The asymmetric unit membrane (AUM) of mammalian bladder epithelium is believed to be involved in strengthening and stabilizing the urothelial apical surface, thus preventing the cells from rupturing during bladder distention. The major protein components of AUM are uroplakins (UPKs): UPK1A, UPK1B, UPK2, and UPK3.
Pathology
UPK3 mutations in renal adysplasia (15888565)
