Open AccessCloning of the gamma-aminobutyric acid (GABA) rho 1 cDNA: a GABA receptor subunit highly expressed in the retina.
Author(s) -
Garry R. Cutting,
Lili Lü,
Bruce F. O’Hara,
Laura Kasch,
Chahrzad MontroseRafizadeh,
David M. Donovan,
Shoichi Shimada,
S. E. Antonarakis,
William B. Guggino,
George R. Uhl
Publication year - 1991
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.88.7.2673
Subject(s) - biology , cdna library , gabaa receptor , complementary dna , microbiology and biotechnology , muscimol , protein subunit , biochemistry , gamma aminobutyric acid , receptor , gene
Type A gamma-aminobutyric acid (GABAA) receptors are a family of ligand-gated chloride channels that are the major inhibitory neurotransmitter receptors in the nervous system. Molecular cloning has revealed diversity in the subunits that compose this heterooligomeric receptor, but each previously elucidated subunit displays amino acid similarity in conserved structural elements. We have used these highly conserved regions to identify additional members of this family by using the polymerase chain reaction (PCR). One PCR product was used to isolate a full-length cDNA from a human retina cDNA library. The mature protein predicted from this cDNA sequence in 458 amino acids long and displays between 30 and 38% amino acid similarity to the previously identified GABAA subunits. This gene is expressed primarily in the retina but transcripts are also detected in the brain, lung, and thymus. Injection of Xenopus oocytes with RNA transcribed in vitro produces a GABA-responsive chloride conductance and expression of the cDNA in COS cells yields GABA-displaceable muscimol binding. These features are consistent with our identification of a GABA subunit, GABA rho 1, with prominent retinal expression that increases the diversity and tissue specificity of this ligand-gated ion-channel receptor family.