title: The Saccharomyces cerevisiae actin-related protein Arp2 is involved in the actin cytoskeleton.
abstract: Arp2p is an essential yeast actin-related protein. Disruption of the corresponding ARP2 gene leads to a terminal phenotype characterized by the presence of a single large bud. Thus, Arp2p may be important for a late stage of the cell cycle (Schwob, E., and R.P. Martin, 1992. Nature (Lond.). 355:179-182). We have localized Arp2p by indirect immunofluorescence. Specific peptide antibodies revealed punctate staining under the plasma membrane, which partially colocalizes with actin. Temperature-sensitive arp2 mutations were created by PCR mutagenesis and selected by an ade2/SUP11 sectoring screen. One temperature-sensitive mutant that was characterized, arp2-H330L, was osmosensitive and had an altered actin cytoskeleton at a nonpermissive temperature, suggesting a role of Arp2p in the actin cytoskeleton. Random budding patterns were observed in both haploid and diploid arp2-H330L mutant cells. Endocytosis, as judged by Lucifer yellow uptake, was severely reduced in the mutant, at all temperatures. In addition, genetic interaction was observed between temperature-sensitive alleles arp2-H330L and cdc10-1. CDC10 is a gene encoding a neck filament-associated protein that is necessary for polarized growth and cytokinesis. Overall, the immunolocalization, mutant phenotypes, and genetic interaction suggest that the Arp2 protein is an essential component of the actin cytoskeleton that is involved in membrane growth and polarity, as well as in endocytosis.
authors.affiliation: Institut de Biologie Moléculaire et Cellulaire du C.N.R.S. U.P.R. 9005, Strasbourg, France.
authors.forename: V
authors.initials: V
authors.lastname: Moreau
authors.forename: A
authors.initials: A
authors.lastname: Madania
authors.forename: R P
authors.initials: RP
authors.lastname: Martin
authors.forename: B
authors.initials: B
authors.lastname: Winson
mesh_terms: D008841:Actin Cytoskeleton / Q000648:ultrastructure*; D051377:Actin-Related Protein 2; D000199:Actins / Q000502:physiology*; D000595:Amino Acid Sequence; D001483:Base Sequence; D002451:Cell Compartmentation; D018797:Cell Cycle Proteins / Q000502:physiology*; D002455:Cell Division; D003598:Cytoskeletal Proteins; D017931:DNA Primers / Q000737:chemistry; D004705:Endocytosis; D005656:Fungal Proteins / Q000502:physiology*; D020558:GTP Phosphohydrolases; D005816:Genetic Complementation Test; D007158:Immunologic Techniques; D008565:Membrane Proteins; D008840:Microfilament Proteins / Q000502:physiology; D008969:Molecular Sequence Data; D009994:Osmolar Concentration; D010455:Peptides / Q000737:chemistry / Q000276:immunology; D012441:Saccharomyces cerevisiae / Q000648:ultrastructure*; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; D014157:Transcription Factors; D014617:Vacuoles / Q000648:ultrastructure
chemical_list: D051377:Actin-Related Protein 2; D000199:Actins; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; D017931:DNA Primers; D005656:Fungal Proteins; D008565:Membrane Proteins; D008840:Microfilament Proteins; D010455:Peptides; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; D014157:Transcription Factors; C061178:cdc10 protein, S pombe; C512892:CDC10 protein, S cerevisiae; D020558:GTP Phosphohydrolases