Current knowledge of (pro)renin receptor as an accessory protein of vacuolar H+-ATPase.

The (pro)renin receptor (P)RR is a receptor for renin and prorenin, not only allowing local production of angiotensin I from angiotensinogen, but also inducing intracellular signaling. Intriguingly, (P)RR is also called ATP6AP2 because a (P)RR fragment was demonstrated to be associated with vacuolar-type H+-ATPase (V-ATPase), which is of importance for the maintenance of intracellular pH. Recent studies implicate that deletion of (P)RR results in the dysfunction of V-ATPase, suggesting that the (P)RR is essential for its role as a proton pump. Furthermore, the novel function of (P)RR as an adaptor protein between the Wnt receptor complex and the V-ATPase was discovered. Thus, (P)RR is a multi-functional molecule with functions beyond renin and prorenin. This review focuses on the current knowledge and issues of (P)RR and V-ATPase.