{"gene":"MIS18BP1","run_date":"2026-06-10T02:59:50","timeline":{"discoveries":[{"year":2011,"finding":"CENP-C directly binds M18BP1 through conserved domains in CENP-C, and depletion of CENP-C prevents M18BP1 targeting to metaphase centromeres and inhibits CENP-A chromatin assembly, establishing CENP-C as the recruitment factor linking existing CENP-A chromatin to new CENP-A nucleosome assembly machinery.","method":"Co-immunoprecipitation, depletion (RNAi/knockdown) with centromere localization and CENP-A assembly readouts, direct binding assays","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal binding assay plus depletion phenotype, independently replicated by a second lab (PMID:22540025)","pmids":["21911481"],"is_preprint":false},{"year":2012,"finding":"M18BP1 interacts with CENP-C in mouse embryonic stem cells; the interaction domain in M18BP1 maps to a central region containing the conserved SANT domain, and in CENP-C to its C-terminus. Knockdown of CENP-C reduces M18BP1 association and CENP-A levels at centromeres.","method":"Interaction screen against 16 core centromeric proteins, domain mapping by Co-IP/pulldown, CENP-C knockdown with centromere localization readout","journal":"Nucleus (Austin, Tex.)","confidence":"High","confidence_rationale":"Tier 2 / Strong — domain-mapped interaction with functional depletion phenotype, replicates findings of PMID:21911481 in a second model system","pmids":["22540025"],"is_preprint":false},{"year":2017,"finding":"A Mis18α:Mis18β 4:2 hexamer (formed by Yippee domains) binds two copies of M18BP1 through M18BP1's 140 N-terminal residues. CDK1 phosphorylation at two conserved sites in this region destabilizes binding to Mis18α:Mis18β, limiting complex formation to G1. CDK1 therefore controls Mis18 complex recruitment to centromeres by regulating M18BP1 oligomerization on the Mis18α:Mis18β scaffold.","method":"Biochemical reconstitution, in vitro CDK1 phosphorylation assay, phosphomutant analysis, viral 2A co-expression strategy, cell-based centromere localization assay","journal":"eLife","confidence":"High","confidence_rationale":"Tier 1 / Strong — reconstitution with defined stoichiometry, mutagenesis of phosphosites, and cell-based validation in a single rigorous study","pmids":["28059702"],"is_preprint":false},{"year":2017,"finding":"Xenopus M18BP1 directly and cell-cycle-dependently binds CENP-A nucleosomes using a conserved motif (resembling the CENP-C nucleosome-binding motif) to recruit the Mis18 complex to interphase centromeres and promote new CENP-A assembly. CENP-C competes with M18BP1 for CENP-A nucleosome binding at centromeres.","method":"Xenopus egg extract CENP-A assembly assay, direct nucleosome binding assay, competition assay between M18BP1 and CENP-C, motif mutagenesis","journal":"Developmental cell","confidence":"High","confidence_rationale":"Tier 1 / Strong — cell-free reconstitution, direct binding with motif mutagenesis, competitive binding demonstrated, multiple orthogonal methods","pmids":["28743005"],"is_preprint":false},{"year":2019,"finding":"Xenopus M18BP1 localizes to centromeres during metaphase by binding CENP-C through its conserved SANTA domain, and CDK phosphorylation of M18BP1 is required for this metaphase M18BP1/CENP-C interaction. Mutations disrupting this interaction also cause defective nuclear localization of M18BP1 in interphase and impair CENP-A nucleosome assembly.","method":"Xenopus egg extract and cell-based assays, phosphomutant analysis, domain-deletion analysis, centromere localization and CENP-A assembly readouts","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 2 / Strong — phosphomutant dissection plus multiple functional readouts (localization, nuclear targeting, CENP-A assembly) with orthogonal methods","pmids":["30606714"],"is_preprint":false},{"year":2023,"finding":"In metaphase, M18BP1 (M18BP1.S subunit) binds CENP-C and thereby competitively inhibits HJURP access to centromeres, preventing premature CENP-A assembly; removal of both this inhibitory activity and HJURP phosphorylation is required to allow CENP-A assembly.","method":"Xenopus cell-free centromere assembly assay, competitive binding analysis, phosphomutant HJURP rescue experiments","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 1 / Strong — cell-free reconstitution with defined mutants, two complementary inhibitory mechanisms dissected, multiple orthogonal approaches","pmids":["37141119"],"is_preprint":false},{"year":2021,"finding":"The extended N-terminal tail of C. elegans CENP-A directly binds KNL-2 (M18BP1 ortholog); this interaction is essential for CENP-A loading at centromeres and partially substitutes for the absent Scm3/HJURP chaperone in nematodes. Removal of the structured N-tail region prevents CENP-A loading, kinetochore assembly, and causes defective chromosome condensation.","method":"Direct binding assay (pulldown), N-tail deletion/mutation analysis, RNAi-based functional assays in C. elegans, kinetochore assembly and chromosome condensation readouts","journal":"Molecular biology of the cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — direct binding confirmed by pulldown, functional rescue experiments, conservation validated in C. briggsae, multiple orthogonal methods","pmids":["33852350"],"is_preprint":false},{"year":2021,"finding":"CDK-1 phosphorylates C. elegans KNL-2 in vitro; mutation of three C-terminal CDK-1 phosphorylation sites causes chromosome condensation defects and reduced mitotic levels of condensin II on chromosomes, without affecting CENP-A loading or kinetochore localization, thereby separating the KNL-2 functions in CENP-A loading and chromosome condensation.","method":"In vitro CDK-1 phosphorylation assay, phosphodeficient mutant worm strains, condensin II and CENP-A localization assays, embryonic lethality quantification","journal":"Journal of cell science","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — in vitro kinase assay combined with phosphomutant functional dissection, two distinct phenotypes clearly separated","pmids":["34734636"],"is_preprint":false},{"year":2025,"finding":"M18BP1 directly binds the CAP-G2 subunit of condensin II and is required for condensin II localization to