Bet1p activates the v-SNARE Bos1p.
Bet1p is a type II membrane protein that is required for vesicular transport between the endoplasmic reticulum and Golgi complex in the yeast Saccharomyces cerevisiae. A domain of Bet1p, that shows potential to be involved in a coiled-coil interaction, is homologous to a region of the neuronal protein SNAP-25. Here, we used in vitro binding studies to demonstrate that Bet1p plays a role in potentiating soluble NSF attachment protein receptor (SNARE) interactions. Mutational analysis points to the coiled-coil region as necessary for Bet1p function, and circular dichroism experiments support this theory. In vitro binding studies were also used to demonstrate that a direct interaction between Bet1p and Bos1p is required for the efficient interaction of the vesicle SNARE with its SNARE target. Genetic studies suggest that the interactions of Bet1p with Bos1p are regulated by the small GTP-binding protein Ypt1p.
Stone
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S
Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut 06510, USA.
Sacher
M
M
Mao
Y
Y
Carr
C
C
Lyons
P
P
Quinn
A M
AM
Ferro-Novick
S
S
D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006224:Cricetinae; D004357:Drug Synergism; D005656:Fungal Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000502:physiology*; D006801:Humans; D008565:Membrane Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000235:genetics; D017433:Protein Structure, Secondary; D050766:Qb-SNARE Proteins; D050767:Qc-SNARE Proteins; D050600:SNARE Proteins; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D050825:Synaptosomal-Associated Protein 25; D033921:Vesicular Transport Proteins
C107845:BET1 protein, S cerevisiae; C068037:BOS1 protein, S cerevisiae; D002352:Carrier Proteins; D005656:Fungal Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D050766:Qb-SNARE Proteins; D050767:Qc-SNARE Proteins; C494208:SNAP25 protein, human; D050600:SNARE Proteins; D029701:Saccharomyces cerevisiae Proteins; D050825:Synaptosomal-Associated Protein 25; D033921:Vesicular Transport Proteins