Component of the vacuolar transporter chaperone (VTC) complex, which plays a role in vacuolar membrane fusion. Required for SEC18/NSF activity in SNARE priming, membrane binding of LMA1 and V(0) trans-complex formation. The VTC complex is an integral membrane heterooligomer composed of VTC1, VTC2, VTC3 and VTC4. The complex interacts with the v-SNARE NYV1 and with the V(0) subunit of V-ATPase VPH1. By low phosphate. Present with 12074 molecules/cell in log phase SD medium. Belongs to the VTC1 family.