{"gene":"EME1","run_date":"2026-06-09T23:54:43","timeline":{"discoveries":[{"year":2001,"finding":"Mus81 and Eme1 form a heterodimeric endonuclease complex that resolves Holliday junctions into linear duplex products. Both subunits are required during meiosis at a late step of meiotic recombination, and the meiotic defect of mus81 mutants is rescued by a bacterial Holliday junction resolvase.","method":"Biochemical endonuclease assay with purified complex, genetic epistasis (rescue by RusA resolvase), co-immunoprecipitation to identify Eme1 as associated partner","journal":"Cell","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro reconstitution of endonuclease activity, genetic rescue experiment, replicated by multiple subsequent studies","pmids":["11719193"],"is_preprint":false},{"year":2002,"finding":"Purified recombinant fission yeast Mus81-Eme1 readily cleaves replication fork structures but cleaves synthetic Holliday junctions relatively poorly in vitro; hypersensitivity of mus81, eme1, and rqh1 mutants to replication fork-stalling agents is suppressed by the Holliday junction resolvase RusA, and synthetic lethality of mus81− rqh1− is also suppressed by RusA.","method":"In vitro endonuclease assay with purified recombinant Mus81-Eme1; genetic epistasis/suppressor analysis with RusA","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Strong — reconstitution in vitro plus genetic epistasis, multiple orthogonal approaches","pmids":["12084712"],"is_preprint":false},{"year":2002,"finding":"Fission yeast Mus81-Eme1 and budding yeast Mus81-Mms4 preferentially cleave reversed replication fork structures (where leading/lagging strands are juxtaposed or a single-stranded tail is present) over normal replication forks or intact Holliday junctions; cleavage occurs predominantly 3–6 bp 5' of the junction point on the leading strand template.","method":"In vitro endonuclease assay with purified recombinant enzymes on defined DNA substrates with cleavage site mapping","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Strong — reconstituted in vitro with defined substrates and cleavage mapping, replicated across two enzyme orthologs","pmids":["12473680"],"is_preprint":false},{"year":2003,"finding":"Human EME1 was identified as the homolog of S. pombe Eme1; purified human Mus81-Eme1 heterodimer is an endonuclease with high specificity for synthetic replication fork structures and 3'-flap substrates, cleaving Holliday junctions ~75-fold less efficiently than flap/fork structures.","method":"Protein purification and in vitro endonuclease assay on multiple defined DNA substrates","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Strong — biochemical reconstitution of human heterodimer with quantitative substrate specificity analysis","pmids":["12721304"],"is_preprint":false},{"year":2003,"finding":"Endogenous and recombinant fission yeast Mus81-Eme1 preferentially cleaves nicked Holliday junctions; cleavage occurs on the strand opposing the nick, resolving the structure by a 'nick and counternick' mechanism with quasi-simultaneous resolving cuts by the endogenous complex.","method":"In vitro endonuclease assay with endogenous and recombinant Mus81-Eme1 on nicked vs intact Holliday junctions; kinetic analysis","journal":"Molecular cell","confidence":"High","confidence_rationale":"Tier 1 / Strong — mechanistic analysis with both endogenous and recombinant enzyme, defining cleavage mechanism","pmids":["14527419"],"is_preprint":false},{"year":2003,"finding":"Purified fission yeast Mus81-Eme1 preferentially cleaves junctions mimicking intermediates formed during the transition from double-strand break to double Holliday junction (nicked HJ-like structures), cleaving in precisely the correct orientation to guarantee crossover formation; Mus81-Eme1 is required for meiotic crossover generation.","method":"In vitro endonuclease assay with purified enzyme; genetic analysis of meiotic crossover frequencies in mus81/eme1 mutants","journal":"Molecular cell","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro reconstitution combined with genetic analysis of meiotic phenotype","pmids":["14527420"],"is_preprint":false},{"year":2003,"finding":"Mouse Eme1 interacts with Mus81 to form a complex that preferentially cleaves 3'-flap structures and replication forks rather than Holliday junctions in vitro; Eme1-/- ES cells are hypersensitive to DNA cross-linking agents (mitomycin C, cisplatin) and exhibit spontaneous genomic instability.","method":"Co-immunoprecipitation, in vitro endonuclease assay, ES cell knockout with drug sensitivity assay and chromosome instability analysis","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — reconstitution of mouse complex, KO phenotype, multiple orthogonal methods","pmids":["14609959"],"is_preprint":false},{"year":2003,"finding":"Fission yeast mus81 mutants have normal or elevated gene conversion frequencies but 20- to 100-fold reduced crossing over, demonstrating that Mus81-Eme1 is specifically required for meiotic crossover resolution and that gene conversion and crossing over are genetically separable.","method":"Genetic analysis of meiotic recombination frequencies in mus81 mutants","journal":"Genetics","confidence":"High","confidence_rationale":"Tier 2 / Strong — rigorous genetic epistasis analysis with quantitative recombination frequency measurements","pmids":["14704204"],"is_preprint":false},{"year":2006,"finding":"Mus81, the catalytic subunit of the Mus81-Eme1 endonuclease, is involved in generating interstrand crosslink-induced DNA double-strand breaks from stalled replication forks during S-phase in mouse ES cells; Mus81 and Rad54 physically interact and function in the same ICL repair pathway.","method":"Mus81-/- mouse ES cells with DSB quantification by PFGE; co-immunoprecipitation of Mus81 and Rad54; double-mutant Mus81-/- Rad54-/- survival analysis","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 2 / Strong — KO cells with specific DSB assay, reciprocal co-IP, genetic epistasis double mutant","pmids":["17036055"],"is_preprint":false},{"year":2008,"finding":"Human Mus81-Eme1 catalyzes coordinate bilateral cleavage of Holliday junction structures sequentially within the lifetime of the enzyme-substrate complex, achieving symmetrical cleavage of cruciform substrates through a highly cooperative mechanism.","method":"Kinetic and enzymatic analysis with highly purified recombinant human Mus81-Eme1 using self-limiting cruciform substrates","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 1 / Moderate — rigorous in vitro kinetic analysis with purified enzyme and mechanistically informative substrates, single lab","pmids":["18310322"],"is_preprint":false},{"year":2008,"finding":"Crystal structure of the Mus81-Eme1 complex was determined; both subunits contain a central nuclease domain and two C-terminal helix-hairpin-helix (HhH) motifs; a flexible 36-residue intradomain linker in Eme1's nuclease domain is essential for DNA recognition; basic residues in Mus81's active site cleft interact with the flexible arm of nicked Holliday junctions to position the opposing junction for catalysis.","method":"X-ray crystallography; functional mutagenesis of Eme1 linker and Mus81 active site residues","journal":"Genes & development","confidence":"High","confidence_rationale":"Tier 1 / Strong — crystal structure combined with functional mutagenesis, provides structural basis for nick-and-counternick mechanism","pmids":["18413719"],"is_preprint":false},{"year":2008,"finding":"Human Rad54 physically interacts with Mus81 (not Eme1) and stimulates Mus81-Eme1 endonuclease activity on Holliday junction-like intermediates in vitro; this stimulation is species-specific (S. cerevisiae Rad54 does not stimulate human Mus81-Eme1) and requires ATP-dependent formation of specific Rad54-DNA complexes.","method":"In vitro endonuclease stimulation assay; co-immunoprecipitation; species-specificity controls","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 1–2 / Moderate — in vitro reconstitution of stimulation, co-IP, mechanistic dissection with species controls and ATP requirements","pmids":["19017809"],"is_preprint":false},{"year":2008,"finding":"EGFR-Src signaling activates STAT3, which binds the promoter of EME1 to transcriptionally upregulate EME1 expression in response to topoisomerase I inhibition, reducing DNA damage and enhancing cell survival.","method":"Chromatin immunoprecipitation (STAT3 binding to EME1 promoter); reporter assay; STAT3 activation analysis; EGFR/Src pathway inhibition","journal":"Cancer research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP demonstrating STAT3 binding to EME1 promoter plus