id: Q13112 gene_symbol: CHAF1B product_type: PROTEIN status: COMPLETE taxon: id: NCBITaxon:9606 label: Homo sapiens description: >- CHAF1B (p60, CAF-1 subunit B) is the WD40-repeat medium subunit of Chromatin Assembly Factor 1 (CAF-1), a heterotrimeric histone H3-H4 chaperone composed of CHAF1A (p150), CHAF1B (p60), and RBBP4 (p48). Within CAF-1, p60 bridges the large subunit CHAF1A and the histone-binding subunit RBBP4, and the direct p150-p60 interaction is required for CAF-1-mediated nucleosome assembly. CAF-1 performs the first step of nucleosome assembly by depositing newly synthesized histones H3.1-H4 onto DNA in a replication-coupled (DNA-synthesis-dependent) manner, and it is also recruited to chromatin undergoing DNA repair. CHAF1B is built from an N-terminal seven-bladed WD40 beta-propeller and a C-terminal disordered region that is heavily phosphorylated in a cell-cycle-dependent fashion. The active complex resides in the nucleus, where it concentrates at DNA replication foci during S phase; during mitosis the p60 subunit is hyperphosphorylated, CAF-1 is inactivated, and p60 is displaced into the cytoplasm. The gene maps to chromosome 21q22. existing_annotations: - term: id: GO:0005634 label: nucleus evidence_type: IBA original_reference_id: GO_REF:0000033 qualifier: is_active_in review: summary: >- Phylogenetically-inferred nuclear localization. The active CAF-1 complex, including CHAF1B, is nuclear and concentrates at DNA replication foci during S phase, so this is the correct primary site of action. action: ACCEPT reason: >- Nuclear localization is well supported experimentally for human CAF-1 in interphase, where p150 and p60 are bound to the nucleus and concentrate at sites of intranuclear DNA replication during S phase. supported_by: - reference_id: PMID:9614144 supporting_text: >- In interphase, p150 and p60 are bound to the nucleus, but they predominantly dissociate from chromatin during mitosis. During S phase, p150 and p60 are concentrated at sites of intranuclear DNA replication. reference_section_type: ABSTRACT - term: id: GO:0005634 label: nucleus evidence_type: IEA original_reference_id: GO_REF:0000044 qualifier: located_in review: summary: >- Electronic transfer of nuclear localization from the UniProt subcellular location vocabulary. Redundant with the IBA/NAS nucleus annotations but correct; retained as non-core duplicate of the primary nuclear assignment. action: KEEP_AS_NON_CORE reason: >- Correct localization but a redundant electronic duplicate of the experimentally supported nucleus annotation. supported_by: - reference_id: file:human/CHAF1B/CHAF1B-uniprot.txt supporting_text: 'SUBCELLULAR LOCATION: Nucleus {ECO:0000269|PubMed:9614144}.' - term: id: GO:0005737 label: cytoplasm evidence_type: IEA original_reference_id: GO_REF:0000044 qualifier: located_in review: summary: >- Electronic transfer of cytoplasmic localization. CHAF1B is cytoplasmic only as the inactive, hyperphosphorylated M-phase form displaced from chromatin; this is a secondary, regulated location, not the site of CAF-1 activity. action: KEEP_AS_NON_CORE reason: >- Cytoplasmic localization is real but corresponds to the inactive M-phase pool of p60 displaced into the cytosol, not the active nuclear function. supported_by: - reference_id: file:human/CHAF1B/CHAF1B-uniprot.txt supporting_text: >- Cytoplasm {ECO:0000269|PubMed:9614144}. Note=DNA replication foci. Cytoplasmic in M phase. - term: id: GO:0006335 label: DNA replication-dependent chromatin assembly evidence_type: IEA original_reference_id: GO_REF:0000002 qualifier: involved_in review: summary: >- InterPro2GO electronic transfer of the core CAF-1 process. Correct and consistent with the direct experimental annotations of the same term, but redundant with them. action: KEEP_AS_NON_CORE reason: >- Electronic InterPro2GO duplicate of the experimentally supported core process term; correct but redundant. supported_by: - reference_id: PMID:8858152 supporting_text: >- copurifies with a chromatin assembly complex (CAC), which contains the three subunits of CAF-1 (p150, p60, p48) and H3 and H4, and promotes DNA replication-dependent chromatin assembly. reference_section_type: ABSTRACT - term: id: GO:0005515 label: protein binding evidence_type: IPI original_reference_id: PMID:16980972 qualifier: enables