{"gene":"MMS19","run_date":"2026-06-10T02:59:50","timeline":{"discoveries":[{"year":2012,"finding":"MMS19 is a member of the cytosolic iron-sulfur protein assembly (CIA) machinery, functioning as part of a CIA targeting complex that specifically interacts with and facilitates iron-sulfur (Fe-S) cluster insertion into apoproteins involved in methionine biosynthesis, DNA replication, DNA repair, and telomere maintenance. MMS19 serves as an adapter between early-acting CIA components (CIAO1, IOP1/NARFL, MIP18/FAM96B) and a subset of cellular Fe-S proteins.","method":"Co-immunoprecipitation, mass spectrometry, in vitro binding assays, RNAi knockdown with defined cellular phenotypes (Fe-S protein instability)","journal":"Science","confidence":"High","confidence_rationale":"Tier 2 / Strong — two independent labs published simultaneously with reciprocal Co-IP, MS interactome, and KO phenotype; replicated findings","pmids":["22678362","22678361"],"is_preprint":false},{"year":2012,"finding":"MMS19 forms a complex with the CIA proteins CIAO1, IOP1, and MIP18 in the cytoplasm, and also binds directly to multiple nuclear Fe-S proteins involved in DNA metabolism. Knockout of Mms19 in mice causes preimplantation lethality, and loss of MMS19 leads to failure of Fe-S cluster transfer to target proteins and consequent Fe-S protein instability.","method":"Co-immunoprecipitation, siRNA knockdown, Mms19 knockout mouse model","journal":"Science","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, KO model with defined phenotype, replicated by independent lab same year","pmids":["22678361"],"is_preprint":false},{"year":2010,"finding":"MMS19 forms a complex with XPD (a TFIIH subunit) and MIP18, FAM96B, CIAO1, and ANT2, designated the MMXD complex, that does not contain other TFIIH subunits. MMS19, MIP18, and XPD localize to the mitotic spindle during mitosis. siRNA knockdown of MMS19, MIP18, or XPD leads to improper chromosome segregation and accumulation of nuclei with abnormal shapes.","method":"Co-immunoprecipitation, siRNA knockdown, immunofluorescence localization to mitotic spindle","journal":"Molecular Cell","confidence":"High","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP identifying complex composition, direct localization experiment, KD with defined mitotic phenotype, single lab with multiple orthogonal methods","pmids":["20797633"],"is_preprint":false},{"year":2012,"finding":"MMS19 simultaneously binds CIAO1 and Fe-S proteins, confirming its role as a central CIA component bridging cluster donor proteins and apoprotein recipients. MIP18 also interacts with both CIAO1 and Fe-S proteins by binding Fe-S cluster coordinating regions. ANT2 interacts with Fe-S apoproteins and MMS19 within the CIA complex but not with the individual proteins.","method":"Co-immunoprecipitation, mass spectrometry-based interactome analysis, in vitro binding","journal":"The Journal of Biological Chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP with defined binding partners, single lab, two orthogonal methods (Co-IP and MS)","pmids":["23150669"],"is_preprint":false},{"year":2013,"finding":"MMS19, MIP18, and CIAO1 form a tight 'core' CIA complex, while IOP1 is an 'external' component. Deficiency in any core component leads to down-regulation of all core components; IOP1 knockdown does not affect core component levels. MIP18 bridges MMS19 and CIAO1, and MMS19 interacts directly with target Fe-S apoproteins.","method":"Co-immunoprecipitation (in vivo and in vitro), siRNA knockdown with Western blot quantification","journal":"The Journal of Biological Chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo and in vitro Co-IP, knockdown experiments, single lab with two orthogonal methods","pmids":["23585563"],"is_preprint":false},{"year":2000,"finding":"Human MMS19 (hMMS19) directly interacts with the XPB and XPD helicase subunits of the NER-transcription factor TFIIH, as shown by co-immunoprecipitation. hMMS19 is localized to the nucleus, consistent with a repair function.","method":"Co-immunoprecipitation, nuclear localization by subcellular fractionation/immunofluorescence","journal":"Nucleic Acids Research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP demonstrating XPB/XPD interaction, direct localization experiment, single lab","pmids":["11071939"],"is_preprint":false},{"year":2001,"finding":"Human MMS19 interacts with the N-terminal PAS-A/B domain of the nuclear receptor coactivator RAC3 in vivo and in vitro via a conserved C-terminal domain of hMMS19. hMMS19 also interacts with estrogen receptors in a ligand-independent manner but not with retinoic acid receptor or thyroid hormone receptor. Overexpression of full-length hMMS19 enhances ER-mediated transcriptional activation by stimulating AF-1 activity of ERα but not AF-2 activity.","method":"Co-immunoprecipitation (in vivo and in vitro), overexpression/dominant-negative assays, transcriptional reporter assay","journal":"The Journal of Biological Chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo and in vitro Co-IP, functional reporter assays, single lab with multiple orthogonal methods","pmids":["11279242"],"is_preprint":false},{"year":1996,"finding":"Yeast MMS19 is required for both nucleotide excision repair (NER) and RNA polymerase II transcription. mms19Δ cell extracts are deficient in Pol II transcription; this defect is corrected by addition of purified TFIIH but not by purified Mms19 protein. Mms19 is not a component of TFIIH or Pol II holoenzyme, but affects their activity as an upstream regulatory element.","method":"Genetic deletion (mms19Δ), in vitro transcription and NER reconstitution assays, complementation with purified TFIIH","journal":"Molecular and Cellular Biology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro reconstitution assays, genetic deletion, complementation with purified proteins; single lab with multiple orthogonal methods","pmids":["8943333"],"is_preprint":false},{"year":2008,"finding":"Yeast Mms19 functions in NER by sustaining adequate cellular concentration of the TFIIH component Rad3 (XPD homologue). In mms19 mutant cells, Rad3 and Ssl2 (XPB homologue) protein levels are significantly reduced (up to 3.5-fold for Rad3). Overexpression of Rad3 from a plasmid restores proficient NER and UV resistance in mms19 mutants, while overexpression of Ssl2 has no effect on repair.","method":"Genetic deletion