Uroplakin 2 (UPK2)

Uroplakin 2 is one of the proteins of the highly conserved urothelium-specific integral membrane proteins of the asymmetric unit membrane which forms urothelium apical plaques in mammals. The asymmetric unit membrane is believed to strengthen the urothelium by preventing cell rupture during bladder distention. The encoded protein is expressed in the peripheral blood of bladder cancer patients with transitional cell carcinomas. Western blot analysis detected UPK2 at an apparent molecular mass slightly lower than that of 15-kD bovine Upk2. Electron microscopy revealed that AUMs isolated from cattle, dog, mouse, and monkey were 12-nm protein particles forming hexagonally packed crystalline patches.