chromatin at mitotic entry. The condensin II antagonist MCPH1 also binds CAP-G2 and outcompetes M18BP1 during interphase; a switch from MCPH1 to M18BP1 at mitotic onset activates condensin II for chromosome condensation.","method":"Genetic and proteomic approaches, direct binding assay (M18BP1–CAP-G2 interaction), competitive binding assay (MCPH1 vs M18BP1 for CAP-G2), condensin II chromatin localization and chromosome condensation readouts","journal":"Molecular cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — direct binding identified, competition assay, genetic and proteomic validation, functional chromosome condensation phenotype","pmids":["40614722"],"is_preprint":false},{"year":2024,"finding":"In C. elegans oocytes, KNL-2 (M18BP1 ortholog) recruits the nucleoporin MEL-28/ELYS at meiotic kinetochores through a specific N-terminal domain, independently of its canonical CENP-A loading factor activity. KNL-2 and MEL-28/ELYS are interdependent for kinetochore localization and together support outer kinetochore assembly in meiosis I in parallel to the canonical CENP-A/CENP-C pathway.","method":"RNAi and Degron-based depletion, engineered N-terminal domain mutants, kinetochore localization assays in C. elegans oocytes, co-depletion epistasis","journal":"Current biology : CB","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — epistasis and domain mutant analysis in a single lab, multiple depletions but no direct binding reconstitution reported in abstract","pmids":["39353426"],"is_preprint":false},{"year":2024,"finding":"In chicken DT40 cells, tethering of CENP-C or CENP-I induces CENP-A incorporation at a non-centromeric locus in the absence of Knl2/MIS18BP1, and CENP-C co-immunoprecipitates with HJURP independently of Knl2, indicating that CENP-C can recruit CENP-A via HJURP binding without requiring Knl2.","method":"Artificial tethering assay, auxin-inducible degron (AID)-based knockout, Co-immunoprecipitation in DT40 cells","journal":"Journal of cell science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — AID knockout combined with tethering and Co-IP, single lab, functional readout of CENP-A incorporation","pmids":["38319136"],"is_preprint":false},{"year":2026,"finding":"Artificial M18BP1 dimerization in human cells bypasses the need for MIS18α/β, allowing identification of at least four determinants of M18BP1 centromere localization: the SANTA domain (whose first crystal structure was reported) plus linear motifs in disordered neighboring regions that interact with the 16-subunit CCAN. Cell-cycle-dependent dimerization of M18BP1 on MIS18α/β promotes recognition of multivalent centromeric CENP-A assemblies followed by PLK1 and HJURP cooption and new CENP-A deposition.","method":"Artificial dimerization constructs in human cells, SANTA domain crystal structure, interaction footprint mapping on CCAN, centromere localization and CENP-A deposition assays","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 1 / Strong — crystal structure of SANTA domain combined with functional dimerization constructs, CCAN interaction footprint, and CENP-A deposition readout in a single study","pmids":["41629527"],"is_preprint":false},{"year":2026,"finding":"Phosphorylation of Xenopus M18BP1 (by cell-cycle kinases) in metaphase disrupts its binding to CENP-A nucleosomes; relief of this phosphorylation in interphase enables M18BP1 binding to CENP-A nucleosomes and CENP-A nucleosome assembly, defining a phosphoregulatory switch that restricts new CENP-A assembly to interphase.","method":"Xenopus egg extract CENP-A assembly assay, phosphomutant analysis of M18BP1, direct CENP-A nucleosome binding assay","journal":"EMBO reports","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — cell-free reconstitution with phosphomutants and direct nucleosome binding, multiple orthogonal methods (peer-reviewed version of preprint)","pmids":["41680291"],"is_preprint":false}],"current_model":"MIS18BP1 (M18BP1) is a central epigenetic regulator of centromere identity that recruits the CENP-A chaperone HJURP to centromeres by assembling onto a Mis18α:Mis18β hexamer scaffold; its centromere localization is cell-cycle-regulated by CDK phosphorylation, which controls its binding to both Mis18α:Mis18β (via the N-terminal 140 residues) and directly to CENP-A nucleosomes and CENP-C (via its SANTA domain), ensuring that new CENP-A assembly is restricted to G1; additionally, M18BP1 directly activates condensin II by binding CAP-G2 at mitotic entry, coupling centromere identity maintenance with chromosome condensation."},"narrative":{"mechanistic_narrative":"MIS18BP1 (M18BP1/KNL-2) is a central epigenetic licensing factor for centromere identity that couples recognition of existing CENP-A chromatin to the deposition of new CENP-A nucleosomes, restricting this assembly to a defined cell-cycle window [PMID:28743005, PMID:41629527]. It is recruited to centromeres by directly binding the constitutive centromere protein CENP-C through its conserved SANT/SANTA domain, and loss of CENP-C abolishes both M18BP1 targeting and downstream CENP-A assembly [PMID:21911481, PMID:22540025]. M18BP1 also reads existing centromeres directly by binding CENP-A nucleosomes via a conserved motif resembling that of CENP-C, with the two proteins competing for the same nucleosomal surface [PMID:28743005]. Productive function requires M18BP1 to dimerize on a Mis18α:Mis18β 4:2 hexamer scaffold through its N-terminal 140 residues, an assembly that licenses recognition of multivalent CENP-A arrays and subsequent cooption of PLK1 and the CENP-A chaperone HJURP for new CENP-A deposition [PMID:28059702, PMID:41629527]. This entire cycle is governed by CDK/cell-cycle phosphorylation: phosphorylation destabilizes M18BP1 binding to both the Mis18α:Mis18β scaffold and to CENP-A nucleosomes, and in metaphase M18BP1–CENP-C binding competitively blocks HJURP access, so that dephosphorylation in G1/interphase is required to permit CENP-A loading [PMID:28059702, PMID:37141119, PMID:41680291]. Beyond centromere licensing, M18BP1 directly binds the CAP-G2 subunit of condensin II and activates it for mitotic chromosome condensation, displacing the condensin II antagonist MCPH1 at mitotic onset — a function genetically separable from CENP-A loading [PMID:34734636, PMID:40614722].","teleology":[{"year":2011,"claim":"Established how new CENP-A assembly machinery is templated onto pre-existing centromeres by identifying CENP-C as the direct recruitment factor for M18BP1.","evidence":"Co-IP, direct binding assays, and CENP-C depletion with centromere localization and CENP-A assembly readouts in human cells","pmids":["21911481"],"confidence":"High","gaps":["Did not define the M18BP1 domain mediating the interaction","Did not resolve cell-cycle regulation of the interaction"]},{"year":2012,"claim":"Mapped the M18BP1–CENP-C interaction to the central SANT domain of M18BP1 and the CENP-C C-terminus, confirming the recruitment axis in a second model system.","evidence":"Centromere interaction screen, domain mapping by Co-IP/pulldown, and CENP-C knockdown in mouse embryonic stem cells","pmids":["22540025"],"confidence":"High","gaps":["Did not address how the interaction is restricted by the cell cycle","Did not reconstitute the interaction biochemically"]},{"year":2017,"claim":"Defined the molecular architecture and cell-cycle gating of the Mis18 complex, showing M18BP1 dimerizes on a Mis18α:Mis18β hexamer and that CDK1 phosphorylation of its N-terminus times complex formation to G1.","evidence":"Biochemical reconstitution with defined stoichiometry, in vitro CDK1 phosphorylation, phosphomutant analysis, and cell-based centromere localization","pmids":["28059702"],"confidence":"High","gaps":["Did not establish how the assembled complex recognizes centromeric chromatin","Did not link scaffold assembly to HJURP recruitment"]},{"year":2017,"claim":"Revealed that M18BP1 directly reads CENP-A nucleosomes through a CENP-C-like motif and competes with CENP-C, providing a chromatin-recognition mechanism for centromere identity.","evidence":"Xenopus egg extract assembly assay, direct nucleosome binding, competition assay, and motif mutagenesis","pmids":["28743005"],"confidence":"High","gaps":["Did not resolve how nucleosome binding and CENP-C binding are coordinated in vivo","Did not define the phosphoregulation of nucleosome binding"]},{"year":2019,"claim":"Showed that CDK phosphorylation of M18BP1 is required for its metaphase SANTA-domain-mediated CENP-C binding and for its nuclear localization, integrating localization control with assembly competence.","evidence":"Xenopus egg extract and cell-based assays with phosphomutant and domain-deletion analysis","pmids":["30606714"],"confidence":"High","gaps":["Did not reconcile metaphase CENP-C binding with the licensing of G1 assembly","Did not identify the responsible kinase sites in detail"]},{"year":2021,"claim":"Demonstrated in C. elegans that the CENP-A N-tail directly binds KNL-2/M18BP1 and can partially substitute for the absent HJURP, illuminating an evolutionarily divergent CENP-A loading route.","evidence":"Direct pulldown, N-tail deletion analysis, and RNAi functional assays with kinetochore and condensation readouts","pmids":["33852350"],"confidence":"High","gaps":["Relationship to the HJURP-dependent vertebrate pathway not addressed","Structural basis of the N-tail interaction unresolved"]},{"year":2021,"claim":"Genetically separated M18BP1's two activities by showing CDK-1 phosphorylation of C-terminal KNL-2 sites controls condensin II loading and chromosome condensation independently of CENP-A loading.","evidence":"In vitro CDK-1 phosphorylation, phosphodeficient mutant worms, condensin II/CENP-A localization, and lethality quantification","pmids":["34734636"],"confidence":"High","gaps":["Did not identify the direct condensin II contact","Mechanism of condensin II activation not resolved"]},{"year":2024,"claim":"Identified a non-canonical KNL-2 function in meiotic kinetochore assembly via recruitment of the nucleoporin MEL-28/ELYS, expanding M18BP1's roles beyond CENP-A loading.","evidence":"RNAi/degron depletion, N-terminal domain mutants, and co-depletion epistasis in C. elegans oocytes","pmids":["39353426"],"confidence":"Medium","gaps":["No direct binding reconstitution reported","Single-lab epistasis without structural validation"]},{"year":2024,"claim":"Showed that CENP-C can recruit CENP-A via HJURP independently of Knl2/MIS18BP1 in chicken cells, defining the boundary of M18BP1's requirement in the pathway.","evidence":"Artificial tethering, auxin-inducible degron knockout, and Co-IP in DT40 cells","pmids":["38319136"],"confidence":"Medium","gaps":["Physiological contribution of the Knl2-independent route unclear","Single-lab; potential species-specific behavior"]},{"year":2023,"claim":"Established a metaphase inhibitory mechanism whereby M18BP1–CENP-C binding competitively blocks HJURP, requiring its relief plus HJURP dephosphorylation to permit CENP-A assembly.","evidence":"Xenopus cell-free assembly assay, competitive binding analysis, and phosphomutant HJURP rescue","pmids":["37141119"],"confidence":"High","gaps":["How the inhibitory and recruitment roles of M18BP1 are temporally switched not fully resolved","Structural basis of HJURP exclusion not defined"]},{"year":2025,"claim":"Identified M18BP1's direct condensin II activation mechanism: it binds CAP-G2 and displaces the antagonist MCPH1 at mitotic onset to license condensation.","evidence":"Genetic and proteomic approaches, direct M18BP1–CAP-G2 binding, MCPH1 competition, and condensation readouts","pmids":["40614722"],"confidence":"High","gaps":["Structural basis of the M18BP1/MCPH1 switch on CAP-G2 unresolved","How this is coordinated with M18BP1's CENP-A licensing role unclear"]},{"year":2026,"claim":"Provided the first SANTA domain crystal structure and showed that dimerization-driven M18BP1 recognizes multivalent CENP-A assemblies via multiple CCAN-contacting motifs before PLK1/HJURP cooption.","evidence":"Artificial dimerization constructs, SANTA domain crystal structure, CCAN interaction footprint mapping, and CENP-A deposition assays in human cells","pmids":["41629527"],"confidence":"High","gaps":["Higher-order architecture of the M18BP1–CCAN–CENP-A assembly not resolved","Temporal order of PLK1 and HJURP cooption not fully defined"]},{"year":2026,"claim":"Defined a phosphoregulatory switch on M18BP1's CENP-A nucleosome binding, showing metaphase phosphorylation disrupts binding while interphase dephosphorylation enables assembly.","evidence":"Xenopus egg extract assembly assay, phosphomutant analysis, and direct CENP-A nucleosome binding","pmids":["41680291"],"confidence":"High","gaps":["Identity of all responsible kinases/phosphatases not fully resolved","Integration with the CENP-C-binding switch not detailed"]},{"year":null,"claim":"How M18BP1's dual roles in CENP-A licensing and condensin II activation are coordinated within a single mitotic timeline, and the structural basis of its multivalent CCAN/CENP-A recognition, remain open.