"year":2022,"claim":"Human DCAF12 was shown to antagonize IAPs directly by BIR-domain binding and apoptosis-induced nucleocytoplasmic translocation, mechanizing the apoptotic role first seen in flies and adding NF-κB suppression.","evidence":"Co-IP with multiple IAPs, subcellular fractionation upon apoptotic stimuli, BIR domain mapping, caspase and NF-κB assays","pmids":["35459779"],"confidence":"Medium","gaps":["Whether this is independent of ubiquitin ligase activity not fully resolved","Trigger of translocation not defined","Single lab"]},{"year":null,"claim":"How DCAF12 toggles between degradative and non-degradative ubiquitination, and between ligase-dependent and IAP-antagonist roles, and what governs its substrate repertoire in different tissues, remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No unifying model for choice of ubiquitin outcome","Regulation of substrate selection across contexts unknown","Mechanistic basis of nuclear-cytoplasmic shuttling uncharacterized"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[3,6,8]},{"term_id":"GO:0016874","term_label":"ligase activity","supporting_discovery_ids":[0,1,3,7]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[1,3,6]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[5]}],"localization":[{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[5]},{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[5]},{"term_id":"GO:0005815","term_label":"microtubule organizing center","supporting_discovery_ids":[9]}],"pathway":[{"term_id":"R-HSA-392499","term_label":"Metabolism of proteins","supporting_discovery_ids":[0,1,3,7]},{"term_id":"R-HSA-9612973","term_label":"Autophagy","supporting_discovery_ids":[0]},{"term_id":"R-HSA-5357801","term_label":"Programmed Cell Death","supporting_discovery_ids":[4,5]},{"term_id":"R-HSA-69306","term_label":"DNA Replication","supporting_discovery_ids":[7]}],"complexes":["CRL4-DCAF12 (CUL4-RBX1-DDB1-DCAF12) E3 ubiquitin ligase"],"partners":["DDB1","CUL4","MOV10","CCT5","MAGEA3","MCMBP","XIAP"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q5T6F0","full_name":"DDB1- and CUL4-associated factor 12","aliases":["Centrosome-related protein TCC52","Testis cancer centrosome-related protein","WD repeat-containing protein 40A"],"length_aa":453,"mass_kda":50.5,"function":"Substrate-recognition component of a DCX (DDB1-CUL4-X-box) E3 ubiquitin-protein ligase complex of the DesCEND (destruction via C-end degrons) pathway, which recognizes a C-degron located at the extreme C terminus of target proteins, leading to their ubiquitination and degradation (PubMed:16949367, PubMed:16964240, PubMed:29779948). The C-degron recognized by the DesCEND pathway is usually a motif of less than ten residues and can be present in full-length proteins, truncated proteins or proteolytically cleaved forms (PubMed:29779948). The DCX(DCAF12) complex specifically recognizes proteins with a diglutamate (Glu-Glu) at the C-terminus, such as MAGEA3, MAGEA6 and CCT5, leading to their ubiquitination and degradation (PubMed:29779948, PubMed:31267705). Ubiquitination of MAGEA3, MAGEA6 by DCX(DCAF12) complex is required for starvation-induced autophagy (PubMed:31267705). Also directly recognizes the C-terminal glutamate-leucine (Glu-Leu) degron as an alternative degron in proteins such as MOV10, leading to their ubiquitination and degradation. Controls the protein level of MOV10 during spermatogenesis and in T cells, especially after their activation (PubMed:34065512)","subcellular_location":"Cytoplasm; Cytoplasm, cytoskeleton, microtubule organizing center, centrosome; Nucleus","url":"https://www.uniprot.org/uniprotkb/Q5T6F0/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/DCAF12","classification":"Not Classified","n_dependent_lines":9,"n_total_lines":1208,"dependency_fraction":0.0074503311258278145},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"DDB1","stoichiometry":0.2},{"gene":"VPS35","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/DCAF12","total_profiled":1310},"omim":[{"mim_id":"620087","title":"DDB1- AND CUL4-ASSOCIATED FACTOR 12; DCAF12","url":"https://www.omim.org/entry/620087"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/DCAF12"},"hgnc":{"alias_symbol":["DKFZP434O125","MGC1058","CT102","TCC52"],"prev_symbol":["KIAA1892","WDR40A"]},"alphafold":{"accession":"Q5T6F0","domains":[{"cath_id":"2.130.10.10","chopping":"81-377_385-451","consensus_level":"high","plddt":91.8516,"start":81,"end":451}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q5T6F0","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q5T6F0-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q5T6F0-F1-predicted_aligned_error_v6.png","plddt_mean":84.31},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=DCAF12","jax_strain_url":"https://www.jax.org/strain/search?query=DCAF12"},"sequence":{"accession":"Q5T6F0","fasta_url":"https://rest.uniprot.org/uniprotkb/Q5T6F0.