{"gene":"MSH4","run_date":"2026-06-10T02:59:51","timeline":{"discoveries":[{"year":2001,"finding":"Yeast Msh4 localizes to discrete foci on meiotic chromosomes and colocalizes with Zip2 (a synapsis initiation protein); both Zip2 and Zip1 are required for normal chromosomal localization of Msh4. Epistasis tests show msh4 and zip1 affect the same subset of meiotic crossovers. msh4 null mutants show delayed SC formation and reduced synapsis (~50% nuclei), decreased crossover frequency, and substantially reduced crossover interference.","method":"Immunolocalization/colocalization on meiotic chromosomes; genetic epistasis analysis; msh4 null mutant phenotypic analysis","journal":"Genetics","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal genetic and cytological approaches, multiple orthogonal methods (epistasis, localization, null mutant phenotype), replicated context","pmids":["11454751"],"is_preprint":false},{"year":2000,"finding":"Human MSH4 physically interacts with hMLH1; the two proteins are co-immunoprecipitated independently of DNA or ATP. The interaction domain maps to the amino-terminal part of hMSH4, while the ATP-binding/helix-turn-helix region does not bind hMLH1. Immunolocalization shows MSH4 foci along the synaptonemal complex diminish as pachynema progresses, at which point MLH1 foci appear and colocalize with MSH4, suggesting sequential roles in synapsis then crossover resolution.","method":"Co-immunoprecipitation; domain mapping; immunolocalization on meiotic chromosomes","journal":"FASEB Journal","confidence":"High","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP with domain mapping plus independent immunolocalization, single lab but two orthogonal methods","pmids":["10928988"],"is_preprint":false},{"year":2002,"finding":"MSH4 physically interacts with MLH3 in mouse meiotic cells; the MSH4 protein is co-immunoprecipitated with MLH3 from mouse spermatocyte extracts. Additionally, both human MLH3 isoforms (hMLH3 and hMLH3Δ7) interact in vitro with hMSH4, supporting a role for the MSH4–MLH3 complex in mammalian meiotic recombination.","method":"Co-immunoprecipitation from mouse meiotic cell extracts; in vitro interaction assay","journal":"Human Molecular Genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP from native tissue plus in vitro interaction, single lab, two orthogonal approaches","pmids":["12095912"],"is_preprint":false},{"year":2004,"finding":"Human MSH4 physically interacts with both RAD51 and DMC1 (RecA homologs that initiate DNA strand exchange); these interactions were demonstrated biochemically. Immunolocalization shows a subset of MSH4 foci on mouse meiotic chromosomes colocalize with DMC1/RAD51 complexes, placing MSH4 at early recombination intermediates after strand exchange initiation.","method":"Biochemical interaction assay (pulldown/Co-IP); immunolocalization on mouse meiotic chromosomes","journal":"Molecular Human Reproduction","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — biochemical interaction plus independent immunolocalization, single lab, two orthogonal methods","pmids":["15489243"],"is_preprint":false},{"year":2003,"finding":"Human MSH4 physically interacts with VHL tumor suppressor-binding protein 1 (VBP1); hMSH4 and VBP1 colocalize in mammalian cells. A splice variant (hMSH4sv) encoding a truncated hMSH4 retains VBP1 binding but loses hMSH5 binding. Three-hybrid analysis shows VBP1 can compete with hMSH5 for hMSH4 binding, suggesting VBP1 levels regulate availability of the hMSH4–hMSH5 heterodimer.","method":"Co-IP/pulldown; colocalization; yeast three-hybrid competition assay","journal":"Cancer Research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple interaction assays (Co-IP, three-hybrid, colocalization) in single lab","pmids":["12591739"],"is_preprint":false},{"year":2000,"finding":"Epistasis analysis of msh4 and exo1 in yeast shows that double mutants have synergistically reduced spore viability compared to either single mutant, despite no further reduction in crossover frequency, indicating msh4 and exo1 affect meiotic viability through distinct mechanisms. msh4 affects both frequency and distribution (interference) of crossovers, while exo1 primarily reduces crossover frequency through early DNA resection.","method":"Genetic epistasis (double mutant analysis); crossover frequency measurement; spore viability assay","journal":"Chromosoma","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean genetic epistasis with multiple phenotypic readouts, single lab","pmids":["10855499"],"is_preprint":false},{"year":2010,"finding":"Mutagenesis of 57 conserved residues in yeast Msh4 and Msh5 identified 'threshold' msh4/5-t alleles that show wild-type spore viability and crossover interference but up to twofold reduced crossing over on large/medium chromosomes, establishing that the Msh4–Msh5 complex promotes crossover formation and SC assembly, and that a minimum crossover threshold is required for meiotic viability. The Msh5 subunit is more sensitive to mutagenesis than Msh4.","method":"Systematic site-directed mutagenesis; crossover frequency measurement; spore viability assay; SC assembly analysis; triple mutant epistasis","journal":"PLoS Genetics","confidence":"High","confidence_rationale":"Tier 1 / Strong — systematic mutagenesis of defined residues with multiple phenotypic readouts (crossover frequency, interference, viability, SC assembly) and epistasis, single rigorous study","pmids":["20865162"],"is_preprint":false},{"year":2021,"finding":"In vivo genome-wide ChIP shows that Msh5 (as part of the Msh4–Msh5 complex) associates with DSB hotspots, chromosome axes, and centromeres in meiotic yeast. Efficient binding to DSB hotspots and axes requires DSB formation and resection, and is enhanced by double Holliday junction structures. The