Uroplakin-2 (IPR009952)

Short name: Uroplakin-2

Overlapping homologous superfamilies


Family relationships



This family contains Uroplakin-2, which is approximately 180 residues long and seems to be restricted to mammals. Uroplakin II is an integral membrane protein, and is one of the components of the apical plaques of mammalian urothelium formed by the asymmetric unit membrane - this is believed to play a role in strengthening the urothelial apical surface to prevent the cells from rupturing during bladder distension [PMID: 8175808].

Uroplakins (UPs) are a family of proteins that associate with each other to form plaques on the apical surface of the urothelium, the pseudo-stratified epithelium lining the urinary tract from renal pelvis to the bladder outlet [PMID: 27729990, PMID: 17183244]. UPs are classified into 3 types: UPIa and UPIb, UPII, and UPIIIa and IIIb. UPIs are tetraspanins that have four transmembrane domains separating one large and one small extracellular domain while UPII and UPIIIs are single-pass transmembrane proteins. UPIa and UPIb form specific heterodimers with UPII and UPIII, respectively, which allows them to exit the endoplasmatic rediculum. UPII/UPIa and UPIIIs/UPIb form heterotetramers and six of these tetramers form the 16nm particle, seen in the hexagonal array of the asymmetric unit membrane, which is believed to form a urinary tract barrier [PMID: 7760330]. Uroplakins are also believed to play a role during urinary tract morphogenesis [PMID: 19340092, PMID: 17183244].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.