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No integrated structural model of the full M18BP1-centromere assembly","Mechanistic coupling between condensation and CENP-A licensing functions undefined"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0042393","term_label":"histone binding","supporting_discovery_ids":[3,12]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,2,8]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[5,8]}],"localization":[{"term_id":"GO:0005694","term_label":"chromosome","supporting_discovery_ids":[0,3,4]},{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[4]}],"pathway":[{"term_id":"GO:0005815","term_label":"microtubule organizing center","supporting_discovery_ids":[0,2,11]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[2,8]},{"term_id":"R-HSA-4839726","term_label":"Chromatin organization","supporting_discovery_ids":[3,11]}],"complexes":["Mis18 complex (Mis18α:Mis18β:M18BP1)","condensin II"],"partners":["CENP-C","MIS18A","MIS18B","CENP-A","HJURP","CAP-G2","MCPH1","MEL-28/ELYS"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q6P0N0","full_name":"Mis18-binding protein 1","aliases":["Kinetochore-associated protein KNL-2 homolog","HsKNL-2","P243"],"length_aa":1132,"mass_kda":129.1,"function":"Required for recruitment of CENPA to centromeres and normal chromosome segregation during mitosis","subcellular_location":"Nucleus; Chromosome, centromere","url":"https://www.uniprot.org/uniprotkb/Q6P0N0/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":true,"resolved_as":"","url":"https://depmap.org/portal/gene/MIS18BP1","classification":"Common Essential","n_dependent_lines":1172,"n_total_lines":1208,"dependency_fraction":0.9701986754966887},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/MIS18BP1","total_profiled":1310},"omim":[{"mim_id":"618139","title":"MIS18-BINDING PROTEIN 1; MIS18BP1","url":"https://www.omim.org/entry/618139"},{"mim_id":"618137","title":"MIS18 KINETOCHORE PROTEIN A: MIS18A","url":"https://www.omim.org/entry/618137"},{"mim_id":"612667","title":"HOLLIDAY JUNCTION RECOGNITION PROTEIN; HJURP","url":"https://www.omim.org/entry/612667"},{"mim_id":"606020","title":"OPA-INTERACTING PROTEIN 5; OIP5","url":"https://www.omim.org/entry/606020"},{"mim_id":"602098","title":"POLO-LIKE KINASE 1; PLK1","url":"https://www.omim.org/entry/602098"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Nucleoli","reliability":"Approved"},{"location":"Cytosol","reliability":"Additional"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"bone marrow","ntpm":38.5}],"url":"https://www.proteinatlas.org/search/MIS18BP1"},"hgnc":{"alias_symbol":["M18BP1","FLJ11186","KIAA1903","KNL2"],"prev_symbol":["C14orf106"]},"alphafold":{"accession":"Q6P0N0","domains":[{"cath_id":"-","chopping":"380-492","consensus_level":"medium","plddt":87.1994,"start":380,"end":492},{"cath_id":"1.10.10.60","chopping":"882-924","consensus_level":"medium","plddt":88.1307,"start":882,"end":924}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q6P0N0","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q6P0N0-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q6P0N0-F1-predicted_aligned_error_v6.png","plddt_mean":48.31},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=MIS18BP1","jax_strain_url":"https://www.jax.org/strain/search?query=MIS18BP1"},"sequence":{"accession":"Q6P0N0","fasta_url":"https://rest.uniprot.org/uniprotkb/Q6P0N0.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q6P0N0/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q6P0N0"}},"corpus_meta":[{"pmid":"21911481","id":"PMC_21911481","title":"CENP-C recruits M18BP1 to centromeres to promote CENP-A chromatin assembly.","date":"2011","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/21911481","citation_count":188,"is_preprint":false},{"pmid":"22540025","id":"PMC_22540025","title":"CENP-C facilitates the recruitment of M18BP1 to centromeric chromatin.","date":"2012","source":"Nucleus (Austin, Tex.)","url":"https://pubmed.ncbi.nlm.nih.gov/22540025","citation_count":111,"is_preprint":false},{"pmid":"28059702","id":"PMC_28059702","title":"CDK-regulated dimerization of M18BP1 on a Mis18 hexamer is necessary for CENP-A loading.","date":"2017","source":"eLife","url":"https://pubmed.ncbi.nlm.nih.gov/28059702","citation_count":72,"is_preprint":false},{"pmid":"28743005","id":"PMC_28743005","title":"Xenopus laevis M18BP1 Directly Binds Existing CENP-A Nucleosomes to Promote Centromeric Chromatin Assembly.","date":"2017","source":"Developmental 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biology","url":"https://pubmed.ncbi.nlm.nih.gov/37141119","citation_count":15,"is_preprint":false},{"pmid":"35671323","id":"PMC_35671323","title":"Recurrent Plant-Specific Duplications of KNL2 and Its Conserved Function as a Kinetochore Assembly Factor.","date":"2022","source":"Molecular biology and evolution","url":"https://pubmed.ncbi.nlm.nih.gov/35671323","citation_count":14,"is_preprint":false},{"pmid":"33852350","id":"PMC_33852350","title":"The N-terminal tail of C. elegans CENP-A interacts with KNL-2 and is essential for centromeric chromatin assembly.","date":"2021","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/33852350","citation_count":12,"is_preprint":false},{"pmid":"40614722","id":"PMC_40614722","title":"Condensin II activation by M18BP1.","date":"2025","source":"Molecular cell","url":"https://pubmed.ncbi.nlm.nih.gov/40614722","citation_count":10,"is_preprint":false},{"pmid":"38319136","id":"PMC_38319136","title":"Artificial tethering of constitutive centromere-associated network