Immunological characterization of K+ channel components from the Shaker locus and differential distribution of splicing variants in Drosophila.

Antibodies were raised to three portions of the predicted sequences of Shaker, a gene that encodes a family of K+ channel components that are produced by the alternative splicing of transcripts. On immunoblots, the protein products appear to be 65,000-85,000 daltons in size. No smaller products were detected. Immunocytochemistry has revealed a nonuniform distribution of Shaker products in the brain of the adult fly. By comparing antisera directed against regions shared by all the splicing variants to antisera that are directed against one particular group of splicing variants, we have determined that there is a differential distribution of that group of variants. Thus, the alternative splicing of Shaker transcripts appears to produce different subtypes of A-channels in different tissues.