title: Histone H2A.Z acid patch residues required for deposition and function.
abstract: The incorporation of histone variants is one mechanism used by the eukaryotic cell to alter the generally repressive chromatin template. However, the exact molecular mechanisms that direct this incorporation are not well understood. The SWR1 chromatin remodeling complex that binds to and directs incorporation of histone variant H2A.Z into chromatin has been characterized, but significantly less information is available concerning the requirements on the H2A.Z target molecule. We performed an unbiased mutagenic screen designed to elucidate the function of H2A.Z in Saccharomyces cerevisiae. The screen identified residues within the conserved acidic patch of H2A.Z as being important for the function of the variant. We characterized single point mutations in the patch that are phenotypically sensitive to a variety of growth conditions and are expressed at lower protein levels, but are functionally defective (htz1-D99A, htz1-D99K, and htz1-E101K). The mutants were significantly less detectable by chromatin immunoprecipitation at PHO5, a gene previously described to be enriched for H2A.Z. These results identify acidic patch residues of H2A.Z that are critical for mediating deposition and function in chromatin, and represent potential candidates for the interaction of H2A.Z with its deposition and/or targeting machinery.
authors.affiliation: Department of Microbiology, University of Virginia Health System, University of Virginia, P.O. Box 800734, Charlottesville, VA 22908-0734, USA. kurt.jensen@neurology.ufl.edu
authors.forename: Kurt
authors.initials: K
authors.lastname: Jensen
authors.forename: Maria Soledad
authors.initials: MS
authors.lastname: Santisteban
authors.forename: Craig
authors.initials: C
authors.lastname: Urekar
authors.forename: M Mitchell
authors.initials: MM
authors.lastname: Smith
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism; D000483:Alleles; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution / Q000235:genetics; D000596:Amino Acids / Q000378:metabolism*; D047369:Chromatin Immunoprecipitation; D017124:Conserved Sequence / Q000235:genetics; D018628:Gene Dosage / Q000235:genetics; D005820:Genetic Testing; D006657:Histones / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D009707:Nucleosomes / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D013329:Structure-Activity Relationship
chemical_list: D000596:Amino Acids; D006657:Histones; C493530:Htz1 protein, S cerevisiae; D050505:Mutant Proteins; D009707:Nucleosomes; D029701:Saccharomyces cerevisiae Proteins; D000135:Acid Phosphatase; C488916:PHO5 protein, S cerevisiae