review: summary: >- Bare protein binding capturing the CAF-1 p60 interaction with ASF1a/ASF1b. Although this is a biologically meaningful histone-chaperone hand-off, the GO term itself is uninformative as a molecular function. action: MARK_AS_OVER_ANNOTATED reason: >- Per curation guidelines, bare 'protein binding' is uninformative. The underlying ASF1-p60 interaction is better represented by histone chaperone activity and complex membership terms. supported_by: - reference_id: PMID:16980972 supporting_text: >- CAF-1 p60 also uses B domain-like motifs for binding to ASF1a, thereby competing with HIRA. reference_section_type: ABSTRACT - term: id: GO:0005515 label: protein binding evidence_type: IPI original_reference_id: PMID:24981860 qualifier: enables review: summary: >- Bare protein binding from a high-throughput chromatin-related interactome study (interactor ASF1A). Uninformative as a molecular function. action: MARK_AS_OVER_ANNOTATED reason: >- Generic 'protein binding' from a large-scale interaction map; provides no specific molecular function information. supported_by: - reference_id: PMID:24981860 supporting_text: >- Human-chromatin-related protein interactions identify a demethylase complex required for chromosome segregation. reference_section_type: TITLE - term: id: GO:0005515 label: protein binding evidence_type: IPI original_reference_id: PMID:27705803 qualifier: enables review: summary: >- Bare protein binding from a high-throughput Polycomb complexome AP-MS map (interactor ASF1B). Uninformative as a molecular function. action: MARK_AS_OVER_ANNOTATED reason: >- Generic 'protein binding' from a large-scale interaction map; provides no specific molecular function information. supported_by: - reference_id: PMID:27705803 supporting_text: A High-Density Map for Navigating the Human Polycomb Complexome. reference_section_type: TITLE - term: id: GO:0005515 label: protein binding evidence_type: IPI original_reference_id: PMID:28514442 qualifier: enables review: summary: >- Bare protein binding from the BioPlex high-throughput AP-MS interactome (interactor ASF1B). Uninformative as a molecular function. action: MARK_AS_OVER_ANNOTATED reason: >- Generic 'protein binding' from a large-scale interaction map; provides no specific molecular function information. supported_by: - reference_id: PMID:28514442 supporting_text: >- Architecture of the human interactome defines protein communities and disease networks. reference_section_type: TITLE - term: id: GO:0005515 label: protein binding evidence_type: IPI original_reference_id: PMID:33961781 qualifier: enables review: summary: >- Bare protein binding from the BioPlex dual proteome-scale interactome (interactor ASF1B). Uninformative as a molecular function. action: MARK_AS_OVER_ANNOTATED reason: >- Generic 'protein binding' from a large-scale interaction map; provides no specific molecular function information. supported_by: - reference_id: PMID:33961781 supporting_text: >- Dual proteome-scale networks reveal cell-specific remodeling of the human interactome. reference_section_type: TITLE - term: id: GO:0005515 label: protein binding evidence_type: IPI original_reference_id: PMID:40205054 qualifier: enables review: summary: >- Bare protein binding from a high-throughput multimodal cell-map study (interactor ASF1B). Uninformative as a molecular function. action: MARK_AS_OVER_ANNOTATED reason: >- Generic 'protein binding' from a large-scale interaction map; provides no specific molecular function information. supported_by: - reference_id: PMID:40205054 supporting_text: >- Multimodal cell maps as a foundation for structural and functional genomics. reference_section_type: TITLE - term: id: GO:0006335 label: DNA replication-dependent chromatin assembly evidence_type: IDA original_reference_id: PMID:14718166 qualifier: involved_in review: summary: >- Direct evidence that CAF-1 (containing CHAF1B) mediates the DNA-synthesis-dependent nucleosome assembly pathway via histone H3.1-H4 deposition. This is the core biological process of the gene. action: ACCEPT reason: >- CHAF1B is an essential subunit of the CAF-1 complex that mediates replication-coupled (DNA-synthesis-dependent) nucleosome assembly, the gene's defining process. supported_by: - reference_id: PMID:14718166 supporting_text: >- The H3.1 and H3.3 