Required for the assembly of the V0 complex of the vacuolar ATPase (V-ATPase) in the endoplasmic reticulum.
Endoplasmic reticulum membrane ; Multi-pass membrane protein . Endoplasmic reticulum-Golgi intermediate compartment membrane ; Multi-pass membrane protein . Cytoplasmic vesicle, COPII-coated vesicle membrane ; Multi-pass membrane protein .