Required for vesicular transport between the endoplasmic reticulum and the Golgi apparatus. Together with GNA12 promotes CDH5 localization to plasma membrane. Interacts with PRKCABP, and disrupts the interaction between GRIA2 and PRKCABP, leading to the internalization of GRIA2 (PubMed:11931741). Found in a complex with VAMP8 (PubMed:9614193). Component of a SNARE-like complex that contains at least ZW10, USE1L, RINT1, STX18 and NAPA/SNAP-alpha (By similarity). Interacts with VTI1A (By similarity). Interacts with STX12 (PubMed:9507000). Interacts with GNA12 (via N-terminus); the interaction promotes CDH5 localization to plasma membrane (By similarity). Belongs to the SNAP family.