functional pathway analysis, single lab","pmids":["18245483"],"is_preprint":false},{"year":2008,"finding":"Mammalian Eme1 interacts with Np95 (an E3 ubiquitin ligase involved in chromatin modification); Eme1 and Np95 co-localize on nuclear chromatin following camptothecin treatment and this co-localization depends on the Np95 RING finger domain.","method":"Co-immunoprecipitation; co-localization by immunofluorescence; RING finger mutant analysis","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — co-IP and co-localization with functional domain mutant, single lab, limited mechanistic follow-up","pmids":["18692478"],"is_preprint":false},{"year":2011,"finding":"Wee1 kinase physically interacts with Mus81 in vivo and regulates genomic stability during DNA replication through the Mus81-Eme1 endonuclease; the DNA damage response induced by Wee1 depletion critically depends on Mus81-Eme1, and co-depletion of Mus81 and Wee1 abrogates the S-phase delay caused by Wee1 loss.","method":"Co-immunoprecipitation (Wee1-Mus81 interaction); RNAi co-depletion epistasis; cell cycle analysis","journal":"The Journal of cell biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP plus epistatic co-depletion analysis, single lab","pmids":["21859861"],"is_preprint":false},{"year":2011,"finding":"Mus81/Eme1 endonuclease complex generates DNA double-strand breaks at replication forks when Chk1 activity is compromised; Mus81/Eme1-dependent DNA damage (rather than increased fork stalling) is the cause of incomplete replication in Chk1-deficient cells, and Mus81/Eme1 depletion alleviates the S-phase progression defects of Chk1-deficient cells.","method":"RNAi depletion of Mus81/Eme1 in Chk1-inhibited cells; DSB quantification; S-phase progression analysis","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic epistasis by co-depletion with defined phenotypic readout, single lab","pmids":["21858151"],"is_preprint":false},{"year":2012,"finding":"Budding yeast Mus81-Mms4 nuclease activity is strictly regulated during the mitotic cell cycle by CDK (Cdc28)- and Polo-like kinase (Cdc5)-dependent phosphorylation of the non-catalytic subunit Mms4 (EME1 ortholog); phosphorylation occurs only after bulk DNA synthesis and before chromosome segregation and is absolutely required for Mus81-Mms4 function.","method":"Cell cycle phosphorylation analysis; phosphorylation-defective mms4 mutant; in vitro nuclease assay; genetic sensitivity assays","journal":"Nucleic acids research","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — phosphorylation analysis with mutant constructs, in vitro nuclease activity measurement, genetic phenotypes, multiple orthogonal methods","pmids":["22730299"],"is_preprint":false},{"year":2013,"finding":"In human cells, SLX1-SLX4 and MUS81-EME1 associate at the G2/M transition in response to CDK-mediated phosphorylation to form a stable SLX-MUS holoenzyme that can be reconstituted in vitro; the SLX-MUS complex functions as a Holliday junction resolvase that coordinates the active sites of both endonucleases, achieving more efficient and orchestrated HJ resolution than SLX1-SLX4 alone.","method":"Co-immunoprecipitation; in vitro reconstitution of SLX-MUS holoenzyme; biochemical HJ cleavage assay; cell depletion with chromosome segregation phenotyping","journal":"Molecular cell","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — in vitro reconstitution, co-IP, biochemical assays, cellular phenotype, multiple orthogonal methods","pmids":["24076221"],"is_preprint":false},{"year":2013,"finding":"In mouse cells, SLX1 and MUS81-EME1 act together to resolve Holliday junctions in a manner requiring tethering to the SLX4 scaffold; SLX1, like MUS81-EME1, is required for repair of DNA interstrand crosslinks.","method":"Mouse Slx1 and Slx4 gene disruption; HJ resolution assay; ICL repair assays; structure-function analysis","journal":"Molecular cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — mouse genetics combined with biochemical HJ resolution and ICL repair assays","pmids":["24076219"],"is_preprint":false},{"year":2013,"finding":"In fission yeast, Mus81-Eme1 Holliday junction resolvase is activated in response to DNA damage through both Cdc2(CDK1)- and Rad3(ATR)-dependent phosphorylation of Eme1; this activation prevents gross chromosomal rearrangements in cells lacking the BLM-related helicase Rqh1.","method":"Phosphorylation site mapping of Eme1; kinase-dead and phospho-mutant analysis; chromosome rearrangement assays; in vitro endonuclease activity measurements","journal":"Nature structural & molecular biology","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — phosphorylation site identification with functional mutants, in vitro activity assays, and genetic phenotype, multiple methods","pmids":["23584455"],"is_preprint":false},{"year":2013,"finding":"ERCC1 and MUS81-EME1 co-localize with FANCD2 on mitotic chromosomes at common fragile sites; depletion of either ERCC1 or MUS81-EME1 impairs processing of late replication intermediates/under-replicated DNA at CFSs during mitosis, leading to increased chromosome bridges during anaphase and DNA damage accumulation in the following G1 phase.","method":"Immunofluorescence co-localization on mitotic chromosomes; RNAi depletion; chromosome bridge quantification","journal":"Nature cell biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — direct localization experiment tied to functional consequence, co-depletion phenotype, replicated for both nucleases","pmids":["23811686"],"is_preprint":false},{"year":2013,"finding":"FANCA physically interacts with MUS81 and recruits it to interstrand crosslink (ICL) lesions; purified MUS81-EME1 incises DNA at the 5' side of a psoralen ICL in fork structures, and FANCA greatly enhances this MUS81-EME1-mediated ICL incision activity.","method":"Co-immunoprecipitation; laser-induced ICL formation in cells; in vitro endonuclease assay with ICL-containing substrates; truncated FANCA analysis","journal":"Nucleic acids research","confidence":"High","confidence_rationale":"Tier 1–2 / Moderate — in vitro reconstitution of ICL incision, co-IP, cellular ICL recruitment experiment, multiple orthogonal methods","pmids":["24170812"],"is_preprint":false},{"year":2014,"finding":"Crystal structures of human Mus81-Eme1 bound to 3'-flap DNA substrates reveal substrate-induced conformational changes; key structural features include a hydrophobic wedge in Mus81 that separates pre- and post-nick duplex DNA, and a '5' end binding pocket' that hosts the 5' nicked end of post-nick DNA; these features drive sharp DNA bending and incision strand placement at the active site, explaining the preferential cleavage of 3'-flap substrates with 5' nicked ends.","method":"X-ray crystallography of human Mus81-Eme1-DNA complexes; biochemical and biophysical validation","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 1 / Strong — multiple crystal structures with bound substrates combined with biochemical validation, mechanistic structural explanation","pmids":["24733841"],"is_preprint":false},{"year":2016,"finding":"HIV-1 Vpr down-regulates both MUS81 and EME1 by hijacking the host CRL4-DCAF1 E3 ubiquitin ligase complex; this down-regulation is independent of SLX4-SLX1 and does not require direct Vpr interaction with MUS81-EME1.","method":"Co-immunoprecipitation; Vpr mutant analysis; ubiquitin ligase complex perturbation; protein level quantification","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — mechanistic dissection with multiple Vpr mutants and co-IP, single lab","pmids":["27354282"],"is_preprint":false},{"year":2016,"finding":"Gen1 and Eme1 play redundant roles in HJ resolution, DNA repair, and meiotic recombination in mice; combined homozygous Gen1 and Eme1 mutations cause synthetic lethality during early embryonic development.","method":"Mouse genetics; MEF cell survival assays with DNA-damaging agents; meiotic recombination analysis in double mutants","journal":"DNA and cell biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — mouse genetic epistasis with defined phenotypic readouts, single lab","pmids":["27383418"],"is_preprint":false},{"year":2018,"finding":"CK2 kinase phosphorylates MUS81 at Serine 87 in late-G2/mitosis and upon mild replication stress; this phosphorylation promotes MUS81 interaction with SLX4, enhancing MUS81 complex function; S87 phosphorylation is suppressed in S-phase and is mainly detected in MUS81 molecules associated with EME1.","method":"Phosphorylation site mapping; phosphomimic and phosphoablative MUS81 mutants; co-immunoprecipitation (MUS81-SLX4); cell cycle analysis; DSB detection","journal":"Nucleic acids research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — phosphorylation