title: The RabGAP proteins Gyp5p and Gyl1p recruit the BAR domain protein Rvs167p for polarized exocytosis.
abstract: The Rab GTPase-activating proteins (GAP) Gyp5p and Gyl1p are involved in the control of polarized exocytosis at the small-bud stage in Saccharomyces cerevisiae. Both Gyp5p and Gyl1p interact with the N-Bin1/Amphiphysin/Rvs167 (BAR) domain protein Rvs167p, but the biological function of this interaction is unclear. We show here that Gyp5p and Gyl1p recruit Rvs167p to the small-bud tip, where it plays a role in polarized exocytosis. In gyp5Δgyl1Δ cells, Rvs167p is not correctly localized to the small-bud tip. Both P473L mutation in the SH3 domain of Rvs167p and deletion of the proline-rich regions of Gyp5p and Gyl1p disrupt the interaction of Rvs167p with Gyp5p and Gyl1p and impair the localization of Rvs167p to the tips of small buds. We provide evidence for the accumulation of secretory vesicles in small buds of rvs167Δ cells and for defective Bgl2p secretion in rvs167Δ cultures enriched in small-budded cells at 13°C, implicating Rvs167p in polarized exocytosis. Moreover, both the accumulation of secretory vesicles in Rvs167p P473L cells cultured at 13°C and secretion defects in cells producing Gyp5p and Gyl1p without proline-rich regions strongly suggest that the function of Rvs167p in exocytosis depends on its ability to interact with Gyp5p and Gyl1p.
authors.affiliation: Univ Paris-Sud, Institut de Génétique et Microbiologie, CNRS UMR8621, Bâtiment 400, Orsay F-91405, France.
authors.forename: Magali
authors.initials: M
authors.lastname: Prigent
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Boy-Marcotte
authors.forename: Laurent
authors.initials: L
authors.lastname: Chesneau
authors.forename: Kimberley
authors.initials: K
authors.lastname: Gibson
authors.forename: Sophie
authors.initials: S
authors.lastname: Dupré-Crochet
authors.forename: Hélène
authors.initials: H
authors.lastname: Tisserand
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Verbavatz
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Cuif
mesh_terms: D005089:Exocytosis / Q000235:genetics / Q000502:physiology*; D020690:GTPase-Activating Proteins / Q000235:genetics / Q000378:metabolism; D004693:Glucan Endo-1,3-beta-D-Glucosidase / Q000378:metabolism; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000378:metabolism; D011392:Proline / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D022142:Secretory Vesicles / Q000378:metabolism; D020691:rab GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D018909:src Homology Domains
chemical_list: D020690:GTPase-Activating Proteins; C504621:Gyl1 protein, S cerevisiae; C504620:Gyp5 protein, S cerevisiae; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; C082282:RVS167 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C075637:amphiphysin; D011392:Proline; C080389:BGL2 protein, S cerevisiae; D004693:Glucan Endo-1,3-beta-D-Glucosidase; D020691:rab GTP-Binding Proteins