The synaptobrevin-related domains of Bos1p and Sec22p bind to the syntaxin-like region of Sed5p.
SNAREs (soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptors) are cytoplasmically oriented membrane proteins that reside on vesicular carriers (v-SNARE) and target organelles (t-SNARE). The pairing of a stage-specific v-SNARE with its cognate t-SNARE may mediate the specificity of membrane traffic. In the yeast Saccharomyces cerevisiae transport between the endoplasmic reticulum and Golgi complex employs two v-SNAREs, Bos1p and Sec22p, each containing a domain that is related to the neuronal v-SNARE synaptobrevin. Sed5p, which is homologous to syntaxin, is the t-SNARE that functions at this stage of the secretory pathway. Here we report that regions of Bos1p and Sec22p, which are homologous to synaptobrevin, bind to the syntaxin-like domain of Sed5p. Furthermore, we demonstrate that efficient v-SNARE/t-SNARE interactions require the participation of both v-SNAREs, indicating that, unlike post-Golgi membrane traffic, the active form of the endoplasmic reticulum to Golgi v-SNARE is a heteromeric complex.
Sacher
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M
Howard Hughes Medical Institute and the Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06510, USA.
Stone
S
S
Ferro-Novick
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S
D001665:Binding Sites; D001692:Biological Transport; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D050765:Qa-SNARE Proteins; D050766:Qb-SNARE Proteins; D050683:R-SNARE Proteins; D011956:Receptors, Cell Surface / Q000378:metabolism*; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D017384:Sequence Deletion; D033921:Vesicular Transport Proteins
C068037:BOS1 protein, S cerevisiae; D005656:Fungal Proteins; D008565:Membrane Proteins; D050765:Qa-SNARE Proteins; D050766:Qb-SNARE Proteins; D050683:R-SNARE Proteins; D011956:Receptors, Cell Surface; D029701:Saccharomyces cerevisiae Proteins; C106909:Sec22 protein, S cerevisiae; C077554:Sed5 protein, S cerevisiae; D033921:Vesicular Transport Proteins