Characterization of the yeast amphiphysins Rvs161p and Rvs167p reveals roles for the Rvs heterodimer in vivo.
We have used comprehensive synthetic lethal screens and biochemical assays to examine the biological role of the yeast amphiphysin homologues Rvs161p and Rvs167p, two proteins that play a role in regulation of the actin cytoskeleton, endocytosis, and sporulation. We found that unlike some forms of amphiphysin, Rvs161p-Rvs167p acts as an obligate heterodimer during vegetative growth and neither Rvs161p nor Rvs167p forms a homodimer in vivo. RVS161 and RVS167 have an identical set of 49 synthetic lethal interactions, revealing functions for the Rvs proteins in cell polarity, cell wall synthesis, and vesicle trafficking as well as a shared role in mating. Consistent with these roles, we show that the Rvs167p-Rvs161p heterodimer, like its amphiphysin homologues, can bind to phospholipid membranes in vitro, suggesting a role in vesicle formation and/or fusion. Our genetic screens also reveal that the interaction between Abp1p and the Rvs167p Src homology 3 (SH3) domain may be important under certain conditions, providing the first genetic evidence for a role for the SH3 domain of Rvs167p. Our studies implicate heterodimerization of amphiphysin family proteins in various functions related to cell polarity, cell integrity, and vesicle trafficking during vegetative growth and the mating response.
Friesen
Helena
H
Department of Medical Genetics and Microbiology, Banting and Best Department of Medical Research, University of Toronto, Toronto, Ontario, Canada M5S 1A8.
Humphries
Christine
C
Ho
Yuen
Y
Schub
Oliver
O
Colwill
Karen
K
Andrews
Brenda
B
D000199:Actins / Q000378:metabolism; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism; D002417:Cattle; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002686:Chitin / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000737:chemistry* / Q000378:metabolism*; D019281:Dimerization; D004171:Diploidy; D017353:Gene Deletion; D049770:Genes, Mating Type, Fungal; D005816:Genetic Complementation Test; D007313:Insecta; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000378:metabolism*; D010675:Pheromones / Q000494:pharmacology; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000378:metabolism*; D013816:Thermodynamics; D018909:src Homology Domains
D000199:Actins; D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; D010675:Pheromones; C089181:RVS161 protein, S cerevisiae; C082282:RVS167 protein, S cerevisiae; C082265:SLA1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D002686:Chitin; C075637:amphiphysin