NAP1

Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0000785 chromatin	IBA GO_REF:0000033	KEEP AS NON CORE	Summary: The PTN000221934 IBD node propagates chromatin as a broad site of action for the NAP/SET/Vps75 family. Nap1 itself has direct H2A-H2B chaperone evidence and nuclear nucleosome-assembly/remodeling roles, so the broad chromatin component assignment is retained as biologically compatible but non-core. Reason: PTN000221934 carries chromatin, nucleus, chromatin binding, and histone binding calls for the broad NAP/SET/Vps75 family node. Chromatin is a compatible site-of-action term for Nap1's nuclear H2A-H2B deposition and eviction activity, but the nucleus and H2A-H2B chaperone rows are more specific. Propagation Review Root cause: NO FAILURE NON CORE Sources checked: PANTHER:PTN000221934 SUPPORTS TRANSFER The current PTHR11875 PAINT slice places chromatin at PTN000221934. The inherited chromatin component is compatible with Nap1 but broader than its direct H2A-H2B chaperone activity.
GO:0005634 nucleus	IBA GO_REF:0000033	ACCEPT	Summary: Nap1 functions in both the cytosol and the nucleus. Falcon deep research notes that Nap1 is mostly cytoplasmic but also functions in the nucleus, where it supports H2A-H2B release, nucleosome assembly, and nucleosome disassembly. The nucleus IBA is retained as a core site of Nap1 action. Reason: Nap1's predominant steady-state pool is cytosolic, but its direct H2A-H2B deposition and eviction reactions also act in the nucleus. The PAINT node is supported by budding-yeast NAP1 itself, and the core H2A-H2B chaperone activities require the nucleus as an authentic site of action. Propagation Review Root cause: NO FAILURE CORE Sources checked: PANTHER:PTN000221934 SUPPORTS TRANSFER PTN000221934 is the current PAINT node for the NAP-family nucleus IBA; the descendant experimental evidence includes budding-yeast SGD:S000001756/NAP1 itself. Supporting Evidence: file:yeast/NAP1/NAP1-deep-research-falcon.md but also acts in the nucleus where it supports targeted histone release/import, nucleosome assembly and remodeling during transcription
GO:0006334 nucleosome assembly	IBA GO_REF:0000033	ACCEPT	Summary: Nucleosome assembly is a core biological process for NAP1. Falcon deep research supports that Nap1 is a conserved nucleosome assembly protein that promotes correct nucleosome organization by delivering H2A-H2B dimers into nucleosomes rather than allowing random histone-DNA association. Reason: PTN000221935 correctly propagates the conserved NAP-family role in H2A-H2B deposition during nucleosome assembly; budding-yeast Nap1 has direct descendant evidence for the same process. Propagation Review Root cause: NO FAILURE CORE Sources checked: PANTHER:PTN000221935 SUPPORTS TRANSFER PTN000221935 is the current eukaryote-scoped IBD node for nucleosome assembly in PTHR11875 and includes budding-yeast NAP1 itself among the experimental descendant evidence. Supporting Evidence: file:yeast/NAP1/NAP1-deep-research-falcon.md Nap1 is proposed to recruit H2A-H2B to maintain ordered nucleosome arrangement
GO:0042393 histone binding	IBA GO_REF:0000033	ACCEPT	Summary: Histone binding is a core molecular function of NAP1. Falcon deep research confirms the primary substrate is the H2A-H2B dimer, which Nap1 binds with nanomolar affinity as a stable homodimer, shielding the basic DNA-binding surfaces of the histones. Reason: Histone binding is the direct client-recognition activity underlying Nap1's H2A-H2B, H3-H4, and H2AZ-H2B chaperone rows, and PTN000221934 matches the conserved NAP-family histone-binding placement. Propagation Review Root cause: NO FAILURE CORE Sources checked: PANTHER:PTN000221934 SUPPORTS TRANSFER PTN000221934 is the current broad NAP-family PAINT node for histone binding; the descendant experimental evidence includes SGD:S000001756/NAP1 and SGD:S000005190/VPS75, and budding-yeast Nap1 shows no lineage-specific loss of H2A-H2B binding or chaperoning. Supporting Evidence: file:yeast/NAP1/NAP1-deep-research-falcon.md The primary substrate of Nap1 is the H2A–H2B dimer file:yeast/NAP1/NAP1-deep-research-falcon.md Nagae et al. describe Nap1 as a ~48 kDa monomer that forms a stable homodimer and binds a single H2A–H2B dimer with nanomolar affinity
GO:0003682 chromatin binding	IBA GO_REF:0000033	KEEP AS NON CORE	Summary: The PTN000221934 IBD node transfers chromatin binding as a broad NAP/SET-family interaction context. The term is less informative than H2A-H2B histone complex chaperone activity, so it is kept as non-core. Reason: Nap1 can act on nucleosomal H2A-H2B substrates, but its curated direct activity is the more specific GO:0000511 H2A-H2B histone complex chaperone activity. This broader chromatin-binding IBA does not add a distinct biochemical output and is retained only as a non-core inherited interaction context. Propagation Review Root cause: TERM SCOPING PROBLEM Failure modes: GRANULARITY MISMATCH Sources checked: PANTHER:PTN000221934 SUPPORTS TRANSFER PTN000221934 is the current PTHR11875 node for chromatin binding. The inherited term is less precise than Nap1's direct H2A-H2B chaperone activity but remains compatible with the nucleosomal substrate context.