site identified with functional mutants and co-IP, single lab","pmids":["29850896"],"is_preprint":false},{"year":2020,"finding":"Mus81-Eme1 aberrantly cleaves under-replicated DNA engaged in mitotic DNA synthesis when Chk1 is depleted, causing chromosome segregation defects; supplementing cells with nucleosides to complete mitotic DNA synthesis restrains this Mus81-Eme1-dependent DNA damage.","method":"Chk1 depletion with RNAi; Mus81-Eme1 co-depletion epistasis; nucleoside supplementation rescue; chromosome segregation quantification","journal":"Science advances","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — epistatic co-depletion with mechanistic rescue, single lab","pmids":["33298441"],"is_preprint":false},{"year":2022,"finding":"In fission yeast, direct phosphorylation of Eme1 by the Rad3(ATR) checkpoint kinase is essential for catalytic stimulation of Mus81-Eme1; Chk1-mediated phosphorylation also contributes when combined with Rad3ATR phosphorylation; two SUMO-interacting motifs (SIMs) in the N-terminal domain of Eme1 are also required for cell survival in the absence of Rqh1BLM; abrogating bimodal phosphorylation plus mutating the SIMs is incompatible with rqh1Δ cell viability.","method":"Rad3ATR phosphorylation site identification and mutagenesis; in vitro kinase assay; endonuclease activity assay; SIM mutant analysis; genetic viability assays","journal":"PLoS genetics","confidence":"High","confidence_rationale":"Tier 1–2 / Moderate — direct in vitro phosphorylation assay, functional mutagenesis of phospho-sites and SIMs, genetic epistasis, multiple orthogonal methods","pmids":["35452455"],"is_preprint":false},{"year":2022,"finding":"CDK1-cyclin B phosphorylates SLX4 residues T1544, T1561, and T1571 in the MUS81-binding region (SLX4MBR); phosphorylated SLX4MBR drives folding of an SAP domain which mediates high-affinity interaction with MUS81-EME1 and relaxes the substrate specificity of MUS81-EME1 to stimulate cleavage of replication and recombination structures.","method":"In vitro CDK1-cyclin B kinase assay; structural analysis of phospho-SLX4MBR; biochemical MUS81-EME1 cleavage assay; co-immunoprecipitation","journal":"Cell reports","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro reconstitution of CDK1 phosphorylation, structure determination, endonuclease activity assay, co-IP, multiple orthogonal methods in one study","pmids":["36288699"],"is_preprint":false},{"year":2025,"finding":"SETD1A-dependent transcription of EME1 correlates with sensitivity to PARP inhibitor Olaparib in BRCA1- or ATM-deficient cancer cells; loss of SETD1A or EME1 drives resistance to Olaparib and partially restores homologous recombination.","method":"siRNA/CRISPR depletion of SETD1A and EME1; HR assay; Olaparib cell viability; RNAseq","journal":"British journal of cancer","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic depletion with functional HR and viability readouts, single lab","pmids":["39994444"],"is_preprint":false}],"current_model":"EME1 is the non-catalytic subunit of the heterodimeric Mus81-EME1 structure-selective endonuclease, which cleaves branched DNA structures including nicked Holliday junctions (by a nick-and-counternick mechanism), 3'-flap substrates, and stalled/reversed replication forks to promote meiotic crossover formation, replication fork restart, and interstrand crosslink repair; its activity is tightly cell-cycle regulated through CDK1-, Polo-like kinase-, ATR-, and CK2-mediated phosphorylation of EME1 (or its scaffold partner SLX4), and at G2/M it assembles with SLX1-SLX4 into the SLX-MUS holoenzyme for coordinated Holliday junction resolution, with additional regulation through physical interactions with Rad54, FANCA, Wee1, and Np95."},"narrative":{"mechanistic_narrative":"EME1 is the non-catalytic subunit of the heterodimeric Mus81-EME1 structure-selective endonuclease that resolves branched DNA intermediates arising during recombination and replication, thereby promoting meiotic crossover formation, replication fork processing, and interstrand crosslink repair [PMID:11719193, PMID:14609959]. The complex preferentially cleaves replication fork structures, 3'-flaps, and nicked Holliday junctions over intact Holliday junctions, resolving nicked junctions through a nick-and-counternick mechanism in which incision occurs on the strand opposing the nick [PMID:12721304, PMID:14527419, PMID:12473680]; the human enzyme can also achieve symmetrical bilateral cleavage of cruciform substrates through a cooperative, sequential mechanism [PMID:18310322]. Crystal structures of Mus81-EME1 bound to DNA define both subunits as carrying a central nuclease domain and C-terminal helix-hairpin-helix motifs, with a flexible EME1 intradomain linker essential for DNA recognition and a Mus81 hydrophobic wedge and 5'-end binding pocket that bend and position the substrate for incision [PMID:18413719, PMID:24733841]. EME1-dependent cleavage is genetically required for meiotic crossing over, where it acts specifically at crossover resolution while leaving gene conversion intact [PMID:14527420, PMID:14704204], and Eme1-deficient cells show hypersensitivity to crosslinking agents and spontaneous genomic instability [PMID:14609959]. At the G2/M transition CDK-dependent phosphorylation drives assembly of MUS81-EME1 with SLX1-SLX4 into the SLX-MUS holoenzyme for coordinated Holliday junction resolution [PMID:24076221, PMID:36288699], and enzyme activity is further controlled by cell-cycle and checkpoint kinases including CDK/Polo-like kinase, ATR, Chk1, and CK2 acting on EME1 or its scaffold partner SLX4 [PMID:22730299, PMID:23584455, PMID:35452455, PMID:29850896]. MUS81-EME1 cooperates with FANCA, which recruits it to and stimulates incision at interstrand crosslinks [PMID:24170812], localizes with ERCC1 and FANCD2 to common fragile sites to process under-replicated DNA in mitosis [PMID:23811686], and produces deleterious DNA breaks at replication forks when Chk1 is compromised [PMID:21858151, PMID:33298441]. EME1 expression is transcriptionally regulated through STAT3 and SETD1A, and its levels influence sensitivity to topoisomerase and PARP inhibitors [PMID:18245483, PMID:39994444].","teleology":[{"year":2001,"claim":"Established that EME1 is an obligate partner of Mus81 in a heterodimeric endonuclease and that this activity functions late in meiotic recombination, framing EME1 as a junction-resolving factor.","evidence":"Purified-complex endonuclease assay and genetic rescue of mus81 meiotic defect by the bacterial resolvase RusA, with co-IP identifying Eme1","pmids":["11719193"],"confidence":"High","gaps":["Did not define which branched substrate is the physiological target in vivo","Catalytic versus structural roles of the two subunits not yet separated"]},{"year":2002,"claim":"Resolved the apparent substrate paradox by showing the enzyme cleaves replication fork and reversed-fork structures efficiently but synthetic Holliday junctions poorly, redirecting attention toward replication intermediates.","evidence":"In vitro endonuclease assays on defined substrates with cleavage-site mapping plus RusA suppressor genetics in fission and budding yeast","pmids":["12084712","12473680"],"confidence":"High","gaps":["Did not reconcile in vitro fork preference with the genetic requirement for crossover resolution","Cleavage-site choice on physiological in vivo substrates not established"]},{"year":2003,"claim":"Demonstrated conservation and substrate specificity of the human and mouse enzymes and defined the nick-and-counternick mechanism for nicked Holliday junctions, linking biochemistry to meiotic crossover and crosslink-repair phenotypes.","evidence":"Purified human/mouse heterodimer endonuclease assays, kinetic analysis of nicked vs intact junctions, ES-cell knockout drug-sensitivity, and meiotic recombination genetics","pmids":["12721304","14527419","14527420","14609959","14704204"],"confidence":"High","gaps":["How nicked junction intermediates are generated in vivo not established","Crossover-versus-gene-conversion separation mechanistically unexplained"]},{"year":2006,"claim":"Placed Mus81-EME1 in the interstrand-crosslink repair pathway by showing it generates ICL-induced double-strand breaks at S-phase forks and physically and genetically interacts with Rad54.","evidence":"Mus81-/- ES cells with PFGE DSB quantification, reciprocal co-IP, and Mus81/Rad54 double-mutant survival analysis","pmids":["17036055"],"confidence":"High","gaps":["Whether Rad54 acts before or after EME1-dependent incision unclear","EME1's direct contribution distinct from Mus81 not isolated"]},{"year":2008,"claim":"Provided the