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q5T6F0/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q5T6F0"}},"corpus_meta":[{"pmid":"21325547","id":"PMC_21325547","title":"Evaluation of a DNA microarray (Check-MDR CT102) for rapid detection of TEM, SHV, and CTX-M extended-spectrum β-lactamases and of KPC, OXA-48, VIM, IMP, and NDM-1 carbapenemases.","date":"2011","source":"Journal of clinical microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/21325547","citation_count":101,"is_preprint":false},{"pmid":"31267705","id":"PMC_31267705","title":"Regulation of MAGE-A3/6 by the CRL4-DCAF12 ubiquitin ligase and nutrient availability.","date":"2019","source":"EMBO reports","url":"https://pubmed.ncbi.nlm.nih.gov/31267705","citation_count":39,"is_preprint":false},{"pmid":"34065512","id":"PMC_34065512","title":"CRL4-DCAF12 Ubiquitin Ligase Controls MOV10 RNA Helicase during Spermatogenesis and T Cell Activation.","date":"2021","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/34065512","citation_count":21,"is_preprint":false},{"pmid":"30670470","id":"PMC_30670470","title":"Cul4 ubiquitin ligase cofactor DCAF12 promotes neurotransmitter release and homeostatic plasticity.","date":"2019","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/30670470","citation_count":19,"is_preprint":false},{"pmid":"36715408","id":"PMC_36715408","title":"Recognition of the CCT5 di-Glu degron by CRL4DCAF12 is dependent on TRiC assembly.","date":"2023","source":"The EMBO journal","url":"https://pubmed.ncbi.nlm.nih.gov/36715408","citation_count":19,"is_preprint":false},{"pmid":"26972874","id":"PMC_26972874","title":"Control of apoptosis by Drosophila DCAF12.","date":"2016","source":"Developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/26972874","citation_count":18,"is_preprint":false},{"pmid":"35508302","id":"PMC_35508302","title":"Activity and Tissue Distribution of Antisense Oligonucleotide CT102 Encapsulated with Cytidinyl/Cationic Lipid against Hepatocellular Carcinoma.","date":"2022","source":"Molecular pharmaceutics","url":"https://pubmed.ncbi.nlm.nih.gov/35508302","citation_count":16,"is_preprint":false},{"pmid":"18957058","id":"PMC_18957058","title":"Novel centrosome protein, TCC52, is a cancer-testis antigen.","date":"2008","source":"Cancer science","url":"https://pubmed.ncbi.nlm.nih.gov/18957058","citation_count":10,"is_preprint":false},{"pmid":"38665159","id":"PMC_38665159","title":"Probing the CRL4DCAF12 interactions with MAGEA3 and CCT5 di-Glu C-terminal degrons.","date":"2024","source":"PNAS nexus","url":"https://pubmed.ncbi.nlm.nih.gov/38665159","citation_count":5,"is_preprint":false},{"pmid":"35459779","id":"PMC_35459779","title":"DCAF12 promotes apoptosis and inhibits NF-κB activation by acting as an endogenous antagonist of IAPs.","date":"2022","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/35459779","citation_count":5,"is_preprint":false},{"pmid":"35655486","id":"PMC_35655486","title":"DCAF12 and HSPA1A May Serve as Potential Diagnostic Biomarkers for Myasthenia Gravis.","date":"2022","source":"BioMed research international","url":"https://pubmed.ncbi.nlm.nih.gov/35655486","citation_count":4,"is_preprint":false},{"pmid":"41047465","id":"PMC_41047465","title":"DCAF12 Ubiquitin Ligase Promotes Lung Cancer Metastasis by Modulating the TRiC/CCT Chaperonin Complex.","date":"2025","source":"Advanced science (Weinheim, Baden-Wurttemberg, Germany)","url":"https://pubmed.ncbi.nlm.nih.gov/41047465","citation_count":2,"is_preprint":false},{"pmid":"41145411","id":"PMC_41145411","title":"CRL4DCAF12 regulation of MCMBP ensures optimal licensing of DNA replication.","date":"2025","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/41145411","citation_count":1,"is_preprint":false},{"pmid":"41175836","id":"PMC_41175836","title":"Anti-IGF-1R antisense oligonucleotide CT102: A promising therapeutic agent for graves' ophthalmopathy.","date":"2025","source":"The Journal of pharmacology and experimental