axis protein Red1 is required for Msh5 association with axes and DSB hotspots but not centromeres. Msh5 binding correlates with DSB frequency and is enriched on small chromosomes.","method":"Genome-wide ChIP-seq in wild-type and meiotic mutants (spo11Δ, zip3Δ, red1Δ, etc.)","journal":"Genetics","confidence":"High","confidence_rationale":"Tier 2 / Strong — genome-wide in vivo binding with multiple genetic backgrounds tested, multiple orthogonal observations, single rigorous study","pmids":["34849874"],"is_preprint":false},{"year":2017,"finding":"A homozygous donor splice-site mutation in MSH4 (exon 17 skipping) causes primary ovarian insufficiency. Exon trapping experiments confirmed the splice defect. The resulting in-frame deletion (p.Ile743_Lys785del) ablates the Walker B motif of the ATP-binding domain, predicted to inactivate MSH4 ATPase activity, establishing that intact MSH4 ATP-binding function is required for human female meiosis.","method":"Exon trapping experiment; whole-exome sequencing; Sanger segregation analysis","journal":"Human Molecular Genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — exon trapping directly demonstrates splice defect; protein-level inference of ATPase inactivation is computational, single lab","pmids":["28541421"],"is_preprint":false},{"year":2025,"finding":"EXO1 directly interacts with MSH4 (within the MutSγ complex); a single point mutation in EXO1 (W371E) disrupts this interaction and completely abolishes EXO1's ability to activate DNA nicking by MutLγ (MLH1-MLH3) without affecting EXO1's intrinsic nuclease activity. EXO1 also interacts with MLH1 via its MIP motif and with dsDNA; integrity of dsDNA-binding residues (but not the nuclease catalytic magnesium-coordinating residues) is required for MutSγ-MutLγ activation. This defines EXO1 as an integral structural component of the meiotic resolvase complex.","method":"In vitro protein interaction assays; site-directed mutagenesis; in vitro DNA nicking/endonuclease assay","journal":"Nature Communications","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro reconstitution with point mutagenesis and functional endonuclease assay; multiple residues tested; single rigorous study with multiple orthogonal methods","pmids":["40319035"],"is_preprint":false},{"year":2013,"finding":"Homology modeling of the S. cerevisiae Msh4–Msh5 complex based on bacterial MutS crystal structures identifies predicted residues critical for Msh4–Msh5 heterodimer formation, DNA binding, and explains asymmetry in the complex. Structural analysis reconciles three classes of msh4/5 point mutation phenotypes (null-like, intermediate, crossover-only defects) with likely effects on protein stability or DNA interactions.","method":"Computational homology modeling integrated with previously characterized point mutation phenotype data","journal":"PLoS One","confidence":"Low","confidence_rationale":"Tier 4 / Weak — purely computational modeling with no direct experimental validation of the structural predictions in this study","pmids":["24244354"],"is_preprint":false},{"year":2025,"finding":"HEIP1 directly interacts with HEI10 and orchestrates recruitment of the MutSγ complex (MSH4–MSH5) along with E3 ligases (HEI10, RNF212, RNF212B) to maturing crossover sites during mouse meiosis; loss of HEIP1 abolishes crossing over and fertility in both sexes, placing HEIP1 upstream of MSH4–MSH5 in the pro-crossover pathway.","method":"Mouse knockout; immunolocalization; co-IP/interaction assay","journal":"bioRxiv (preprint)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — KO phenotype plus Co-IP interaction, preprint, single lab, not yet peer-reviewed","pmids":["bio_10.1101_2025.08.25.672081"],"is_preprint":true},{"year":2025,"finding":"In yeast, Msh4 (as part of the ZMM group) exhibits anti-mismatch-repair activity in intraspecies hybrid zygotes, promoting class I interhomolog crossover formation while limiting MMR to favor noncrossover formation by Sgs1 and preventing class II crossovers by Mms4•Mus81. This places Msh4 after D-loop formation and upstream of the NCO/CO decision.","method":"Genetic analysis in SK1/S288c hybrid yeast; crossover frequency measurement; epistasis with MMR and HR mutants","journal":"bioRxiv (preprint)","confidence":"Low","confidence_rationale":"Tier 2 / Weak — genetic epistasis in hybrid zygotes, preprint, single lab, not yet peer-reviewed","pmids":["bio_10.1101_2025.02.08.636946"],"is_preprint":true}],"current_model":"MSH4 (MutS homolog 4) is a meiosis-specific protein that functions as an obligate heterodimer with MSH5 (MutSγ complex); it localizes to meiotic chromosome axes at DSB hotspots in a manner dependent on axis protein Red1 and synapsis factors Zip1/Zip2, stabilizes early recombination intermediates (single-end invasions and double Holliday junctions) to promote class I crossover formation and crossover interference, physically interacts with MLH1, MLH3, RAD51, DMC1, EXO1, and VBP1, and is activated by EXO1 (via direct MSH4 contact) to stimulate MutLγ endonuclease-mediated resolution of Holliday junctions into crossovers; loss-of-function mutations in humans cause meiotic arrest leading to azoospermia and primary ovarian insufficiency."