and overexpression, Western blot quantification, UV sensitivity complementation assay","journal":"PNAS","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic rescue experiment with defined molecular phenotype, single lab, two orthogonal methods","pmids":["18836076"],"is_preprint":false},{"year":1997,"finding":"Yeast mms19 deletion mutant cell-free extracts are deficient for NER in vitro, and the mutant is defective in both transcription-coupled and global genome NER in vivo, as demonstrated by inability to remove cyclobutane-pyrimidine dimers from both transcribed and non-transcribed sequences.","method":"In vitro NER assay, nucleotide-level CPD removal analysis (in vivo strand-specific repair)","journal":"Nucleic Acids Research","confidence":"Medium","confidence_rationale":"Tier 1 / Moderate — in vitro NER reconstitution and strand-specific in vivo repair assay, single lab with two orthogonal methods","pmids":["9321645"],"is_preprint":false},{"year":2006,"finding":"Deletion analysis of MMS19 domains reveals three structurally distinct domains with separable functions: domain A is required for transcription but not NER; domain B is required for NER but not transcription; the C-terminal HEAT repeat domain (domain C) is essential for both NER and transcription functions.","method":"Domain deletion analysis with complementation of yeast mms19Δ mutant phenotypes (UV sensitivity, thermosensitivity)","journal":"DNA Repair","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — systematic domain-deletion/complementation with two defined phenotypic readouts, single lab","pmids":["16797255"],"is_preprint":false},{"year":2018,"finding":"Drosophila Mms19 functions in mitosis by allowing CAK (Cdk7/Cyclin H/Mat1) to become fully active as a Cdk1-activating kinase. Mms19 physically and genetically interacts with Xpd, and this interaction prevents Xpd from binding to the CAK complex; Xpd bound to Mms19 frees CAK to phosphorylate Cdk1 and facilitate progression to metaphase. Mitotic defects in Mms19-deficient Drosophila cells can be rescued by overexpression of the CAK complex.","method":"Genetic rescue (CAK overexpression in Mms19 mutants), physical interaction studies (Co-IP), loss-of-function with mitotic phenotype readout","journal":"Development","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic epistasis (rescue by CAK overexpression) combined with physical interaction studies, single lab with two orthogonal methods","pmids":["29361561"],"is_preprint":false},{"year":2020,"finding":"Drosophila Mms19 promotes spindle and astral microtubule (MT) growth, MT stability, and bundling in neural stem cells through two mechanisms: (1) by stimulating the mitotic kinase cascade to trigger localization of the TACC/Msps MT regulatory complex to the centrosome, and (2) by directly binding to microtubules to stimulate MT stability and bundling.","method":"Loss-of-function with mitotic phenotype quantification, kinase cascade rescue experiments, direct MT-binding assay","journal":"PLoS Genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct MT-binding assay, genetic rescue, KO phenotype with defined readouts; single lab with multiple orthogonal methods","pmids":["33211700"],"is_preprint":false},{"year":2016,"finding":"Human DNA polymerase ε catalytic subunit (POLE1) phosphorylated at serine-1940 interacts with MMS19, but this interaction is not essential: mutation of serine-1940 to alanine caused no defect in proliferation or survival, even after DNA damage. The POLE1-CIAO1 interaction is independent of serine-1940 phosphorylation.","method":"Co-immunoprecipitation, site-directed mutagenesis, cell survival assay","journal":"DNA Repair","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP with mutagenesis, functional cell assay; interaction shown but noted as non-essential (negative functional result)","pmids":["27235625"],"is_preprint":false},{"year":2017,"finding":"MMS19 localizes to the inner membrane of mitochondria and participates in mitochondrial DNA (mtDNA) oxidative damage repair. MMS19 knockdown leads to decreased mtDNA copy number, diminished mtDNA repair capacity, and elevated mtDNA common deletion after oxidative stress. Immunoprecipitation-mass spectrometry identified interaction of MMS19 with ANT2, a mitochondrial ATP metabolism protein.","method":"Subcellular fractionation/mitochondrial localization, siRNA knockdown, immunoprecipitation-mass spectrometry","journal":"Biochemistry and Cell Biology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, fractionation-based localization with functional KD readout; mitochondrial localization contradicts the established cytosolic/nuclear localization in other studies, lowering confidence","pmids":["29035693"],"is_preprint":false},{"year":2023,"finding":"The transcription factor c-MYC directly activates MMS19 expression in bladder cancer cells, as demonstrated by ChIP and luciferase reporter assays, establishing c-MYC as a transcriptional regulator of MMS19.","method":"Chromatin immunoprecipitation (ChIP), luciferase reporter assay","journal":"Tissue & Cell","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, ChIP and reporter assay establish transcriptional regulation but no mechanistic insight into MMS19 protein function","pmids":["37201439"],"is_preprint":false},{"year":2024,"finding":"Patients with MMS19 homozygous in-frame deletion mutations develop a lethal neurodegenerative phenotype with microcephaly, brain malformations, and recurrent infections. Patient-derived fibroblasts show profound alterations in proteome, metabolome, and lipidome, consistent with general failure of cytosolic and nuclear Fe-S protein maturation. MMS19 deficiency was confirmed to be detrimental in zebrafish models.","method":"Genome sequencing, patient fibroblast proteomics/metabolomics/lipidomics, zebrafish knockout model","journal":"Genetics in Medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — human genetic evidence combined with zebrafish KO and multi-omic patient fibroblast analysis; single report with multiple orthogonal methods","pmids":["38411040"],"is_preprint":false}],"current_model":"MMS19 is a scaffold/adapter component of the cytosolic iron-sulfur protein assembly (CIA) targeting complex that bridges early CIA factors (CIAO1, MIP18/FAM96B, IOP1) to recipient Fe-S apoproteins involved in DNA replication, repair, and telomere maintenance; it also facilitates proper chromosome segregation via a TFIIH-independent MMXD complex containing XPD, and in Drosophila promotes mitotic kinase activity by competitively binding XPD to free the CAK complex (Cdk7/CycH/Mat1) to activate Cdk1, as well as directly stabilizing spindle microtubules."