structural basis for substrate recognition and bilateral cleavage, revealing how the EME1 linker and Mus81 active-site cleft position branched DNA for coordinated incision.","evidence":"Crystal structure of the Mus81-Eme1 complex with functional mutagenesis, plus kinetic analysis of cooperative cruciform cleavage","pmids":["18413719","18310322"],"confidence":"High","gaps":["Structure lacked a bound DNA substrate at this stage","Regulation of the catalytic cycle in cells not addressed"]},{"year":2008,"claim":"Identified physical and transcriptional regulators of EME1, including Rad54 stimulation of activity, Np95 chromatin co-localization, and STAT3-driven transcriptional upregulation after topoisomerase inhibition.","evidence":"In vitro stimulation assays with species controls, co-IP, immunofluorescence co-localization, and ChIP/reporter analysis of the EME1 promoter","pmids":["19017809","18692478","18245483"],"confidence":"Medium","gaps":["Functional consequence of Np95 co-localization not defined","Whether STAT3 regulation operates outside topoisomerase-inhibited cells unknown"]},{"year":2011,"claim":"Connected Mus81-EME1 to checkpoint control, showing that loss of Wee1 or Chk1 unleashes EME1-dependent fork cleavage that drives replication stress and DNA damage.","evidence":"Co-IP of Wee1-Mus81 and RNAi co-depletion epistasis with cell-cycle and DSB readouts in checkpoint-deficient cells","pmids":["21859861","21858151"],"confidence":"Medium","gaps":["Direct phosphoregulation of EME1 by these kinases not demonstrated here","Single-lab epistasis without reconstitution"]},{"year":2013,"claim":"Defined cell-cycle and checkpoint phosphorylation as the master switch activating the enzyme and showed that CDK-triggered assembly into the SLX-MUS holoenzyme coordinates Holliday junction resolution at G2/M.","evidence":"Phospho-site mapping and mutant analysis (Cdc2/Rad3 on Eme1; CDK on the holoenzyme), in vitro reconstitution of SLX-MUS, HJ cleavage assays, and chromosome-segregation phenotyping","pmids":["22730299","23584455","24076221","24076219"],"confidence":"High","gaps":["Precise phospho-sites on mammalian EME1 versus SLX4 not fully resolved","How phosphorylation restructures the active site biochemically unclear"]},{"year":2013,"claim":"Established the roles of MUS81-EME1 at interstrand crosslinks and common fragile sites, showing FANCA-dependent recruitment and stimulation of ICL incision and FANCD2/ERCC1 co-localization needed for mitotic processing of under-replicated DNA.","evidence":"Co-IP, cellular ICL recruitment, in vitro ICL-substrate incision assays, and mitotic-chromosome immunofluorescence with co-depletion phenotypes","pmids":["24170812","23811686"],"confidence":"High","gaps":["Order of FANCA recruitment relative to other Fanconi factors not resolved","Distinct EME1 contribution to fragile-site processing not isolated from Mus81"]},{"year":2014,"claim":"Captured the enzyme bound to its substrate, defining the hydrophobic wedge and 5'-end binding pocket that bend DNA and explain preferential 3'-flap cleavage.","evidence":"X-ray crystallography of human Mus81-Eme1-DNA complexes with biochemical and biophysical validation","pmids":["24733841"],"confidence":"High","gaps":["Structure of a productive Holliday-junction-bound state not obtained","How phosphoregulation alters the captured conformation unknown"]},{"year":2016,"claim":"Revealed pathological and viral regulation of EME1 abundance, with HIV-1 Vpr hijacking CRL4-DCAF1 to degrade MUS81-EME1, and demonstrated GEN1/EME1 redundancy in junction resolution in mice.","evidence":"Co-IP, Vpr mutant and ubiquitin-ligase perturbation analysis, and Gen1/Eme1 double-mutant mouse genetics","pmids":["27354282","27383418"],"confidence":"Medium","gaps":["Functional rationale for viral targeting of EME1 unresolved","Degree of GEN1/EME1 redundancy in human cells untested"]},{"year":2022,"claim":"Refined the activation logic by showing direct ATR/Chk1 phosphorylation and SUMO-interacting motifs on Eme1, and by showing CDK1 phosphorylation of SLX4 folds an SAP domain that binds and relaxes MUS81-EME1 substrate specificity.","evidence":"In vitro kinase and endonuclease assays, phospho-site and SIM mutagenesis, structural analysis of phospho-SLX4MBR, and genetic viability assays","pmids":["35452455","36288699","29850896"],"confidence":"High","gaps":["Integration of EME1-intrinsic versus SLX4-mediated regulation in a single model incomplete","Role of EME1 SUMO interactions in mammalian cells not tested"]},{"year":2025,"claim":"Linked EME1 expression to therapeutic vulnerability, showing SETD1A-driven EME1 transcription sets PARP-inhibitor sensitivity in HR-deficient cancers.","evidence":"siRNA/CRISPR depletion of SETD1A and EME1 with HR assays, Olaparib viability, and RNAseq","pmids":["39994444"],"confidence":"Medium","gaps":["Mechanism by which EME1 loss restores HR not defined","Generality across tumor genotypes untested"]},{"year":null,"claim":"How the multiple phosphorylation, SUMO, and scaffold inputs are integrated to switch EME1 between protective junction resolution and deleterious fork cleavage in vivo remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No unified model coupling EME1 regulation to substrate choice in cells","Distinct contributions of EME1 versus Mus81 to each pathway not fully separated"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140097","term_label":"catalytic activity, acting on DNA","supporting_discovery_ids":[0,2,3,4,9]},{"term_id":"GO:0016787","term_label":"hydrolase activity","supporting_discovery_ids":[0,3,6]},{"term_id":"GO:0003677","term_label":"DNA binding","supporting_discovery_ids":[10,22]}],"localization":[{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[13]},{"term_id":"GO:0000228","term_label":"nuclear chromosome","supporting_discovery_ids":[20]}],"pathway":[{"term_id":"R-HSA-73894","term_label":"DNA Repair","supporting_discovery_ids":[6,21,8]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[16,17,20]},{"term_id":"R-HSA-69306","term_label":"DNA Replication","supporting_discovery_ids":[2,15,26]},{"term_id":"R-HSA-1474165","term_label":"Reproduction","supporting_discovery_ids":[5,7,24]}],"complexes":["Mus81-EME1","SLX-MUS holoenzyme"],"partners":["MUS81","SLX4","SLX1","RAD54","FANCA","WEE1","ERCC1","UHRF1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q96AY2","full_name":"Structure-specific endonuclease subunit EME1","aliases":["Crossover junction endonuclease EME1","Essential meiotic structure-specific endonuclease 1","MMS4 homolog","hMMS4"],"length_aa":570,"mass_kda":63.3,"function":"Non-catalytic subunit of the structure-specific, heterodimeric DNA endonuclease MUS81-EME1 which is involved in the maintenance of genome stability. In the complex, EME1 is required for DNA cleavage, participating in DNA recognition and bending (PubMed:12686547, PubMed:12721304, PubMed:14617801, PubMed:17289582, PubMed:24733841, PubMed:24813886, PubMed:35290797, PubMed:39015284). MUS81-EME1 cleaves 3'-flaps and nicked Holliday junctions, and exhibit limited endonuclease activity with 5' flaps and nicked double-stranded DNAs (PubMed:24733841, PubMed:35290797). Active during prometaphase, MUS81-EME1 resolves mitotic recombination intermediates, including Holliday junctions, which form during homologous recombination (PubMed:14617801, PubMed:24813886)","subcellular_location":"Nucleus, nucleolus","url":"https://www.uniprot.org/uniprotkb/Q96AY2/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/EME1","classification":"Not Classified","n_dependent_lines":17,"n_total_lines":1208,"dependency_fraction":0.014072847682119206},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/EME1","total_profiled":1310},"omim":[{"mim_id":"615823","title":"SLX1 HOMOLOG B, STRUCTURE-SPECIFIC ENDONUCLEASE SUBUNIT; SLX1B","url":"https://www.omim.org/entry/615823"},{"mim_id":"615822","title":"SLX1 HOMOLOG A, STRUCTURE-SPECIFIC ENDONUCLEASE SUBUNIT; SLX1A","url":"https://www.omim.org/entry/615822"},{"mim_id":"613278","title":"SLX4 STRUCTURE-SPECIFIC ENDONUCLEASE SUBUNIT; SLX4","url":"https://www.omim.org/entry/613278"},{"mim_id":"611415","title":"POLYMERASE (DNA-DIRECTED), DELTA 3, ACCESSORY SUBUNIT; POLD3","url":"https://www.omim.org/entry/611415"},{"mim_id":"610886","title":"ESSENTIAL MEIOTIC STRUCTURE-SPECIFIC ENDONUCLEASE 2; EME2","url":"https://www.omim.org/entry/610886"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Nucleoplasm","reliability":"Approved"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in some","driving_tissues":[{"tissue":"bone 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Carcinoma Cells.","date":"2026","source":"FASEB journal : official publication of the Federation of American Societies for Experimental Biology","url":"https://pubmed.ncbi.nlm.nih.gov/41532283","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2024.09.19.613851","title":"Potential Cancer Biomarkers: Mitotic Intra-S DNA Damage Checkpoint Genes","date":"2024-09-20","source":"bioRxiv","url":"https://doi.org/10.1101/2024.09.19.613851","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":22699,"output_tokens":7313,"usd":0.088896,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":16312,"output_tokens":4864,"usd":0.10158,"stage2_stop_reason":"end_turn"},"total_usd":0.190476,"stage1_batch_id":"msgbatch_01AsR7g8dGTEiEw9U83bJeWn","stage2_batch_id":"msgbatch_01YV5ZyxtFNUZEjxRcpd9jzb","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2001,\n      \"finding\": \"Mus81 and Eme1 form a heterodimeric endonuclease complex that resolves Holliday junctions into linear duplex products. Both subunits are required during meiosis at a late step of meiotic recombination, and the meiotic defect of mus81 mutants is rescued by a bacterial Holliday junction resolvase.