Involved in the targeting and/or fusion of transport vesicles to their target membrane (By similarity). Major SNARE protein of synaptic vesicles which mediates fusion of synaptic vesicles to release neurotransmitters. Essential for fast vesicular exocytosis and activity-dependent neurotransmitter release as well as fast endocytosis that mediates rapid reuse of synaptic vesicles (By similarity). Modulates the gating characteristics of the delayed rectifier voltage-dependent potassium channel KCNB1 (By similarity). Part of the SNARE core complex containing SNAP25, VAMP2 and STX1A. This complex binds to CPLX1. Interacts with BVES and STX4 (By similarity). Interacts with VAPA and VAPB. Interacts with WDFY2, PRKCZ and PRKCI. Forms a complex with WDFY2 and PRKCZ (By similarity). Interacts (via N-terminus) with KCNB1 (via N-terminus and C-terminus); stimulates the channel inactivation rate of KCNB1 (By similarity). Interacts with SEPT8; the interaction inhibits interaction of VAMP2 with SYP. Interacts with SYP; the interaction is inhibited by interaction with SEPT8 (By similarity). Interacts with PICALM. Interacts with alpha-synuclein/SNCA (By similarity). Interacts with STX3 (By similarity). Colocalizes with PRKCZ and WDFY2 in intracellular vesicles. Phosphorylated by PRKCZ in vitro and this phosphorylation is increased in the presence of WDFY2. Belongs to the synaptobrevin family.