QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online June 23, 2005
doi: 10.1242/10.1242/jcs.02405

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wassmer, T. Articles by Cohen, J. Search for Related Content PubMed PubMed Citation Articles by Wassmer, T. Articles by Cohen, J. Social Bookmarking                         What's this?

The vacuolar proton-ATPase plays a major role in several membrane-bounded organelles in Paramecium

¹ Centre National de la Recherche Scientifique, Centre de Génétique Moleculaire, Avenue de la Terasse, Bâtiment 26, F-91198 Gif-sur-Yvette cedex, France
² Universität Konstanz, Fachbereich Biologie, Universitätsstraße 10, 78457 Konstanz, Germany

^* Author for correspondence (e-mail: thomas.wassmer{at}uni-konstanz.de)

Accepted 23 March 2005

The vacuolar proton-ATPase (V-ATPase) is a multisubunit enzyme complex that is able to transfer protons over membranes against an electrochemical potential under ATP hydrolysis. The enzyme consists of two subcomplexes: V₀, which is membrane embedded; and V₁, which is cytosolic. V₀ was also reported to be involved in fusion of vacuoles in yeast. We identified six genes encoding c-subunits (proteolipids) of V₀ and two genes encoding F-subunits of V₁ and studied the role of the V-ATPase in trafficking in Paramecium. Green fluorescent protein (GFP) fusion proteins allowed a clear subcellular localization of c- and F-subunits in the contractile vacuole complex of the osmoregulatory system and in food vacuoles. Several other organelles were also detected, in particular dense core secretory granules (trichocysts). The functional significance of the V-ATPase in Paramecium was investigated by RNA interference (RNAi), using a recently developed feeding method. A novel strategy was used to block the expression of all six c- or both F-subunits simultaneously. The V-ATPase was found to be crucial for osmoregulation, the phagocytotic pathway and the biogenesis of dense core secretory granules. No evidence was found supporting participation of V₀ in membrane fusion.

Key words: V-ATPase, RNAi, Contractile vacuole, Phagosome, Trichocyst

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				C. Schilde, K. Lutter, R. Kissmehl, and H. Plattner Molecular Identification of a SNAP-25-Like SNARE Protein in Paramecium Eukaryot. Cell, August 1, 2008; 7(8): 1387 - 1402. [Abstract] [Full Text] [PDF]

				E.-M. Ladenburger, I. Korn, N. Kasielke, T. Wassmer, and H. Plattner An Ins(1,4,5)P3 receptor in Paramecium is associated with the osmoregulatory system J. Cell Sci., September 1, 2006; 119(17): 3705 - 3717. [Abstract] [Full Text] [PDF]

				T. Wassmer, R. Kissmehl, J. Cohen, and H. Plattner Seventeen a-Subunit Isoforms of Paramecium V-ATPase Provide High Specialization in Localization and Function Mol. Biol. Cell, February 1, 2006; 17(2): 917 - 930. [Abstract] [Full Text] [PDF]

				D. Gogendeau, A.-M. Keller, A. Yanagi, J. Cohen, and F. Koll Nd6p, a Novel Protein with RCC1-Like Domains Involved in Exocytosis in Paramecium tetraurelia Eukaryot. Cell, December 1, 2005; 4(12): 2129 - 2139. [Abstract] [Full Text] [PDF]