Table 1.

Comparison of cloned facilitated urea transportersa

Isoformb Synonyms Species Tissuec MW (kD)d Reference
UT-A1UT1RatKidney96(45)
UT-A2UT2Rabbit, rat, humanKidney43(31, 38, 39, 41)
UT-A3RatKidney45(46)
UT-A4RatKidney43(46)
UT-B1HUT11, Rach1, UT3Human, ratBone marrow, kidney42 to 43(59, 61, 135)
UT-B2 UT11 Rat Brain 45 (60)
  • a MW, molecular weight.

  • b Isoform names are based on the systematic nomenclature for urea transporters proposed in reference 11.

  • c Indicates tissue from which this isoform was originally cloned.

  • d Predicted molecular mass based on amino acid sequence.