Uroplakin 3A (UPK3A)

Uroplakins (UPK) are integral membrane proteins that form 2-dimensional crystalline arrays termed urothelial plaques that cover more than 90% of the apical urothelial surface. The asymmetric unit membrane (AUM) forms the apical plaques of urothelium and is believed to strengthen the urothelial apical surface and prevent the cells from rupturing during bladder distention. The 4 major conserved integral membrane proteins of the AUM are UPK1A, UPK1B , UPK2, and UPK3A.

UPK3A encodes a member of the uroplakin family, a group of transmembrane proteins that form complexes on the apical surface of the bladder epithelium. Mutations in this gene may be associated with renal adysplasia. Alternatively spliced transcript variants have been described.