GABA (γ-amino-butyric acid) neurotransmission:: Identification and fine mapping of the human GABAB receptor gene

GABA (gamma-amino-butyric acid) receptors are a family of proteins involved in the GABAergic neurotransmission of the mammalian central nervous system (CNS). They have physiological importance and clinical relevance in several diseases. We report the identification, cloning, and fine mapping of the human cDNA for GABA, receptor. A 4.2-Kb cDNA containing an open reading frame for a predicted protein of 960 aa was isolated from a fetal brain cDNA library. It had a strong identity (91.5%) with the rat GABA, receptor (rGB1A) nucleotide sequence, that corresponded to 98.6%, identity at the amino acid level. Expression of the GABA(B) at the transcription level was detected by Northern analysis in all brain areas examined. The GABA,receptor has been mapped to human chromosome 6p21.3 within the HLA class I region close to the HLA-F gene. Susceptibility loci for multiple sclerosis, epilepsy, and schizophrenia have been suggested to map in this region. (C) 1998 Academic Press.