Anti-Uroplakin Ib/UPIb antibody [UPK1B/3081]

Supplementary info

Activity summary

Uroplakin Ib (UPIb) also known as UPK1B is a type I integral membrane protein belonging to the uroplakin family. UPIb has a molecular mass of around 25 kDa. It is expressed in the apical surface of urothelial cells which line the urinary bladder and other parts of the urinary tract. The protein plays a structural role contributing to the formation of the asymmetrical unit membrane (AUM) an important component of the urothelial barrier.

Biological function summary

UPIb functions as part of a larger uroplakin complex essential for maintaining the urothelial surface structure. This protein works in concert with Uroplakin Ia Uroplakin II and Uroplakin III to form UPIa/UPIb heterodimers and facilitate protective plaque formation on the urothelial surface. The uroplakin complex ensures impermeability and mechanical stability in the urothelium critically protecting the underlying tissues from urine's toxic and osmotic effects.

Pathways

UPIb plays an essential role in the processes of cell differentiation and urothelial development. It interacts with transmembrane proteins within the uroplakin complex supporting the endocytosis and recycling pathways in the bladder's epithelial cells. The protein influences pathways pertinent to epithelial cell adhesion and communication working closely with uroplakin-associated proteins such as Uroplakin II and Uroplakin IIIa.

Associated diseases and disorders

UPIb is linked to bladder-related conditions due to its involvement in maintaining the urothelial barrier's integrity. Defects or misregulation in UPIb expression have associations with bladder cancer and interstitial cystitis. In bladder cancer abnormal uroplakin expression patterns including UPIb may indicate changes in the differentiation state of cancerous cells. In interstitial cystitis impaired urothelial barrier functions may link to UPIb's disrupted interactions with proteins such as Uroplakin IIIa.