GO:0003677 DNA binding	IEA GO_REF:0000043	REMOVE	Summary: The retired UniProt keyword DNA-binding row should not be retained for Nap1; Nap1's acidic surfaces mimic DNA to shield histone H2A-H2B rather than representing a core naked-DNA-binding function. Reason: UniProt withdrew this keyword row in the current source. Nap1's core H2A-H2B chaperone chemistry is better described as acidic DNA mimicry that binds and stabilizes histones, so a naked DNA-binding keyword is misleading. Supporting Evidence: PMID:38571760 glutamylation of these chaperone polyelectrolyte acidic stretches functions to enhance DNA electrostatic mimicry, promoting the binding and stabilization of H2A/H2B heterodimers and facilitating nucleosome assembly
GO:0005634 nucleus	IEA GO_REF:0000120	ACCEPT	Summary: Manual review: nucleus is a core site for NAP1 H2A-H2B deposition and eviction reactions. Reason: Retained as consistent with the self-seeded PAINT nucleus IBA and with Nap1's direct nuclear H2A-H2B chaperone activities.
GO:0005737 cytoplasm	IEA GO_REF:0000044	ACCEPT	Summary: Manual review: cytoplasm is the predominant steady-state localization of NAP1 and the principal site of its core H2A-H2B chaperone activity. Reason: Accepted as core, consistent with the IDA cytoplasm annotation (PMID:7622566); the cytoplasm is the predominant steady-state localization where Nap1 carries out its core H2A-H2B chaperone activity.
GO:0005935 cellular bud neck	IEA GO_REF:0000044	KEEP AS NON CORE	Summary: Bud-neck localization is valid for a peripheral mitotic Nap1 pool. Reason: Nap1 localizes to the bud neck in G2/M cells, consistent with its Gin4/septin-associated mitotic role; this location is secondary to the cytosolic and nuclear H2A-H2B chaperone cycle. Supporting Evidence: PMID:18086883 In exponentially growing cells, wild-type and mutant Nap1 GFP fusions were predominantly cytoplasmic and able to localize to the bud neck in G 2 /M cells (Fig. 7A ).
GO:0005940 septin ring	IEA GO_REF:0000117	KEEP AS NON CORE	Summary: Septin-ring association is compatible with the peripheral Gin4/septin complex role but is not a core Nap1 location. Reason: The ARBA septin-ring row is broader than direct Gin4-complex membership but matches Nap1's mitotic complex with Gin4, Bni5, and septins at the bud-neck scaffold. Supporting Evidence: PMID:12058072 We show that during mitosis Gin4 is assembled into a multiprotein complex that includes Nap1, Bni5, the septins, and at least two molecules of Gin4.
GO:0006334 nucleosome assembly	IEA GO_REF:0000002	ACCEPT	Summary: Nucleosome assembly is a core Nap1 process and is an appropriate InterPro2GO inference from the NAP family. Reason: Nap1 directly chaperones H2A-H2B for deposition into nucleosomes; the InterPro2GO row is a valid broad electronic assertion of that core activity. Supporting Evidence: PMID:27225933 Mutants that interfere with Nap1 oligomerization exhibit severe nucleosome assembly defects showing that oligomerization is essential for the chaperone function.
GO:0005515 protein binding	IPI PMID:10688190 A comprehensive analysis of protein-protein interactions in ...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, histone binding, homodimer formation, or cyclin binding, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:11805837 Systematic identification of protein complexes in Saccharomy...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, histone binding, homodimer formation, or cyclin binding, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:12058072 Cell cycle-dependent assembly of a Gin4-septin complex.	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, histone binding, homodimer formation, or cyclin binding, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:14645854 ATP-driven exchange of histone H2AZ variant catalyzed by SWR...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, histone binding, homodimer formation, or cyclin binding, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:14759368 High-definition macromolecular composition of yeast RNA-proc...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, histone binding, homodimer formation, or cyclin binding, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:15045029 A protein complex containing the conserved Swi2/Snf2-related...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, histone binding, homodimer formation, or cyclin binding, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:16299494 A phosphatase complex that dephosphorylates gammaH2AX regula...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, histone binding, homodimer formation, or cyclin binding, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:16429126 Proteome survey reveals modularity of the yeast cell machine...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, histone binding, homodimer formation, or cyclin binding, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:16554755 Global landscape of protein complexes in the yeast Saccharom...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, histone binding, homodimer formation, or cyclin binding, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:18467557 An in vivo map of the yeast protein interactome.	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, histone binding, homodimer formation, or cyclin binding, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:18719252 High-quality binary protein interaction map of the yeast int...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, histone binding, homodimer formation, or cyclin binding, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:19172749 Histone chaperone specificity in Rtt109 activation.	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, histone binding, homodimer formation, or cyclin binding, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:19536198 An atlas of chaperone-protein interactions in Saccharomyces ...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, histone binding, homodimer formation, or cyclin binding, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:20489023 A global protein kinase and phosphatase interaction network ...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, histone binding, homodimer formation, or cyclin binding, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:21179020 Defining the budding yeast chromatin-associated interactome.	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, histone binding, homodimer formation, or cyclin binding, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:23468594 A safeguard mechanism regulates Rho GTPases to coordinate cy...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, histone binding, homodimer formation, or cyclin binding, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:25416945 A memory system of negative polarity cues prevents replicati...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, histone binding, homodimer formation, or cyclin binding, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:37968396 The social and structural architecture of the yeast protein ...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, histone binding, homodimer formation, or cyclin binding, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:9214386 Control of mitotic events by Nap1 and the Gin4 kinase.	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, histone binding, homodimer formation, or cyclin binding, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:9813092 The septins are required for the mitosis-specific activation...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, histone binding, homodimer formation, or cyclin binding, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0042802 identical protein binding	IPI PMID:16432217 The structure of nucleosome assembly protein 1.	KEEP AS NON CORE	Summary: Nap1 homodimerization is a real self-association property, but it is subordinate to the H2A-H2B histone-chaperone activity. Reason: Nap1 functions as a stable homodimer when it binds H2A-H2B. Retaining identical protein binding as non-core preserves the experimentally observed self-interaction without treating homodimerization as a separate core molecular activity; self-association is quaternary-state context for the GO:0000511 chaperone function.