\",\n      \"method\": \"Biochemical endonuclease assay with purified complex, genetic epistasis (rescue by RusA resolvase), co-immunoprecipitation to identify Eme1 as associated partner\",\n      \"journal\": \"Cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro reconstitution of endonuclease activity, genetic rescue experiment, replicated by multiple subsequent studies\",\n      \"pmids\": [\"11719193\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"Purified recombinant fission yeast Mus81-Eme1 readily cleaves replication fork structures but cleaves synthetic Holliday junctions relatively poorly in vitro; hypersensitivity of mus81, eme1, and rqh1 mutants to replication fork-stalling agents is suppressed by the Holliday junction resolvase RusA, and synthetic lethality of mus81− rqh1− is also suppressed by RusA.\",\n      \"method\": \"In vitro endonuclease assay with purified recombinant Mus81-Eme1; genetic epistasis/suppressor analysis with RusA\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — reconstitution in vitro plus genetic epistasis, multiple orthogonal approaches\",\n      \"pmids\": [\"12084712\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"Fission yeast Mus81-Eme1 and budding yeast Mus81-Mms4 preferentially cleave reversed replication fork structures (where leading/lagging strands are juxtaposed or a single-stranded tail is present) over normal replication forks or intact Holliday junctions; cleavage occurs predominantly 3–6 bp 5' of the junction point on the leading strand template.\",\n      \"method\": \"In vitro endonuclease assay with purified recombinant enzymes on defined DNA substrates with cleavage site mapping\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — reconstituted in vitro with defined substrates and cleavage mapping, replicated across two enzyme orthologs\",\n      \"pmids\": [\"12473680\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"Human EME1 was identified as the homolog of S. pombe Eme1; purified human Mus81-Eme1 heterodimer is an endonuclease with high specificity for synthetic replication fork structures and 3'-flap substrates, cleaving Holliday junctions ~75-fold less efficiently than flap/fork structures.\",\n      \"method\": \"Protein purification and in vitro endonuclease assay on multiple defined DNA substrates\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — biochemical reconstitution of human heterodimer with quantitative substrate specificity analysis\",\n      \"pmids\": [\"12721304\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"Endogenous and recombinant fission yeast Mus81-Eme1 preferentially cleaves nicked Holliday junctions; cleavage occurs on the strand opposing the nick, resolving the structure by a 'nick and counternick' mechanism with quasi-simultaneous resolving cuts by the endogenous complex.\",\n      \"method\": \"In vitro endonuclease assay with endogenous and recombinant Mus81-Eme1 on nicked vs intact Holliday junctions; kinetic analysis\",\n      \"journal\": \"Molecular cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — mechanistic analysis with both endogenous and recombinant enzyme, defining cleavage mechanism\",\n      \"pmids\": [\"14527419\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"Purified fission yeast Mus81-Eme1 preferentially cleaves junctions mimicking intermediates formed during the transition from double-strand break to double Holliday junction (nicked HJ-like structures), cleaving in precisely the correct orientation to guarantee crossover formation; Mus81-Eme1 is required for meiotic crossover generation.\",\n      \"method\": \"In vitro endonuclease assay with purified enzyme; genetic analysis of meiotic crossover frequencies in mus81/eme1 mutants\",\n      \"journal\": \"Molecular cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro reconstitution combined with genetic analysis of meiotic phenotype\",\n      \"pmids\": [\"14527420\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"Mouse Eme1 interacts with Mus81 to form a complex that preferentially cleaves 3'-flap structures and replication forks rather than Holliday junctions in vitro; Eme1-/- ES cells are hypersensitive to DNA cross-linking agents (mitomycin C, cisplatin) and exhibit spontaneous genomic instability.\",\n      \"method\": \"Co-immunoprecipitation, in vitro endonuclease assay, ES cell knockout with drug sensitivity assay and chromosome instability analysis\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — reconstitution of mouse complex, KO phenotype, multiple orthogonal methods\",\n      \"pmids\": [\"14609959\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"Fission yeast mus81 mutants have normal or elevated gene conversion frequencies but 20- to 100-fold reduced crossing over, demonstrating that Mus81-Eme1 is specifically required for meiotic crossover resolution and that gene conversion and crossing over are genetically separable.\",\n      \"method\": \"Genetic analysis of meiotic recombination frequencies in mus81 mutants\",\n      \"journal\": \"Genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — rigorous genetic epistasis analysis with quantitative recombination frequency measurements\",\n      \"pmids\": [\"14704204\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"Mus81, the catalytic subunit of the Mus81-Eme1 endonuclease, is involved in generating interstrand crosslink-induced DNA double-strand breaks from stalled replication forks during S-phase in mouse ES cells; Mus81 and Rad54 physically interact and function in the same ICL repair pathway.\",\n      \"method\": \"Mus81-/- mouse ES cells with DSB quantification by PFGE; co-immunoprecipitation of Mus81 and Rad54; double-mutant Mus81-/- Rad54-/- survival analysis\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — KO cells with specific DSB assay, reciprocal co-IP, genetic epistasis double mutant\",\n      \"pmids\": [\"17036055\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"Human Mus81-Eme1 catalyzes coordinate bilateral cleavage of Holliday junction structures sequentially within the lifetime of the enzyme-substrate complex, achieving symmetrical cleavage of cruciform substrates through a highly cooperative mechanism.\",\n      \"method\": \"Kinetic and enzymatic analysis with highly purified recombinant human Mus81-Eme1 using self-limiting cruciform substrates\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — rigorous in vitro kinetic analysis with purified enzyme and mechanistically informative substrates, single lab\",\n      \"pmids\": [\"18310322\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"Crystal structure of the Mus81-Eme1 complex was determined; both subunits contain a central nuclease domain and two C-terminal helix-hairpin-helix (HhH) motifs; a flexible 36-residue intradomain linker in Eme1's nuclease domain is essential for DNA recognition; basic residues in Mus81's active site cleft interact with the flexible arm of nicked Holliday junctions to position the opposing junction for catalysis.\",\n      \"method\": \"X-ray crystallography; functional mutagenesis of Eme1 linker and Mus81 active site residues\",\n      \"journal\": \"Genes & development\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — crystal structure combined with functional mutagenesis, provides structural basis for nick-and-counternick mechanism\",\n      \"pmids\": [\"18413719\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"Human Rad54 physically interacts with Mus81 (not Eme1) and stimulates Mus81-Eme1 endonuclease activity on Holliday junction-like intermediates in vitro; this stimulation is species-specific (S. cerevisiae Rad54 does not stimulate human Mus81-Eme1) and requires ATP-dependent formation of specific Rad54-DNA complexes.