proteins induces CENP-A deposition without Knl2 in DT40 cells.","date":"2024","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/38319136","citation_count":6,"is_preprint":false},{"pmid":"40205244","id":"PMC_40205244","title":"MIS18BP1 promotes bladder cancer cell proliferation and growth via inactivating P53 signaling pathway.","date":"2025","source":"Medical oncology (Northwood, London, England)","url":"https://pubmed.ncbi.nlm.nih.gov/40205244","citation_count":4,"is_preprint":false},{"pmid":"34734636","id":"PMC_34734636","title":"Mitotic chromosome condensation requires phosphorylation of the centromeric protein KNL-2 in C. elegans.","date":"2021","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/34734636","citation_count":4,"is_preprint":false},{"pmid":"40561118","id":"PMC_40561118","title":"Ubiquitin-dependent proteolysis of KNL2 driven by APC/CCDC20 is critical for centromere integrity and mitotic fidelity.","date":"2025","source":"The Plant cell","url":"https://pubmed.ncbi.nlm.nih.gov/40561118","citation_count":2,"is_preprint":false},{"pmid":"39353426","id":"PMC_39353426","title":"Regulation of outer kinetochore assembly during meiosis I and II by CENP-A and KNL-2/M18BP1 in C. elegans oocytes.","date":"2024","source":"Current biology : CB","url":"https://pubmed.ncbi.nlm.nih.gov/39353426","citation_count":1,"is_preprint":false},{"pmid":"40791504","id":"PMC_40791504","title":"Regulation of X. laevis M18BP1 centromeric localization and CENP-A assembly.","date":"2025","source":"bioRxiv : the preprint server for biology","url":"https://pubmed.ncbi.nlm.nih.gov/40791504","citation_count":1,"is_preprint":false},{"pmid":"41629527","id":"PMC_41629527","title":"M18BP1 valency and a distributed interaction footprint determine epigenetic centromere specification in humans.","date":"2026","source":"The EMBO journal","url":"https://pubmed.ncbi.nlm.nih.gov/41629527","citation_count":1,"is_preprint":false},{"pmid":"41680291","id":"PMC_41680291","title":"Phosphorylation of Xenopus M18BP1 governs centromeric localization and CENP-A nucleosome assembly.","date":"2026","source":"EMBO reports","url":"https://pubmed.ncbi.nlm.nih.gov/41680291","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.07.15.664882","title":"Regulation of  <i>X. laevis</i>  M18BP1 centromeric localization and CENP-A assembly","date":"2025-07-15","source":"bioRxiv","url":"https://doi.org/10.1101/2025.07.15.664882","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.07.30.605747","title":"Structural Basis of βKNL2 Centromeric Targeting Mechanism and Its Role in Plant-Specific Kinetochore Assembly","date":"2024-07-30","source":"bioRxiv","url":"https://doi.org/10.1101/2024.07.30.605747","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":11600,"output_tokens":3598,"usd":0.044385,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":11137,"output_tokens":4355,"usd":0.08228,"stage2_stop_reason":"end_turn"},"total_usd":0.126665,"stage1_batch_id":"msgbatch_01BbTCMyrRPyhtEq6b1MdwCN","stage2_batch_id":"msgbatch_011dEed5bbxYvTAaQWKJevxu","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2011,\n      \"finding\": \"CENP-C directly binds M18BP1 through conserved domains in CENP-C, and depletion of CENP-C prevents M18BP1 targeting to metaphase centromeres and inhibits CENP-A chromatin assembly, establishing CENP-C as the recruitment factor linking existing CENP-A chromatin to new CENP-A nucleosome assembly machinery.\",\n      \"method\": \"Co-immunoprecipitation, depletion (RNAi/knockdown) with centromere localization and CENP-A assembly readouts, direct binding assays\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal binding assay plus depletion phenotype, independently replicated by a second lab (PMID:22540025)\",\n      \"pmids\": [\"21911481\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"M18BP1 interacts with CENP-C in mouse embryonic stem cells; the interaction domain in M18BP1 maps to a central region containing the conserved SANT domain, and in CENP-C to its C-terminus. Knockdown of CENP-C reduces M18BP1 association and CENP-A levels at centromeres.\",\n      \"method\": \"Interaction screen against 16 core centromeric proteins, domain mapping by Co-IP/pulldown, CENP-C knockdown with centromere localization readout\",\n      \"journal\": \"Nucleus (Austin, Tex.)\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — domain-mapped interaction with functional depletion phenotype, replicates findings of PMID:21911481 in a second model system\",\n      \"pmids\": [\"22540025\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"A Mis18α:Mis18β 4:2 hexamer (formed by Yippee domains) binds two copies of M18BP1 through M18BP1's 140 N-terminal residues. CDK1 phosphorylation at two conserved sites in this region destabilizes binding to Mis18α:Mis18β, limiting complex formation to G1. CDK1 therefore controls Mis18 complex recruitment to centromeres by regulating M18BP1 oligomerization on the Mis18α:Mis18β scaffold.\",\n      \"method\": \"Biochemical reconstitution, in vitro CDK1 phosphorylation assay, phosphomutant analysis, viral 2A co-expression strategy, cell-based centromere localization assay\",\n      \"journal\": \"eLife\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — reconstitution with defined stoichiometry, mutagenesis of phosphosites, and cell-based validation in a single rigorous study\",\n      \"pmids\": [\"28059702\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Xenopus M18BP1 directly and cell-cycle-dependently binds CENP-A nucleosomes using a conserved motif (resembling the CENP-C nucleosome-binding motif) to recruit the Mis18 complex to interphase centromeres and promote new CENP-A assembly. CENP-C competes with M18BP1 for CENP-A nucleosome binding at centromeres.\",\n      \"method\": \"Xenopus egg extract CENP-A assembly assay, direct nucleosome binding assay, competition assay between M18BP1 and CENP-C, motif mutagenesis\",\n      \"journal\": \"Developmental cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — cell-free reconstitution, direct binding with motif mutagenesis, competitive binding demonstrated, multiple orthogonal methods\",\n      \"pmids\": [\"28743005\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Xenopus M18BP1 localizes to centromeres during metaphase by binding CENP-C through its conserved SANTA domain, and CDK phosphorylation of M18BP1 is required for this metaphase M18BP1/CENP-C interaction. Mutations disrupting this interaction also cause defective nuclear localization of M18BP1 in interphase and impair CENP-A nucleosome assembly.