complexes contain distinct histone chaperones, CAF-1 and HIRA, that we show are necessary to mediate DNA-synthesis-dependent and -independent nucleosome assembly, respectively. reference_section_type: ABSTRACT - term: id: GO:0005654 label: nucleoplasm evidence_type: IDA original_reference_id: GO_REF:0000052 qualifier: located_in review: summary: >- Immunofluorescence (HPA) nucleoplasmic localization, consistent with the nuclear site of CAF-1 action. Retained as a non-core refinement of the primary nucleus annotation. action: KEEP_AS_NON_CORE reason: >- Consistent nuclear/nucleoplasmic localization; a more granular but non-core refinement of the core nucleus assignment. supported_by: - reference_id: PMID:9614144 supporting_text: In interphase, p150 and p60 are bound to the nucleus. reference_section_type: ABSTRACT - term: id: GO:0000785 label: chromatin evidence_type: IDA original_reference_id: PMID:9614144 qualifier: located_in review: summary: >- CAF-1 binds chromatin and concentrates at replication foci during S phase, dissociating during mitosis. Chromatin localization is consistent with the gene's role in chromatin assembly on replicating DNA. action: ACCEPT reason: >- CHAF1B/CAF-1 acts directly on chromatin at sites of DNA replication; chromatin localization is well supported and integral to its function. supported_by: - reference_id: PMID:9614144 supporting_text: >- In interphase, p150 and p60 are bound to the nucleus, but they predominantly dissociate from chromatin during mitosis. During S phase, p150 and p60 are concentrated at sites of intranuclear DNA replication. reference_section_type: ABSTRACT - term: id: GO:0006335 label: DNA replication-dependent chromatin assembly evidence_type: IDA original_reference_id: PMID:9614144 qualifier: involved_in review: summary: >- Direct evidence that human CAF-1 (including p60) mediates nucleosome assembly coupled to DNA synthesis. Core process of the gene. action: ACCEPT reason: >- Replication-coupled nucleosome assembly is the defining function of CAF-1 and its CHAF1B subunit. supported_by: - reference_id: PMID:9614144 supporting_text: >- Human CAF-1 efficiently mediates nucleosome assembly during complementary DNA strand synthesis in G1, S, and G2 phase cytosolic extracts. reference_section_type: ABSTRACT - term: id: GO:0033186 label: CAF-1 complex evidence_type: IPI original_reference_id: PMID:9614144 qualifier: part_of review: summary: >- CHAF1B (p60) is a core subunit of the CAF-1 complex together with CHAF1A (p150) and RBBP4 (p48). This is the defining complex membership of the gene. action: ACCEPT reason: >- CHAF1B is one of the three constitutive subunits of CAF-1; complex membership is central to its identity and function. supported_by: - reference_id: PMID:9614144 supporting_text: >- All three subunits of human CAF-1 (p150, p60, and p48) are present during the entire cell cycle. reference_section_type: ABSTRACT - term: id: GO:0006335 label: DNA replication-dependent chromatin assembly evidence_type: IDA original_reference_id: PMID:8858152 qualifier: involved_in review: summary: >- The chromatin assembly complex containing the three CAF-1 subunits and histones H3/H4 promotes DNA replication-dependent chromatin assembly. Core process. action: ACCEPT reason: >- Direct biochemical evidence that the CAF-1-containing complex promotes replication-dependent chromatin assembly, the gene's core process. supported_by: - reference_id: PMID:8858152 supporting_text: >- copurifies with a chromatin assembly complex (CAC), which contains the three subunits of CAF-1 (p150, p60, p48) and H3 and H4, and promotes DNA replication-dependent chromatin assembly. reference_section_type: ABSTRACT - term: id: GO:0032991 label: protein-containing complex evidence_type: IDA original_reference_id: PMID:14718166 qualifier: part_of review: summary: >- Generic complex membership. CHAF1B is part of the specific CAF-1 complex (GO:0033186), so the root-level protein-containing complex term is an over-general annotation. action: MARK_AS_OVER_ANNOTATED reason: >- The specific CAF-1 complex term is annotated and is far more informative; the generic protein-containing complex term adds no information. supported_by: - reference_id: PMID:14718166 supporting_text: >- these complexes possess one molecule each of H3.1/H3.3 and