\",\n      \"method\": \"In vitro endonuclease stimulation assay; co-immunoprecipitation; species-specificity controls\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — in vitro reconstitution of stimulation, co-IP, mechanistic dissection with species controls and ATP requirements\",\n      \"pmids\": [\"19017809\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"EGFR-Src signaling activates STAT3, which binds the promoter of EME1 to transcriptionally upregulate EME1 expression in response to topoisomerase I inhibition, reducing DNA damage and enhancing cell survival.\",\n      \"method\": \"Chromatin immunoprecipitation (STAT3 binding to EME1 promoter); reporter assay; STAT3 activation analysis; EGFR/Src pathway inhibition\",\n      \"journal\": \"Cancer research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP demonstrating STAT3 binding to EME1 promoter plus functional pathway analysis, single lab\",\n      \"pmids\": [\"18245483\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"Mammalian Eme1 interacts with Np95 (an E3 ubiquitin ligase involved in chromatin modification); Eme1 and Np95 co-localize on nuclear chromatin following camptothecin treatment and this co-localization depends on the Np95 RING finger domain.\",\n      \"method\": \"Co-immunoprecipitation; co-localization by immunofluorescence; RING finger mutant analysis\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — co-IP and co-localization with functional domain mutant, single lab, limited mechanistic follow-up\",\n      \"pmids\": [\"18692478\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"Wee1 kinase physically interacts with Mus81 in vivo and regulates genomic stability during DNA replication through the Mus81-Eme1 endonuclease; the DNA damage response induced by Wee1 depletion critically depends on Mus81-Eme1, and co-depletion of Mus81 and Wee1 abrogates the S-phase delay caused by Wee1 loss.\",\n      \"method\": \"Co-immunoprecipitation (Wee1-Mus81 interaction); RNAi co-depletion epistasis; cell cycle analysis\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP plus epistatic co-depletion analysis, single lab\",\n      \"pmids\": [\"21859861\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"Mus81/Eme1 endonuclease complex generates DNA double-strand breaks at replication forks when Chk1 activity is compromised; Mus81/Eme1-dependent DNA damage (rather than increased fork stalling) is the cause of incomplete replication in Chk1-deficient cells, and Mus81/Eme1 depletion alleviates the S-phase progression defects of Chk1-deficient cells.\",\n      \"method\": \"RNAi depletion of Mus81/Eme1 in Chk1-inhibited cells; DSB quantification; S-phase progression analysis\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic epistasis by co-depletion with defined phenotypic readout, single lab\",\n      \"pmids\": [\"21858151\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Budding yeast Mus81-Mms4 nuclease activity is strictly regulated during the mitotic cell cycle by CDK (Cdc28)- and Polo-like kinase (Cdc5)-dependent phosphorylation of the non-catalytic subunit Mms4 (EME1 ortholog); phosphorylation occurs only after bulk DNA synthesis and before chromosome segregation and is absolutely required for Mus81-Mms4 function.\",\n      \"method\": \"Cell cycle phosphorylation analysis; phosphorylation-defective mms4 mutant; in vitro nuclease assay; genetic sensitivity assays\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — phosphorylation analysis with mutant constructs, in vitro nuclease activity measurement, genetic phenotypes, multiple orthogonal methods\",\n      \"pmids\": [\"22730299\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"In human cells, SLX1-SLX4 and MUS81-EME1 associate at the G2/M transition in response to CDK-mediated phosphorylation to form a stable SLX-MUS holoenzyme that can be reconstituted in vitro; the SLX-MUS complex functions as a Holliday junction resolvase that coordinates the active sites of both endonucleases, achieving more efficient and orchestrated HJ resolution than SLX1-SLX4 alone.\",\n      \"method\": \"Co-immunoprecipitation; in vitro reconstitution of SLX-MUS holoenzyme; biochemical HJ cleavage assay; cell depletion with chromosome segregation phenotyping\",\n      \"journal\": \"Molecular cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — in vitro reconstitution, co-IP, biochemical assays, cellular phenotype, multiple orthogonal methods\",\n      \"pmids\": [\"24076221\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"In mouse cells, SLX1 and MUS81-EME1 act together to resolve Holliday junctions in a manner requiring tethering to the SLX4 scaffold; SLX1, like MUS81-EME1, is required for repair of DNA interstrand crosslinks.\",\n      \"method\": \"Mouse Slx1 and Slx4 gene disruption; HJ resolution assay; ICL repair assays; structure-function analysis\",\n      \"journal\": \"Molecular cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — mouse genetics combined with biochemical HJ resolution and ICL repair assays\",\n      \"pmids\": [\"24076219\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"In fission yeast, Mus81-Eme1 Holliday junction resolvase is activated in response to DNA damage through both Cdc2(CDK1)- and Rad3(ATR)-dependent phosphorylation of Eme1; this activation prevents gross chromosomal rearrangements in cells lacking the BLM-related helicase Rqh1.\",\n      \"method\": \"Phosphorylation site mapping of Eme1; kinase-dead and phospho-mutant analysis; chromosome rearrangement assays; in vitro endonuclease activity measurements\",\n      \"journal\": \"Nature structural & molecular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — phosphorylation site identification with functional mutants, in vitro activity assays, and genetic phenotype, multiple methods\",\n      \"pmids\": [\"23584455\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"ERCC1 and MUS81-EME1 co-localize with FANCD2 on mitotic chromosomes at common fragile sites; depletion of either ERCC1 or MUS81-EME1 impairs processing of late replication intermediates/under-replicated DNA at CFSs during mitosis, leading to increased chromosome bridges during anaphase and DNA damage accumulation in the following G1 phase.\",\n      \"method\": \"Immunofluorescence co-localization on mitotic chromosomes; RNAi depletion; chromosome bridge quantification\",\n      \"journal\": \"Nature cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — direct localization experiment tied to functional consequence, co-depletion phenotype, replicated for both nucleases\",\n      \"pmids\": [\"23811686\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"FANCA physically interacts with MUS81 and recruits it to interstrand crosslink (ICL) lesions; purified MUS81-EME1 incises DNA at the 5' side of a psoralen ICL in fork structures, and FANCA greatly enhances this MUS81-EME1-mediated ICL incision activity.\",\n      \"method\": \"Co-immunoprecipitation; laser-induced ICL formation in cells; in vitro endonuclease assay with ICL-containing substrates; truncated FANCA analysis\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — in vitro reconstitution of ICL incision, co-IP, cellular ICL recruitment experiment, multiple orthogonal methods\",\n      \"pmids\": [\"24170812\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Crystal structures of human Mus81-Eme1 bound to 3'-flap DNA substrates reveal substrate-induced conformational changes; key structural features include a hydrophobic wedge in Mus81 that separates pre- and post-nick duplex DNA, and a '5' end binding pocket' that hosts the 5' nicked end of post-nick DNA; these features drive sharp DNA bending and incision strand placement at the active site, explaining the preferential cleavage of 3'-flap substrates with 5' nicked ends.\",\n      \"method\": \"X-ray crystallography of human Mus81-Eme1-DNA complexes; biochemical and biophysical validation\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — multiple crystal structures with bound substrates combined with biochemical validation, mechanistic structural explanation\",\n      \"pmids\": [\"24733841\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"HIV-1 Vpr down-regulates both MUS81 and EME1 by hijacking the host CRL4-DCAF1 E3 ubiquitin ligase complex; this down-regulation is independent of SLX4-SLX1 and does not require direct Vpr interaction with MUS81-EME1.