\",\n      \"method\": \"Xenopus egg extract and cell-based assays, phosphomutant analysis, domain-deletion analysis, centromere localization and CENP-A assembly readouts\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — phosphomutant dissection plus multiple functional readouts (localization, nuclear targeting, CENP-A assembly) with orthogonal methods\",\n      \"pmids\": [\"30606714\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"In metaphase, M18BP1 (M18BP1.S subunit) binds CENP-C and thereby competitively inhibits HJURP access to centromeres, preventing premature CENP-A assembly; removal of both this inhibitory activity and HJURP phosphorylation is required to allow CENP-A assembly.\",\n      \"method\": \"Xenopus cell-free centromere assembly assay, competitive binding analysis, phosphomutant HJURP rescue experiments\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — cell-free reconstitution with defined mutants, two complementary inhibitory mechanisms dissected, multiple orthogonal approaches\",\n      \"pmids\": [\"37141119\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"The extended N-terminal tail of C. elegans CENP-A directly binds KNL-2 (M18BP1 ortholog); this interaction is essential for CENP-A loading at centromeres and partially substitutes for the absent Scm3/HJURP chaperone in nematodes. Removal of the structured N-tail region prevents CENP-A loading, kinetochore assembly, and causes defective chromosome condensation.\",\n      \"method\": \"Direct binding assay (pulldown), N-tail deletion/mutation analysis, RNAi-based functional assays in C. elegans, kinetochore assembly and chromosome condensation readouts\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — direct binding confirmed by pulldown, functional rescue experiments, conservation validated in C. briggsae, multiple orthogonal methods\",\n      \"pmids\": [\"33852350\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"CDK-1 phosphorylates C. elegans KNL-2 in vitro; mutation of three C-terminal CDK-1 phosphorylation sites causes chromosome condensation defects and reduced mitotic levels of condensin II on chromosomes, without affecting CENP-A loading or kinetochore localization, thereby separating the KNL-2 functions in CENP-A loading and chromosome condensation.\",\n      \"method\": \"In vitro CDK-1 phosphorylation assay, phosphodeficient mutant worm strains, condensin II and CENP-A localization assays, embryonic lethality quantification\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — in vitro kinase assay combined with phosphomutant functional dissection, two distinct phenotypes clearly separated\",\n      \"pmids\": [\"34734636\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"M18BP1 directly binds the CAP-G2 subunit of condensin II and is required for condensin II localization to chromatin at mitotic entry. The condensin II antagonist MCPH1 also binds CAP-G2 and outcompetes M18BP1 during interphase; a switch from MCPH1 to M18BP1 at mitotic onset activates condensin II for chromosome condensation.\",\n      \"method\": \"Genetic and proteomic approaches, direct binding assay (M18BP1–CAP-G2 interaction), competitive binding assay (MCPH1 vs M18BP1 for CAP-G2), condensin II chromatin localization and chromosome condensation readouts\",\n      \"journal\": \"Molecular cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — direct binding identified, competition assay, genetic and proteomic validation, functional chromosome condensation phenotype\",\n      \"pmids\": [\"40614722\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"In C. elegans oocytes, KNL-2 (M18BP1 ortholog) recruits the nucleoporin MEL-28/ELYS at meiotic kinetochores through a specific N-terminal domain, independently of its canonical CENP-A loading factor activity. KNL-2 and MEL-28/ELYS are interdependent for kinetochore localization and together support outer kinetochore assembly in meiosis I in parallel to the canonical CENP-A/CENP-C pathway.\",\n      \"method\": \"RNAi and Degron-based depletion, engineered N-terminal domain mutants, kinetochore localization assays in C. elegans oocytes, co-depletion epistasis\",\n      \"journal\": \"Current biology : CB\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — epistasis and domain mutant analysis in a single lab, multiple depletions but no direct binding reconstitution reported in abstract\",\n      \"pmids\": [\"39353426\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"In chicken DT40 cells, tethering of CENP-C or CENP-I induces CENP-A incorporation at a non-centromeric locus in the absence of Knl2/MIS18BP1, and CENP-C co-immunoprecipitates with HJURP independently of Knl2, indicating that CENP-C can recruit CENP-A via HJURP binding without requiring Knl2.\",\n      \"method\": \"Artificial tethering assay, auxin-inducible degron (AID)-based knockout, Co-immunoprecipitation in DT40 cells\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — AID knockout combined with tethering and Co-IP, single lab, functional readout of CENP-A incorporation\",\n      \"pmids\": [\"38319136\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"Artificial M18BP1 dimerization in human cells bypasses the need for MIS18α/β, allowing identification of at least four determinants of M18BP1 centromere localization: the SANTA domain (whose first crystal structure was reported) plus linear motifs in disordered neighboring regions that interact with the 16-subunit CCAN. Cell-cycle-dependent dimerization of M18BP1 on MIS18α/β promotes recognition of multivalent centromeric CENP-A assemblies followed by PLK1 and HJURP cooption and new CENP-A deposition.