title: Suppressor analysis of a histone defect identifies a new function for the hda1 complex in chromosome segregation.
abstract: Histones are essential for the compaction of DNA into chromatin and therefore participate in all chromosomal functions. Specific mutations in HTA1, one of the two Saccharomyces cerevisiae genes encoding histone H2A, have been previously shown to cause chromosome segregation defects, including an increase in ploidy associated with altered pericentromeric chromatin structure, suggesting a role for histone H2A in kinetochore function. To identify proteins that may interact with histone H2A in the control of ploidy and chromosome segregation, we performed a genetic screen for suppressors of the increase-in-ploidy phenotype associated with one of the H2A mutations. We identified five genes, HHT1, MKS1, HDA1, HDA2, and HDA3, four of which encode proteins directly connected to chromatin function: histone H3 and each of the three subunits of the Hda1 histone deacetylase complex. Our results show that Hda3 has functions distinct from Hda2 and Hda1 and that it is required for normal chromosome segregation and cell cycle progression. In addition, HDA3 shows genetic interactions with kinetochore components, emphasizing a role in centromere function, and all three Hda proteins show association with centromeric DNA. These findings suggest that the Hda1 deacetylase complex affects histone function at the centromere and that Hda3 has a distinctive participation in chromosome segregation. Moreover, these suppressors provide the basis for future studies regarding histone function in chromosome segregation.
authors.affiliation: Department of Biological Sciences, University of Arkansas, Fayetteville 72701, USA.
authors.forename: Hasna
authors.initials: H
authors.lastname: Kanta
authors.forename: Lisa
authors.initials: L
authors.lastname: Laprade
authors.forename: Abeer
authors.initials: A
authors.lastname: Almutairi
authors.forename: Inés
authors.initials: I
authors.lastname: Pinto
mesh_terms: D000483:Alleles; D002453:Cell Cycle / Q000235:genetics; D002843:Chromatin / Q000235:genetics; D020090:Chromosome Segregation / Q000235:genetics*; D015825:Chromosomes, Fungal / Q000235:genetics; D004271:DNA, Fungal / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal / Q000235:genetics; D006655:Histone Deacetylases / Q000378:metabolism*; D006657:Histones / Q000235:genetics* / Q000378:metabolism*; D018386:Kinetochores; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D011003:Ploidies; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D013489:Suppression, Genetic / Q000235:genetics*
chemical_list: D002843:Chromatin; D004271:DNA, Fungal; D005656:Fungal Proteins; D006657:Histones; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; C499673:HDA1 protein, S cerevisiae; D006655:Histone Deacetylases