},"narrative":{"mechanistic_narrative":"MSH4 is a meiosis-specific MutS homolog that acts as a pro-crossover factor by stabilizing recombination intermediates and channeling them toward class I crossover formation with crossover interference [PMID:11454751, PMID:20865162]. It localizes to discrete foci along meiotic chromosomes in a manner dependent on the synapsis initiation proteins Zip1 and Zip2, and msh4 loss delays synaptonemal complex assembly, lowers crossover frequency, and abolishes most crossover interference [PMID:11454751]; as part of the Msh4-Msh5 (MutSγ) complex it associates in vivo with DSB hotspots, chromosome axes and centromeres, with hotspot and axis binding requiring DSB formation and resection, enhanced by double Holliday junction structures, and dependent on the axis protein Red1 [PMID:34849874]. MSH4 functions through a series of physical partners: it binds the MutL components MLH1 and MLH3 via its amino-terminal region, with MSH4 foci giving way to MLH1 foci as pachynema progresses, indicating sequential synapsis then resolution roles [PMID:10928988, PMID:12095912], and it contacts the strand-exchange recombinases RAD51 and DMC1 at early recombination intermediates [PMID:15489243]. EXO1 directly binds MSH4 within MutSγ, and this contact is required to activate MutLγ (MLH1-MLH3) endonuclease nicking that resolves joint molecules into crossovers, establishing EXO1 as an integral structural component of the meiotic resolvase machinery [PMID:40319035]. Availability of the MSH4-MSH5 heterodimer is modulated by VBP1, which competes with MSH5 for MSH4 binding [PMID:12591739]. In humans, a homozygous MSH4 splice-site mutation that deletes the Walker B motif of the ATP-binding domain causes primary ovarian insufficiency, demonstrating that intact MSH4 ATP-binding function is required for human meiosis [PMID:28541421].","teleology":[{"year":2000,"claim":"Establishing that MSH4 physically links to the MutL machinery answered how a MutS homolog could connect synapsis to crossover resolution, defining an amino-terminal MLH1-binding interface distinct from the ATP/HTH region.","evidence":"Co-immunoprecipitation, domain mapping, and immunolocalization of human MSH4 and hMLH1 on meiotic chromosomes","pmids":["10928988"],"confidence":"High","gaps":["Whether MSH4 acts alone or only as a heterodimer with MSH5 in MLH1 binding not resolved here","Functional consequence of the temporal handoff from MSH4 to MLH1 foci not tested"]},{"year":2000,"claim":"Genetic epistasis distinguished MSH4 and EXO1 contributions to meiosis, showing they promote spore viability through separate mechanisms despite both affecting crossovers.","evidence":"Yeast msh4 exo1 double-mutant analysis with crossover frequency and spore viability readouts","pmids":["10855499"],"confidence":"Medium","gaps":["The basis for synergistic viability loss not mechanistically defined","Did not anticipate the later-defined direct EXO1-MSH4 physical/functional partnership"]},{"year":2001,"claim":"Cytological and epistasis analysis placed Msh4 in the synapsis/crossover pathway, showing its chromosomal localization depends on Zip1/Zip2 and that it governs crossover interference.","evidence":"Immunolocalization with Zip2, genetic epistasis with zip1, and msh4 null phenotyping in yeast","pmids":["11454751"],"confidence":"High","gaps":["Molecular nature of the DNA/intermediate Msh4 stabilizes not defined","Mechanism by which Zip1/Zip2 recruit Msh4 unknown"]},{"year":2002,"claim":"Demonstrating MSH4-MLH3 interaction extended the MutS-MutL link to a second MutL subunit, supporting an MSH4-MLH3 module in mammalian recombination.","evidence":"Co-IP from mouse spermatocyte extracts and in vitro interaction with human MLH3 isoforms","pmids":["12095912"],"confidence":"Medium","gaps":["Single lab, no reciprocal in vivo validation","Functional contribution of MLH3 isoform differences not tested"]},{"year":2003,"claim":"Identifying VBP1 as an MSH4 partner that competes with MSH5 introduced a possible regulatory mechanism for controlling MutSγ heterodimer availability.","evidence":"Co-IP, colocalization, and yeast three-hybrid competition with a truncated hMSH4 splice variant","pmids":["12591739"],"confidence":"Medium","gaps":["Physiological relevance of VBP1 competition in meiotic cells not shown","Whether VBP1 regulates MSH4 in vivo untested"]},{"year":2004,"claim":"Linking MSH4 to RAD51 and DMC1 positioned the protein at early post-strand-exchange recombination intermediates rather than only at later resolution steps.","evidence":"Biochemical interaction assays and colocalization on mouse meiotic chromosomes","pmids":["15489243"],"confidence":"Medium","gaps":["Direct versus bridged interaction not distinguished","Functional consequence of recombinase contact not tested"]},{"year":2010,"claim":"Systematic mutagenesis separated MSH4-MSH5 functions, showing the complex promotes both crossover formation and SC assembly and that a crossover threshold is required for viability.","evidence":"Site-directed mutagenesis of 57 conserved residues in yeast with crossover, interference, viability, and SC readouts","pmids":["20865162"],"confidence":"High","gaps":["Biochemical activities of threshold alleles not directly measured","Differential sensitivity of Msh5 versus Msh4 not structurally explained"]},{"year":2013,"claim":"Homology modeling provided a structural rationale for MSH4-MSH5 heterodimer formation, DNA binding, and the phenotypic classes of point mutants.","evidence":"Computational homology modeling on bacterial MutS templates integrated with prior mutant phenotypes","pmids":["24244354"],"confidence":"Low","gaps":["Purely computational with no experimental structural validation in this study","Predicted interface residues not directly tested"]},{"year":2017,"claim":"A human disease mutation established that MSH4 ATP-binding function is essential for female meiosis, connecting the gene to primary ovarian insufficiency.","evidence":"Whole-exome sequencing, segregation, and exon trapping confirming exon 17 skipping deleting the Walker B motif","pmids":["28541421"],"confidence":"Medium","gaps":["ATPase inactivation inferred computationally, not measured","Male phenotype of this allele not characterized"]},{"year":2021,"claim":"Genome-wide ChIP defined where MutSγ binds in vivo and the requirements for that binding, showing dependence on DSB