\",\n      \"method\": \"Artificial dimerization constructs in human cells, SANTA domain crystal structure, interaction footprint mapping on CCAN, centromere localization and CENP-A deposition assays\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — crystal structure of SANTA domain combined with functional dimerization constructs, CCAN interaction footprint, and CENP-A deposition readout in a single study\",\n      \"pmids\": [\"41629527\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"Phosphorylation of Xenopus M18BP1 (by cell-cycle kinases) in metaphase disrupts its binding to CENP-A nucleosomes; relief of this phosphorylation in interphase enables M18BP1 binding to CENP-A nucleosomes and CENP-A nucleosome assembly, defining a phosphoregulatory switch that restricts new CENP-A assembly to interphase.\",\n      \"method\": \"Xenopus egg extract CENP-A assembly assay, phosphomutant analysis of M18BP1, direct CENP-A nucleosome binding assay\",\n      \"journal\": \"EMBO reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — cell-free reconstitution with phosphomutants and direct nucleosome binding, multiple orthogonal methods (peer-reviewed version of preprint)\",\n      \"pmids\": [\"41680291\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"MIS18BP1 (M18BP1) is a central epigenetic regulator of centromere identity that recruits the CENP-A chaperone HJURP to centromeres by assembling onto a Mis18α:Mis18β hexamer scaffold; its centromere localization is cell-cycle-regulated by CDK phosphorylation, which controls its binding to both Mis18α:Mis18β (via the N-terminal 140 residues) and directly to CENP-A nucleosomes and CENP-C (via its SANTA domain), ensuring that new CENP-A assembly is restricted to G1; additionally, M18BP1 directly activates condensin II by binding CAP-G2 at mitotic entry, coupling centromere identity maintenance with chromosome condensation.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"MIS18BP1 (M18BP1/KNL-2) is a central epigenetic licensing factor for centromere identity that couples recognition of existing CENP-A chromatin to the deposition of new CENP-A nucleosomes, restricting this assembly to a defined cell-cycle window [#3, #11]. It is recruited to centromeres by directly binding the constitutive centromere protein CENP-C through its conserved SANT/SANTA domain, and loss of CENP-C abolishes both M18BP1 targeting and downstream CENP-A assembly [#0, #1]. M18BP1 also reads existing centromeres directly by binding CENP-A nucleosomes via a conserved motif resembling that of CENP-C, with the two proteins competing for the same nucleosomal surface [#3]. Productive function requires M18BP1 to dimerize on a Mis18\\u03b1:Mis18\\u03b2 4:2 hexamer scaffold through its N-terminal 140 residues, an assembly that licenses recognition of multivalent CENP-A arrays and subsequent cooption of PLK1 and the CENP-A chaperone HJURP for new CENP-A deposition [#2, #11]. This entire cycle is governed by CDK/cell-cycle phosphorylation: phosphorylation destabilizes M18BP1 binding to both the Mis18\\u03b1:Mis18\\u03b2 scaffold and to CENP-A nucleosomes, and in metaphase M18BP1\\u2013CENP-C binding competitively blocks HJURP access, so that dephosphorylation in G1/interphase is required to permit CENP-A loading [#2, #5, #12]. Beyond centromere licensing, M18BP1 directly binds the CAP-G2 subunit of condensin II and activates it for mitotic chromosome condensation, displacing the condensin II antagonist MCPH1 at mitotic onset \\u2014 a function genetically separable from CENP-A loading [#7, #8].\",\n  \"teleology\": [\n    {\n      \"year\": 2011,\n      \"claim\": \"Established how new CENP-A assembly machinery is templated onto pre-existing centromeres by identifying CENP-C as the direct recruitment factor for M18BP1.\",\n      \"evidence\": \"Co-IP, direct binding assays, and CENP-C depletion with centromere localization and CENP-A assembly readouts in human cells\",\n      \"pmids\": [\"21911481\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define the M18BP1 domain mediating the interaction\", \"Did not resolve cell-cycle regulation of the interaction\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Mapped the M18BP1\\u2013CENP-C interaction to the central SANT domain of M18BP1 and the CENP-C C-terminus, confirming the recruitment axis in a second model system.\",\n      \"evidence\": \"Centromere interaction screen, domain mapping by Co-IP/pulldown, and CENP-C knockdown in mouse embryonic stem cells\",\n      \"pmids\": [\"22540025\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not address how the interaction is restricted by the cell cycle\", \"Did not reconstitute the interaction biochemically\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Defined the molecular architecture and cell-cycle gating of the Mis18 complex, showing M18BP1 dimerizes on a Mis18\\u03b1:Mis18\\u03b2 hexamer and that CDK1 phosphorylation of its N-terminus times complex formation to G1.\",\n      \"evidence\": \"Biochemical reconstitution with defined stoichiometry, in vitro CDK1 phosphorylation, phosphomutant analysis, and cell-based centromere localization\",\n      \"pmids\": [\"28059702\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not establish how the assembled complex recognizes centromeric chromatin\", \"Did not link scaffold assembly to HJURP recruitment\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Revealed that M18BP1 directly reads CENP-A nucleosomes through a CENP-C-like motif and competes with CENP-C, providing a chromatin-recognition mechanism for centromere identity.\",\n      \"evidence\": \"Xenopus egg extract assembly assay, direct nucleosome binding, competition assay, and motif mutagenesis\",\n      \"pmids\": [\"28743005\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not resolve how nucleosome binding and CENP-C binding are coordinated in vivo\", \"Did not define the phosphoregulation of nucleosome binding\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Showed that CDK phosphorylation of M18BP1 is required for its metaphase SANTA-domain-mediated CENP-C binding and for its nuclear localization, integrating localization control with assembly competence.