Uroplakin-1a explained

Uroplakin-1a (UP1a) is a protein that in humans is encoded by the UPK1A gene.^{[1] [2] [3]}

The protein encoded by this gene is a member of the transmembrane 4 superfamily, also known as the tetraspanin family. Most of these members are cell-surface proteins that are characterized by the presence of four hydrophobic domains.

The proteins mediate signal transduction events that play a role in the regulation of cell development, activation, growth and motility. This encoded protein is found in the asymmetrical unit membrane (AUM) where it can complex with other transmembrane 4 superfamily proteins.

UP1a may play a role in normal bladder epithelial physiology, possibly in regulating membrane permeability of superficial umbrella cells or in stabilizing the apical membrane through AUM/cytoskeletal interactions.

Further reading

• Berditchevski F . Complexes of tetraspanins with integrins: more than meets the eye . J. Cell Sci. . 114 . Pt 23 . 4143–51 . 2002 . 10.1242/jcs.114.23.4143 . 11739647 .
• Yu J, Lin JH, Wu XR, Sun TT . Uroplakins Ia and Ib, two major differentiation products of bladder epithelium, belong to a family of four transmembrane domain (4TM) proteins . J. Cell Biol. . 125 . 1 . 171–82 . 1994 . 8138569 . 10.1083/jcb.125.1.171 . 2120008 .
• Wu XR, Medina JJ, Sun TT . Selective interactions of UPIa and UPIb, two members of the transmembrane 4 superfamily, with distinct single transmembrane-domained proteins in differentiated urothelial cells . J. Biol. Chem. . 270 . 50 . 29752–9 . 1996 . 8530366 . 10.1074/jbc.270.50.29752 . free .
• Ogawa K, Johansson SL, Cohen SM . Immunohistochemical analysis of uroplakins, urothelial specific proteins, in ovarian Brenner tumors, normal tissues, and benign and neoplastic lesions of the female genital tract . Am. J. Pathol. . 155 . 4 . 1047–50 . 1999 . 10514386 . 10.1016/S0002-9440(10)65206-6. 1867018 .
• Kageyama S, Yoshiki T, Isono T, etal . High expression of human uroplakin Ia in urinary bladder transitional cell carcinoma . Jpn. J. Cancer Res. . 93 . 5 . 523–31 . 2003 . 12036448 . 5927031 . 10.1111/j.1349-7006.2002.tb01287.x.
• Tu L, Sun TT, Kreibich G . Specific heterodimer formation is a prerequisite for uroplakins to exit from the endoplasmic reticulum . Mol. Biol. Cell . 13 . 12 . 4221–30 . 2003 . 12475947 . 10.1091/mbc.E02-04-0211 . 138628 .
• Strausberg RL, Feingold EA, Grouse LH, etal . Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences . Proc. Natl. Acad. Sci. U.S.A. . 99 . 26 . 16899–903 . 2003 . 12477932 . 10.1073/pnas.242603899 . 139241 . 2002PNAS...9916899M . free .
• Grimwood J, Gordon LA, Olsen A, etal . The DNA sequence and biology of human chromosome 19 . Nature . 428 . 6982 . 529–35 . 2004 . 15057824 . 10.1038/nature02399 . 2004Natur.428..529G . free .
• Book: Yuasa T, Yoshiki T, Isono T, etal . Molecular Cloning and Expression of Uroplakins in Transitional Cell Carcinoma . Advances in Experimental Medicine and Biology . 2003 . Bladder Disease, Part A . 539 . Pt A . 33–46 . 15088894 . 10.1007/978-1-4419-8889-8_3. 978-1-4613-4707-1 .
• Gerhard DS, Wagner L, Feingold EA, etal . The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC) . Genome Res. . 14 . 10B . 2121–7 . 2004 . 15489334 . 10.1101/gr.2596504 . 528928 .
• Hall GD, Weeks RJ, Olsburgh J, etal . Transcriptional control of the human urothelial-specific gene, uroplakin Ia . Biochim. Biophys. Acta . 1729 . 2 . 126–34 . 2005 . 15913809 . 10.1016/j.bbaexp.2005.04.004 .

Notes and References

1. Lobban ED, Smith BA, Hall GD, Harnden P, Roberts P, Selby PJ, Trejdosiewicz LK, Southgate J . Uroplakin gene expression by normal and neoplastic human urothelium . Am J Pathol . 153 . 6 . 1957–67 . Dec 1998 . 9846985 . 1866332 . 10.1016/S0002-9440(10)65709-4 .
2. Yuasa T, Yoshiki T, Isono T, Tanaka T, Hayashida H, Okada Y . Expression of transitional cell-specific genes, uroplakin Ia and II, in bladder cancer: detection of circulating cancer cells in the peripheral blood of metastatic patients . Int J Urol . 6 . 6 . 286–92 . Sep 1999 . 10404304 . 10.1046/j.1442-2042.1999.00064.x . 43597402 .
3. Web site: Entrez Gene: UPK1A uroplakin 1A.