The third gamma subunit of the gamma-aminobutyric acid type A receptor family

Proc Natl Acad Sci U S A. 1992 Feb 15;89(4):1433-7. doi: 10.1073/pnas.89.4.1433.

Abstract

Cloned cDNAs encoding a member of the gamma-aminobutyric acid type A receptor gamma-subunit class were isolated from rat-brain-mRNA-derived libraries. The gamma 3 mRNA is present in cortex, claustrum, caudate putamen, and some thalamic nuclei, particularly the medial geniculate nucleus, where it is the predominant gamma-subunit transcript. The gamma 3 gene is expressed at very low levels in cerebellum and hippocampus. In coexpression experiments with the alpha 1 and beta 2 subunits, gamma 3 imparts benzodiazepine binding to gamma-aminobutyric acid type A receptors and forms gamma-aminobutyric acid-gated benzodiazepine-modulated chloride channels that exhibit a larger conductance than alpha 1 beta 2 receptor channels. Furthermore, the presence of gamma 3 in place of gamma 2 in alpha 1 beta 2 gamma x receptors generates a marked decrease in the affinity of agonists while leaving the affinity of antagonists or negative modulators largely unaffected.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Benzodiazepines / pharmacology*
  • Brain / physiology*
  • Brain Mapping
  • Cloning, Molecular
  • Electrophysiology
  • Gene Expression
  • Ion Channel Gating
  • Molecular Sequence Data
  • Nucleic Acid Hybridization
  • Oligodeoxyribonucleotides / chemistry
  • RNA, Messenger / genetics
  • Rats
  • Receptors, GABA-A / classification
  • Receptors, GABA-A / drug effects
  • Receptors, GABA-A / genetics*
  • Receptors, GABA-A / physiology

Substances

  • Oligodeoxyribonucleotides
  • RNA, Messenger
  • Receptors, GABA-A
  • Benzodiazepines

Associated data

  • GENBANK/M81142