NAP1 / YKR048C Overview

Standard Name
NAP1 1
Systematic Name
Feature Type
ORF , Verified
Histone chaperone and assembly chaperone for Rps6a/b; involved in histone exchange, replacing histone H2A-H2B dimers or histone variant dimers from assembled nucleosomes; promotes solubility of Rps6a, and 40S ribosomal subunit biogenesis; role in transport of H2A and H2B histones to the nucleus; regulates microtubule dynamics during mitosis; interacts with mitotic cyclin Clb2p; controls bud morphogenesis; phosphorylated by CK2; protein abundance increases in response to DNA replication stress 2 3 4 5 6 7 8
Name Description
Nucleosome Assembly Protein 1
Comparative Info
Sequence Details


The S. cerevisiae Reference Genome sequence is derived from laboratory strain S288C. Download DNA or protein sequence, view genomic context and coordinates. Click "Sequence Details" to view all sequence information for this locus, including that for other strains.

Protein Details


Basic sequence-derived (length, molecular weight, isoelectric point) and experimentally-determined (median abundance, median absolute deviation) protein information. Click "Protein Details" for further information about the protein such as half-life, abundance, domains, domains shared with other proteins, protein sequence retrieval for various strains, physico-chemical properties, protein modification sites, and external identifiers for the protein.

Phosphorylated by CK2; protein abundance increases in response to DNA replication stress
Length (a.a.)
Mol. Weight (Da)
Isoelectric Point
Median Abundance (molecules/cell)
12358 +/- 4247
Half-life (hr)


Curated mutant alleles for the specified gene, listed alphabetically. Click on the allele name to open the allele page. Click "SGD search" to view all alleles in search results. Click "YeastMine" to view all alleles in YeastMine.

View all NAP1 alleles in SGD search | YeastMine

Gene Ontology Details

Gene Ontology

GO Annotations consist of four mandatory components: a gene product, a term from one of the three Gene Ontology (GO) controlled vocabularies (Molecular Function, Biological Process, and Cellular Component), a reference, and an evidence code. SGD has manually curated and high-throughput GO Annotations, both derived from the literature, as well as computational, or predicted, annotations. Click "Gene Ontology Details" to view all GO information and evidence for this locus as well as biological processes it shares with other genes.

Histone-binding protein that stimulates the RSC chromatin remodeling complex; assembly chaperone for ribosomal protein, Rps6a/b; cyclin-binding protein; involved in nucleosome assembly and disassembly, ribosomal small subunit biogenesis, bud growth, and NLS-containing nuclear import of histones; positively regulates microtubule polymerization and transcription elongation; localizes to the cytoplasm, the cell division site and the bud neck septin collar between S phase and late anaphase

View computational annotations

Molecular Function

Manually Curated

Cellular Component

Manually Curated


Macromolecular complex annotations are imported from the Complex Portal. These annotations have been derived from physical molecular interaction evidence extracted from the literature and cross-referenced in the entry, or by curator inference from information on homologs in closely related species or by inference from scientific background.

Phenotype Details


Phenotype annotations for a gene are curated single mutant phenotypes that require an observable (e.g., "cell shape"), a qualifier (e.g., "abnormal"), a mutant type (e.g., null), strain background, and a reference. In addition, annotations are classified as classical genetics or high-throughput (e.g., large scale survey, systematic mutation set). Whenever possible, allele information and additional details are provided. Click "Phenotype Details" to view all phenotype annotations and evidence for this locus as well as phenotypes it shares with other genes.

Non-essential gene; null mutation decreases nuclear import of histones H2A and H2B, and causes elongated buds, increased resistance to benomyl and acetate, but increased sensitivity to rapamycin; in systematic studies null mutants show increased biofilm formation, sensitivity to Calcofluor White and DMSO, and decreased anaerobic growth
Interaction Details


Interaction annotations are curated by BioGRID and include physical or genetic interactions observed between at least two genes. An interaction annotation is composed of the interaction type, name of the interactor, assay type (e.g., Two-Hybrid), annotation type (e.g., manual or high-throughput), and a reference, as well as other experimental details. Click "Interaction Details" to view all interaction annotations and evidence for this locus, including an interaction visualization.

797 total interactions for 470 unique genes

Physical Interactions

  • Affinity Capture-MS: 198
  • Affinity Capture-RNA: 5
  • Affinity Capture-Western: 65
  • Biochemical Activity: 12
  • Co-crystal Structure: 3
  • Co-purification: 1
  • FRET: 2
  • PCA: 14
  • Proximity Label-MS: 2
  • Reconstituted Complex: 25
  • Two-hybrid: 29

Genetic Interactions

  • Dosage Growth Defect: 2
  • Negative Genetic: 328
  • Phenotypic Enhancement: 13
  • Phenotypic Suppression: 4
  • Positive Genetic: 62
  • Synthetic Growth Defect: 21
  • Synthetic Lethality: 4
  • Synthetic Rescue: 7
Regulation Details


The number of putative Regulators (genes that regulate it) and Targets (genes it regulates) for the given locus, based on experimental evidence. This evidence includes data generated through high-throughput techniques. Click "Regulation Details" to view all regulation annotations, shared GO enrichment among regulation Targets, and a regulator/target diagram for the locus.

Expression Details


Expression data are derived from records contained in the Gene Expression Omnibus (GEO), and are first log2 transformed and normalized. Referenced datasets may contain one or more condition(s), and as a result there may be a greater number of conditions than datasets represented in a single clickable histogram bar. The histogram division at 0.0 separates the down-regulated (green) conditions and datasets from those that are up-regulated (red). Click "Expression Details" to view all expression annotations and details for this locus, including a visualization of genes that share a similar expression pattern.

Literature Details


All manually curated literature for the specified gene, organized into topics according to their relevance to the gene (Primary Literature, Additional Literature, or Review). Click "Literature Details" to view all literature information for this locus, including shared literature between genes.