H4, suggesting that histones H3 and H4 exist as dimeric units that are important intermediates in nucleosome formation. reference_section_type: ABSTRACT - term: id: GO:0000785 label: chromatin evidence_type: IDA original_reference_id: PMID:14718166 qualifier: located_in review: summary: >- CAF-1 acts on chromatin during replication-coupled H3.1-H4 deposition; chromatin localization is consistent with the gene's nucleosome assembly role. action: ACCEPT reason: >- Chromatin is the direct substrate location for CAF-1-mediated nucleosome assembly; well supported and functionally integral. supported_by: - reference_id: PMID:14718166 supporting_text: >- The H3.1 and H3.3 complexes contain distinct histone chaperones, CAF-1 and HIRA, that we show are necessary to mediate DNA-synthesis-dependent and -independent nucleosome assembly, respectively. reference_section_type: ABSTRACT - term: id: GO:0033186 label: CAF-1 complex evidence_type: IDA original_reference_id: PMID:8858152 qualifier: part_of review: summary: >- CHAF1B is a constitutive subunit of the CAF-1 complex (with CHAF1A and RBBP4). Defining complex membership. action: ACCEPT reason: >- Core CAF-1 complex membership, biochemically demonstrated in the chromatin assembly complex containing all three subunits. supported_by: - reference_id: PMID:8858152 supporting_text: >- a chromatin assembly complex (CAC), which contains the three subunits of CAF-1 (p150, p60, p48) and H3 and H4. reference_section_type: ABSTRACT - term: id: GO:0005829 label: cytosol evidence_type: HDA original_reference_id: PMID:16780588 qualifier: colocalizes_with review: summary: >- High-throughput colocalization with the cytosol. CHAF1B is cytosolic only as the inactive M-phase form translocated out of the nucleus during cell division; this is a regulated secondary location, not the site of activity. action: KEEP_AS_NON_CORE reason: >- The cytosolic pool corresponds to the inactive M-phase form of p60; it is a genuine but non-core, cell-cycle-restricted location. supported_by: - reference_id: PMID:16780588 supporting_text: >- The chromatin assembly factor I p60 subunit (CHAF1B) protein translocated from the nucleus into the cytoplasm during cell division. reference_section_type: RESULTS - term: id: GO:0005654 label: nucleoplasm evidence_type: HDA original_reference_id: PMID:16780588 qualifier: colocalizes_with review: summary: >- High-throughput colocalization with the nucleoplasm, consistent with the nuclear site of CAF-1 action at interphase. action: KEEP_AS_NON_CORE reason: >- Nucleoplasmic localization is consistent with the core nuclear function but is a non-core refinement supported by high-throughput data. supported_by: - reference_id: PMID:16780588 supporting_text: >- most of the CHAF1B protein localizing in the nucleus at interphase, where it is involved in chromatin assembly and DNA replication. reference_section_type: RESULTS - term: id: GO:0005634 label: nucleus evidence_type: NAS original_reference_id: PMID:9614144 qualifier: located_in review: summary: >- Nuclear localization of CAF-1/p60 in interphase, where the complex performs replication-coupled chromatin assembly. Core localization. action: ACCEPT reason: >- The active CAF-1 complex including CHAF1B is nuclear; this is the primary site of its function. supported_by: - reference_id: PMID:9614144 supporting_text: In interphase, p150 and p60 are bound to the nucleus. reference_section_type: ABSTRACT - term: id: GO:0005737 label: cytoplasm evidence_type: NAS original_reference_id: PMID:9614144 qualifier: located_in review: summary: >- Cytoplasmic localization corresponds to the inactive, hyperphosphorylated M-phase form of p60 displaced from chromatin; a regulated secondary location. action: KEEP_AS_NON_CORE reason: >- Real but non-core; reflects the inactive mitotic pool rather than the active nuclear function. supported_by: - reference_id: PMID:9614144 supporting_text: >- In mitosis, the p60 subunit of inactive CAF-1 is hyperphosphorylated. reference_section_type: ABSTRACT - term: id: GO:0042393 label: histone binding evidence_type: NAS original_reference_id: PMID:7600578 qualifier: enables review: summary: >- CAF-1 p150/p60 form complexes with newly synthesized histones H3 and acetylated H4, and p60 binds histones H3.1/H3.2/H3.1t. Histone binding is a core molecular