Vam3 Background Information The interaction between v-SNAREs on transport vesicles and t-SNAREs on target membranes is required for membrane traffic in eukaryotic cells (1). VAM3 encodes Vam3 with a hydrophobic transmembrane segment at its carboxy terminus (2). The amino-terminus of Vam3 is required for coordination of priming and docking during homotypic vacuole fusion (3). Vam3 is a syntaxin related protein that provides the t-SNARE function in a late step of the vacuolar assembly (2). Furthermore, this multispecificity syntaxin homologue, Vam3, is essential for autophagic and biosynthetic protein transport to the vacuole (4). Vam3 is localized to the vacuole where it mediates delivery of cargoes from both the carboxypeptidase Y and the alkaline phosphatase pathways (5). VAM genes (for vacuolar morphology) mutants have defective vacuolar morphologies and assembly in the yeast Saccharomyces cerevisiae (6).