therapeutics","url":"https://pubmed.ncbi.nlm.nih.gov/41175836","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2024.11.26.625391","title":"CRL4  <sup>DCAF12</sup>  regulation of MCMBP ensures optimal licensing of DNA replication","date":"2024-11-28","source":"bioRxiv","url":"https://doi.org/10.1101/2024.11.26.625391","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":8852,"output_tokens":2764,"usd":0.034008,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":9972,"output_tokens":3781,"usd":0.072193,"stage2_stop_reason":"end_turn"},"total_usd":0.106201,"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\": 2019,\n      \"finding\": \"CRL4-DCAF12 E3 ubiquitin ligase mediates proteasome-dependent degradation of MAGE-A3/6 proteins in response to nutrient deprivation, and this degradation is required for starvation-induced autophagy.\",\n      \"method\": \"Proteomic analysis of MAGE-A3/6 interactors, proteasome inhibitor assays, CRL4-DCAF12 complex identification, functional autophagy assays\",\n      \"journal\": \"EMBO reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — proteomic identification of E3 ligase complex plus functional autophagy readout, single lab\",\n      \"pmids\": [\"31267705\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"CRL4-DCAF12 recognizes a C-terminal acidic amino acid degron on MOV10 (an RNA helicase) and promotes its proteasome- and CRL-dependent degradation; loss of Dcaf12 in mice elevates MOV10 levels, impairs spermatogenesis, and disrupts T cell activation.\",\n      \"method\": \"Affinity purification of CRL4-DCAF12 complexes, proteasome inhibitor assays, Dcaf12 knockout mice, analysis of MOV10 protein levels, spermatogenesis and T cell phenotyping\",\n      \"journal\": \"International journal of molecular sciences\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal complex purification, CRL dependence assay, and in vivo KO mouse with defined cellular phenotypes across two biological contexts\",\n      \"pmids\": [\"34065512\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Drosophila DCAF12 acts as a cofactor of Cullin4 (Cul4) ubiquitin ligase at synapses: presynaptically it promotes evoked neurotransmitter release and synaptic homeostatic potentiation; postsynaptically (in muscle nuclei) it down-regulates glutamate receptor subunits GluRIIA, GluRIIC, and GluRIID in a Cul4-dependent manner.\",\n      \"method\": \"Genetic deletion in Drosophila, presynaptic vs postsynaptic rescue experiments, electrophysiology at larval NMJs, genetic epistasis with Cul4\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic epistasis, tissue-specific rescue, electrophysiological readouts, multiple independent functions dissected\",\n      \"pmids\": [\"30670470\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"Cryo-EM structure of DDB1-DCAF12-CCT5 complex at 2.8 Å shows DCAF12 acts as a WD40 β-propeller substrate receptor that binds the C-terminal di-Glu (double glutamate) motif of CCT5 via a positively charged central pocket; DCAF12 ubiquitinates monomeric CCT5 but not CCT5 assembled into the TRiC complex, indicating CRL4DCAF12 functions in Assembly Quality Control.\",\n      \"method\": \"Cryo-EM structure determination, biochemical ubiquitination assays with monomeric vs. assembled CCT5, mutagenesis of degron contacts\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — near-atomic cryo-EM structure plus reconstituted in vitro ubiquitination assay with functional validation of assembly state dependence\",\n      \"pmids\": [\"36715408\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Drosophila DCAF12 is required for Diap1 (Drosophila IAP1) cleavage in response to pro-apoptotic signals and is necessary and sufficient for RHG (Reaper, Hid, Grim)-mediated apoptosis; loss of DCAF12 impairs elimination of supernumerary cells and enhances tumor growth caused by loss of neoplastic tumor suppressors.\",\n      \"method\": \"Drosophila genetic loss-of-function, apoptosis assays, genetic epistasis with pro-apoptotic and tumor suppressor genes\",\n      \"journal\": \"Developmental biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Drosophila KO with defined apoptotic phenotype and epistasis, single lab\",\n      \"pmids\": [\"26972874\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Human DCAF12 binds multiple IAP family members (XIAP, cIAP1, cIAP2, BRUCE) via their BIR domains; in response to apoptotic stimuli DCAF12 translocates from the nucleus to the cytoplasm where it blocks XIAP–caspase interactions to facilitate caspase activation; DCAF12 also suppresses NF-κB activation in an IAP-binding-dependent manner.