},"narrative":{"mechanistic_narrative":"MMS19 is a scaffold component of the cytosolic iron-sulfur protein assembly (CIA) machinery that targets Fe-S cluster insertion to a defined subset of apoproteins acting in DNA replication, repair, telomere maintenance, and methionine biosynthesis [PMID:22678362, PMID:22678361]. It nucleates a core CIA targeting complex with MIP18/FAM96B and CIAO1, in which MIP18 bridges MMS19 and CIAO1 while IOP1/NARFL acts as a more peripheral upstream component; loss of any core subunit destabilizes the others and abolishes Fe-S transfer to recipient apoproteins [PMID:22678361, PMID:23585563]. MMS19 binds CIAO1 and recipient Fe-S apoproteins simultaneously, functioning as the adapter that couples cluster donors to apoprotein acceptors [PMID:23150669]. Beyond cluster delivery, MMS19 directly engages the XPD/XPB helicase subunits of TFIIH and assembles a distinct TFIIH-independent MMXD complex (MMS19-MIP18-XPD-CIAO1-FAM96B-ANT2) that localizes to the mitotic spindle and is required for accurate chromosome segregation [PMID:11071939, PMID:20797633]. In yeast, Mms19 supports both nucleotide excision repair and RNA polymerase II transcription by maintaining cellular levels of the TFIIH subunits Rad3/XPD and Ssl2/XPB, with separable protein domains governing the repair versus transcription functions [PMID:8943333, PMID:18836076, PMID:16797255]. In Drosophila, Mms19 additionally promotes mitosis by sequestering Xpd to free the CAK (Cdk7/Cyclin H/Mat1) complex for Cdk1 activation and by directly binding and stabilizing spindle microtubules [PMID:29361561, PMID:33211700]. Human loss-of-function causes a lethal neurodegenerative disorder with microcephaly and brain malformations driven by global failure of cytosolic and nuclear Fe-S protein maturation [PMID:38411040].","teleology":[{"year":1996,"claim":"Established that Mms19 is required for both NER and Pol II transcription yet is not itself a TFIIH or holoenzyme subunit, defining it as an upstream regulatory factor rather than a core machine component.","evidence":"yeast mms19Δ genetic deletion with in vitro transcription/NER reconstitution and TFIIH complementation","pmids":["8943333"],"confidence":"High","gaps":["Did not identify the molecular target through which Mms19 regulates TFIIH activity","No direct biochemical mechanism for the transcription defect"]},{"year":1997,"claim":"Clarified the scope of the repair defect, showing mms19 loss impairs both transcription-coupled and global-genome NER at the level of dimer removal.","evidence":"in vitro NER assay and strand-specific CPD removal analysis in yeast","pmids":["9321645"],"confidence":"Medium","gaps":["Did not establish whether the defect is direct or secondary to TFIIH dysfunction"]},{"year":2000,"claim":"Provided the first physical link between human MMS19 and the repair machinery by demonstrating direct interaction with TFIIH helicase subunits XPB and XPD.","evidence":"co-immunoprecipitation and nuclear localization in human cells","pmids":["11071939"],"confidence":"Medium","gaps":["Did not determine functional consequence of the XPB/XPD interaction","Single lab without reciprocal validation across systems"]},{"year":2001,"claim":"Suggested a transcriptional-coactivation role by linking MMS19 to nuclear receptor signaling via RAC3 and estrogen receptor AF-1 stimulation.","evidence":"in vivo/in vitro Co-IP and ER reporter assays in human cells","pmids":["11279242"],"confidence":"Medium","gaps":["This activity has not been integrated with the later CIA/Fe-S function","Not independently confirmed"]},{"year":2006,"claim":"Mapped MMS19 into separable functional modules, showing distinct domains drive transcription versus NER and a C-terminal HEAT domain is essential for both.","evidence":"domain-deletion complementation of yeast phenotypes","pmids":["16797255"],"confidence":"Medium","gaps":["Domain assignments not connected to specific binding partners","No structural model of the domains"]},{"year":2008,"claim":"Resolved the mechanism of the NER defect by showing Mms19 sustains Rad3/XPD protein levels, with Rad3 overexpression rescuing repair.","evidence":"genetic deletion/overexpression with Western blot and UV-sensitivity rescue in yeast","pmids":["18836076"],"confidence":"Medium","gaps":["Did not explain why Mms19 loss destabilizes Rad3 (later linked to Fe-S maturation)","Single-lab study"]},{"year":2010,"claim":"Identified the MMXD complex as a TFIIH-independent assembly of MMS19, MIP18, CIAO1, FAM96B and XPD that localizes to the spindle and is required for proper chromosome segregation.","evidence":"reciprocal Co-IP, immunofluorescence and siRNA mitotic phenotyping in human cells","pmids":["20797633"],"confidence":"High","gaps":["Did not define how the complex acts on the spindle mechanistically","Relationship of MMXD to Fe-S maturation not yet established"]},{"year":2012,"claim":"Defined MMS19's central biological role as a CIA targeting-complex adapter that delivers Fe-S clusters to DNA-metabolism apoproteins, unifying the prior repair and transcription phenotypes as downstream consequences of Fe-S maturation failure.","evidence":"co-IP, MS interactome, RNAi/KO phenotyping and an Mms19 knockout mouse (preimplantation lethal), reported by two independent labs","pmids":["22678362","22678361"],"confidence":"High","gaps":["Did not resolve the structural basis of cluster transfer","Selectivity rules for which apoproteins are served not fully defined"]},{"year":2013,"claim":"Refined complex architecture, establishing a tight MMS19-MIP18-CIAO1 core (with MIP18 bridging) and IOP1 as an external component, and showing MMS19 contacts apoprotein recipients directly.","evidence":"in vivo/in vitro Co-IP and knockdown stability analysis in human cells (and JBC interactome mapping)","pmids":["23585563","23150669"],"confidence":"Medium","gaps":["No atomic-resolution structure of the core complex","Mechanism of apoprotein recognition unresolved"]},{"year":2018,"claim":"Revealed a mitotic-kinase mechanism in which Mms19 sequesters Xpd to free CAK for Cdk1 activation, connecting Mms19 