Yeast ASF1 protein is required for cell cycle regulation of histone gene transcription.
Transcription of the four yeast histone gene pairs (HTA1-HTB1, HTA2-HTB2, HHT1-HHF1, and HHT2-HHF2) is repressed during G1, G2, and M. For all except HTA2-HTB2, this repression requires several trans-acting factors, including the products of the HIR genes, HIR1, HIR2, and HIR3. ASF1 is a highly conserved protein that has been implicated in transcriptional silencing and chromatin assembly. In this analysis, we show that HIR1 interacts with ASF1 in a two-hybrid analysis. Further, asf1 mutants, like hir mutants, are defective in repression of histone gene transcription during the cell cycle and in cells arrested in early S phase in response to hydroxyurea. asf1 and hir1 mutations also show very similar synergistic interactions with mutations in cac2, a subunit of the yeast chromatin assembly factor CAF-I. The results suggest that ASF1 and HIR1 function in the same pathway to create a repressive chromatin structure in the histone genes during the cell cycle.
Sutton
A
A
Department of Biochemistry and Cell Biology, State University of New York, Stony Brook, NY 11794, USA.
Bucaria
J
J
Osley
M A
MA
Sternglanz
R
R
D015153:Blotting, Western; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000502:physiology*; D002467:Cell Nucleus / Q000378:metabolism; D002469:Cell Separation; D002843:Chromatin / Q000378:metabolism; D056504:Chromatin Assembly Factor-1; D002868:Chromosomal Proteins, Non-Histone; D002872:Chromosome Deletion; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology; D005434:Flow Cytometry; D005656:Fungal Proteins / Q000502:physiology*; D017353:Gene Deletion; D020868:Gene Silencing; D049452:Green Fluorescent Proteins; D006657:Histones / Q000378:metabolism*; D006918:Hydroxyurea / Q000494:pharmacology; D008164:Luminescent Proteins / Q000378:metabolism; D018832:Molecular Chaperones; D009154:Mutation; D010641:Phenotype; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D012313:RNA / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D013997:Time Factors; D014158:Transcription, Genetic; D020798:Two-Hybrid System Techniques
C109731:ASF1 protein, S cerevisiae; D018797:Cell Cycle Proteins; D002843:Chromatin; D056504:Chromatin Assembly Factor-1; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D006657:Histones; D008164:Luminescent Proteins; D018832:Molecular Chaperones; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D049452:Green Fluorescent Proteins; D012313:RNA; D006918:Hydroxyurea