\",\n      \"method\": \"Co-immunoprecipitation of DCAF12 with IAPs, subcellular fractionation/localization upon apoptotic stimuli, domain-mapping (BIR domain binding), caspase activation assays, NF-κB reporter assays\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP with multiple IAPs, translocation experiments, functional caspase and NF-κB assays; single lab\",\n      \"pmids\": [\"35459779\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Cryo-EM structure of DDB1-DCAF12-MAGEA3 complex at 3.17 Å identifies key DCAF12 WD40-domain residues responsible for recognizing the C-terminal di-Glu degron of MAGEA3; biophysical and NanoBRET assays show nanomolar-affinity interactions between DCAF12 and C-terminal degron peptides of both MAGEA3 and CCT5 in vitro and in cells.\",\n      \"method\": \"Cryo-EM structure determination, NanoBRET proximity assays, biophysical binding assays (in vitro and cellular)\",\n      \"journal\": \"PNAS nexus\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — atomic-resolution cryo-EM structure plus orthogonal biophysical and cell-based binding assays; single lab but multiple methods\",\n      \"pmids\": [\"38665159\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"CRL4DCAF12 facilitates proteasomal degradation of MCMBP (MCM-binding protein), thereby enabling incorporation of MCM2 into MCM3-7 subcomplexes and assembly of nascent MCM2-7 complexes; loss of CRL4DCAF12 reduces chromatin-bound nascent MCMs, causes accelerated replication forks, and induces replication stress.\",\n      \"method\": \"Identification of MCMBP as CRL4DCAF12 substrate, CRL4DCAF12 KO cells, chromatin fractionation, DNA fiber assays, replication stress markers\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — substrate identification with KO phenotype, multiple orthogonal methods (fractionation, DNA fiber, replication stress assays), peer-reviewed\",\n      \"pmids\": [\"41145411\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"DCAF12 catalyzes non-degradative ubiquitination of TRiC/CCT subunits, which enhances chaperonin assembly and folding of cytoskeletal clients (β-actin, tubulin) and oncogenic clients (STAT3, Raptor, mLST8), thereby activating YAP, STAT3, and mTOR pathways to promote lung cancer metastasis.\",\n      \"method\": \"DCAF12 knockdown in vitro and in vivo metastasis assays, ubiquitination assays of TRiC/CCT subunits, proteostasis/chaperonin assembly assays, pathway activation (YAP/STAT3/mTOR) readouts, pharmacological inhibition with HSF1A\",\n      \"journal\": \"Advanced science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — KD with in vitro and in vivo phenotypes plus ubiquitination and pathway assays; single lab, relatively new findings\",\n      \"pmids\": [\"41047465\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"TCC52 (DCAF12) localizes to the centrosome, as identified by subcellular localization studies in a cancer-testis antigen characterization study.\",\n      \"method\": \"Subcellular localization/immunostaining identifying centrosomal localization\",\n      \"journal\": \"Cancer science\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single localization observation without functional follow-up, single lab\",\n      \"pmids\": [\"18957058\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"DCAF12 is the substrate receptor subunit of the CUL4-RBX1-DDB1-DCAF12 (CRL4DCAF12) E3 ubiquitin ligase complex; it uses a WD40 β-propeller domain with a positively charged central pocket to recognize C-terminal di-Glu (double glutamate) degrons on substrates including MAGE-A3/6, MOV10, CCT5 (preferentially in its monomeric, unassembled form), and MCMBP, driving their proteasomal degradation to regulate autophagy, RNA silencing, chaperonin assembly quality control, and MCM complex biogenesis/DNA replication licensing; additionally, DCAF12 can catalyze non-degradative ubiquitination of TRiC/CCT subunits to enhance chaperonin function and downstream oncogenic signaling, and it acts as an IAP antagonist by translocating from nucleus to cytoplasm upon apoptotic stimuli to block XIAP–caspase interactions and facilitate caspase activation.