GO:0042802 identical protein binding	IPI PMID:18467557 An in vivo map of the yeast protein interactome.	KEEP AS NON CORE	Summary: Nap1 homodimerization is a real self-association property, but it is subordinate to the H2A-H2B histone-chaperone activity. Reason: Nap1 functions as a stable homodimer when it binds H2A-H2B. Retaining identical protein binding as non-core preserves the experimentally observed self-interaction without treating homodimerization as a separate core molecular activity; self-association is quaternary-state context for the GO:0000511 chaperone function.
GO:0042802 identical protein binding	IPI PMID:18719252 High-quality binary protein interaction map of the yeast int...	KEEP AS NON CORE	Summary: Nap1 homodimerization is a real self-association property, but it is subordinate to the H2A-H2B histone-chaperone activity. Reason: Nap1 functions as a stable homodimer when it binds H2A-H2B. Retaining identical protein binding as non-core preserves the experimentally observed self-interaction without treating homodimerization as a separate core molecular activity; self-association is quaternary-state context for the GO:0000511 chaperone function.
GO:0042802 identical protein binding	IPI PMID:21179020 Defining the budding yeast chromatin-associated interactome.	KEEP AS NON CORE	Summary: Nap1 homodimerization is a real self-association property, but it is subordinate to the H2A-H2B histone-chaperone activity. Reason: Nap1 functions as a stable homodimer when it binds H2A-H2B. Retaining identical protein binding as non-core preserves the experimentally observed self-interaction without treating homodimerization as a separate core molecular activity; self-association is quaternary-state context for the GO:0000511 chaperone function.
GO:0140597 protein carrier activity	IDA PMID:31062022 Tsr4 and Nap1, two novel members of the ribosomal protein ch...	KEEP AS NON CORE	Summary: PMID:31062022 identifies Nap1 as a dedicated carrier chaperone for the ribosomal protein Rps6/eS6 that binds Rps6 and promotes Rps6 solubility in vitro. Reason: Retained as non-core because this annotation describes Nap1's peripheral ribosomal-protein client carrier activity rather than its core H2A-H2B histone complex chaperone activity. Supporting Evidence: PMID:31062022 We report the identification of Nap1 and Tsr4 as direct binding partners of Rps6 and Rps2, respectively. Both factors promote the solubility of their r-protein clients in vitro. PMID:31062022 Nap1 interacts with a large, mostly eukaryote-specific binding surface of Rps6.
GO:0000511 H2A-H2B histone complex chaperone activity	IDA PMID:39601790 Nap1 and Kap114 co-chaperone H2A-H2B and facilitate targeted...	ACCEPT	Summary: This is the core molecular function of NAP1. Falcon deep research (anchored on Fung et al. 2024, the source of this PMID) establishes that Nap1 forms a stable homodimer that binds H2A-H2B, shields their DNA-binding surfaces, and cooperates with the importin Kap114 and RanGTP to chaperone H2A-H2B for nucleosome assembly, forming a quaternary Nap1_2-H2A-H2B-Kap114-RanGTP complex. Reason: PMID:39601790 directly supports Nap1 H2A-H2B chaperone activity by resolving the Nap1-Kap114-H2A-H2B-RanGTP handoff complex that explains targeted H2A-H2B release for nucleosome assembly. Supporting Evidence: file:yeast/NAP1/NAP1-deep-research-falcon.md Nap1 forms a stable homodimer file:yeast/NAP1/NAP1-deep-research-falcon.md Kap114, H2A–H2B, and Nap1\_2 form equimolar complexes, including a quaternary Nap1\_2•H2A–H2B•Kap114•RanGTP assembly
GO:0006334 nucleosome assembly	IDA PMID:39601790 Nap1 and Kap114 co-chaperone H2A-H2B and facilitate targeted...	ACCEPT	Summary: Fung et al. directly showed that Nap1 and Kap114 cooperate to protect H2A-H2B and transfer it into nucleosomes in the presence of RanGTP. Reason: The biochemical and cryo-EM evidence in PMID:39601790 supports Nap1's core role in delivering H2A-H2B for specific nucleosome assembly in the nucleus. Supporting Evidence: PMID:39601790 DNA competition and nucleosome assembly assays confirmed that in the presence of RanGTP, Kap114 and Nap1 cooperate to shield H2A-H2B from non-specific aggregation with DNA and transfer H2A-H2B effectively and specifically into nucleosomes.