formation, resection, and the axis protein Red1.","evidence":"Msh5 ChIP-seq across spo11Δ, zip3Δ, red1Δ and other meiotic mutants in yeast","pmids":["34849874"],"confidence":"High","gaps":["Msh4-specific binding inferred from Msh5 ChIP","How dHJ structures enhance binding mechanistically not resolved"]},{"year":2025,"claim":"Reconstitution defined EXO1 as a direct MSH4 partner and integral resolvase component, required to activate MutLγ endonuclease independent of EXO1 catalytic activity.","evidence":"In vitro interaction assays, EXO1 point mutagenesis (W371E), and DNA nicking assays with MutSγ-MutLγ","pmids":["40319035"],"confidence":"High","gaps":["Structure of the assembled MutSγ-MutLγ-EXO1 resolvase not determined","In vivo requirement of the W371E contact in mammals not tested"]},{"year":2025,"claim":"Upstream and pathway-context studies placed MSH4-MSH5 recruitment under HEIP1/HEI10 control and assigned Msh4 anti-MMR activity in the noncrossover/crossover decision.","evidence":"Mouse Heip1 knockout with immunolocalization and Co-IP (preprint); yeast hybrid-zygote genetic epistasis with MMR and HR mutants (preprint)","pmids":["bio_10.1101_2025.08.25.672081","bio_10.1101_2025.02.08.636946"],"confidence":"Low","gaps":["Both findings are unreviewed preprints from single labs","Direct biochemical demonstration of Msh4 anti-MMR activity not provided"]},{"year":null,"claim":"How ATP binding/hydrolysis by the MSH4-MSH5 sliding clamp couples intermediate stabilization to crossover designation and interference at the molecular level remains unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["No experimental structure of the MutSγ-DNA-resolvase assembly","Mechanistic basis of crossover interference imposed by MSH4 not defined","Direct measurement of MSH4 ATPase coupling to function lacking"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140657","term_label":"ATP-dependent activity","supporting_discovery_ids":[8]},{"term_id":"GO:0003677","term_label":"DNA binding","supporting_discovery_ids":[7,10]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[9]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[1,9]}],"localization":[{"term_id":"GO:0000228","term_label":"nuclear chromosome","supporting_discovery_ids":[0,1,7]}],"pathway":[{"term_id":"R-HSA-1474165","term_label":"Reproduction","supporting_discovery_ids":[0,8]},{"term_id":"R-HSA-73894","term_label":"DNA Repair","supporting_discovery_ids":[9,7]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[6,0]}],"complexes":["MutSγ (MSH4-MSH5)","meiotic resolvase (MutSγ-MutLγ-EXO1)"],"partners":["MSH5","MLH1","MLH3","RAD51","DMC1","EXO1","VBP1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"O15457","full_name":"MutS protein homolog 4","aliases":[],"length_aa":936,"mass_kda":104.8,"function":"Involved in meiotic recombination. Required for reciprocal recombination and proper segregation of homologous chromosomes at meiosis","subcellular_location":"Chromosome","url":"https://www.uniprot.org/uniprotkb/O15457/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/MSH4","classification":"Not Classified","n_dependent_lines":3,"n_total_lines":1208,"dependency_fraction":0.0024834437086092716},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/MSH4","total_profiled":1310},"omim":[{"mim_id":"619938","title":"PREMATURE OVARIAN FAILURE 20; POF20","url":"https://www.omim.org/entry/619938"},{"mim_id":"619937","title":"SPERMATOGENIC FAILURE 74; SPGF74","url":"https://www.omim.org/entry/619937"},{"mim_id":"619276","title":"BREAK REPAIR MEIOTIC RECOMBINASE RECRUITMENT FACTOR 1; BRME1","url":"https://www.omim.org/entry/619276"},{"mim_id":"618968","title":"CHROMOSOME 1 OPEN READING FRAME 146; C1ORF146","url":"https://www.omim.org/entry/618968"},{"mim_id":"618166","title":"CYCLIN N-TERMINAL DOMAIN-CONTAINING PROTEIN 1; CNTD1","url":"https://www.omim.org/entry/618166"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Nucleoplasm","reliability":"Approved"},{"location":"Equatorial segment","reliability":"Additional"},{"location":"Flagellar centriole","reliability":"Additional"},{"location":"Mid piece","reliability":"Additional"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in some","driving_tissues":[{"tissue":"epididymis","ntpm":1.7},{"tissue":"testis","ntpm":4.0}],"url":"https://www.proteinatlas.org/search/MSH4"},"hgnc":{"alias_symbol":[],"prev_symbol":[]},"alphafold":{"accession":"O15457","domains":[{"cath_id":"3.30.420.110","chopping":"157-308","consensus_level":"high","plddt":79.9656,"start":157,"end":308},{"cath_id":"1.10.1420.10","chopping":"343-476_604-633","consensus_level":"medium","plddt":87.0109,"start":343,"end":633},{"cath_id":"1.10.1420.10","chopping":"497-547_554-601","consensus_level":"medium","plddt":82.4315,"start":497,"end":601},{"cath_id":"3.40.50.300","chopping":"637-841","consensus_level":"high","plddt":85.0777,"start":637,"end":841},{"cath_id":"1.10.287","chopping":"883-924","consensus_level":"medium","plddt":82.8367,"start":883,"end":924}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/O15457","model_url":"https://alphafold.ebi.ac.uk/files/AF-O15457-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-O15457-F1-predicted_aligned_error_v6.png","plddt_mean":74.25},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=MSH4","jax_strain_url":"https://www.jax.org/strain/search?query=MSH4"},"sequence":{"accession":"O15457","fasta_url":"https://rest.uniprot.org/uniprotkb/O15457.