Localization of the urea transporter UT-B protein in human and rat erythrocytes and tissues.
A new polyclonal antibody to the human erythrocyte urea transporter UT-B detects a broad band between 45 and 65 kDa in human erythrocytes and between 37 and 51 kDa in rat erythrocytes. In human erythrocytes, the UT-B protein is the Kidd (Jk) antigen, and Jk(a+b+) erythrocytes express the 45- to 65-kDa band. However, in Jk null erythrocytes [Jk(a-b-)], only a faint band at 55 kDa is detected. In kidney medulla, a broad band between 41 and 54 kDa, as well as a larger band at 98 kDa, is detected. Human and rat kidney show UT-B staining in nonfenestrated endothelial cells in descending vasa recta. UT-B protein and mRNA are detected in rat brain, colon, heart, liver, lung, and testis. When kidney medulla or liver proteins are analyzed with the use of a native gel, only a single protein band is detected. UT-B protein is detected in cultured bovine endothelial cells. We conclude that UT-B protein is expressed in more rat tissues than previously reported, as well as in erythrocytes.
Timmer
R T
RT
Department of Physiology, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
Klein
J D
JD
Bagnasco
S M
SM
Doran
J J
JJ
Verlander
J W
JW
Gunn
R B
RB
Sands
J M
JM
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies; D001011:Aorta / Q000737:chemistry; D001923:Brain Chemistry; D002352:Carrier Proteins / Q000032:analysis* / Q000235:genetics / Q000276:immunology*; D003106:Colon / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D004730:Endothelium, Vascular / Q000737:chemistry; D004912:Erythrocytes / Q000737:chemistry*; D015870:Gene Expression / Q000502:physiology; D006801:Humans; D007668:Kidney / Q000737:chemistry*; D008168:Lung / Q000737:chemistry; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis* / Q000235:genetics / Q000276:immunology*; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D009206:Myocardium / Q000737:chemistry; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D013047:Specific Pathogen-Free Organisms; D013737:Testis / Q000737:chemistry; D000096982:Urea Transporters
D000906:Antibodies; D002352:Carrier Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D012333:RNA, Messenger; D000096982:Urea Transporters