GO:0000511 H2A-H2B histone complex chaperone activity	IDA PMID:27225933 Structural evidence for Nap1-dependent H2A-H2B deposition an...	ACCEPT	Summary: Aguilar-Gurrieri et al. solved the yeast Nap1-H2A-H2B structure and demonstrated H2A-H2B chaperoning by a Nap1 dimer. Reason: The structural and in vitro evidence from PMID:27225933 directly supports H2A-H2B histone complex chaperone activity for Nap1. Supporting Evidence: PMID:27225933 A Nap1 dimer provides an acidic binding surface and asymmetrically engages a single H2A-H2B heterodimer.
GO:0006334 nucleosome assembly	IDA PMID:27225933 Structural evidence for Nap1-dependent H2A-H2B deposition an...	ACCEPT	Summary: Aguilar-Gurrieri et al. showed that Nap1-dependent H2A-H2B deposition is required for normal nucleosome assembly. Reason: ChIP-exo and oligomerization-mutant experiments in PMID:27225933 support a direct role for Nap1-mediated H2A-H2B deposition in nucleosome assembly. Supporting Evidence: PMID:27225933 Mutants that interfere with Nap1 oligomerization exhibit severe nucleosome assembly defects showing that oligomerization is essential for the chaperone function.
GO:0000920 septum digestion after cytokinesis	NAS PMID:12058072 Cell cycle-dependent assembly of a Gin4-septin complex.	KEEP AS NON CORE	Summary: ComplexPortal septum digestion after cytokinesis is a peripheral process context inferred from the mitotic Gin4-septin complex that includes Nap1. Reason: Nap1 is a component of the mitotic Gin4-septin complex, which connects Nap1 to septin/cytokinesis regulation; this cell-division role is non-core relative to Nap1's H2A-H2B chaperone activity. Supporting Evidence: PMID:12058072 We show that during mitosis Gin4 is assembled into a multiprotein complex that includes Nap1, Bni5, the septins, and at least two molecules of Gin4.
GO:0000921 septin ring assembly	NAS PMID:12058072 Cell cycle-dependent assembly of a Gin4-septin complex.	KEEP AS NON CORE	Summary: ComplexPortal septin-ring assembly is a peripheral process context inferred from the mitotic Gin4-septin complex that includes Nap1. Reason: Gin4 and associated septins act in septin localization and bud-neck organization during mitosis; Nap1's membership in that complex supports keeping this annotation as non-core. Supporting Evidence: PMID:12058072 Gin4, a Nim1-related kinase, is required in budding yeast for localization of the septins and for proper control of daughter cell growth during G2/M.
GO:0006607 NLS-bearing protein import into nucleus	IMP PMID:12456659 A role for nucleosome assembly protein 1 in the nuclear tran...	KEEP AS NON CORE	Summary: Nap1 participates in histone H2A-H2B nuclear import in cooperation with the importin Kap114 and the Ran-GTP system. Falcon deep research describes Nap1 escorting H2A-H2B and facilitating targeted release onto assembling nucleosomes in the nucleus. This nuclear-import function is real but is an extension of the core H2A-H2B chaperone activity rather than the gene's primary function. Reason: Histone H2A-H2B import is an authentic Nap1/Kap114-dependent process, but it is an extension of the core H2A-H2B client-chaperone activity rather than an independent molecular output. Supporting Evidence: file:yeast/NAP1/NAP1-deep-research-falcon.md Nap1 interacts with importin Kap114 and Ran-pathway components to escort H2A-H2B and facilitate targeted release onto assembling nucleosomes/tetrasomes in the nucleus
GO:0042274 ribosomal small subunit biogenesis	IGI PMID:31062022 Tsr4 and Nap1, two novel members of the ribosomal protein ch...	KEEP AS NON CORE	Summary: Nap1 acts as a dedicated chaperone for the small-subunit ribosomal protein Rps6/eS6. Reason: PMID:31062022 supports a real Rps6/eS6 chaperone role that contributes to 40S biogenesis, but this client-specific role is peripheral to Nap1's core H2A-H2B histone-chaperone activity. Supporting Evidence: PMID:31062022 Mutation of the essential Tsr4 and deletion of the non-essential Nap1 both enhance the 40S synthesis defects of the corresponding r-protein mutants.
