Involved in the targeting and/or fusion of transport vesicles to their target membrane. Interacts with subunits of the class C core vacuole/endosome tethering (CORVET) complex including VPS11, VCL1, VPS18, VPS33, VPS3 and VPS8. Co-localizes with VPS3. Highly expressed in flowers. Detected in leaves, stems and roots. Belongs to the synaptobrevin family.