to mitotic progression independent of cluster delivery.","evidence":"Drosophila genetic rescue by CAK overexpression plus Co-IP physical interaction","pmids":["29361561"],"confidence":"Medium","gaps":["Not demonstrated in mammalian cells","Single-lab study"]},{"year":2020,"claim":"Showed Mms19 stabilizes spindle and astral microtubules both indirectly via the mitotic kinase cascade/TACC-Msps recruitment and directly by binding microtubules.","evidence":"Drosophila loss-of-function phenotyping, kinase-cascade rescue and direct MT-binding assay","pmids":["33211700"],"confidence":"Medium","gaps":["Direct MT binding not confirmed for human MMS19","Structural basis of MT binding unknown"]},{"year":2024,"claim":"Linked MMS19 to human disease, showing homozygous in-frame deletions cause a lethal neurodegenerative syndrome driven by global cytosolic/nuclear Fe-S maturation failure.","evidence":"genome sequencing, patient-fibroblast multi-omics and zebrafish knockout","pmids":["38411040"],"confidence":"Medium","gaps":["Genotype-phenotype relationship across mutation types not established","Tissue-specific vulnerability mechanism unclear"]},{"year":null,"claim":"How MMS19 mechanistically transfers Fe-S clusters and selects among recipient apoproteins, and whether its mitotic spindle/microtubule roles are conserved in humans and separable from cluster delivery, remain open.","evidence":"no reconstituted transfer mechanism or structure available in the corpus","pmids":[],"confidence":"Low","gaps":["No structure of the CIA targeting complex bound to an apoprotein","Mammalian validation of the CAK/microtubule mechanism lacking","Reconciliation of the reported mitochondrial localization with cytosolic/nuclear roles unresolved"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,1,3,4]},{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[12]}],"localization":[{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[1,3]},{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[5]},{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[2,12]}],"pathway":[{"term_id":"R-HSA-73894","term_label":"DNA Repair","supporting_discovery_ids":[0,7,9]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[2,11]},{"term_id":"R-HSA-74160","term_label":"Gene expression (Transcription)","supporting_discovery_ids":[7]}],"complexes":["CIA targeting complex (MMS19-MIP18-CIAO1)","MMXD complex"],"partners":["CIAO1","FAM96B","IOP1","XPD","XPB","ANT2","POLE1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q96T76","full_name":"MMS19 nucleotide excision repair protein homolog","aliases":["MET18 homolog","MMS19-like protein"],"length_aa":1030,"mass_kda":113.3,"function":"Key component of the cytosolic iron-sulfur protein assembly (CIA) complex, a multiprotein complex that mediates the incorporation of iron-sulfur cluster into apoproteins specifically involved in DNA metabolism and genomic integrity (PubMed:29848660). In the CIA complex, MMS19 acts as an adapter between early-acting CIA components and a subset of cellular target iron-sulfur proteins such as ERCC2/XPD, FANCJ and RTEL1, thereby playing a key role in nucleotide excision repair (NER), homologous recombination-mediated double-strand break DNA repair, DNA replication and RNA polymerase II (POL II) transcription (PubMed:22678361, PubMed:22678362, PubMed:23585563, PubMed:29225034). As part of the mitotic spindle-associated MMXD complex, plays a role in chromosome segregation, probably by facilitating iron-sulfur (Fe-S) cluster assembly into ERCC2/XPD (PubMed:20797633). Together with CIAO2, facilitates the transfer of Fe-S clusters to the motor protein KIF4A, which ensures proper localization of KIF4A to mitotic machinery components to promote the progression of mitosis (PubMed:29848660). Indirectly acts as a transcriptional coactivator of estrogen receptor (ER), via its role in iron-sulfur insertion into some component of the TFIIH-machinery (PubMed:11279242)","subcellular_location":"Nucleus; Cytoplasm, cytoskeleton, spindle; Cytoplasm, cytoskeleton, microtubule organizing center, centrosome","url":"https://www.uniprot.org/uniprotkb/Q96T76/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":true,"resolved_as":"","url":"https://depmap.org/portal/gene/MMS19","classification":"Common Essential","n_dependent_lines":1061,"n_total_lines":1208,"dependency_fraction":0.8783112582781457},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/MMS19","total_profiled":1310},"omim":[{"mim_id":"620960","title":"MULTIPLE MITOCHONDRIAL DYSFUNCTIONS SYNDROME 10; MMDS10","url":"https://www.omim.org/entry/620960"},{"mim_id":"618382","title":"CYTOSOLIC IRON-SULFUR ASSEMBLY COMPONENT 2A; CIAO2A","url":"https://www.omim.org/entry/618382"},{"mim_id":"614778","title":"CYTOSOLIC IRON-SULFUR ASSEMBLY COMPONENT 2B; CIAO2B","url":"https://www.omim.org/entry/614778"},{"mim_id":"614777","title":"MMS19 HOMOLOG, CYTOSOLIC IRON-SULFUR ASSEMBLY COMPONENT; MMS19","url":"https://www.omim.org/entry/614777"},{"mim_id":"604333","title":"WD40 REPEAT-CONTAINING PROTEIN CIAO1; CIAO1","url":"https://www.omim.org/entry/604333"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Enhanced","locations":[{"location":"Nucleoplasm","reliability":"Enhanced"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/MMS19"},"hgnc":{"alias_symbol":["MET18","hMMS19","CIAO4"],"prev_symbol":["MMS19L"]},"alphafold":{"accession":"Q96T76","domains":[{"cath_id":"-","chopping":"571-638_646-733","consensus_level":"medium","plddt":91.2976,"start":571,"end":733},{"cath_id":"1.25.10.10","chopping":"926-1030","consensus_level":"medium","plddt":90.8144,"start":926,"end":1030}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q96T76","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q96T76-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q96T76-F1-predicted_aligned_error_v6.png","plddt_mean":90.75},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=MMS19","jax_strain_url":"https://www.jax.org/strain/search?query=MMS19"},"sequence":{"accession":"Q96T76","fasta_url":"https://rest.uniprot.org/uniprotkb/Q96T76.