GO:0051082 unfolded protein binding	IDA PMID:31062022 Tsr4 and Nap1, two novel members of the ribosomal protein ch...	MODIFY	Summary: The IDA supporting this term comes from PMID:31062022, which identifies Nap1 as a dedicated chaperone for the ribosomal protein Rps6/eS6, promoting its solubility in vitro - not for H2A-H2B. 'Unfolded protein binding' is a defensible generic description of that r-protein chaperoning activity, so the term is retained, but it is peripheral to Nap1's core H2A-H2B histone chaperone function (GO:0000511, GO:0042393), which is independently supported by PMID:39601790 and PMID:27225933. Re-terming this specific annotation to GO:0000511 would misattribute Rps6-chaperone evidence to the histone chaperone function. Reason: GO:0051082 is obsolete and GOA has withdrawn this exact row; the live PMID:31062022 evidence now supports a GO:0044183 protein folding chaperone row for Nap1's peripheral Rps6/eS6 client activity. Proposed replacements: protein folding chaperone Supporting Evidence: PMID:31062022 We report the identification of Nap1 and Tsr4 as direct binding partners of Rps6 and Rps2, respectively. Both factors promote the solubility of their r-protein clients in vitro. PMID:31062022 Nap1 interacts with a large, mostly eukaryote-specific binding surface of Rps6
GO:0005737 cytoplasm	IDA PMID:30341817 Septin-associated proteins Aim44 and Nis1 traffic between th...	ACCEPT	Summary: Manual review: cytoplasm is the predominant steady-state localization of NAP1 and the principal site of its core H2A-H2B chaperone activity. Reason: Accepted as core, consistent with the other cytoplasm annotations; the cytoplasm is the predominant steady-state localization where Nap1 carries out its core H2A-H2B chaperone activity. Supporting Evidence: file:yeast/NAP1/NAP1-deep-research-falcon.md Nap1 is described as the principal cytosolic H2A–H2B chaperone that is mostly cytoplasmic but also functions in the nucleus (implying nucleocytoplasmic shuttling)
GO:0032174 cellular bud neck septin collar	IDA PMID:30341817 Septin-associated proteins Aim44 and Nis1 traffic between th...	KEEP AS NON CORE	Summary: PMID:30341817 showed that endogenous Nap1-mNG can localize to the bud-neck septin collar. Reason: Septin-collar localization is experimentally supported and consistent with Nap1's peripheral Aim44/Nba1/Nis1 and Gin4 bud-neck context, but this location is not the primary H2A-H2B chaperone site. Supporting Evidence: PMID:30341817 Nap1‐mNG displayed a diffuse cytoplasmic pattern and was only found prominently at the bud neck in ≤25% of the cells
GO:0032153 cell division site	IDA PMID:25416945 A memory system of negative polarity cues prevents replicati...	KEEP AS NON CORE	Summary: SGD cell-division-site localization is consistent with Nap1's peripheral bud-neck/cytokinesis-remnant complex context. Reason: The cached PMID:25416945 abstract does not expose the exact Nap1 assay SGD curated, so this row is retained by deference to SGD full-text curation and supported by later full-text evidence placing Nap1 in the Aim44/Nba1/Nis1 bud-neck system. Supporting Evidence: PMID:30341817 This complex reportedly contains Aim44/Gps1 (758 residues), Nba1 (501 residues), Nap1 (417 residues) and Nis1 (407 residues).
GO:0098841 protein localization to cell division site after cytokinesis	IMP PMID:25416945 A memory system of negative polarity cues prevents replicati...	KEEP AS NON CORE	Summary: The protein-localization row captures a peripheral post-cytokinesis role of the Aim44/Nba1/Nap1/Nis1 system. Reason: The cached PMID:25416945 abstract does not expose the exact Nap1 mutant assay SGD curated, so this row is retained by deference to SGD full-text curation while keeping the post-cytokinesis cell-division-site role non-core. Supporting Evidence: PMID:25416945 We revealed a two-step mechanism of loading the Cdc42 antagonist Nba1 into CRMs to mark these compartments as refractory for a second round of Cdc42 activation.
GO:0006334 nucleosome assembly	IDA PMID:1400414 Functional analysis of nucleosome assembly protein, NAP-1. T...	ACCEPT	Summary: Fujii-Nakata et al. assayed recombinant yeast Nap1 fragments and mapped the intrinsic nucleosome-assembly activity. Reason: This older IDA row is directly supported by in vitro nucleosome-assembly assays on yeast Nap1, and the term matches Nap1's core H2A-H2B deposition activity. Supporting Evidence: PMID:1400414 Various deletion fragments of NAP-1 protein were also produced, and their nucleosome assembly activity was examined by supercoiling assay.
GO:0008047 enzyme activator activity	IDA PMID:22308335 Histone density is maintained during transcription mediated ...	UNDECIDED	Summary: The near-root enzyme activator activity row from the RSC/Nap1 transcription paper cannot be evaluated from the abstract-only cache. Reason: PMID:22308335 links Nap1 to RSC-dependent chromatin transcription in vitro, but the cached abstract does not expose an enzyme-activation assay or distinguish generic enzyme activator activity from the more specific RSC ATPase context curated by SGD from the full text. Supporting Evidence: PMID:22308335 Transcription through a nucleosome in vitro requires the ATPase remodels structure of chromatin (RSC) and the histone chaperone nucleosome assembly protein 1 (NAP1).
GO:0031116 positive regulation of microtubule polymerization	IMP PMID:7622567 NAP1 acts with Clb1 to perform mitotic functions and to supp...	KEEP AS NON CORE	Summary: Kellogg and Murray support a peripheral Nap1 role in Clb-dependent mitotic microtubule regulation. Reason: The abstract explicitly links Nap1 to regulation of microtubule dynamics during mitosis. This Clb-dependent mitotic role is retained as non-core. Supporting Evidence: PMID:7622567 NAP1 plays a role in regulation of microtubule dynamics during mitosis.
