Cloning and characterization of the vasopressin-regulated urea transporter

Nature. 1993 Oct 28;365(6449):844-7. doi: 10.1038/365844a0.


Urea is the principal end product of nitrogen metabolism in mammals. Movement of urea across cell membranes was originally thought to occur by lipid-phase permeation, but recent studies have revealed the existence of specialized transporters with a low affinity for urea (Km > 200 mM)2. Here we report the isolation of a complementary DNA from rabbit renal medulla that encodes a 397-amino-acid membrane glycoprotein, UT2, with the functional characteristics of the vasopressin-sensitive urea transporter previously described in in vitro-perfused inner medullary collecting ducts. UT2 is not homologous to any known protein and displays a unique pattern of hydrophobicity. Because of the central role of this transporter in fluid balance and nitrogen metabolism, the study of this protein will provide important insights into the urinary concentrating mechanism and nitrogen balance.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Blotting, Northern
  • Carrier Proteins / genetics*
  • Carrier Proteins / metabolism
  • Cloning, Molecular
  • In Vitro Techniques
  • Kidney Medulla / metabolism*
  • Membrane Glycoproteins / genetics*
  • Membrane Glycoproteins / metabolism
  • Membrane Transport Proteins*
  • Molecular Sequence Data
  • Oocytes
  • Phosphorylation
  • Polymerase Chain Reaction
  • RNA, Messenger / metabolism
  • Rabbits
  • Urea / metabolism*
  • Vasopressins / physiology*
  • Xenopus


  • Carrier Proteins
  • Membrane Glycoproteins
  • Membrane Transport Proteins
  • RNA, Messenger
  • urea transporter
  • Vasopressins
  • Urea