\",\n      \"method\": \"Co-immunoprecipitation; Vpr mutant analysis; ubiquitin ligase complex perturbation; protein level quantification\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mechanistic dissection with multiple Vpr mutants and co-IP, single lab\",\n      \"pmids\": [\"27354282\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Gen1 and Eme1 play redundant roles in HJ resolution, DNA repair, and meiotic recombination in mice; combined homozygous Gen1 and Eme1 mutations cause synthetic lethality during early embryonic development.\",\n      \"method\": \"Mouse genetics; MEF cell survival assays with DNA-damaging agents; meiotic recombination analysis in double mutants\",\n      \"journal\": \"DNA and cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mouse genetic epistasis with defined phenotypic readouts, single lab\",\n      \"pmids\": [\"27383418\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"CK2 kinase phosphorylates MUS81 at Serine 87 in late-G2/mitosis and upon mild replication stress; this phosphorylation promotes MUS81 interaction with SLX4, enhancing MUS81 complex function; S87 phosphorylation is suppressed in S-phase and is mainly detected in MUS81 molecules associated with EME1.\",\n      \"method\": \"Phosphorylation site mapping; phosphomimic and phosphoablative MUS81 mutants; co-immunoprecipitation (MUS81-SLX4); cell cycle analysis; DSB detection\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — phosphorylation site identified with functional mutants and co-IP, single lab\",\n      \"pmids\": [\"29850896\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Mus81-Eme1 aberrantly cleaves under-replicated DNA engaged in mitotic DNA synthesis when Chk1 is depleted, causing chromosome segregation defects; supplementing cells with nucleosides to complete mitotic DNA synthesis restrains this Mus81-Eme1-dependent DNA damage.\",\n      \"method\": \"Chk1 depletion with RNAi; Mus81-Eme1 co-depletion epistasis; nucleoside supplementation rescue; chromosome segregation quantification\",\n      \"journal\": \"Science advances\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — epistatic co-depletion with mechanistic rescue, single lab\",\n      \"pmids\": [\"33298441\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"In fission yeast, direct phosphorylation of Eme1 by the Rad3(ATR) checkpoint kinase is essential for catalytic stimulation of Mus81-Eme1; Chk1-mediated phosphorylation also contributes when combined with Rad3ATR phosphorylation; two SUMO-interacting motifs (SIMs) in the N-terminal domain of Eme1 are also required for cell survival in the absence of Rqh1BLM; abrogating bimodal phosphorylation plus mutating the SIMs is incompatible with rqh1Δ cell viability.\",\n      \"method\": \"Rad3ATR phosphorylation site identification and mutagenesis; in vitro kinase assay; endonuclease activity assay; SIM mutant analysis; genetic viability assays\",\n      \"journal\": \"PLoS genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — direct in vitro phosphorylation assay, functional mutagenesis of phospho-sites and SIMs, genetic epistasis, multiple orthogonal methods\",\n      \"pmids\": [\"35452455\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"CDK1-cyclin B phosphorylates SLX4 residues T1544, T1561, and T1571 in the MUS81-binding region (SLX4MBR); phosphorylated SLX4MBR drives folding of an SAP domain which mediates high-affinity interaction with MUS81-EME1 and relaxes the substrate specificity of MUS81-EME1 to stimulate cleavage of replication and recombination structures.\",\n      \"method\": \"In vitro CDK1-cyclin B kinase assay; structural analysis of phospho-SLX4MBR; biochemical MUS81-EME1 cleavage assay; co-immunoprecipitation\",\n      \"journal\": \"Cell reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro reconstitution of CDK1 phosphorylation, structure determination, endonuclease activity assay, co-IP, multiple orthogonal methods in one study\",\n      \"pmids\": [\"36288699\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"SETD1A-dependent transcription of EME1 correlates with sensitivity to PARP inhibitor Olaparib in BRCA1- or ATM-deficient cancer cells; loss of SETD1A or EME1 drives resistance to Olaparib and partially restores homologous recombination.\",\n      \"method\": \"siRNA/CRISPR depletion of SETD1A and EME1; HR assay; Olaparib cell viability; RNAseq\",\n      \"journal\": \"British journal of cancer\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic depletion with functional HR and viability readouts, single lab\",\n      \"pmids\": [\"39994444\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"EME1 is the non-catalytic subunit of the heterodimeric Mus81-EME1 structure-selective endonuclease, which cleaves branched DNA structures including nicked Holliday junctions (by a nick-and-counternick mechanism), 3'-flap substrates, and stalled/reversed replication forks to promote meiotic crossover formation, replication fork restart, and interstrand crosslink repair; its activity is tightly cell-cycle regulated through CDK1-, Polo-like kinase-, ATR-, and CK2-mediated phosphorylation of EME1 (or its scaffold partner SLX4), and at G2/M it assembles with SLX1-SLX4 into the SLX-MUS holoenzyme for coordinated Holliday junction resolution, with additional regulation through physical interactions with Rad54, FANCA, Wee1, and Np95.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"EME1 is the non-catalytic subunit of the heterodimeric Mus81-EME1 structure-selective endonuclease that resolves branched DNA intermediates arising during recombination and replication, thereby promoting meiotic crossover formation, replication fork processing, and interstrand crosslink repair [#0, #6]. The complex preferentially cleaves replication fork structures, 3'-flaps, and nicked Holliday junctions over intact Holliday junctions, resolving nicked junctions through a nick-and-counternick mechanism in which incision occurs on the strand opposing the nick [#3, #4, #2]; the human enzyme can also achieve symmetrical bilateral cleavage of cruciform substrates through a cooperative, sequential mechanism [#9]. Crystal structures of Mus81-EME1 bound to DNA define both subunits as carrying a central nuclease domain and C-terminal helix-hairpin-helix motifs, with a flexible EME1 intradomain linker essential for DNA recognition and a Mus81 hydrophobic wedge and 5'-end binding pocket that bend and position the substrate for incision [#10, #22]. EME1-dependent cleavage is genetically required for meiotic crossing over, where it acts specifically at crossover resolution while leaving gene conversion intact [#5, #7], and Eme1-deficient cells show hypersensitivity to crosslinking agents and spontaneous genomic instability [#6]. At the G2/M transition CDK-dependent phosphorylation drives assembly of MUS81-EME1 with SLX1-SLX4 into the SLX-MUS holoenzyme for coordinated Holliday junction resolution [#17, #28], and enzyme activity is further controlled by cell-cycle and checkpoint kinases including CDK/Polo-like kinase, ATR, Chk1, and CK2 acting on EME1 or its scaffold partner SLX4 [#16, #19, #27, #25]. MUS81-EME1 cooperates with FANCA, which recruits it to and stimulates incision at interstrand crosslinks [#21], localizes with ERCC1 and FANCD2 to common fragile sites to process under-replicated DNA in mitosis [#20], and produces deleterious DNA breaks at replication forks when Chk1 is compromised [#15, #26]. EME1 expression is transcriptionally regulated through STAT3 and SETD1A, and its levels influence sensitivity to topoisomerase and PARP inhibitors [#12, #29].\",\n  \"teleology\": [\n    {\n      \"year\": 2001,\n      \"claim\": \"Established that EME1 is an obligate partner of Mus81 in a heterodimeric endonuclease and that this activity functions late in meiotic recombination, framing EME1 as a junction-resolving factor.\",\n      \"evidence\": \"Purified-complex endonuclease assay and genetic rescue of mus81 meiotic defect by the bacterial resolvase RusA, with co-IP identifying Eme1\",\n      \"pmids\": [\"11719193\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define which branched substrate is the physiological target in vivo\", \"Catalytic versus structural roles of the two subunits not yet separated\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Resolved the apparent substrate paradox by showing the enzyme cleaves replication fork and reversed-fork structures efficiently but synthetic Holliday junctions poorly, redirecting attention toward replication intermediates.