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/O15457/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/O15457"}},"corpus_meta":[{"pmid":"11454751","id":"PMC_11454751","title":"The budding yeast Msh4 protein functions in chromosome synapsis and the regulation of crossover distribution.","date":"2001","source":"Genetics","url":"https://pubmed.ncbi.nlm.nih.gov/11454751","citation_count":164,"is_preprint":false},{"pmid":"10928988","id":"PMC_10928988","title":"MSH4 acts in conjunction with MLH1 during mammalian meiosis.","date":"2000","source":"FASEB journal : official publication of the Federation of American Societies for Experimental Biology","url":"https://pubmed.ncbi.nlm.nih.gov/10928988","citation_count":113,"is_preprint":false},{"pmid":"9299235","id":"PMC_9299235","title":"Cloning and expression analysis of a meiosis-specific MutS homolog: the human MSH4 gene.","date":"1997","source":"Genomics","url":"https://pubmed.ncbi.nlm.nih.gov/9299235","citation_count":85,"is_preprint":false},{"pmid":"12095912","id":"PMC_12095912","title":"The DNA mismatch-repair MLH3 protein interacts with MSH4 in meiotic cells, supporting a role for this MutL homolog in mammalian 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anti-PD-L1 antibody in a metastatic bladder cancer associated with novel MSH4 mutation and microsatellite instability.","date":"2020","source":"Journal for immunotherapy of cancer","url":"https://pubmed.ncbi.nlm.nih.gov/32221012","citation_count":15,"is_preprint":false},{"pmid":"35596132","id":"PMC_35596132","title":"Recombination rates in pigs differ between breeds, sexes and individuals, and are associated with the RNF212, SYCP2, PRDM7, MEI1 and MSH4 loci.","date":"2022","source":"Genetics, selection, evolution : GSE","url":"https://pubmed.ncbi.nlm.nih.gov/35596132","citation_count":14,"is_preprint":false},{"pmid":"3110178","id":"PMC_3110178","title":"Biological activity, binding, and metabolic fate of Ac-[Nle4, D-Phe7]alpha-MSH4-11NH2 with the F1 variant of B16 melanoma cells.","date":"1987","source":"Journal of cellular physiology","url":"https://pubmed.ncbi.nlm.nih.gov/3110178","citation_count":14,"is_preprint":false},{"pmid":"34849874","id":"PMC_34849874","title":"Regulation of 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Epistasis tests show msh4 and zip1 affect the same subset of meiotic crossovers. msh4 null mutants show delayed SC formation and reduced synapsis (~50% nuclei), decreased crossover frequency, and substantially reduced crossover interference.\",\n      \"method\": \"Immunolocalization/colocalization on meiotic chromosomes; genetic epistasis analysis; msh4 null mutant phenotypic analysis\",\n      \"journal\": \"Genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal genetic and cytological approaches, multiple orthogonal methods (epistasis, localization, null mutant phenotype), replicated context\",\n      \"pmids\": [\"11454751\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"Human MSH4 physically interacts with hMLH1; the two proteins are co-immunoprecipitated independently of DNA or ATP. The interaction domain maps to the amino-terminal part of hMSH4, while the ATP-binding/helix-turn-helix region does not bind hMLH1. Immunolocalization shows MSH4 foci along the synaptonemal complex diminish as pachynema progresses, at which point MLH1 foci appear and colocalize with MSH4, suggesting sequential roles in synapsis then crossover resolution.\",\n      \"method\": \"Co-immunoprecipitation; domain mapping; immunolocalization on meiotic chromosomes\",\n      \"journal\": \"FASEB Journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP with domain mapping plus independent immunolocalization, single lab but two orthogonal methods\",\n      \"pmids\": [\"10928988\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"MSH4 physically interacts with MLH3 in mouse meiotic cells; the MSH4 protein is co-immunoprecipitated with MLH3 from mouse spermatocyte extracts. Additionally, both human MLH3 isoforms (hMLH3 and hMLH3Δ7) interact in vitro with hMSH4, supporting a role for the MSH4–MLH3 complex in mammalian meiotic recombination.\",\n      \"method\": \"Co-immunoprecipitation from mouse meiotic cell extracts; in vitro interaction assay\",\n      \"journal\": \"Human Molecular Genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP from native tissue plus in vitro interaction, single lab, two orthogonal approaches\",\n      \"pmids\": [\"12095912\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"Human MSH4 physically interacts with both RAD51 and DMC1 (RecA homologs that initiate DNA strand exchange); these interactions were demonstrated biochemically. Immunolocalization shows a subset of MSH4 foci on mouse meiotic chromosomes colocalize with DMC1/RAD51 complexes, placing MSH4 at early recombination intermediates after strand exchange initiation.\",\n      \"method\": \"Biochemical interaction assay (pulldown/Co-IP); immunolocalization on mouse meiotic chromosomes\",\n      \"journal\": \"Molecular Human Reproduction\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — biochemical interaction plus independent immunolocalization, single lab, two orthogonal methods\",\n      \"pmids\": [\"15489243\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"Human MSH4 physically interacts with VHL tumor suppressor-binding protein 1 (VBP1); hMSH4 and VBP1 colocalize in mammalian cells. A splice variant (hMSH4sv) encoding a truncated hMSH4 retains VBP1 binding but loses hMSH5 binding. Three-hybrid analysis shows VBP1 can compete with hMSH5 for hMSH4 binding, suggesting VBP1 levels regulate availability of the hMSH4–hMSH5 heterodimer.\",\n      \"method\": \"Co-IP/pulldown; colocalization; yeast three-hybrid competition assay\",\n      \"journal\": \"Cancer Research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple interaction assays (Co-IP, three-hybrid, colocalization) in single lab\",\n      \"pmids\": [\"12591739\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"Epistasis analysis of msh4 and exo1 in yeast shows that double mutants have synergistically reduced spore viability compared to either single mutant, despite no further reduction in crossover frequency, indicating msh4 and exo1 affect meiotic viability through distinct mechanisms. msh4 affects both frequency and distribution (interference) of crossovers, while exo1 primarily reduces crossover frequency through early DNA resection.