Mediation of inorganic anion transport by the hydrophobic domain of mouse erythroid band 3 protein expressed in oocytes of Xenopus laevis.
A cDNA clone of the mouse erythroid band 3 protein encoding the 556 amino acid residues of the hydrophobic domain from Thr-374 to the C-terminal Val-929 is shown by immunoprecipitation to be expressed in Xenopus oocytes. Measurements of 36Cl- efflux indicate that the translation product mediates Cl- transport, which is inhibitable reversibly by DNDS or H2DIDS, specific inhibitors of band 3-mediated transport. The apparent KI values are 3.6 microM and 0.094 microM, respectively, and hence similar to those found in the wild type band 3-mediated anion transport. The rapid reversible inhibition by H2DIDS slowly changes to irreversible inhibition. The rate of change increases with increasing pH, again similar as to the wild-type band 3. It is concluded that the hydrophobic domain of band 3 is capable of executing anion transport essentially similar to the full-length band 3, although minor differences with respect to transport and inhibition kinetics cannot be ruled out.
Lepke
S
S
Max-Planck-Institut für Biophysik, Frankfurt/Main, Germany.
Becker
A
A
Passow
H
H
D000595:Amino Acid Sequence; D000818:Animals; D001457:Anion Exchange Protein 1, Erythrocyte / Q000235:genetics / Q000378:metabolism*; D000838:Anions; D001692:Biological Transport; D002712:Chlorides / Q000378:metabolism; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D010063:Ovum / Q000378:metabolism; D011233:Precipitin Tests; D014982:Xenopus laevis
D001457:Anion Exchange Protein 1, Erythrocyte; D000838:Anions; D002712:Chlorides; D004247:DNA