Cloning of an organ of Corti anion exchanger 2 isoform with a truncated C-terminal domain.

ABSTRACT

We have isolated a cDNA clone from a guinea pig organ of Corti library encoding a new isoform of the Anion Exchanger 2 (AE2) protein. This cDNA clone shows an 83 bp deletion in the region that encodes the membrane domain of AE2. Analysis of the overlapping regions of genomic and cDNA clones indicates that the missing portion does not correspond exactly to a constitutive exon. The alternate splicing process that generates this transcript involves internal donor and acceptor sites which introduces a shift in the open reading frame. The resulting polypeptide has a conserved cytoplasmic N-terminal domain but the membrane C-terminal domain has only two of the fourteen membrane spanning regions. An affinity-purified antipeptide antibody to the novel C-terminus detects an 89 kDa polypeptide which agrees with the molecular mass predicted from the cDNA.