title: A yeast actin-related protein homologous to that in vertebrate dynactin complex is important for spindle orientation and nuclear migration.
abstract: Spindle orientation controls nuclear migration and segregation during mitosis. In yeast, defects in dynein and astral microtubules lead to abnormal spindle orientation and nuclear migration. Dynactin complex is necessary for dynein-mediated vesicle motility in vitro. The major polypeptide of dynactin complex is an actin-related protein in the family Arp1. We have identified in S. cerevisiae a novel actin-related gene, ACT5, in the Arp1 family. An act5 null mutant has defects in spindle orientation and nuclear migration, as does overexpression of Act5p. The phenotype of a double mutant lacking dynein and Act5p is similar to that of single mutants. Therefore, dynactin complex is in the same pathway as dynein and may be necessary for the action of dynein in vivo.
authors.affiliation: Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri 63110.
authors.forename: L
authors.initials: L
authors.lastname: Muhua
authors.forename: T S
authors.initials: TS
authors.lastname: Karpova
authors.forename: J A
authors.initials: JA
authors.lastname: Cooper
mesh_terms: D000199:Actins / Q000235:genetics* / Q000502:physiology; D000595:Amino Acid Sequence; D001483:Base Sequence; D002467:Cell Nucleus / Q000502:physiology; D003598:Cytoskeletal Proteins; D000072159:Dynactin Complex; D004398:Dyneins / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics* / Q000502:physiology; D005800:Genes, Fungal / Q000235:genetics; D008868:Microtubule Proteins / Q000235:genetics*; D008869:Microtubule-Associated Proteins; D008969:Molecular Sequence Data; D009154:Mutation / Q000502:physiology; D010802:Phylogeny; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D008941:Spindle Apparatus / Q000502:physiology*
chemical_list: C089021:ARP1 protein, S cerevisiae; D000199:Actins; D003598:Cytoskeletal Proteins; D000072159:Dynactin Complex; D005656:Fungal Proteins; D008868:Microtubule Proteins; D008869:Microtubule-Associated Proteins; D029701:Saccharomyces cerevisiae Proteins; D004398:Dyneins