Molecular characterization of a new urea transporter in the human kidney.
A cDNA clone (HUT2) sharing 61.1% and 89.9% sequence identity with the human erythroid (HUT11) and the rabbit (UT2) urea transporters, respectively, was isolated by homology cloning from a human kidney library. HUT2 transcripts were restricted to the kidney and the HUT2 polypeptide was not immunoprecipitated with blood group Kidd-related antibodies (anti-Jk3) in coupled transcription-translation assays. Functional expression studies in Xenopus oocytes demonstrated that HUT2-mediated urea transport was not inhibited by p-chloromercuribenzene sulfonate (pCMBS) which, however, inhibited the urea flux mediated by HUT11. These findings demonstrate that at least two distinct urea transporters are present in human tissues. By in situ hybridization, the gene encoding HUT2 has been assigned to chromosome 18q12.1-q21-1, as found previously for the Kidd/urea transporter HUT11, suggesting that both genes evolved from duplication of a common ancestor.
Olivès
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B
INSERM U76, GIP-Institut National de la Transfusion Sanguine, Paris, France.
Martial
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Mattei
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MG
Matassi
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G
Rousselet
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G
Ripoche
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P
Cartron
J P
JP
Bailly
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P
D000328:Adult; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001692:Biological Transport; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002887:Chromosomes, Human, Pair 18; D003001:Cloning, Molecular; D018076:DNA, Complementary; D006801:Humans; D007668:Kidney / Q000196:embryology / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D014176:Protein Biosynthesis; D012333:RNA, Messenger; D011817:Rabbits; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution; D014158:Transcription, Genetic; D014982:Xenopus laevis; D000096982:Urea Transporters
D002352:Carrier Proteins; D018076:DNA, Complementary; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D012333:RNA, Messenger; D000096982:Urea Transporters