Small N-terminal deletion by splicing in cerebellar alpha 6 subunit abolishes GABAA receptor function

J Neurochem. 1994 Sep;63(3):1167-70. doi: 10.1046/j.1471-4159.1994.63031167.x.


Sequence variation was found in cDNA coding for the extracellular domain of the rat gamma-aminobutyric acid type A (GABAA) receptor alpha 6 subunit. About 20% of polymerase chain reaction (PCR)-amplified alpha 6 cDNA prepared from rat cerebellar mRNA lacked nucleotides 226-255 as estimated by counting single-stranded phage plaques hybridized specifically to the short (alpha 6S) and long (wild-type) forms of the alpha 6 mRNA. Genomic PCR revealed an intron located upstream of the 30-nucleotide sequence. Both splice forms were detected in the cerebellum by in situ hybridization. Recombinant receptors, resulting from coexpression of the alpha 6S subunit with the GABAA receptor beta 2 and gamma 2 subunits in human embryonic kidney 293 cells, were inactive at binding [3H]muscimol and [3H]Ro 15-4513. In agreement, injection of complementary RNAs encoding the same subunits into Xenopus oocytes produced only weak GABA-induced currents, indistinguishable from those produced by beta 2 gamma 2 receptors. Therefore, the 10 amino acids encoded by the 30-nucleotide fragment may be essential for the correct assembly or folding of the alpha 6 subunit-containing receptors.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cell Line
  • Cerebellum / chemistry*
  • Female
  • Gene Deletion*
  • Gene Transfer Techniques
  • Humans
  • Ion Channel Gating / drug effects
  • Kidney
  • Molecular Sequence Data
  • Oocytes / metabolism
  • Polymerase Chain Reaction
  • RNA Splicing*
  • Rats
  • Receptors, GABA / chemistry*
  • Receptors, GABA / genetics
  • Receptors, GABA / physiology*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism
  • Structure-Activity Relationship
  • Xenopus
  • gamma-Aminobutyric Acid / pharmacology


  • Receptors, GABA
  • Recombinant Proteins
  • gamma-Aminobutyric Acid