title: Vibrio effector protein VopQ inhibits fusion of V-ATPase-containing membranes.
abstract: Vesicle fusion governs many important biological processes, and imbalances in the regulation of membrane fusion can lead to a variety of diseases such as diabetes and neurological disorders. Here we show that the Vibrio parahaemolyticus effector protein VopQ is a potent inhibitor of membrane fusion based on an in vitro yeast vacuole fusion model. Previously, we demonstrated that VopQ binds to the V(o) domain of the conserved V-type H(+)-ATPase (V-ATPase) found on acidic compartments such as the yeast vacuole. VopQ forms a nonspecific, voltage-gated membrane channel of 18 Å resulting in neutralization of these compartments. We now present data showing that VopQ inhibits yeast vacuole fusion. Furthermore, we identified a unique mutation in VopQ that delineates its two functions, deacidification and inhibition of membrane fusion. The use of VopQ as a membrane fusion inhibitor in this manner now provides convincing evidence that vacuole fusion occurs independently of luminal acidification in vitro.
authors.affiliation: Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390; and.
authors.forename: Anju
authors.initials: A
authors.lastname: Sreelatha
authors.affiliation: Departments of Microbiology and.
authors.forename: Terry L
authors.initials: TL
authors.lastname: Bennett
authors.affiliation: Departments of Microbiology and.
authors.forename: Emily M
authors.initials: EM
authors.lastname: Carpinone
authors.affiliation: Departments of Microbiology and.
authors.forename: Kevin M
authors.initials: KM
authors.lastname: O'Brien
authors.affiliation: Departments of Microbiology and.
authors.forename: Kamyron D
authors.initials: KD
authors.lastname: Jordan
authors.affiliation: Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390; and.
authors.forename: Dara L
authors.initials: DL
authors.lastname: Burdette
authors.affiliation: Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390; and.
authors.forename: Kim
authors.initials: K
authors.lastname: Orth
authors.affiliation: Departments of Microbiology and Infectious Diseases, University of Georgia, Athens, GA 30602 vjstarai@uga.edu.
authors.forename: Vincent J
authors.initials: VJ
authors.lastname: Starai
mesh_terms: D000143:Acids / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism*; D004563:Electrochemistry; D006863:Hydrogen-Ion Concentration; D007473:Ion Channels / Q000378:metabolism; D008055:Lipids / Q000737:chemistry; D008561:Membrane Fusion; D050505:Mutant Proteins / Q000378:metabolism; D050600:SNARE Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D025262:Vacuolar Proton-Translocating ATPases / Q000378:metabolism*; D014617:Vacuoles / Q000378:metabolism; D014736:Vibrio parahaemolyticus / Q000378:metabolism*
chemical_list: D000143:Acids; D001426:Bacterial Proteins; D007473:Ion Channels; D008055:Lipids; D050505:Mutant Proteins; D050600:SNARE Proteins; D025262:Vacuolar Proton-Translocating ATPases
keywords: SNARE; Vibrio parahaemolyticus; vesicle fusion; vp1680; yeast vacuole