Catalytic component of a P4-ATPase flippase complex, which catalyzes the hydrolysis of ATP coupled to the transport of glucosylceramide (GlcCer) from the outer to the inner leaflet of the plasma membrane.
Subcellular locations: Cell membrane, Endoplasmic reticulum membrane
Exit from the endoplasmic reticulum requires the presence of TMEM30A, but not that of TMEM30B.