title: Biochemical properties of urea transporters.
abstract: Urea and urea transporters (UT) are critical to the production of concentrated urine and hence in maintaining body fluid balance. The UT-A1 urea transporter is the major and most important UT isoform in the kidney. Native UT-A1, expressed in the terminal inner medullary collecting duct (IMCD) epithelial cells, is a glycosylated protein with two glycoforms of 117 and 97 kDa. Vasopressin is the major hormone in vivo that rapidly increases urea permeability in the IMCD through increases in phosphorylation and apical plasma-membrane accumulation of UT-A1. The cell signaling pathway for vasopressin-mediated UT-A1 phosphorylation and activity involves two cAMP-dependent signaling pathways: protein kinase A (PKA) and exchange protein activated by cAMP (Epac). In this chapter, we will discuss UT-A1 regulation by phosphorylation, ubiquitination, and glycosylation.
authors.affiliation: Department of Physiology, and Renal Division Department of Medicine, Emory University School of Medicine, Whitehead Research Building Room 605N, 615 Michael Street, Atlanta, GA, 30322, USA, gchen3@emory.edu.
authors.forename: Guangping
authors.initials: G
authors.lastname: Chen
mesh_terms: D001692:Biological Transport / Q000187:drug effects; D000242:Cyclic AMP / Q000378:metabolism; D006801:Humans; D007679:Kidney Medulla / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000378:metabolism*; D008954:Models, Biological; D010766:Phosphorylation / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D014508:Urea / Q000378:metabolism*; D014667:Vasopressins / Q000378:metabolism / Q000494:pharmacology; D000096982:Urea Transporters
chemical_list: D000242:Cyclic AMP; D026901:Membrane Transport Proteins; D014508:Urea; D014667:Vasopressins; D000096982:Urea Transporters