\",\n      \"method\": \"Genetic epistasis (double mutant analysis); crossover frequency measurement; spore viability assay\",\n      \"journal\": \"Chromosoma\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean genetic epistasis with multiple phenotypic readouts, single lab\",\n      \"pmids\": [\"10855499\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"Mutagenesis of 57 conserved residues in yeast Msh4 and Msh5 identified 'threshold' msh4/5-t alleles that show wild-type spore viability and crossover interference but up to twofold reduced crossing over on large/medium chromosomes, establishing that the Msh4–Msh5 complex promotes crossover formation and SC assembly, and that a minimum crossover threshold is required for meiotic viability. The Msh5 subunit is more sensitive to mutagenesis than Msh4.\",\n      \"method\": \"Systematic site-directed mutagenesis; crossover frequency measurement; spore viability assay; SC assembly analysis; triple mutant epistasis\",\n      \"journal\": \"PLoS Genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — systematic mutagenesis of defined residues with multiple phenotypic readouts (crossover frequency, interference, viability, SC assembly) and epistasis, single rigorous study\",\n      \"pmids\": [\"20865162\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"In vivo genome-wide ChIP shows that Msh5 (as part of the Msh4–Msh5 complex) associates with DSB hotspots, chromosome axes, and centromeres in meiotic yeast. Efficient binding to DSB hotspots and axes requires DSB formation and resection, and is enhanced by double Holliday junction structures. The axis protein Red1 is required for Msh5 association with axes and DSB hotspots but not centromeres. Msh5 binding correlates with DSB frequency and is enriched on small chromosomes.\",\n      \"method\": \"Genome-wide ChIP-seq in wild-type and meiotic mutants (spo11Δ, zip3Δ, red1Δ, etc.)\",\n      \"journal\": \"Genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genome-wide in vivo binding with multiple genetic backgrounds tested, multiple orthogonal observations, single rigorous study\",\n      \"pmids\": [\"34849874\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"A homozygous donor splice-site mutation in MSH4 (exon 17 skipping) causes primary ovarian insufficiency. Exon trapping experiments confirmed the splice defect. The resulting in-frame deletion (p.Ile743_Lys785del) ablates the Walker B motif of the ATP-binding domain, predicted to inactivate MSH4 ATPase activity, establishing that intact MSH4 ATP-binding function is required for human female meiosis.\",\n      \"method\": \"Exon trapping experiment; whole-exome sequencing; Sanger segregation analysis\",\n      \"journal\": \"Human Molecular Genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — exon trapping directly demonstrates splice defect; protein-level inference of ATPase inactivation is computational, single lab\",\n      \"pmids\": [\"28541421\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"EXO1 directly interacts with MSH4 (within the MutSγ complex); a single point mutation in EXO1 (W371E) disrupts this interaction and completely abolishes EXO1's ability to activate DNA nicking by MutLγ (MLH1-MLH3) without affecting EXO1's intrinsic nuclease activity. EXO1 also interacts with MLH1 via its MIP motif and with dsDNA; integrity of dsDNA-binding residues (but not the nuclease catalytic magnesium-coordinating residues) is required for MutSγ-MutLγ activation. This defines EXO1 as an integral structural component of the meiotic resolvase complex.\",\n      \"method\": \"In vitro protein interaction assays; site-directed mutagenesis; in vitro DNA nicking/endonuclease assay\",\n      \"journal\": \"Nature Communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro reconstitution with point mutagenesis and functional endonuclease assay; multiple residues tested; single rigorous study with multiple orthogonal methods\",\n      \"pmids\": [\"40319035\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Homology modeling of the S. cerevisiae Msh4–Msh5 complex based on bacterial MutS crystal structures identifies predicted residues critical for Msh4–Msh5 heterodimer formation, DNA binding, and explains asymmetry in the complex. Structural analysis reconciles three classes of msh4/5 point mutation phenotypes (null-like, intermediate, crossover-only defects) with likely effects on protein stability or DNA interactions.\",\n      \"method\": \"Computational homology modeling integrated with previously characterized point mutation phenotype data\",\n      \"journal\": \"PLoS One\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 4 / Weak — purely computational modeling with no direct experimental validation of the structural predictions in this study\",\n      \"pmids\": [\"24244354\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"HEIP1 directly interacts with HEI10 and orchestrates recruitment of the MutSγ complex (MSH4–MSH5) along with E3 ligases (HEI10, RNF212, RNF212B) to maturing crossover sites during mouse meiosis; loss of HEIP1 abolishes crossing over and fertility in both sexes, placing HEIP1 upstream of MSH4–MSH5 in the pro-crossover pathway.