May be required for vacuolar fusion. Overexpression leads to fragmentation of vacuoles, missorting of the vacuolar enzyme carboxypeptidase Y (CPY) to the exterior of the cell and accumulation of multivesicular bodies inside the cell. Homomultimer. Interacts with YPT7 and VPS33. Binds to various phospholipids. Present with 2840 molecules/cell in log phase SD medium.