title: end5, end6, and end7: mutations that cause actin delocalization and block the internalization step of endocytosis in Saccharomyces cerevisiae.
abstract: Four mutants defective in endocytosis were isolated by screening a collection of temperature-sensitive yeast mutants. Three mutations define new END genes: end5-1, end6-1, and end7-1. The fourth mutation is in END4, a gene identified previously. The end5-1, end6-1, and end7-1 mutations do not affect vacuolar protein localization, indicating that the defect in each mutant is specific for internalization at the plasma membrane. Interestingly, localization of actin patches on the plasma membrane is affected in each of the mutants. end5-1, end6-1, and end7-1 are allelic to VRP1, RVS161, and ACT1, respectively. VRP1 and RVS161 are required for correct actin localization and ACT1 encodes actin. To our surprise, the end6-1 mutation fails to complement the act1-1 mutation. Disruption of the RVS167 gene, which is homologous to END6/RVS161 and which is also required for correct actin localization, also blocks endocytosis. The end7-1 mutant allele has a glycine 48 to aspartic acid substitution in the DNase I-binding loop of actin. We propose that Vrp1p, Rvs161p, and Rvs167p are components of a cytoskeletal structure that contains actin and fimbrin and that is required for formation of endocytic vesicles at the plasma membrane.
authors.affiliation: Department of Biochemistry, Biozentrum of the University of Basel, Switzerland.
authors.forename: A L
authors.initials: AL
authors.lastname: Munn
authors.forename: B J
authors.initials: BJ
authors.lastname: Stevenson
authors.forename: M I
authors.initials: MI
authors.lastname: Geli
authors.forename: H
authors.initials: H
authors.lastname: Riezman
mesh_terms: D000199:Actins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D000483:Alleles; D000595:Amino Acid Sequence; D001483:Base Sequence; D001692:Biological Transport; D002874:Chromosome Mapping; D015825:Chromosomes, Fungal; D003433:Crosses, Genetic; D003598:Cytoskeletal Proteins; D017931:DNA Primers; D004705:Endocytosis / Q000235:genetics / Q000502:physiology; D005656:Fungal Proteins / Q000096:biosynthesis* / Q000235:genetics; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D008040:Genetic Linkage; D005838:Genotype; D007700:Kinetics; D000072235:Mating Factor; D008840:Microfilament Proteins; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016296:Mutagenesis; D010455:Peptides / Q000378:metabolism*; D010675:Pheromones / Q000378:metabolism; D010957:Plasmids; D016133:Polymerase Chain Reaction; D017433:Protein Structure, Secondary; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins; D013696:Temperature
chemical_list: D000199:Actins; D003598:Cytoskeletal Proteins; D017931:DNA Primers; D005656:Fungal Proteins; D008840:Microfilament Proteins; D010455:Peptides; D010675:Pheromones; C089181:RVS161 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C090350:VRP1 protein, S cerevisiae; D000072235:Mating Factor