ROLE OF VESICLE-ASSOCIATED SYNTAXIN-5 IN THE ASSEMBLY OF PRE-GOLGI INTERMEDIATES

Syntaxins are thought to function during vesicular transport as recept ors on the target membrane and to contribute to the specificity of mem brane docking and fusion by interacting with vesicle-associated recept ors. Here, syntaxin 5 (Syn5) was shown to be an integral component of endoplasmic reticulum-derived transport vesicles. This pool, but not t he target, Golgi-associated Syn5 pool, was essential for the assembly of vesicular-tubular pre-Golgi intermediates and the delivery of cargo to the Golgi. The requirement for vesicle-associated Syn5 in transpor t suggests a reevaluation of the basis for operation of the early secr etory pathway.