Referenced in: none

Automatically associated channels: Kir2.3

Title: Alternative splicing of a 51-nucleotide exon that encodes a putative protein kinase C phosphorylation site generates two forms of the chicken gamma-aminobutyric acidA receptor beta 2 subunit.

Authors: R J Harvey, M A Chinchetru, M G Darlison

Journal, date & volume: J. Neurochem., 1994 Jan , 62, 10-6

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/7505310

Abstract
Complementary DNAs that encode two forms of the chicken gamma-aminobutyric acid type A (GABAA) receptor beta 2 subunit have been isolated. These polypeptides differ by the presence of (beta 2L) or absence (beta 2S) of 17 amino acids, which contain a possible target for phosphorylation by protein kinase C, in the large intracellular loop between the third and fourth membrane-spanning domains. The extra sequence in the chicken beta 2L subunit is not found in previously published GABAA receptor beta 2-subunit sequences. Analysis of genomic DNA has revealed that the two beta 2-subunit mRNAs arise by alternative splicing of a novel 51-nucleotide exon. Although the two beta 2-subunit transcripts appear to be present in 1-day-old chick brain at similar steady-state levels, we have been unable to detect an mRNA for the long form of the beta 2 subunit in either the bovine or the rat. Because the various GABAA receptor genes are thought to have arisen by duplication of a common ancestor, our data, taken together with that on the gamma 2 subunit, which occurs in two forms that arise by alternative splicing of a 24-nucleotide exons, suggest that the coding region of the primordial gene or one of its very early descendants contained 10 exons, not nine as previously thought.