Mapping of the beta 2 subunit gene (GABRB2) to microdissected human chromosome 5q34-q35 defines a gene cluster for the most abundant GABAA receptor isoform

Genomics. 1994 Oct;23(3):528-33. doi: 10.1006/geno.1994.1539.


The gamma-aminobutyric acid receptor (GABAAR) is a multisubunit Cl- channel that mediates most fast inhibitory synaptic transmission in the central nervous system. Molecular evolution has given rise to many genetic variants of GABAAR subunits, including alpha 1-6, beta 1-4, gamma 1-4, delta, and rho 1-2, suggesting that an enormous number of combinations of subunits are possible. Here we report that the beta 2 gene is located on chromosome 5q34-q35, defining a cluster comprising alpha 1, beta 2, and gamma 2 genes that together code for the most abundant GABAAR isoform. The fact that intron position is conserved in the beta 1-3 genes, taken together with the observation that chromosomes 4 and 15 also contain distinct alpha-beta-gamma gene clusters, strongly suggests that an ancestral alpha-beta-gamma cluster was duplicated and translocated to at least two different chromosomes. This organization of GABAAR gene clusters may have been preserved as linkage provides a mechanism for facilitating coordinate gene expression.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Biological Evolution
  • Chickens
  • Chromosome Mapping
  • Chromosomes, Human, Pair 5*
  • Conserved Sequence
  • DNA Primers
  • Exons
  • Hominidae / genetics*
  • Humans
  • Hybrid Cells
  • Introns
  • Macromolecular Substances
  • Mice
  • Molecular Sequence Data
  • Multigene Family*
  • Polymerase Chain Reaction
  • Rats
  • Receptors, GABA-A / biosynthesis
  • Receptors, GABA-A / genetics*
  • Sequence Homology, Amino Acid


  • DNA Primers
  • Macromolecular Substances
  • Receptors, GABA-A