function of this histone chaperone subunit. Cryo-EM structural work (Liu et al. 2023, Science) specifically identifies p60/CHAF1B as the principal H3-H4-binding subunit of human CAF-1, contacting H4 through its ventral beta-propeller surface and engaging a partially unfolded H3 region; this is direct, subunit-specific structural support for histone binding by CHAF1B itself rather than only by the holo-complex. action: ACCEPT reason: >- CHAF1B directly contacts histones in the CAF-1 complex (newly synthesized H3-H4; H3.1/H3.2/H3.1t), supporting histone binding as a core MF. The falcon deep-research report (summarizing Liu et al. 2023 cryo-EM) adds subunit-resolved structural evidence that p60 is the principal H3-H4-binding component and is required for CAF-1 histone binding, reinforcing this as a direct molecular function of CHAF1B. supported_by: - reference_id: PMID:7600578 supporting_text: >- p150 and p60 form complexes with newly synthesized histones H3 and acetylated H4 in human cell extracts. reference_section_type: ABSTRACT - reference_id: file:human/CHAF1B/CHAF1B-uniprot.txt supporting_text: Interacts with histones H3.1, H3.2 and H3.1t (PubMed:33857403). - reference_id: file:human/CHAF1B/CHAF1B-deep-research-falcon.md supporting_text: >- The primary molecular function of CHAF1B is to serve as the principal histone H3-H4 binding subunit within the CAF-1 complex. - term: id: GO:0003682 label: chromatin binding evidence_type: TAS original_reference_id: PMID:7600578 qualifier: enables review: summary: >- Chromatin binding is consistent with CAF-1 acting on replicating chromatin, but it is a generic molecular function relative to the more informative histone chaperone / histone binding activities of CHAF1B. action: KEEP_AS_NON_CORE reason: >- Supported but generic; histone binding and histone chaperone activity are more informative descriptors of the molecular function. supported_by: - reference_id: PMID:9614144 supporting_text: >- During S phase, p150 and p60 are concentrated at sites of intranuclear DNA replication. reference_section_type: ABSTRACT - term: id: GO:0140713 label: histone chaperone activity evidence_type: IC original_reference_id: file:human/CHAF1B/CHAF1B-uniprot.txt qualifier: enables review: summary: Proposed annotation not present in the current GOA for CHAF1B. action: NEW reason: >- CHAF1B is a subunit of the CAF-1 histone H3-H4 chaperone and directly binds newly synthesized histones H3-H4 (and H3.1/H3.2/H3.1t). The molecular function of the complex is histone chaperone activity, which is not currently captured in the CHAF1B GOA and would be more informative than the existing bare protein binding annotations. Cryo-EM structural work (Liu et al. 2023) shows p60 is not merely a passive scaffold but is required for CAF-1 histone binding and nucleosome assembly activity, supporting a subunit-level histone chaperone activity annotation. supported_by: - reference_id: file:human/CHAF1B/CHAF1B-uniprot.txt supporting_text: >- Acts as a component of the histone chaperone complex chromatin assembly factor 1 (CAF-1), which assembles histone octamers onto DNA during replication and repair. - reference_id: file:human/CHAF1B/CHAF1B-deep-research-falcon.md supporting_text: >- CHAF1B directly binds H3-H4 and is absolutely required for CAF-1's nucleosome assembly activity core_functions: - description: >- CHAF1B is the WD40 medium subunit (p60) of the CAF-1 histone H3-H4 chaperone, binding newly synthesized histones H3.1-H4 and acting as a histone chaperone within the complex. molecular_function: id: GO:0140713 label: histone chaperone activity supported_by: - reference_id: PMID:7600578 supporting_text: >- p150 and p60 form complexes with newly synthesized histones H3 and acetylated H4 in human cell extracts. reference_section_type: ABSTRACT - reference_id: file:human/CHAF1B/CHAF1B-deep-research-falcon.md supporting_text: >- The p60 subunit binds one histone H3-H4 heterodimer mainly through its ventral surface area, which is enriched with negatively charged residues along with several tyrosine and phenylalanine residues - description: >- As a subunit of CAF-1, CHAF1B mediates the first step of nucleosome assembly, depositing newly synthesized H3.1-H4 onto DNA in a replication- and repair-coupled manner. directly_involved_in: - id: GO:0006335 label: