Alternative splicing of the guanine nucleotide-binding regulatory protein Goα generates four distinct mRNAs

Abstract

Goα a guanine nucleotide-binding (G) protein abundant in brain and other neural tissues, has been implicated in ion channel regulation. Concerted efforts in several laboratories have revealed multiple Goα mRNAs and protein isoforms in different contexts. Goα is a single copy gene in mammalian species, although the structure, number and tissue localization of Goα mRNAs reported by investigators are inconsistent. To define the cell-specific expression of alternatively spliced variants of Goα mRNA, we employed several strategies, including Northern hybridizations with sequence-specific ollgonucleotides, selective digestions of Goα mRNA using RNase H, and adaptations of the polymer-ase chain reaction. Four distinct alternatively spliced variants were identified, a 5.7-kb Goα.,2 mRNA and three Goα1 mRNAs with different 3′ UTRs. The UTRs of the three Goα1s are composed of different combinations of what have been referred to as UTR-A and UTR-B. The sequences of the spliced segments are well conserved among mammalian species, suggesting a functional role for these alternatively spliced 3′ UTRs in post-transcriptional and/or tissue-specific regulation of Goα expression. The position of the intron-exon splice boundary at nucleotide 31 following T of the TGA stop codon Is conserved in the Glα2 and Glalpha;3 genes, consistent with the notion that similar alternative splicing of 3′ UTRs occurs in products of these related genes. © 1994 Oxford University Press.