GO:0005737 cytoplasm	IDA PMID:7622566 Members of the NAP/SET family of proteins interact specifica...	ACCEPT	Summary: Cytoplasm is the predominant localization of Nap1. Falcon deep research describes Nap1 as the principal cytosolic H2A-H2B chaperone that handles newly synthesized H2A-H2B before nuclear import, implying nucleocytoplasmic shuttling. This is the major site of action even though Nap1 also functions in the nucleus. Reason: Accepted as core. The cytoplasm is the predominant steady-state localization of Nap1 and the principal site of its core H2A-H2B histone-chaperone activity, where Nap1 handles newly synthesized H2A-H2B before nuclear import. Falcon deep research (Fung et al. 2024) describes Nap1 as the principal cytosolic H2A-H2B chaperone that is mostly cytoplasmic, so this IDA localization is elevated from non-core to a core location. Supporting Evidence: file:yeast/NAP1/NAP1-deep-research-falcon.md Nap1 is described as the principal cytosolic H2A–H2B chaperone that is mostly cytoplasmic but also functions in the nucleus (implying nucleocytoplasmic shuttling)
GO:0006334 nucleosome assembly	IDA PMID:2016313 Identification and molecular cloning of yeast homolog of nuc...	ACCEPT	Summary: Ishimi and Kikuchi cloned and characterized yeast NAP1 by nucleosome assembly activity. Reason: This older IDA row is directly supported by purified yeast Nap1 activity equivalent to mammalian NAP-I in an in vitro nucleosome-assembly assay. Supporting Evidence: PMID:2016313 The 60-kDa protein purified from the extracts had an activity equivalent to that of NAP-I from mouse and human cells.
GO:0006337 nucleosome disassembly	IDA PMID:16492771 Chromatin remodeling by nucleosome disassembly in vitro.	ACCEPT	Summary: Nucleosome disassembly via H2A-H2B eviction is a genuine Nap1 activity. Falcon deep research (anchored on Nagae et al. 2023) shows that Nap1 can dismantle an H2A-H2B dimer from a partially unwrapped nucleosome, with its acidic C-terminal flexible tails engaging an otherwise buried histone interface via a 'penetrating fuzzy binding' mechanism; removal is slow from fully wrapped nucleosomes but greatly accelerated by translocase-induced partial DNA unwrapping. Reason: Nap1 can evict H2A-H2B from partially unwrapped nucleosomes, so this nucleosome-disassembly row is a direct manifestation of the same H2A-H2B chaperone activity used in nucleosome assembly. Supporting Evidence: file:yeast/NAP1/NAP1-deep-research-falcon.md Nap1 can also act in H2A–H2B eviction/dismantling, particularly when nucleosomal DNA is partially unwrapped file:yeast/NAP1/NAP1-deep-research-falcon.md Nap1 acidic C-terminal flexible tails can engage an H2A–H2B interface that is normally buried in the nucleosome file:yeast/NAP1/NAP1-deep-research-falcon.md Nap1 can remove H2A–H2B from fully wrapped nucleosomes only slowly at low temperature, but removal is accelerated when DNA is partially unwrapped
GO:0007117 budding cell bud growth	IMP PMID:13680156 Saccharomyces cerevisiae Ats1p interacts with Nap1p, a cytop...	KEEP AS NON CORE	Summary: Nap1 is connected to polar-to-isotropic bud-growth switching through its mitotic Clb2 regulatory role and Ats1 interaction. Reason: PMID:13680156 supports a Nap1 effect on bud morphology and the switch from polar to isotropic bud growth; this mitotic morphogenesis role is peripheral to H2A-H2B histone chaperoning. Supporting Evidence: PMID:13680156 Loss of Nap1p results in a delayed switch from polar to isotropic bud growth.
GO:0030332 cyclin binding	IPI PMID:7622566 Members of the NAP/SET family of proteins interact specifica...	KEEP AS NON CORE	Summary: Nap1 binds the B-type cyclin Clb2, linking its histone-chaperone activity to mitotic regulation and suppression of polar bud growth. Falcon deep research notes these reported functional interactions with mitotic regulators (Clb2 and Gin4). This is a peripheral, organism-specific function rather than the core chaperone activity, so it is retained as non-core. Reason: Clb2 binding is experimentally supported and captures one branch of Nap1's peripheral mitotic regulation, rather than the core H2A-H2B histone-chaperone activity. Supporting Evidence: file:yeast/NAP1/NAP1-deep-research-falcon.md Nap1 physically/functionally interacts with mitotic regulators including Clb2 and Gin4, linking histone-chaperone activity to mitotic functions and suppression of polar bud growth
GO:0032968 positive regulation of transcription elongation by RNA polymerase II	IDA PMID:22308335 Histone density is maintained during transcription mediated ...	KEEP AS NON CORE	Summary: Nap1 supports transcription-coupled chromatin dynamics by managing H2A-H2B during polymerase passage. Falcon deep research shows that partial nucleosome unwrapping by a translocase dramatically facilitates Nap1-mediated H2A-H2B dimer dismantling, consistent with a role in nucleosome disassembly/reassembly cycles linked to transcription. This is a downstream consequence of the core chaperone activity rather than a primary function. Reason: RSC-dependent transcription through chromatin is compatible with Nap1 H2A-H2B eviction and redeposition on transcribed nucleosomes, but this process annotation remains downstream of the histone-chaperone activity. Supporting Evidence: file:yeast/NAP1/NAP1-deep-research-falcon.md partial nucleosome unwrapping by a translocase dramatically facilitates Nap1-mediated H2A–H2B dimer dismantling
GO:0042393 histone binding	IDA PMID:17289584 Chz1, a nuclear chaperone for histone H2AZ.	ACCEPT	Summary: The Chz1 paper supports Nap1 association with unincorporated H2AZ, consistent with broad histone binding. Reason: H2AZ-H2B association is one specific instance of Nap1's broader histone-binding capacity and is compatible with the core H2A-H2B chaperone mechanism. Supporting Evidence: PMID:17289584 the pool of unincorporated histone H2AZ has previously been found in association with Nap1
GO:0042393 histone binding	IDA PMID:21348863 Assembly states of the nucleosome assembly protein 1 (NAP-1)...	ACCEPT	Summary: Noda et al. support NAP-1 histone binding and higher-order NAP-1 assembly in solution. Reason: The row is a broad SGD histone-binding assertion. PMID:21348863 is compatible with Nap1 histone-client binding, and newer direct H2A-H2B evidence independently establishes this as a core Nap1 function. Supporting Evidence: PMID:21348863 Additionally, MS was used to measure the stoichiometry of the interaction between the human NAP-1 dimer and the histone H2A-H2B dimer or H3-H4 tetramer. PMID:23973327 We identify the interaction surface between H2A-H2B and Nap1 and confirm its relevance both in vitro and in vivo.