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"DCAF12 is the substrate-receptor subunit of a CUL4-DDB1 (CRL4) E3 ubiquitin ligase that recognizes substrates through a C-terminal acidic di-glutamate degron and directs their proteasomal degradation to regulate diverse cellular processes [#1, #3]. Structurally, DCAF12 uses a WD40 β-propeller with a positively charged central pocket to engage the C-terminal di-Glu motif, binding degron peptides of CCT5 and MAGEA3 with nanomolar affinity [#3, #6]. Through this degron-recognition mechanism CRL4DCAF12 degrades MAGE-A3/6 in response to nutrient deprivation to enable starvation-induced autophagy [#0], degrades the RNA helicase MOV10 — a function required in mice for normal spermatogenesis and T cell activation [#1], degrades monomeric (but not TRiC-assembled) CCT5 as a chaperonin assembly quality-control step [#3], and degrades MCMBP to license incorporation of MCM2 into MCM2-7 complexes, preventing replication stress [#7]. Beyond canonical degradation, DCAF12 catalyzes non-degradative ubiquitination of TRiC/CCT subunits that enhances chaperonin folding of cytoskeletal and oncogenic clients and activates YAP, STAT3, and mTOR signaling to promote lung cancer metastasis [#8]. Independently of its ligase role, DCAF12 acts as an IAP antagonist: it binds the BIR domains of XIAP, cIAP1/2, and BRUCE and, upon apoptotic stimuli, translocates from nucleus to cytoplasm to block XIAP–caspase interactions and facilitate caspase activation, a function conserved in Drosophila where DCAF12 is required for IAP cleavage and RHG-mediated apoptosis [#4, #5]. In Drosophila it also functions as a Cul4 cofactor at synapses, controlling neurotransmitter release and glutamate receptor abundance [#2].\",\n  \"teleology\": [\n    {\n      \"year\": 2008,\n      \"claim\": \"Initial characterization placed the cancer-testis antigen TCC52/DCAF12 at a subcellular location, providing a first physical anchor before any biochemical function was known.\",\n      \"evidence\": \"Subcellular immunostaining in a cancer-testis antigen study\",\n      \"pmids\": [\"18957058\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Single localization observation without functional follow-up\", \"No link to ubiquitin ligase activity established\", \"Centrosomal localization not corroborated by later mechanistic studies\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Drosophila genetics established that DCAF12 is required for apoptosis, showing it is necessary and sufficient for RHG-mediated death and limits tumor growth, but left the molecular mechanism open.\",\n      \"evidence\": \"Drosophila loss-of-function, apoptosis assays, genetic epistasis with pro-apoptotic and tumor suppressor genes\",\n      \"pmids\": [\"26972874\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct biochemical mechanism for IAP cleavage not defined\", \"Single model organism\", \"Relationship to ubiquitin ligase activity unresolved\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Identification of CRL4-DCAF12 as the E3 ligase degrading MAGE-A3/6 under starvation defined DCAF12 as a substrate receptor coupling protein degradation to autophagy regulation.\",\n      \"evidence\": \"Proteomic interactor analysis, proteasome inhibitor assays, complex identification, autophagy functional assays\",\n      \"pmids\": [\"31267705\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Degron recognition basis not yet structurally resolved\", \"Single lab\", \"Physiological scope beyond starvation unclear\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Synaptic studies in Drosophila showed DCAF12 acts as a Cul4 cofactor with distinct pre- and postsynaptic roles, broadening its function beyond apoptosis to neuronal regulation.\",\n      \"evidence\": \"Genetic deletion, tissue-specific rescue, NMJ electrophysiology, epistasis with Cul4\",\n      \"pmids\": [\"30670470\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Synaptic substrates of CRL4DCAF12 not identified\", \"Conservation in mammalian neurons untested\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Discovery of MOV10 as a substrate recognized via a C-terminal acidic degron, combined with knockout mice, tied DCAF12-mediated degradation to RNA silencing control and in vivo phenotypes in spermatogenesis and T cell activation.\",\n      \"evidence\": \"Reciprocal complex purification, CRL dependence assays, Dcaf12 knockout mice, protein-level and phenotypic analysis\",\n      \"pmids\": [\"34065512\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Atomic basis of degron recognition not resolved here\", \"Full substrate repertoire in vivo unknown\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"A cryo-EM structure of DDB1-DCAF12-CCT5 explained substrate selection at near-atomic resolution and revealed assembly-state-dependent ubiquitination, establishing CRL4DCAF12 in chaperonin assembly quality control.