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q96T76/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q96T76"}},"corpus_meta":[{"pmid":"22678362","id":"PMC_22678362","title":"MMS19 assembles iron-sulfur proteins required for DNA metabolism and genomic integrity.","date":"2012","source":"Science (New York, N.Y.)","url":"https://pubmed.ncbi.nlm.nih.gov/22678362","citation_count":232,"is_preprint":false},{"pmid":"22678361","id":"PMC_22678361","title":"MMS19 links cytoplasmic iron-sulfur cluster assembly to DNA metabolism.","date":"2012","source":"Science (New York, N.Y.)","url":"https://pubmed.ncbi.nlm.nih.gov/22678361","citation_count":194,"is_preprint":false},{"pmid":"20797633","id":"PMC_20797633","title":"MMXD, a TFIIH-independent XPD-MMS19 protein complex involved in chromosome segregation.","date":"2010","source":"Molecular cell","url":"https://pubmed.ncbi.nlm.nih.gov/20797633","citation_count":104,"is_preprint":false},{"pmid":"392238","id":"PMC_392238","title":"Three additional genes involved in pyrimidine dimer removal in Saccharomyces cerevisiae: RAD7, RAD14 and MMS19.","date":"1979","source":"Molecular & general genetics : MGG","url":"https://pubmed.ncbi.nlm.nih.gov/392238","citation_count":63,"is_preprint":false},{"pmid":"11279242","id":"PMC_11279242","title":"The human homologue of the yeast DNA repair and TFIIH regulator MMS19 is an AF-1-specific coactivator of estrogen receptor.","date":"2001","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/11279242","citation_count":54,"is_preprint":false},{"pmid":"8943333","id":"PMC_8943333","title":"Dual requirement for the yeast MMS19 gene in DNA repair and RNA polymerase II transcription.","date":"1996","source":"Molecular and cellular biology","url":"https://pubmed.ncbi.nlm.nih.gov/8943333","citation_count":49,"is_preprint":false},{"pmid":"19318433","id":"PMC_19318433","title":"Nucleotide excision repair pathway polymorphisms and pancreatic cancer risk: evidence for role of MMS19L.","date":"2009","source":"Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology","url":"https://pubmed.ncbi.nlm.nih.gov/19318433","citation_count":39,"is_preprint":false},{"pmid":"23150669","id":"PMC_23150669","title":"The mammalian proteins MMS19, MIP18, and ANT2 are involved in cytoplasmic iron-sulfur cluster protein assembly.","date":"2012","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/23150669","citation_count":39,"is_preprint":false},{"pmid":"23585563","id":"PMC_23585563","title":"IOP1 protein is an external component of the human cytosolic iron-sulfur cluster assembly (CIA) machinery and functions in the MMS19 protein-dependent CIA pathway.","date":"2013","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/23585563","citation_count":37,"is_preprint":false},{"pmid":"27193999","id":"PMC_27193999","title":"The cytosolic Fe-S cluster assembly component MET18 is required for the full enzymatic activity of ROS1 in active DNA 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MMS19 serves as an adapter between early-acting CIA components (CIAO1, IOP1/NARFL, MIP18/FAM96B) and a subset of cellular Fe-S proteins.\",\n      \"method\": \"Co-immunoprecipitation, mass spectrometry, in vitro binding assays, RNAi knockdown with defined cellular phenotypes (Fe-S protein instability)\",\n      \"journal\": \"Science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — two independent labs published simultaneously with reciprocal Co-IP, MS interactome, and KO phenotype; replicated findings\",\n      \"pmids\": [\"22678362\", \"22678361\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"MMS19 forms a complex with the CIA proteins CIAO1, IOP1, and MIP18 in the cytoplasm, and also binds directly to multiple nuclear Fe-S proteins involved in DNA metabolism. Knockout of Mms19 in mice causes preimplantation lethality, and loss of MMS19 leads to failure of Fe-S cluster transfer to target proteins and consequent Fe-S protein instability.\",\n      \"method\": \"Co-immunoprecipitation, siRNA knockdown, Mms19 knockout mouse model\",\n      \"journal\": \"Science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, KO model with defined phenotype, replicated by independent lab same year\",\n      \"pmids\": [\"22678361\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"MMS19 forms a complex with XPD (a TFIIH subunit) and MIP18, FAM96B, CIAO1, and ANT2, designated the MMXD complex, that does not contain other TFIIH subunits. MMS19, MIP18, and XPD localize to the mitotic spindle during mitosis. siRNA knockdown of MMS19, MIP18, or XPD leads to improper chromosome segregation and accumulation of nuclei with abnormal shapes.\",\n      \"method\": \"Co-immunoprecipitation, siRNA knockdown, immunofluorescence localization to mitotic spindle\",\n      \"journal\": \"Molecular Cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP identifying complex composition, direct localization experiment, KD with defined mitotic phenotype, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"20797633\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"MMS19 simultaneously binds CIAO1 and Fe-S proteins, confirming its role as a central CIA component bridging cluster donor proteins and apoprotein recipients. MIP18 also interacts with both CIAO1 and Fe-S proteins by binding Fe-S cluster coordinating regions. ANT2 interacts with Fe-S apoproteins and MMS19 within the CIA complex but not with the individual proteins.\",\n      \"method\": \"Co-immunoprecipitation, mass spectrometry-based interactome analysis, in vitro binding\",\n      \"journal\": \"The Journal of Biological Chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP with defined binding partners, single lab, two orthogonal methods (Co-IP and MS)\",\n      \"pmids\": [\"23150669\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"MMS19, MIP18, and CIAO1 form a tight 'core' CIA complex, while IOP1 is an 'external' component. Deficiency in any core component leads to down-regulation of all core components; IOP1 knockdown does not affect core component levels. MIP18 bridges MMS19 and CIAO1, and MMS19 interacts directly with target Fe-S apoproteins.\",\n      \"method\": \"Co-immunoprecipitation (in vivo and in vitro), siRNA knockdown with Western blot quantification\",\n      \"journal\": \"The Journal of Biological Chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo and in vitro Co-IP, knockdown experiments, single lab with two orthogonal methods\",\n      \"pmids\": [\"23585563\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"Human MMS19 (hMMS19) directly interacts with the XPB and XPD helicase subunits of the NER-transcription factor TFIIH, as shown by co-immunoprecipitation. hMMS19 is localized to the nucleus, consistent with a repair function.