\",\n      \"method\": \"Mouse knockout; immunolocalization; co-IP/interaction assay\",\n      \"journal\": \"bioRxiv (preprint)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — KO phenotype plus Co-IP interaction, preprint, single lab, not yet peer-reviewed\",\n      \"pmids\": [\"bio_10.1101_2025.08.25.672081\"],\n      \"is_preprint\": true\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"In yeast, Msh4 (as part of the ZMM group) exhibits anti-mismatch-repair activity in intraspecies hybrid zygotes, promoting class I interhomolog crossover formation while limiting MMR to favor noncrossover formation by Sgs1 and preventing class II crossovers by Mms4•Mus81. This places Msh4 after D-loop formation and upstream of the NCO/CO decision.\",\n      \"method\": \"Genetic analysis in SK1/S288c hybrid yeast; crossover frequency measurement; epistasis with MMR and HR mutants\",\n      \"journal\": \"bioRxiv (preprint)\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 2 / Weak — genetic epistasis in hybrid zygotes, preprint, single lab, not yet peer-reviewed\",\n      \"pmids\": [\"bio_10.1101_2025.02.08.636946\"],\n      \"is_preprint\": true\n    }\n  ],\n  \"current_model\": \"MSH4 (MutS homolog 4) is a meiosis-specific protein that functions as an obligate heterodimer with MSH5 (MutSγ complex); it localizes to meiotic chromosome axes at DSB hotspots in a manner dependent on axis protein Red1 and synapsis factors Zip1/Zip2, stabilizes early recombination intermediates (single-end invasions and double Holliday junctions) to promote class I crossover formation and crossover interference, physically interacts with MLH1, MLH3, RAD51, DMC1, EXO1, and VBP1, and is activated by EXO1 (via direct MSH4 contact) to stimulate MutLγ endonuclease-mediated resolution of Holliday junctions into crossovers; loss-of-function mutations in humans cause meiotic arrest leading to azoospermia and primary ovarian insufficiency.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"MSH4 is a meiosis-specific MutS homolog that acts as a pro-crossover factor by stabilizing recombination intermediates and channeling them toward class I crossover formation with crossover interference [#0, #6]. It localizes to discrete foci along meiotic chromosomes in a manner dependent on the synapsis initiation proteins Zip1 and Zip2, and msh4 loss delays synaptonemal complex assembly, lowers crossover frequency, and abolishes most crossover interference [#0]; as part of the Msh4-Msh5 (MutSγ) complex it associates in vivo with DSB hotspots, chromosome axes and centromeres, with hotspot and axis binding requiring DSB formation and resection, enhanced by double Holliday junction structures, and dependent on the axis protein Red1 [#7]. MSH4 functions through a series of physical partners: it binds the MutL components MLH1 and MLH3 via its amino-terminal region, with MSH4 foci giving way to MLH1 foci as pachynema progresses, indicating sequential synapsis then resolution roles [#1, #2], and it contacts the strand-exchange recombinases RAD51 and DMC1 at early recombination intermediates [#3]. EXO1 directly binds MSH4 within MutSγ, and this contact is required to activate MutLγ (MLH1-MLH3) endonuclease nicking that resolves joint molecules into crossovers, establishing EXO1 as an integral structural component of the meiotic resolvase machinery [#9]. Availability of the MSH4-MSH5 heterodimer is modulated by VBP1, which competes with MSH5 for MSH4 binding [#4]. In humans, a homozygous MSH4 splice-site mutation that deletes the Walker B motif of the ATP-binding domain causes primary ovarian insufficiency, demonstrating that intact MSH4 ATP-binding function is required for human meiosis [#8].\",\n  \"teleology\": [\n    {\n      \"year\": 2000,\n      \"claim\": \"Establishing that MSH4 physically links to the MutL machinery answered how a MutS homolog could connect synapsis to crossover resolution, defining an amino-terminal MLH1-binding interface distinct from the ATP/HTH region.\",\n      \"evidence\": \"Co-immunoprecipitation, domain mapping, and immunolocalization of human MSH4 and hMLH1 on meiotic chromosomes\",\n      \"pmids\": [\"10928988\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether MSH4 acts alone or only as a heterodimer with MSH5 in MLH1 binding not resolved here\", \"Functional consequence of the temporal handoff from MSH4 to MLH1 foci not tested\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Genetic epistasis distinguished MSH4 and EXO1 contributions to meiosis, showing they promote spore viability through separate mechanisms despite both affecting crossovers.\",\n      \"evidence\": \"Yeast msh4 exo1 double-mutant analysis with crossover frequency and spore viability readouts\",\n      \"pmids\": [\"10855499\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"The basis for synergistic viability loss not mechanistically defined\", \"Did not anticipate the later-defined direct EXO1-MSH4 physical/functional partnership\"]\n    },\n    {\n      \"year\": 2001,\n      \"claim\": \"Cytological and epistasis analysis placed Msh4 in the synapsis/crossover pathway, showing its chromosomal localization depends on Zip1/Zip2 and that it governs crossover interference.\",\n      \"evidence\": \"Immunolocalization with Zip2, genetic epistasis with zip1, and msh4 null phenotyping in yeast\",\n      \"pmids\": [\"11454751\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular nature of the DNA/intermediate Msh4 stabilizes not defined\", \"Mechanism by which Zip1/Zip2 recruit Msh4 unknown\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Demonstrating MSH4-MLH3 interaction extended the MutS-MutL link to a second MutL subunit, supporting an MSH4-MLH3 module in mammalian recombination.\",\n      \"evidence\": \"Co-IP from mouse spermatocyte extracts and in vitro interaction with human MLH3 isoforms\",\n      \"pmids\": [\"12095912\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab, no reciprocal in vivo validation\", \"Functional contribution of MLH3 isoform differences not tested\"]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"Identifying VBP1 as an MSH4 partner that competes with MSH5 introduced a possible regulatory mechanism for controlling MutSγ heterodimer availability.