\",\n      \"evidence\": \"2.8 Å cryo-EM structure, reconstituted ubiquitination of monomeric vs. assembled CCT5, degron-contact mutagenesis\",\n      \"pmids\": [\"36715408\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How DCAF12 discriminates monomeric from assembled CCT5 mechanistically\", \"In vivo consequences of CCT5 degradation not fully mapped\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"A second structure with MAGEA3 plus biophysical/cellular binding assays generalized the di-Glu degron recognition mechanism across substrates, defining the receptor residues and nanomolar binding affinities.\",\n      \"evidence\": \"3.17 Å cryo-EM structure, NanoBRET, in vitro and cellular biophysical binding assays\",\n      \"pmids\": [\"38665159\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Degron prediction across the full substrate space not completed\", \"Single lab\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Identification of MCMBP as a CRL4DCAF12 substrate connected the ligase to MCM2-7 assembly and DNA replication licensing, with loss causing replication stress.\",\n      \"evidence\": \"Substrate identification, KO cells, chromatin fractionation, DNA fiber assays, replication stress markers\",\n      \"pmids\": [\"41145411\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether MCMBP carries a canonical di-Glu degron not stated\", \"Cell-cycle regulation of this activity unknown\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Demonstration of non-degradative TRiC/CCT ubiquitination revealed a second mode of DCAF12 action that enhances chaperonin folding and drives YAP/STAT3/mTOR signaling and lung cancer metastasis.\",\n      \"evidence\": \"Knockdown with in vitro/in vivo metastasis assays, ubiquitination assays, pathway activation readouts, HSF1A inhibition\",\n      \"pmids\": [\"41047465\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Ubiquitin linkage type and how it avoids degradation not defined\", \"Reconciliation with degradative CCT5 regulation unclear\", \"Single lab\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Human DCAF12 was shown to antagonize IAPs directly by BIR-domain binding and apoptosis-induced nucleocytoplasmic translocation, mechanizing the apoptotic role first seen in flies and adding NF-κB suppression.\",\n      \"evidence\": \"Co-IP with multiple IAPs, subcellular fractionation upon apoptotic stimuli, BIR domain mapping, caspase and NF-κB assays\",\n      \"pmids\": [\"35459779\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether this is independent of ubiquitin ligase activity not fully resolved\", \"Trigger of translocation not defined\", \"Single lab\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How DCAF12 toggles between degradative and non-degradative ubiquitination, and between ligase-dependent and IAP-antagonist roles, and what governs its substrate repertoire in different tissues, remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No unifying model for choice of ubiquitin outcome\", \"Regulation of substrate selection across contexts unknown\", \"Mechanistic basis of nuclear-cytoplasmic shuttling uncharacterized\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [3, 6, 8]},\n      {\"term_id\": \"GO:0016874\", \"supporting_discovery_ids\": [0, 1, 3, 7]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [1, 3, 6]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [5]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [5]},\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [5]},\n      {\"term_id\": \"GO:0005815\", \"supporting_discovery_ids\": [9]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [0, 1, 3, 7]},\n      {\"term_id\": \"R-HSA-9612973\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"R-HSA-5357801\", \"supporting_discovery_ids\": [4, 5]},\n      {\"term_id\": \"R-HSA-69306\", \"supporting_discovery_ids\": [7]}\n    ],\n    \"complexes\": [\"CRL4-DCAF12 (CUL4-RBX1-DDB1-DCAF12) E3 ubiquitin ligase\"],\n    \"partners\": [\"DDB1\", \"CUL4\", \"MOV10\", \"CCT5\", \"MAGEA3\", \"MCMBP\", \"XIAP\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"tie","faith_supported":6,"faith_total":6,"faith_pct":100.0}}