title: The nuclear actin-related protein Act3p/Arp4 influences yeast cell shape and bulk chromatin organization.
abstract: ACT3/ARP4 is an essential gene, coding for the actin-related protein Act3p/Arp4 of Saccharomyces cerevisiae located within the nucleus. Act3p/Arp4 is a stoichiometric component of the NuA4, INO80, and SWR1 chromatin modulating complexes, and recruits these complexes onto chromatin for their proper chromatin functions. Mutated Act3p/Arp4 leads to impairment of the functions of these complexes and affects transcription of specific genes. Our results revealed significant disorder in the cell size and shape of act3/arp4 mutant cells, when grown at permissive temperature. act3/arp4 mutants have also demonstrated an increase in their nuclear diameters, thus suggesting that Act3p/Arp4 is a key regulator in the maintenance of cellular shape and nuclear organization. Furthermore, the use of Chromatin Yeast Comet Assay (ChYCA) for assessment of single-cell bulk chromatin organization in act3/arp4 mutant cells allowed us to detect an elevated sensitivity toward nuclease action, denoting differences in higher-order chromatin structure of the mutants.
authors.affiliation: Laboratory of Yeast Molecular Genetics, Institute of Molecular Biology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria. miloshev@obzor.bio21.bas.bg
authors.forename: Milena
authors.initials: M
authors.lastname: Georgieva
authors.forename: Masahiko
authors.initials: M
authors.lastname: Harata
authors.forename: George
authors.initials: G
authors.lastname: Miloshev
mesh_terms: D051378:Actin-Related Protein 3 / Q000502:physiology*; D000199:Actins / Q000502:physiology*; D002467:Cell Nucleus; D002843:Chromatin / Q000648:ultrastructure*; D009154:Mutation; D009687:Nuclear Proteins / Q000502:physiology*; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000502:physiology*
chemical_list: C102245:ARP3 protein, S cerevisiae; D051378:Actin-Related Protein 3; D000199:Actins; C088827:Arp4 protein, S cerevisiae; D002843:Chromatin; D009687:Nuclear Proteins; D029701:Saccharomyces cerevisiae Proteins