\",\n      \"evidence\": \"In vitro endonuclease assays on defined substrates with cleavage-site mapping plus RusA suppressor genetics in fission and budding yeast\",\n      \"pmids\": [\"12084712\", \"12473680\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not reconcile in vitro fork preference with the genetic requirement for crossover resolution\", \"Cleavage-site choice on physiological in vivo substrates not established\"]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"Demonstrated conservation and substrate specificity of the human and mouse enzymes and defined the nick-and-counternick mechanism for nicked Holliday junctions, linking biochemistry to meiotic crossover and crosslink-repair phenotypes.\",\n      \"evidence\": \"Purified human/mouse heterodimer endonuclease assays, kinetic analysis of nicked vs intact junctions, ES-cell knockout drug-sensitivity, and meiotic recombination genetics\",\n      \"pmids\": [\"12721304\", \"14527419\", \"14527420\", \"14609959\", \"14704204\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How nicked junction intermediates are generated in vivo not established\", \"Crossover-versus-gene-conversion separation mechanistically unexplained\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Placed Mus81-EME1 in the interstrand-crosslink repair pathway by showing it generates ICL-induced double-strand breaks at S-phase forks and physically and genetically interacts with Rad54.\",\n      \"evidence\": \"Mus81-/- ES cells with PFGE DSB quantification, reciprocal co-IP, and Mus81/Rad54 double-mutant survival analysis\",\n      \"pmids\": [\"17036055\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether Rad54 acts before or after EME1-dependent incision unclear\", \"EME1's direct contribution distinct from Mus81 not isolated\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Provided the structural basis for substrate recognition and bilateral cleavage, revealing how the EME1 linker and Mus81 active-site cleft position branched DNA for coordinated incision.\",\n      \"evidence\": \"Crystal structure of the Mus81-Eme1 complex with functional mutagenesis, plus kinetic analysis of cooperative cruciform cleavage\",\n      \"pmids\": [\"18413719\", \"18310322\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structure lacked a bound DNA substrate at this stage\", \"Regulation of the catalytic cycle in cells not addressed\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Identified physical and transcriptional regulators of EME1, including Rad54 stimulation of activity, Np95 chromatin co-localization, and STAT3-driven transcriptional upregulation after topoisomerase inhibition.\",\n      \"evidence\": \"In vitro stimulation assays with species controls, co-IP, immunofluorescence co-localization, and ChIP/reporter analysis of the EME1 promoter\",\n      \"pmids\": [\"19017809\", \"18692478\", \"18245483\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional consequence of Np95 co-localization not defined\", \"Whether STAT3 regulation operates outside topoisomerase-inhibited cells unknown\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Connected Mus81-EME1 to checkpoint control, showing that loss of Wee1 or Chk1 unleashes EME1-dependent fork cleavage that drives replication stress and DNA damage.\",\n      \"evidence\": \"Co-IP of Wee1-Mus81 and RNAi co-depletion epistasis with cell-cycle and DSB readouts in checkpoint-deficient cells\",\n      \"pmids\": [\"21859861\", \"21858151\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct phosphoregulation of EME1 by these kinases not demonstrated here\", \"Single-lab epistasis without reconstitution\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Defined cell-cycle and checkpoint phosphorylation as the master switch activating the enzyme and showed that CDK-triggered assembly into the SLX-MUS holoenzyme coordinates Holliday junction resolution at G2/M.\",\n      \"evidence\": \"Phospho-site mapping and mutant analysis (Cdc2/Rad3 on Eme1; CDK on the holoenzyme), in vitro reconstitution of SLX-MUS, HJ cleavage assays, and chromosome-segregation phenotyping\",\n      \"pmids\": [\"22730299\", \"23584455\", \"24076221\", \"24076219\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Precise phospho-sites on mammalian EME1 versus SLX4 not fully resolved\", \"How phosphorylation restructures the active site biochemically unclear\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Established the roles of MUS81-EME1 at interstrand crosslinks and common fragile sites, showing FANCA-dependent recruitment and stimulation of ICL incision and FANCD2/ERCC1 co-localization needed for mitotic processing of under-replicated DNA.\",\n      \"evidence\": \"Co-IP, cellular ICL recruitment, in vitro ICL-substrate incision assays, and mitotic-chromosome immunofluorescence with co-depletion phenotypes\",\n      \"pmids\": [\"24170812\", \"23811686\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Order of FANCA recruitment relative to other Fanconi factors not resolved\", \"Distinct EME1 contribution to fragile-site processing not isolated from Mus81\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Captured the enzyme bound to its substrate, defining the hydrophobic wedge and 5'-end binding pocket that bend DNA and explain preferential 3'-flap cleavage.\",\n      \"evidence\": \"X-ray crystallography of human Mus81-Eme1-DNA complexes with biochemical and biophysical validation\",\n      \"pmids\": [\"24733841\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structure of a productive Holliday-junction-bound state not obtained\", \"How phosphoregulation alters the captured conformation unknown\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Revealed pathological and viral regulation of EME1 abundance, with HIV-1 Vpr hijacking CRL4-DCAF1 to degrade MUS81-EME1, and demonstrated GEN1/EME1 redundancy in junction resolution in mice.\",\n      \"evidence\": \"Co-IP, Vpr mutant and ubiquitin-ligase perturbation analysis, and Gen1/Eme1 double-mutant mouse genetics\",\n      \"pmids\": [\"27354282\", \"27383418\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional rationale for viral targeting of EME1 unresolved\", \"Degree of GEN1/EME1 redundancy in human cells untested\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Refined the activation logic by showing direct ATR/Chk1 phosphorylation and SUMO-interacting motifs on Eme1, and by showing CDK1 phosphorylation of SLX4 folds an SAP domain that binds and relaxes MUS81-EME1 substrate specificity.\",\n      \"evidence\": \"In vitro kinase and endonuclease assays, phospho-site and SIM mutagenesis, structural analysis of phospho-SLX4MBR, and genetic viability assays\",\n      \"pmids\": [\"35452455\", \"36288699\", \"29850896\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Integration of EME1-intrinsic versus SLX4-mediated regulation in a single model incomplete\", \"Role of EME1 SUMO interactions in mammalian cells not tested\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Linked EME1 expression to therapeutic vulnerability, showing SETD1A-driven EME1 transcription sets PARP-inhibitor sensitivity in HR-deficient cancers.\",\n      \"evidence\": \"siRNA/CRISPR depletion of SETD1A and EME1 with HR assays, Olaparib viability, and RNAseq\",\n      \"pmids\": [\"39994444\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism by which EME1 loss restores HR not defined\", \"Generality across tumor genotypes untested\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How the multiple phosphorylation, SUMO, and scaffold inputs are integrated to switch EME1 between protective junction resolution and deleterious fork cleavage in vivo remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No unified model coupling EME1 regulation to substrate choice in cells\", \"Distinct contributions of EME1 versus Mus81 to each pathway not fully separated\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140097\", \"supporting_discovery_ids\": [0, 2, 3, 4, 9]},\n      {\"term_id\": \"GO:0016787\", \"supporting_discovery_ids\": [0, 3, 6]},\n      {\"term_id\": \"GO:0003677\", \"supporting_discovery_ids\": [10, 22]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [13]},\n      {\"term_id\": \"GO:0000228\", \"supporting_discovery_ids\": [20]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-73894\", \"supporting_discovery_ids\": [6, 21, 8]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [16, 17, 20]},\n      {\"term_id\": \"R-HSA-69306\", \"supporting_discovery_ids\": [2, 15, 26]},\n      {\"term_id\": \"R-HSA-1474165\", \"supporting_discovery_ids\": [5, 7, 24]}\n    ],\n    \"complexes\": [\"Mus81-EME1\", \"SLX-MUS holoenzyme\"],\n    \"partners\": [\"MUS81\", \"SLX4\", \"SLX1\", \"RAD54\", \"FANCA\", \"WEE1\", \"ERCC1\", \"UHRF1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":7,"faith_total":7,"faith_pct":100.0}}