title: Molecular dissection of ARP1 regions required for nuclear migration and cell wall integrity checkpoint functions in Saccharomyces cerevisiae.
abstract: The dynactin complex is one of the components required for the regulation of the cell wall integrity checkpoint, which ensures the completion of cell wall remodeling before mitosis. The core of the dynactin complex is a backbone filament composed of monomers of an actin-related protein, Arp1, which is also involved in nuclear migration. To examine the molecular basis for the dual functions of the dynactin core subunit Arp1p in yeast, we constructed 32 mutated arp1 alleles. We assessed the effects of the mutations on cell wall integrity checkpoint and nuclear migration functions and identified four categories of mutants: 1) those showing no change from the wild type; 2) those resulting in a defective cell wall integrity checkpoint but normal nuclear migration; 3) those with a normal cell wall integrity checkpoint but defective nuclear migration; and 4) those defective in both the cell wall integrity checkpoint and nuclear migration functions. Our results show a separation of the two functions in the molecular structure of Arp1p and indicate that a local surface region of Arp1p is important in maintaining the cell wall integrity checkpoint function.
authors.affiliation: Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba 277-8562, Japan.
authors.forename: Ryoji
authors.initials: R
authors.lastname: Igarashi
authors.forename: Masaya
authors.initials: M
authors.lastname: Suzuki
authors.forename: Satoru
authors.initials: S
authors.lastname: Nogami
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Ohya
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D002467:Cell Nucleus / Q000502:physiology*; D002473:Cell Wall / Q000378:metabolism* / Q000648:ultrastructure; D003598:Cytoskeletal Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D000072159:Dynactin Complex; D004398:Dyneins / Q000378:metabolism; D016195:G2 Phase / Q000502:physiology; D018816:Genes, cdc; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D046912:Multiprotein Complexes; D016297:Mutagenesis, Site-Directed; D017354:Point Mutation; D011487:Protein Conformation; D025941:Protein Interaction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D013329:Structure-Activity Relationship; D047071:beta-Glucans / Q000378:metabolism
chemical_list: C089021:ARP1 protein, S cerevisiae; D003598:Cytoskeletal Proteins; D000072159:Dynactin Complex; D008869:Microtubule-Associated Proteins; D046912:Multiprotein Complexes; D029701:Saccharomyces cerevisiae Proteins; D047071:beta-Glucans; C033363:beta-1,3-glucan; D004398:Dyneins