\",\n      \"evidence\": \"Co-IP, colocalization, and yeast three-hybrid competition with a truncated hMSH4 splice variant\",\n      \"pmids\": [\"12591739\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Physiological relevance of VBP1 competition in meiotic cells not shown\", \"Whether VBP1 regulates MSH4 in vivo untested\"]\n    },\n    {\n      \"year\": 2004,\n      \"claim\": \"Linking MSH4 to RAD51 and DMC1 positioned the protein at early post-strand-exchange recombination intermediates rather than only at later resolution steps.\",\n      \"evidence\": \"Biochemical interaction assays and colocalization on mouse meiotic chromosomes\",\n      \"pmids\": [\"15489243\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct versus bridged interaction not distinguished\", \"Functional consequence of recombinase contact not tested\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Systematic mutagenesis separated MSH4-MSH5 functions, showing the complex promotes both crossover formation and SC assembly and that a crossover threshold is required for viability.\",\n      \"evidence\": \"Site-directed mutagenesis of 57 conserved residues in yeast with crossover, interference, viability, and SC readouts\",\n      \"pmids\": [\"20865162\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Biochemical activities of threshold alleles not directly measured\", \"Differential sensitivity of Msh5 versus Msh4 not structurally explained\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Homology modeling provided a structural rationale for MSH4-MSH5 heterodimer formation, DNA binding, and the phenotypic classes of point mutants.\",\n      \"evidence\": \"Computational homology modeling on bacterial MutS templates integrated with prior mutant phenotypes\",\n      \"pmids\": [\"24244354\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Purely computational with no experimental structural validation in this study\", \"Predicted interface residues not directly tested\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"A human disease mutation established that MSH4 ATP-binding function is essential for female meiosis, connecting the gene to primary ovarian insufficiency.\",\n      \"evidence\": \"Whole-exome sequencing, segregation, and exon trapping confirming exon 17 skipping deleting the Walker B motif\",\n      \"pmids\": [\"28541421\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"ATPase inactivation inferred computationally, not measured\", \"Male phenotype of this allele not characterized\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Genome-wide ChIP defined where MutSγ binds in vivo and the requirements for that binding, showing dependence on DSB formation, resection, and the axis protein Red1.\",\n      \"evidence\": \"Msh5 ChIP-seq across spo11Δ, zip3Δ, red1Δ and other meiotic mutants in yeast\",\n      \"pmids\": [\"34849874\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Msh4-specific binding inferred from Msh5 ChIP\", \"How dHJ structures enhance binding mechanistically not resolved\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Reconstitution defined EXO1 as a direct MSH4 partner and integral resolvase component, required to activate MutLγ endonuclease independent of EXO1 catalytic activity.\",\n      \"evidence\": \"In vitro interaction assays, EXO1 point mutagenesis (W371E), and DNA nicking assays with MutSγ-MutLγ\",\n      \"pmids\": [\"40319035\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structure of the assembled MutSγ-MutLγ-EXO1 resolvase not determined\", \"In vivo requirement of the W371E contact in mammals not tested\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Upstream and pathway-context studies placed MSH4-MSH5 recruitment under HEIP1/HEI10 control and assigned Msh4 anti-MMR activity in the noncrossover/crossover decision.\",\n      \"evidence\": \"Mouse Heip1 knockout with immunolocalization and Co-IP (preprint); yeast hybrid-zygote genetic epistasis with MMR and HR mutants (preprint)\",\n      \"pmids\": [\"bio_10.1101_2025.08.25.672081\", \"bio_10.1101_2025.02.08.636946\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Both findings are unreviewed preprints from single labs\", \"Direct biochemical demonstration of Msh4 anti-MMR activity not provided\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How ATP binding/hydrolysis by the MSH4-MSH5 sliding clamp couples intermediate stabilization to crossover designation and interference at the molecular level remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No experimental structure of the MutSγ-DNA-resolvase assembly\", \"Mechanistic basis of crossover interference imposed by MSH4 not defined\", \"Direct measurement of MSH4 ATPase coupling to function lacking\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140657\", \"supporting_discovery_ids\": [8]},\n      {\"term_id\": \"GO:0003677\", \"supporting_discovery_ids\": [7, 10]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [9]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [1, 9]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0000228\", \"supporting_discovery_ids\": [0, 1, 7]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1474165\", \"supporting_discovery_ids\": [0, 8]},\n      {\"term_id\": \"R-HSA-73894\", \"supporting_discovery_ids\": [9, 7]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [6, 0]}\n    ],\n    \"complexes\": [\"MutSγ (MSH4-MSH5)\", \"meiotic resolvase (MutSγ-MutLγ-EXO1)\"],\n    \"partners\": [\"MSH5\", \"MLH1\", \"MLH3\", \"RAD51\", \"DMC1\", \"EXO1\", \"VBP1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"tie","faith_supported":5,"faith_total":6,"faith_pct":83.33333333333333}}