DNA replication-dependent chromatin assembly in_complex: id: GO:0033186 label: CAF-1 complex locations: - id: GO:0005634 label: nucleus - id: GO:0000785 label: chromatin supported_by: - reference_id: PMID:8858152 supporting_text: >- a chromatin assembly complex (CAC), which contains the three subunits of CAF-1 (p150, p60, p48) and H3 and H4, and promotes DNA replication-dependent chromatin assembly. reference_section_type: ABSTRACT - description: >- CHAF1B bridges the large subunit CHAF1A (p150) and the histone-binding subunit RBBP4 (p48); the direct CHAF1A-CHAF1B interaction is required for CAF-1-mediated nucleosome assembly. molecular_function: id: GO:0042393 label: histone binding supported_by: - reference_id: PMID:7600578 supporting_text: >- p150 and p60 directly interact and are both required for DNA replication-dependent assembly of nucleosomes. Deletion of the p60-binding domain from the p150 protein prevents chromatin assembly. reference_section_type: ABSTRACT proposed_new_terms: [] suggested_questions: - question: >- Is CHAF1B's histone-chaperone activity exerted only as part of the CAF-1 complex, or does the isolated p60 subunit have an autonomous histone-binding / chaperone role that warrants a gene-level molecular-function annotation? experts: - Kaufman PD - Almouzni G - question: >- Does cell-cycle-dependent phosphorylation of the C-terminal disordered region of CHAF1B directly regulate CAF-1 assembly activity and its nuclear-cytoplasmic partitioning? experts: - Marheineke K - Krude T suggested_experiments: - hypothesis: >- CHAF1B is required for replication-coupled H3.1-H4 deposition and its loss impairs nucleosome assembly genome-wide during S phase. description: >- Acute degradation (e.g., auxin-inducible degron) of CHAF1B in human cells followed by SCAR-seq / nascent-chromatin capture to measure replication-coupled new-histone deposition and parental-histone recycling. experiment_type: replication-coupled nucleosome assembly assay - hypothesis: >- Mitotic hyperphosphorylation of the CHAF1B C-terminal tail inactivates CAF-1 and drives its cytoplasmic relocalization. description: >- Generate phospho-null and phospho-mimetic mutants of the mapped CHAF1B phosphosites and assay CAF-1 nucleosome assembly activity, complex integrity, and subcellular localization across the cell cycle. experiment_type: phosphomutant functional and localization assay references: - id: GO_REF:0000002 title: Gene Ontology annotation through association of InterPro records with GO terms findings: [] - id: GO_REF:0000033 title: Annotation inferences using phylogenetic trees findings: [] - id: GO_REF:0000044 title: Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt findings: [] - id: GO_REF:0000052 title: Gene Ontology annotation based on curation of immunofluorescence data findings: [] - id: PMID:14718166 title: Histone H3.1 and H3.3 complexes mediate nucleosome assembly pathways dependent or independent of DNA synthesis. findings: - statement: >- The H3.1 deposition machinery is the CAF-1 histone chaperone, which mediates DNA-synthesis-dependent (replication-coupled) nucleosome assembly. supporting_text: >- The H3.1 and H3.3 complexes contain distinct histone chaperones, CAF-1 and HIRA, that we show are necessary to mediate DNA-synthesis-dependent and -independent nucleosome assembly, respectively. reference_section_type: ABSTRACT full_text_unavailable: true - id: PMID:16780588 title: Cell array-based intracellular localization screening reveals novel functional features of human chromosome 21 proteins. findings: - statement: >- CHAF1B is nuclear at interphase (chromatin assembly / DNA replication) and translocates to the cytoplasm during cell division. supporting_text: >- The chromatin assembly factor I p60 subunit (CHAF1B) protein translocated from the nucleus into the cytoplasm during cell division. reference_section_type: RESULTS - id: PMID:16980972 title: Structure of a human ASF1a-HIRA complex and insights into specificity of histone chaperone complex assembly. findings: - statement: >- CAF-1 p60 (CHAF1B) uses B-domain-like motifs to bind ASF1a, competing with HIRA for the same surface. supporting_text: >- CAF-1 p60 also uses B domain-like motifs for binding to ASF1a, thereby competing with HIRA. reference_section_type: ABSTRACT - id: PMID:24981860 