NAP family histone chaperone; binds to histones and Rtt109p, stimulating histone acetyltransferase activity; possesses nucleosome assembly activity in vitro; proposed role in vacuolar protein sorting and in double-strand break repair; protein abundance increases in response to DNA replication stress; relocalizes to the cytosol in response to hypoxia
GO Process (3)
GO Function (2)
GO Component (3)
Saccharomyces cerevisiae (S288c)


Transcriptional activator involved in adaptation to weak acid stress; activates transcription of TPO2, YRO2, and other genes encoding membrane stress proteins; HAA1 has a paralog, CUP2, that arose from the whole genome duplication; relocalizes from cytoplasm to nucleus upon DNA replication stress
Saccharomyces cerevisiae (S288c)

Phenotypic Suppression

A genetic interaction is inferred when mutation or over expression of one gene results in suppression of any phenotype (other than lethality/growth defect) associated with mutation or over expression of another gene.


An rtt109-independent role for vps75 in transcription-associated nucleosome dynamics.

Selth LA, Lorch Y, Ocampo-Hafalla MT, Mitter R, Shales M, Krogan NJ, Kornberg RD, Svejstrup JQ

The histone chaperone Vps75 forms a complex with, and stimulates the activity of, the histone acetyltransferase Rtt109. However, Vps75 can also be isolated on its own and might therefore possess Rtt109-independent functions. Analysis of epistatic miniarray profiles showed that VPS75 genetically interacts with factors involved in transcription regulation whereas RTT109 clusters with genes linked to DNA replication/repair. Additional genetic and ... [more]

Mol. Cell. Biol. Aug. 01, 2009; 29(15);4220-34 [Pubmed: 19470761]


  • Low Throughput

Ontology Terms

  • phenotype: resistance to chemicals (APO:0000087)

Additional Notes

  • deletion of Haa1 blocks the resistance to acetic acid coferred by mutation of Vps75 and brings growth rate back to wild type levels in the presence of acetic acid

Curated By

  • BioGRID