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

J Neurochem. 1994 Jan;62(1):10-6. doi: 10.1046/j.1471-4159.1994.62010010.x.


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.

MeSH terms

  • Alternative Splicing*
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Blotting, Northern
  • Brain / metabolism
  • Cattle
  • Chickens / genetics*
  • DNA Primers
  • DNA, Complementary / metabolism
  • Exons*
  • Introns
  • Macromolecular Substances
  • Molecular Sequence Data
  • Phosphorylation
  • Polymerase Chain Reaction
  • Protein Kinase C / metabolism*
  • RNA / isolation & purification
  • Rats
  • Receptors, GABA-A / biosynthesis*
  • Receptors, GABA-A / genetics*
  • Sequence Homology, Amino Acid


  • DNA Primers
  • DNA, Complementary
  • Macromolecular Substances
  • Receptors, GABA-A
  • RNA
  • Protein Kinase C

Associated data

  • GENBANK/X72806
  • GENBANK/X72807