\",\n      \"method\": \"Co-immunoprecipitation, nuclear localization by subcellular fractionation/immunofluorescence\",\n      \"journal\": \"Nucleic Acids Research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP demonstrating XPB/XPD interaction, direct localization experiment, single lab\",\n      \"pmids\": [\"11071939\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"Human MMS19 interacts with the N-terminal PAS-A/B domain of the nuclear receptor coactivator RAC3 in vivo and in vitro via a conserved C-terminal domain of hMMS19. hMMS19 also interacts with estrogen receptors in a ligand-independent manner but not with retinoic acid receptor or thyroid hormone receptor. Overexpression of full-length hMMS19 enhances ER-mediated transcriptional activation by stimulating AF-1 activity of ERα but not AF-2 activity.\",\n      \"method\": \"Co-immunoprecipitation (in vivo and in vitro), overexpression/dominant-negative assays, transcriptional reporter assay\",\n      \"journal\": \"The Journal of Biological Chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo and in vitro Co-IP, functional reporter assays, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"11279242\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1996,\n      \"finding\": \"Yeast MMS19 is required for both nucleotide excision repair (NER) and RNA polymerase II transcription. mms19Δ cell extracts are deficient in Pol II transcription; this defect is corrected by addition of purified TFIIH but not by purified Mms19 protein. Mms19 is not a component of TFIIH or Pol II holoenzyme, but affects their activity as an upstream regulatory element.\",\n      \"method\": \"Genetic deletion (mms19Δ), in vitro transcription and NER reconstitution assays, complementation with purified TFIIH\",\n      \"journal\": \"Molecular and Cellular Biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro reconstitution assays, genetic deletion, complementation with purified proteins; single lab with multiple orthogonal methods\",\n      \"pmids\": [\"8943333\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"Yeast Mms19 functions in NER by sustaining adequate cellular concentration of the TFIIH component Rad3 (XPD homologue). In mms19 mutant cells, Rad3 and Ssl2 (XPB homologue) protein levels are significantly reduced (up to 3.5-fold for Rad3). Overexpression of Rad3 from a plasmid restores proficient NER and UV resistance in mms19 mutants, while overexpression of Ssl2 has no effect on repair.\",\n      \"method\": \"Genetic deletion and overexpression, Western blot quantification, UV sensitivity complementation assay\",\n      \"journal\": \"PNAS\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic rescue experiment with defined molecular phenotype, single lab, two orthogonal methods\",\n      \"pmids\": [\"18836076\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1997,\n      \"finding\": \"Yeast mms19 deletion mutant cell-free extracts are deficient for NER in vitro, and the mutant is defective in both transcription-coupled and global genome NER in vivo, as demonstrated by inability to remove cyclobutane-pyrimidine dimers from both transcribed and non-transcribed sequences.\",\n      \"method\": \"In vitro NER assay, nucleotide-level CPD removal analysis (in vivo strand-specific repair)\",\n      \"journal\": \"Nucleic Acids Research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro NER reconstitution and strand-specific in vivo repair assay, single lab with two orthogonal methods\",\n      \"pmids\": [\"9321645\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"Deletion analysis of MMS19 domains reveals three structurally distinct domains with separable functions: domain A is required for transcription but not NER; domain B is required for NER but not transcription; the C-terminal HEAT repeat domain (domain C) is essential for both NER and transcription functions.\",\n      \"method\": \"Domain deletion analysis with complementation of yeast mms19Δ mutant phenotypes (UV sensitivity, thermosensitivity)\",\n      \"journal\": \"DNA Repair\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — systematic domain-deletion/complementation with two defined phenotypic readouts, single lab\",\n      \"pmids\": [\"16797255\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Drosophila Mms19 functions in mitosis by allowing CAK (Cdk7/Cyclin H/Mat1) to become fully active as a Cdk1-activating kinase. Mms19 physically and genetically interacts with Xpd, and this interaction prevents Xpd from binding to the CAK complex; Xpd bound to Mms19 frees CAK to phosphorylate Cdk1 and facilitate progression to metaphase. Mitotic defects in Mms19-deficient Drosophila cells can be rescued by overexpression of the CAK complex.\",\n      \"method\": \"Genetic rescue (CAK overexpression in Mms19 mutants), physical interaction studies (Co-IP), loss-of-function with mitotic phenotype readout\",\n      \"journal\": \"Development\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic epistasis (rescue by CAK overexpression) combined with physical interaction studies, single lab with two orthogonal methods\",\n      \"pmids\": [\"29361561\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Drosophila Mms19 promotes spindle and astral microtubule (MT) growth, MT stability, and bundling in neural stem cells through two mechanisms: (1) by stimulating the mitotic kinase cascade to trigger localization of the TACC/Msps MT regulatory complex to the centrosome, and (2) by directly binding to microtubules to stimulate MT stability and bundling.\",\n      \"method\": \"Loss-of-function with mitotic phenotype quantification, kinase cascade rescue experiments, direct MT-binding assay\",\n      \"journal\": \"PLoS Genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct MT-binding assay, genetic rescue, KO phenotype with defined readouts; single lab with multiple orthogonal methods\",\n      \"pmids\": [\"33211700\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Human DNA polymerase ε catalytic subunit (POLE1) phosphorylated at serine-1940 interacts with MMS19, but this interaction is not essential: mutation of serine-1940 to alanine caused no defect in proliferation or survival, even after DNA damage. The POLE1-CIAO1 interaction is independent of serine-1940 phosphorylation.