\",\n      \"evidence\": \"Xenopus egg extract and cell-based assays with phosphomutant and domain-deletion analysis\",\n      \"pmids\": [\"30606714\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not reconcile metaphase CENP-C binding with the licensing of G1 assembly\", \"Did not identify the responsible kinase sites in detail\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Demonstrated in C. elegans that the CENP-A N-tail directly binds KNL-2/M18BP1 and can partially substitute for the absent HJURP, illuminating an evolutionarily divergent CENP-A loading route.\",\n      \"evidence\": \"Direct pulldown, N-tail deletion analysis, and RNAi functional assays with kinetochore and condensation readouts\",\n      \"pmids\": [\"33852350\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Relationship to the HJURP-dependent vertebrate pathway not addressed\", \"Structural basis of the N-tail interaction unresolved\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Genetically separated M18BP1's two activities by showing CDK-1 phosphorylation of C-terminal KNL-2 sites controls condensin II loading and chromosome condensation independently of CENP-A loading.\",\n      \"evidence\": \"In vitro CDK-1 phosphorylation, phosphodeficient mutant worms, condensin II/CENP-A localization, and lethality quantification\",\n      \"pmids\": [\"34734636\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not identify the direct condensin II contact\", \"Mechanism of condensin II activation not resolved\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Identified a non-canonical KNL-2 function in meiotic kinetochore assembly via recruitment of the nucleoporin MEL-28/ELYS, expanding M18BP1's roles beyond CENP-A loading.\",\n      \"evidence\": \"RNAi/degron depletion, N-terminal domain mutants, and co-depletion epistasis in C. elegans oocytes\",\n      \"pmids\": [\"39353426\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No direct binding reconstitution reported\", \"Single-lab epistasis without structural validation\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Showed that CENP-C can recruit CENP-A via HJURP independently of Knl2/MIS18BP1 in chicken cells, defining the boundary of M18BP1's requirement in the pathway.\",\n      \"evidence\": \"Artificial tethering, auxin-inducible degron knockout, and Co-IP in DT40 cells\",\n      \"pmids\": [\"38319136\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Physiological contribution of the Knl2-independent route unclear\", \"Single-lab; potential species-specific behavior\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Established a metaphase inhibitory mechanism whereby M18BP1\\u2013CENP-C binding competitively blocks HJURP, requiring its relief plus HJURP dephosphorylation to permit CENP-A assembly.\",\n      \"evidence\": \"Xenopus cell-free assembly assay, competitive binding analysis, and phosphomutant HJURP rescue\",\n      \"pmids\": [\"37141119\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How the inhibitory and recruitment roles of M18BP1 are temporally switched not fully resolved\", \"Structural basis of HJURP exclusion not defined\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Identified M18BP1's direct condensin II activation mechanism: it binds CAP-G2 and displaces the antagonist MCPH1 at mitotic onset to license condensation.\",\n      \"evidence\": \"Genetic and proteomic approaches, direct M18BP1\\u2013CAP-G2 binding, MCPH1 competition, and condensation readouts\",\n      \"pmids\": [\"40614722\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of the M18BP1/MCPH1 switch on CAP-G2 unresolved\", \"How this is coordinated with M18BP1's CENP-A licensing role unclear\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Provided the first SANTA domain crystal structure and showed that dimerization-driven M18BP1 recognizes multivalent CENP-A assemblies via multiple CCAN-contacting motifs before PLK1/HJURP cooption.\",\n      \"evidence\": \"Artificial dimerization constructs, SANTA domain crystal structure, CCAN interaction footprint mapping, and CENP-A deposition assays in human cells\",\n      \"pmids\": [\"41629527\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Higher-order architecture of the M18BP1\\u2013CCAN\\u2013CENP-A assembly not resolved\", \"Temporal order of PLK1 and HJURP cooption not fully defined\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Defined a phosphoregulatory switch on M18BP1's CENP-A nucleosome binding, showing metaphase phosphorylation disrupts binding while interphase dephosphorylation enables assembly.\",\n      \"evidence\": \"Xenopus egg extract assembly assay, phosphomutant analysis, and direct CENP-A nucleosome binding\",\n      \"pmids\": [\"41680291\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Identity of all responsible kinases/phosphatases not fully resolved\", \"Integration with the CENP-C-binding switch not detailed\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How M18BP1's dual roles in CENP-A licensing and condensin II activation are coordinated within a single mitotic timeline, and the structural basis of its multivalent CCAN/CENP-A recognition, remain open.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No integrated structural model of the full M18BP1-centromere assembly\", \"Mechanistic coupling between condensation and CENP-A licensing functions undefined\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0042393\", \"supporting_discovery_ids\": [3, 12]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 2, 8]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [5, 8]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005694\", \"supporting_discovery_ids\": [0, 3, 4]},\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [4]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0005815\", \"supporting_discovery_ids\": [0, 2, 11]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [2, 8]},\n      {\"term_id\": \"R-HSA-4839726\", \"supporting_discovery_ids\": [3, 11]}\n    ],\n    \"complexes\": [\n      \"Mis18 complex (Mis18\\u03b1:Mis18\\u03b2:M18BP1)\",\n      \"condensin II\"\n    ],\n    \"partners\": [\n      \"CENP-C\",\n      \"MIS18A\",\n      \"MIS18B\",\n      \"CENP-A\",\n      \"HJURP\",\n      \"CAP-G2\",\n      \"MCPH1\",\n      \"MEL-28/ELYS\"\n    ],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"tie","faith_supported":6,"faith_total":6,"faith_pct":100.0}}