title: Yeast high mobility group protein HMO1 stabilizes chromatin and is evicted during repair of DNA double strand breaks.
abstract: DNA is packaged into condensed chromatin fibers by association with histones and architectural proteins such as high mobility group (HMGB) proteins. However, this DNA packaging reduces accessibility of enzymes that act on DNA, such as proteins that process DNA after double strand breaks (DSBs). Chromatin remodeling overcomes this barrier. We show here that the Saccharomyces cerevisiae HMGB protein HMO1 stabilizes chromatin as evidenced by faster chromatin remodeling in its absence. HMO1 was evicted along with core histones during repair of DSBs, and chromatin remodeling events such as histone H2A phosphorylation and H3 eviction were faster in absence of HMO1. The facilitated chromatin remodeling in turn correlated with more efficient DNA resection and recruitment of repair proteins; for example, inward translocation of the DNA-end-binding protein Ku was faster in absence of HMO1. This chromatin stabilization requires the lysine-rich C-terminal extension of HMO1 as truncation of the HMO1 C-terminal tail phenocopies hmo1 deletion. Since this is reminiscent of the need for the basic C-terminal domain of mammalian histone H1 in chromatin compaction, we speculate that HMO1 promotes chromatin stability by DNA bending and compaction imposed by its lysine-rich domain and that it must be evicted along with core histones for efficient DSB repair.
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA.
authors.forename: Arvind
authors.initials: A
authors.lastname: Panday
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA.
authors.forename: LiJuan
authors.initials: L
authors.lastname: Xiao
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA agrove@lsu.edu.
authors.forename: Anne
authors.identifier: http://orcid.org/0000-0002-4390-0354
authors.initials: A
authors.lastname: Grove
mesh_terms: D034961:Antigens, Nuclear / Q000378:metabolism; D002843:Chromatin / Q000378:metabolism*; D042002:Chromatin Assembly and Disassembly; D053903:DNA Breaks, Double-Stranded; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000378:metabolism; D017353:Gene Deletion; D056426:Genetic Loci; D006609:High Mobility Group Proteins / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D006657:Histones / Q000378:metabolism; D000072200:Ku Autoantigen; D010766:Phosphorylation; D051135:Rad51 Recombinase / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D017384:Sequence Deletion
chemical_list: D034961:Antigens, Nuclear; D002843:Chromatin; D004268:DNA-Binding Proteins; C103154:HMO1 protein, S cerevisiae; D006609:High Mobility Group Proteins; D006657:Histones; D029701:Saccharomyces cerevisiae Proteins; C495151:RAD51 protein, S cerevisiae; D051135:Rad51 Recombinase; D000072200:Ku Autoantigen