\",\n      \"method\": \"Co-immunoprecipitation, site-directed mutagenesis, cell survival assay\",\n      \"journal\": \"DNA Repair\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP with mutagenesis, functional cell assay; interaction shown but noted as non-essential (negative functional result)\",\n      \"pmids\": [\"27235625\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"MMS19 localizes to the inner membrane of mitochondria and participates in mitochondrial DNA (mtDNA) oxidative damage repair. MMS19 knockdown leads to decreased mtDNA copy number, diminished mtDNA repair capacity, and elevated mtDNA common deletion after oxidative stress. Immunoprecipitation-mass spectrometry identified interaction of MMS19 with ANT2, a mitochondrial ATP metabolism protein.\",\n      \"method\": \"Subcellular fractionation/mitochondrial localization, siRNA knockdown, immunoprecipitation-mass spectrometry\",\n      \"journal\": \"Biochemistry and Cell Biology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, fractionation-based localization with functional KD readout; mitochondrial localization contradicts the established cytosolic/nuclear localization in other studies, lowering confidence\",\n      \"pmids\": [\"29035693\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"The transcription factor c-MYC directly activates MMS19 expression in bladder cancer cells, as demonstrated by ChIP and luciferase reporter assays, establishing c-MYC as a transcriptional regulator of MMS19.\",\n      \"method\": \"Chromatin immunoprecipitation (ChIP), luciferase reporter assay\",\n      \"journal\": \"Tissue & Cell\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, ChIP and reporter assay establish transcriptional regulation but no mechanistic insight into MMS19 protein function\",\n      \"pmids\": [\"37201439\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Patients with MMS19 homozygous in-frame deletion mutations develop a lethal neurodegenerative phenotype with microcephaly, brain malformations, and recurrent infections. Patient-derived fibroblasts show profound alterations in proteome, metabolome, and lipidome, consistent with general failure of cytosolic and nuclear Fe-S protein maturation. MMS19 deficiency was confirmed to be detrimental in zebrafish models.\",\n      \"method\": \"Genome sequencing, patient fibroblast proteomics/metabolomics/lipidomics, zebrafish knockout model\",\n      \"journal\": \"Genetics in Medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — human genetic evidence combined with zebrafish KO and multi-omic patient fibroblast analysis; single report with multiple orthogonal methods\",\n      \"pmids\": [\"38411040\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"MMS19 is a scaffold/adapter component of the cytosolic iron-sulfur protein assembly (CIA) targeting complex that bridges early CIA factors (CIAO1, MIP18/FAM96B, IOP1) to recipient Fe-S apoproteins involved in DNA replication, repair, and telomere maintenance; it also facilitates proper chromosome segregation via a TFIIH-independent MMXD complex containing XPD, and in Drosophila promotes mitotic kinase activity by competitively binding XPD to free the CAK complex (Cdk7/CycH/Mat1) to activate Cdk1, as well as directly stabilizing spindle microtubules.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"MMS19 is a scaffold component of the cytosolic iron-sulfur protein assembly (CIA) machinery that targets Fe-S cluster insertion to a defined subset of apoproteins acting in DNA replication, repair, telomere maintenance, and methionine biosynthesis [#0]. It nucleates a core CIA targeting complex with MIP18/FAM96B and CIAO1, in which MIP18 bridges MMS19 and CIAO1 while IOP1/NARFL acts as a more peripheral upstream component; loss of any core subunit destabilizes the others and abolishes Fe-S transfer to recipient apoproteins [#1, #4]. MMS19 binds CIAO1 and recipient Fe-S apoproteins simultaneously, functioning as the adapter that couples cluster donors to apoprotein acceptors [#3]. Beyond cluster delivery, MMS19 directly engages the XPD/XPB helicase subunits of TFIIH and assembles a distinct TFIIH-independent MMXD complex (MMS19-MIP18-XPD-CIAO1-FAM96B-ANT2) that localizes to the mitotic spindle and is required for accurate chromosome segregation [#5, #2]. In yeast, Mms19 supports both nucleotide excision repair and RNA polymerase II transcription by maintaining cellular levels of the TFIIH subunits Rad3/XPD and Ssl2/XPB, with separable protein domains governing the repair versus transcription functions [#7, #8, #10]. In Drosophila, Mms19 additionally promotes mitosis by sequestering Xpd to free the CAK (Cdk7/Cyclin H/Mat1) complex for Cdk1 activation and by directly binding and stabilizing spindle microtubules [#11, #12]. Human loss-of-function causes a lethal neurodegenerative disorder with microcephaly and brain malformations driven by global failure of cytosolic and nuclear Fe-S protein maturation [#16].\",\n  \"teleology\": [\n    {\n      \"year\": 1996,\n      \"claim\": \"Established that Mms19 is required for both NER and Pol II transcription yet is not itself a TFIIH or holoenzyme subunit, defining it as an upstream regulatory factor rather than a core machine component.\",\n      \"evidence\": \"yeast mms19\\u0394 genetic deletion with in vitro transcription/NER reconstitution and TFIIH complementation\",\n      \"pmids\": [\"8943333\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not identify the molecular target through which Mms19 regulates TFIIH activity\", \"No direct biochemical mechanism for the transcription defect\"]\n    },\n    {\n      \"year\": 1997,\n      \"claim\": \"Clarified the scope of the repair defect, showing mms19 loss impairs both transcription-coupled and global-genome NER at the level of dimer removal.\",\n      \"evidence\": \"in vitro NER assay and strand-specific CPD removal analysis in yeast\",\n      \"pmids\": [\"9321645\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Did not establish whether the defect is direct or secondary to TFIIH dysfunction\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Provided the first physical link between human MMS19 and the repair machinery by demonstrating direct interaction with TFIIH helicase subunits XPB and XPD.