Ypt1p implicated in v-SNARE activation.
Synaptobrevin-like membrane proteins that reside on transport vesicles, called the vesicle SNARE (v-SNARE), play a key role in ensuring that a vesicle targets and fuses with its correct acceptor compartment. Here we show that Bos1p, the v-SNARE of yeast endoplasmic reticulum-to-Golgi transport vesicles, pairs with another integral membrane protein of similar topology (Sec22p) on vesicles. This pairing, which appears to require functional Ypt1p (Rab in mammalian cells), may aid the activity of Bos1p on this compartment. These findings suggest that Rabs regulate the specificity of membrane fusion by selectively activating the v-SNARE on carrier vesicles. Because the v-SNARE resides on more than one membrane, such a regulated activation step may be necessary to prevent the premature fusion of donor and acceptor compartments.
Lian
J P
JP
Department of Cell Biology, Yale University Medical School, New Haven, Connecticut 06510.
Stone
S
S
Jiang
Y
Y
Lyons
P
P
Ferro-Novick
S
S
D001692:Biological Transport; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000378:metabolism*; D005800:Genes, Fungal; D006056:Golgi Apparatus / Q000378:metabolism; D007425:Intracellular Membranes / Q000378:metabolism*; D008561:Membrane Fusion; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D015388:Organelles / Q000378:metabolism*; D050766:Qb-SNARE Proteins; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins; D020691:rab GTP-Binding Proteins
C068037:BOS1 protein, S cerevisiae; D005656:Fungal Proteins; D008565:Membrane Proteins; D050766:Qb-SNARE Proteins; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins; D019204:GTP-Binding Proteins; C060755:YPT1 protein, S cerevisiae; D020691:rab GTP-Binding Proteins