UT-B1 urea transporter is expressed along the urinary and gastrointestinal tracts of the mouse.
Selective transporters account for rapid urea transport across plasma membranes of several cell types. UT-B1 urea transporter is widely distributed in rat and human tissues. Because mice exhibit high urea turnover and are the preferred species for gene engineering, we have delineated UT-B1 tissue expression in murine tissues. A cDNA was cloned from BALB/c mouse kidney, encoding a polypeptide that differed from C57BL/6 mouse UT-B1 by one residue (Val-8-Ala). UT-B1 mRNA was detected by RT-PCR in brain, kidney, bladder, testis, lung, spleen, and digestive tract (liver, stomach, jejunum, colon). Northern blotting revealed seven UT-B1 transcripts in mouse tissues. Immunoblots identified a nonglycosylated UT-B1 protein of 29 kDa in most tissues and of 36 and 32 kDa in testis and liver, respectively. UT-B1 protein of gastrointestinal tract did not undergo N-glycosylation. Immunohistochemistry and in situ hybridization localized UT-B1 in urinary tract urothelium (papillary surface, ureter, bladder, and urethra), prominently on plasma membranes and restricted to the basolateral area in umbrella cells. UT-B1 was found in endothelial cells of descending vasa recta in kidney medulla and in astrocyte processes in brain. Dehydration induced by water deprivation for 2 days caused a tissue-specific decrease in UT-B1 abundance in the urinary bladder and the ureter.
Lucien
N
N
INSERM U76, Institut National de Transfusion Sanguine, 6, rue Alexandre Cabanel, F-75015 Paris, France.
Bruneval
P
P
Lasbennes
F
F
Belair
M F
MF
Mandet
C
C
Cartron
J  P
J
Bailly
P
P
Trinh-Trang-Tan
M M
MM
D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000096:biosynthesis / Q000235:genetics; D003681:Dehydration / Q000378:metabolism; D004064:Digestive System / Q000378:metabolism*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007668:Kidney / Q000378:metabolism; D008297:Male; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D012313:RNA / Q000096:biosynthesis / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013894:Thirst / Q000502:physiology; D014513:Ureter / Q000378:metabolism; D001743:Urinary Bladder / Q000378:metabolism; D014551:Urinary Tract / Q000378:metabolism*; D019459:Urothelium / Q000378:metabolism
D018076:DNA, Complementary; D026901:Membrane Transport Proteins; C452857:urea transporter B, mouse; D012313:RNA