\",\n      \"evidence\": \"co-immunoprecipitation and nuclear localization in human cells\",\n      \"pmids\": [\"11071939\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Did not determine functional consequence of the XPB/XPD interaction\", \"Single lab without reciprocal validation across systems\"]\n    },\n    {\n      \"year\": 2001,\n      \"claim\": \"Suggested a transcriptional-coactivation role by linking MMS19 to nuclear receptor signaling via RAC3 and estrogen receptor AF-1 stimulation.\",\n      \"evidence\": \"in vivo/in vitro Co-IP and ER reporter assays in human cells\",\n      \"pmids\": [\"11279242\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"This activity has not been integrated with the later CIA/Fe-S function\", \"Not independently confirmed\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Mapped MMS19 into separable functional modules, showing distinct domains drive transcription versus NER and a C-terminal HEAT domain is essential for both.\",\n      \"evidence\": \"domain-deletion complementation of yeast phenotypes\",\n      \"pmids\": [\"16797255\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Domain assignments not connected to specific binding partners\", \"No structural model of the domains\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Resolved the mechanism of the NER defect by showing Mms19 sustains Rad3/XPD protein levels, with Rad3 overexpression rescuing repair.\",\n      \"evidence\": \"genetic deletion/overexpression with Western blot and UV-sensitivity rescue in yeast\",\n      \"pmids\": [\"18836076\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Did not explain why Mms19 loss destabilizes Rad3 (later linked to Fe-S maturation)\", \"Single-lab study\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Identified the MMXD complex as a TFIIH-independent assembly of MMS19, MIP18, CIAO1, FAM96B and XPD that localizes to the spindle and is required for proper chromosome segregation.\",\n      \"evidence\": \"reciprocal Co-IP, immunofluorescence and siRNA mitotic phenotyping in human cells\",\n      \"pmids\": [\"20797633\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define how the complex acts on the spindle mechanistically\", \"Relationship of MMXD to Fe-S maturation not yet established\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Defined MMS19's central biological role as a CIA targeting-complex adapter that delivers Fe-S clusters to DNA-metabolism apoproteins, unifying the prior repair and transcription phenotypes as downstream consequences of Fe-S maturation failure.\",\n      \"evidence\": \"co-IP, MS interactome, RNAi/KO phenotyping and an Mms19 knockout mouse (preimplantation lethal), reported by two independent labs\",\n      \"pmids\": [\"22678362\", \"22678361\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not resolve the structural basis of cluster transfer\", \"Selectivity rules for which apoproteins are served not fully defined\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Refined complex architecture, establishing a tight MMS19-MIP18-CIAO1 core (with MIP18 bridging) and IOP1 as an external component, and showing MMS19 contacts apoprotein recipients directly.\",\n      \"evidence\": \"in vivo/in vitro Co-IP and knockdown stability analysis in human cells (and JBC interactome mapping)\",\n      \"pmids\": [\"23585563\", \"23150669\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No atomic-resolution structure of the core complex\", \"Mechanism of apoprotein recognition unresolved\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Revealed a mitotic-kinase mechanism in which Mms19 sequesters Xpd to free CAK for Cdk1 activation, connecting Mms19 to mitotic progression independent of cluster delivery.\",\n      \"evidence\": \"Drosophila genetic rescue by CAK overexpression plus Co-IP physical interaction\",\n      \"pmids\": [\"29361561\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Not demonstrated in mammalian cells\", \"Single-lab study\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Showed Mms19 stabilizes spindle and astral microtubules both indirectly via the mitotic kinase cascade/TACC-Msps recruitment and directly by binding microtubules.\",\n      \"evidence\": \"Drosophila loss-of-function phenotyping, kinase-cascade rescue and direct MT-binding assay\",\n      \"pmids\": [\"33211700\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct MT binding not confirmed for human MMS19\", \"Structural basis of MT binding unknown\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Linked MMS19 to human disease, showing homozygous in-frame deletions cause a lethal neurodegenerative syndrome driven by global cytosolic/nuclear Fe-S maturation failure.\",\n      \"evidence\": \"genome sequencing, patient-fibroblast multi-omics and zebrafish knockout\",\n      \"pmids\": [\"38411040\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Genotype-phenotype relationship across mutation types not established\", \"Tissue-specific vulnerability mechanism unclear\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How MMS19 mechanistically transfers Fe-S clusters and selects among recipient apoproteins, and whether its mitotic spindle/microtubule roles are conserved in humans and separable from cluster delivery, remain open.\",\n      \"evidence\": \"no reconstituted transfer mechanism or structure available in the corpus\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No structure of the CIA targeting complex bound to an apoprotein\", \"Mammalian validation of the CAK/microtubule mechanism lacking\", \"Reconciliation of the reported mitochondrial localization with cytosolic/nuclear roles unresolved\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 1, 3, 4]},\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [12]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [1, 3]},\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [5]},\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [2, 12]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-73894\", \"supporting_discovery_ids\": [0, 7, 9]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [2, 11]},\n      {\"term_id\": \"R-HSA-74160\", \"supporting_discovery_ids\": [7]}\n    ],\n    \"complexes\": [\"CIA targeting complex (MMS19-MIP18-CIAO1)\", \"MMXD complex\"],\n    \"partners\": [\"CIAO1\", \"FAM96B\", \"IOP1\", \"XPD\", \"XPB\", \"ANT2\", \"POLE1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":7,"faith_pct":85.71428571428571}}