Membrane ; Multi-pass membrane protein . Cytoplasmic vesicle, clathrin-coated vesicle membrane ; Multi-pass membrane protein . Cytoplasmic vesicle, secretory vesicle, synaptic vesicle membrane ; Multi-pass membrane protein .
Isoform 1 is expressed at high levels in heart, brain and kidney and also detected in inner ear epithelium, vestibule, testis, epididymis and bladder. Isoform 2 is expressed in heart, kidney, placenta and pancreas. Isoform 2 is not detected in frontal cortex, but is prevalent in all other brain areas.