UT-B1 proteins in rat: tissue distribution and regulation by antidiuretic hormone in kidney.
UT-B1 is the facilitated urea transporter of red blood cells (RBCs) and endothelial cells of descending vasa recta in the kidney. Immunoblotting with a polyclonal antibody against the C-ter sequence of rat UT-B1 revealed UT-B1 as both nonglycosylated (29 kDa) and N-glycosylated (47.5 and 33 kDa) proteins in RBC membranes, kidney medulla, brain, and bladder in rat. In testis, UT-B1 was expressed only as a nonglycosylated protein of 47.5 kDa. Immunocytochemistry confirmed that the location of UT-B1 is restricted to descending vasa recta. In brain, UT-B1 protein was found in astrocytes and ependymal cells. Cell bodies and perivascular end feet of astrocytes were labeled in brain cortex, whereas astrocyte cell processes were labeled in corpus callosum. Flow cytometry analysis of RBCs revealed a good cross-reactivity of the antibody with mouse and human UT-B1. UT-B1 protein expression in rat kidney medulla was downregulated greatly by long-term [deamino-Cys(1),D-Arg(8)]vasopressin infusion and moderately by furosemide treatment. This study discloses an uneven distribution of UT-B1 protein within astrocytes and the regulation of renal UT-B1 protein by antidiuretic hormone.
Trinh-Trang-Tan
M-M
MM
Institut National de la Santé et de la Recherche Médicale Unité 76, Institut National de la Transfusion Sanguine, 75015 Paris, France. trinh@idf.inserm.fr
Lasbennes
F
F
Gane
P
P
Roudier
N
N
Ripoche
P
P
Cartron
J-P
JP
Bailly
P
P
D000595:Amino Acid Sequence; D000818:Animals; D001253:Astrocytes / Q000378:metabolism; D002352:Carrier Proteins / Q000032:analysis / Q000276:immunology / Q000378:metabolism*; D003894:Deamino Arginine Vasopressin / Q000494:pharmacology; D004232:Diuretics / Q000494:pharmacology; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology; D004912:Erythrocytes / Q000737:chemistry / Q000378:metabolism*; D005665:Furosemide / Q000494:pharmacology; D006031:Glycosylation; D006801:Humans; D007150:Immunohistochemistry; D007668:Kidney / Q000737:chemistry / Q000378:metabolism*; D007679:Kidney Medulla / Q000737:chemistry / Q000378:metabolism; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis / Q000276:immunology / Q000378:metabolism*; D026901:Membrane Transport Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley; D012076:Renal Agents / Q000494:pharmacology; D013045:Species Specificity; D014667:Vasopressins / Q000378:metabolism*; D000096982:Urea Transporters
D002352:Carrier Proteins; D003894:Deamino Arginine Vasopressin; D004232:Diuretics; D005665:Furosemide; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D012076:Renal Agents; D014667:Vasopressins; D000096982:Urea Transporters