GO:0000510 H3-H4 histone complex chaperone activity	IDA PMID:21329878 The histone chaperones Nap1 and Vps75 bind histones H3 and H...	KEEP AS NON CORE	Summary: Bowman et al. used PELDOR and protein crosslinking to show that yeast Nap1 binds an H3-H4 tetramer and can deposit tetrameric H3-H4 onto DNA. Reason: H3-H4 histone complex chaperone activity is directly supported for Nap1, but this is retained as non-core because the dominant and repeatedly validated Nap1 substrate is H2A-H2B. Supporting Evidence: PMID:21329878 Using pulsed electron double resonance (PELDOR) measurements and protein crosslinking, we show that two members of this class, Nap1 and Vps75, bind histones in the tetrameric conformation also observed when they are sequestered within the nucleosome.
GO:0000511 H2A-H2B histone complex chaperone activity	IDA PMID:23973327 Chaperone Nap1 shields histone surfaces used in a nucleosome...	ACCEPT	Summary: D'Arcy et al. showed that Nap1 binds H2A-H2B, reduces H2A-H2B conformational sampling, and competes with nucleosomal H2A-H2B interaction surfaces. Reason: The biochemical and in vivo relevance evidence in PMID:23973327 directly supports the core Nap1 H2A-H2B chaperone activity. Supporting Evidence: PMID:23973327 We identify the interaction surface between H2A-H2B and Nap1 and confirm its relevance both in vitro and in vivo. PMID:23973327 The organization of the complex reveals that Nap1 competes with histone-DNA and interhistone interactions observed in the nucleosome, thereby regulating the availability of histones for chromatin assembly.
GO:0005515 protein binding	IPI PMID:10688190 A comprehensive analysis of protein-protein interactions in ...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:10688190 A comprehensive analysis of protein-protein interactions in ...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:11805837 Systematic identification of protein complexes in Saccharomy...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:11805837 Systematic identification of protein complexes in Saccharomy...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:16429126 Proteome survey reveals modularity of the yeast cell machine...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:16429126 Proteome survey reveals modularity of the yeast cell machine...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:16429126 Proteome survey reveals modularity of the yeast cell machine...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:16429126 Proteome survey reveals modularity of the yeast cell machine...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:16429126 Proteome survey reveals modularity of the yeast cell machine...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:18467557 An in vivo map of the yeast protein interactome.	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:18467557 An in vivo map of the yeast protein interactome.	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:18467557 An in vivo map of the yeast protein interactome.	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:18719252 High-quality binary protein interaction map of the yeast int...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:20489023 A global protein kinase and phosphatase interaction network ...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:20489023 A global protein kinase and phosphatase interaction network ...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:20489023 A global protein kinase and phosphatase interaction network ...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:20489023 A global protein kinase and phosphatase interaction network ...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:20489023 A global protein kinase and phosphatase interaction network ...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:21179020 Defining the budding yeast chromatin-associated interactome.	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:25416945 A memory system of negative polarity cues prevents replicati...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:37968396 The social and structural architecture of the yeast protein ...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:37968396 The social and structural architecture of the yeast protein ...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:37968396 The social and structural architecture of the yeast protein ...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:37968396 The social and structural architecture of the yeast protein ...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:37968396 The social and structural architecture of the yeast protein ...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005515 protein binding	IPI PMID:37968396 The social and structural architecture of the yeast protein ...	REMOVE	Summary: The generic IntAct protein-binding row does not define a specific Nap1 molecular activity. Reason: GO:0005515 protein binding is uninformative for Nap1. The functionally meaningful activities and interactions are captured elsewhere as H2A-H2B histone complex chaperone activity, H3-H4 histone complex chaperone activity, histone binding, homodimer formation, cyclin binding, Rps6 carrier activity, or Gin4-complex membership, so this generic interaction-only row should not be retained as a functional GO assertion.
