Mutual control of membrane fission and fusion proteins.
Membrane fusion and fission are antagonistic reactions controlled by different proteins. Dynamins promote membrane fission by GTP-driven changes of conformation and polymerization state, while SNAREs fuse membranes by forming complexes between t- and v-SNAREs from apposed vesicles. Here, we describe a role of the dynamin-like GTPase Vps1p in fusion of yeast vacuoles. Vps1p forms polymers that couple several t-SNAREs together. At the onset of fusion, the SNARE-activating ATPase Sec18p/NSF and the t-SNARE depolymerize Vps1p and release it from the membrane. This activity is independent of the SNARE coactivator Sec17p/alpha-SNAP and of the v-SNARE. Vps1p release liberates the t-SNAREs for initiating fusion and at the same time disrupts fission activity. We propose that reciprocal control between fusion and fission components exists, which may prevent futile cycles of fission and fusion.
Peters
Christopher
C
Département de Biochimie, Université de Lausanne, Chemin des Boveresses 155, 1066 Epalinges, Switzerland. christopher.peters@unil.ch
Baars
Tonie L
TL
Bühler
Susanne
S
Mayer
Andreas
A
D000251:Adenosine Triphosphatases / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism; D034281:Dynamins / Q000235:genetics / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000378:metabolism*; D007425:Intracellular Membranes / Q000378:metabolism*; D008561:Membrane Fusion / Q000235:genetics*; D008565:Membrane Proteins / Q000378:metabolism*; D008954:Models, Biological; D015388:Organelles / Q000378:metabolism*; D021381:Protein Transport / Q000502:physiology; D050765:Qa-SNARE Proteins; D050600:SNARE Proteins; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D052067:Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins; D014617:Vacuoles / Q000378:metabolism; D033921:Vesicular Transport Proteins / Q000378:metabolism*
D002352:Carrier Proteins; D008565:Membrane Proteins; D050765:Qa-SNARE Proteins; C075137:SEC17 protein, S cerevisiae; D050600:SNARE Proteins; D029701:Saccharomyces cerevisiae Proteins; D052067:Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins; C107706:VAM3 protein, S cerevisiae; D033921:Vesicular Transport Proteins; D000251:Adenosine Triphosphatases; D019204:GTP-Binding Proteins; C064404:SEC18 protein, S cerevisiae; C064553:VPS1 protein, S cerevisiae; D034281:Dynamins