Sec3 promotes the initial binary t-SNARE complex assembly and membrane fusion

Abstract

Membrane fusion during exocytosis is mediated by interaction between SNARE proteins on vesicles and the cell membrane, but how SNARE complex assembly is initiated remains unknown. Here, the authors show that interaction of Sec3 with Sso2 on the plasma membrane promotes formation of an Sso2–Sec9 complex, an early step in SNARE assembly, likely by inhibiting Sso2 auto-inhibition.