GO:0005634 nucleus	EXP PMID:18086883 Phosphorylation by casein kinase 2 regulates Nap1 localizati...	ACCEPT	Summary: Nap1 is detected in the nucleus, consistent with the nuclear phase of H2A-H2B import and nucleosome assembly; PMID:18086883 showed that CK2 phosphorylation promotes Nap1 nuclear import. Reason: Nucleus is a core Nap1 localization because Nap1 shuttles into the nucleus with histone cargo and acts there in H2A-H2B deposition and chromatin assembly. Supporting Evidence: PMID:18086883 Nap1 can shuttle between the nucleus and cytoplasm, and we also showed that CK2 phosphorylation promotes the import of Nap1 into the nucleus.
GO:0005737 cytoplasm	EXP PMID:18086883 Phosphorylation by casein kinase 2 regulates Nap1 localizati...	ACCEPT	Summary: PMID:18086883 observed wild-type and phosphosite-mutant Nap1-GFP fusions predominantly in the cytoplasm of exponentially growing cells. Reason: Cytoplasm is a core Nap1 localization because Nap1 is predominantly cytoplasmic at steady state and handles H2A-H2B before nuclear import. Supporting Evidence: PMID:18086883 In exponentially growing cells, wild-type and mutant Nap1 GFP fusions were predominantly cytoplasmic and able to localize to the bud neck in G 2 /M cells (Fig. 7A ).
GO:0005935 cellular bud neck	EXP PMID:18086883 Phosphorylation by casein kinase 2 regulates Nap1 localizati...	KEEP AS NON CORE	Summary: PMID:18086883 showed that Nap1-GFP fusions can localize to the bud neck in G2/M cells. Reason: Bud-neck localization is experimentally supported and fits Nap1's peripheral Gin4/septin-associated mitotic role, but it is secondary to the cytoplasmic and nuclear H2A-H2B chaperone cycle. Supporting Evidence: PMID:18086883 In exponentially growing cells, wild-type and mutant Nap1 GFP fusions were predominantly cytoplasmic and able to localize to the bud neck in G 2 /M cells (Fig. 7A ).
GO:0006457 protein folding	IEA GO_REF:0000108	KEEP AS NON CORE	Summary: This BP annotation is an automatic inter-ontology inference from Nap1's experimentally supported GO:0044183 Rps6/eS6 protein folding chaperone row. Reason: The broad protein-folding process is retained as non-core because it reflects Nap1's peripheral ribosomal-protein client activity rather than its core H2A-H2B histone complex chaperone activity.
GO:0030332 cyclin binding	IPI PMID:7622566 Members of the NAP/SET family of proteins interact specifica...	KEEP AS NON CORE	Summary: PMID:7622566 showed that budding-yeast Nap1 interacts with the B-type cyclin Clb2 but not Clb3. Reason: Cyclin binding is a supported peripheral mitotic regulatory interaction, not the core Nap1 H2A-H2B histone-chaperone activity. Supporting Evidence: PMID:7622566 the S. cerevisiae homolog of NAP1 interacts with Clb2 but not with Clb3.
GO:0042255 ribosome assembly	IPI PMID:31062022 Tsr4 and Nap1, two novel members of the ribosomal protein ch...	KEEP AS NON CORE	Summary: PMID:31062022 identifies Nap1 as a binding partner and solubility factor for the small-subunit ribosomal protein Rps6/eS6. Reason: Ribosome assembly is a broad but compatible process annotation for Nap1's Rps6/eS6 chaperone role, and that role is peripheral to Nap1's core H2A-H2B histone complex chaperone activity. Supporting Evidence: PMID:31062022 Dedicated chaperones protect newly synthesized ribosomal proteins (r-proteins) from aggregation and accompany them on their way to assembly into nascent ribosomes. PMID:31062022 We report the identification of Nap1 and Tsr4 as direct binding partners of Rps6 and Rps2, respectively.
GO:0044183 protein folding chaperone	IPI PMID:31062022 Tsr4 and Nap1, two novel members of the ribosomal protein ch...	KEEP AS NON CORE	Summary: PMID:31062022 directly supports a peripheral Nap1 chaperone activity for the ribosomal protein Rps6/eS6. Reason: Protein folding chaperone is a valid but broad molecular-function description of Nap1's Rps6/eS6 client activity; it should not be treated as the gene's core function because Nap1 is primarily an H2A-H2B histone complex chaperone. Supporting Evidence: PMID:31062022 We report the identification of Nap1 and Tsr4 as direct binding partners of Rps6 and Rps2, respectively. Both factors promote the solubility of their r-protein clients in vitro.
GO:1990317 Gin4 complex	IPI PMID:12058072 Cell cycle-dependent assembly of a Gin4-septin complex.	KEEP AS NON CORE	Summary: Mortensen et al. identified Nap1 as a component of the mitotic Gin4 multiprotein complex that also includes Bni5, septins, and multiple Gin4 molecules. Reason: Gin4-complex membership is supported for Nap1's bud-neck and mitotic regulatory role, but it is peripheral to the core H2A-H2B histone-chaperone activity. Supporting Evidence: PMID:12058072 We show that during mitosis Gin4 is assembled into a multiprotein complex that includes Nap1, Bni5, the septins, and at least two molecules of Gin4.

Gene Description

Existing Annotations Review

Core Functions

References

Deep Research

Falcon

SGD

SGD gene description for NAP1 (yeast)

📚 Additional Documentation

Notes

📄 View Raw YAML