Functional expression and subcellular localization of an anion exchanger cloned from choroid plexus.
We have isolated rat brain cDNA clones encoding AE2, a homologue of the erythrocyte anion exchanger, band 3 (AE1). Immunocytochemistry and in situ hybridization reveal that, in brain, AE2 expression is restricted to the basolateral membrane of the choroid plexus epithelium. Expression of a full-length mouse AE2 cDNA in COS-7 cells resulted in chloride- and bicarbonate-dependent alterations in intracellular pH, demonstrating that AE2 is a Cl/HCO3 exchanger. Cation replacement studies indicate that AE2-mediated exchange is independent of extracellular sodium. COS-7 cells expressing a mutant rat AE2 cDNA clone that lacks the cytoplasmic NH2-terminal 660 amino acids exhibit identical responses to cation and anion substitution. These results indicate that this domain does not play a significant role in either correct insertion of the transporter into the plasma membrane or anion exchange.
Lindsey
A E
AE
Department of Biological Sciences, Stanford University, CA 94305-5020.
Schneider
K
K
Simmons
D M
DM
Baron
R
R
Lee
B S
BS
Kopito
R R
RR
D000595:Amino Acid Sequence; D000818:Animals; D001457:Anion Exchange Protein 1, Erythrocyte / Q000235:genetics; D027321:Anion Transport Proteins; D017920:Antiporters; D002460:Cell Line; D002831:Choroid Plexus / Q000378:metabolism*; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D004848:Epithelium / Q000378:metabolism; D015870:Gene Expression; D015723:Gene Library; D006863:Hydrogen-Ion Concentration; D008565:Membrane Proteins / Q000032:analysis / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D051381:Rats; D064606:SLC4A Proteins; D012689:Sequence Homology, Nucleic Acid; D014162:Transfection
D001457:Anion Exchange Protein 1, Erythrocyte; D027321:Anion Transport Proteins; D017920:Antiporters; D008565:Membrane Proteins; D064606:SLC4A Proteins; D004247:DNA