title: Human-chromatin-related protein interactions identify a demethylase complex required for chromosome segregation. findings: [] - id: PMID:27705803 title: A High-Density Map for Navigating the Human Polycomb Complexome. findings: [] - id: PMID:28514442 title: Architecture of the human interactome defines protein communities and disease networks. findings: [] - id: PMID:33961781 title: Dual proteome-scale networks reveal cell-specific remodeling of the human interactome. findings: [] - id: PMID:40205054 title: Multimodal cell maps as a foundation for structural and functional genomics. findings: [] - id: PMID:7600578 title: 'The p150 and p60 subunits of chromatin assembly factor I: a molecular link between newly synthesized histones and DNA replication.' findings: - statement: >- p150 and p60 directly interact and are both required for replication-dependent nucleosome assembly; they form complexes with newly synthesized H3 and acetylated H4. supporting_text: >- p150 and p60 directly interact and are both required for DNA replication-dependent assembly of nucleosomes. reference_section_type: ABSTRACT full_text_unavailable: true - id: PMID:8858152 title: Nucleosome assembly by a complex of CAF-1 and acetylated histones H3/H4. findings: - statement: >- The chromatin assembly complex contains the three CAF-1 subunits (p150, p60, p48) plus H3 and H4 and promotes DNA replication-dependent chromatin assembly. supporting_text: >- a chromatin assembly complex (CAC), which contains the three subunits of CAF-1 (p150, p60, p48) and H3 and H4, and promotes DNA replication-dependent chromatin assembly. reference_section_type: ABSTRACT full_text_unavailable: true - id: PMID:9614144 title: Nucleosome assembly activity and intracellular localization of human CAF-1 changes during the cell division cycle. findings: - statement: >- All three CAF-1 subunits (p150, p60, p48) are present through the cell cycle; p150/p60 are nuclear and concentrate at replication sites in S phase, and p60 is hyperphosphorylated and inactive in mitosis. supporting_text: >- In interphase, p150 and p60 are bound to the nucleus, but they predominantly dissociate from chromatin during mitosis. During S phase, p150 and p60 are concentrated at sites of intranuclear DNA replication. reference_section_type: ABSTRACT full_text_unavailable: true - id: file:human/CHAF1B/CHAF1B-uniprot.txt title: UniProt entry Q13112 (CAF1B_HUMAN) findings: - statement: >- CHAF1B is a component of the CAF-1 histone chaperone complex (RBBP4, CHAF1B, CHAF1A); CHAF1A binds directly to CHAF1B; interacts with histones H3.1, H3.2, H3.1t. supporting_text: >- Subunit of the CAF-1 complex that contains RBBP4, CHAF1B and CHAF1A. CHAF1A binds directly to CHAF1B. reference_section_type: OTHER - id: file:human/CHAF1B/CHAF1B-deep-research-falcon.md title: Falcon deep research report for CHAF1B reference_review: relevance: HIGH correctness: UNVERIFIED review_notes: >- LLM-synthesized deep-research report (Edison/Falcon); claims are machine-aggregated and not independently verified, so marked UNVERIFIED. The report's own summary table usefully distinguishes CHAF1B/p60 subunit-specific evidence from broader CAF-1 holo-complex inference. The strongest subunit-specific claims trace to the Liu et al. 2023 Science cryo-EM structure (add8673): that the p60 subunit is the principal H3-H4 binding component, contacting histone H4 through its ventral beta-propeller surface and engaging a partially unfolded H3 region, and that CHAF1B is required for CAF-1 histone binding and nucleosome assembly activity. The report also surfaces a CHAF1B-specific genome-stability function (Shrestha et al. 2023, jcs.260944): CHAF1B depletion causes CENP-A mislocalization and chromosomal instability. Many other statements (PCNA recruitment, heterochromatin/H3K9me3-H3K27me3 maintenance, viral latency, transcriptional/cell-fate control, cancer overexpression) are attributed to the CAF-1 holo-complex or to CHAF1B knockdown phenotypes rather than to a direct, isolated p60 molecular activity, and should not be transferred to CHAF1B as subunit-specific molecular functions without primary-source verification. None of the underlying primary papers are in the publications cache; supporting_text quotes below are verbatim from this report, not from the primary articles.