Expression of A Bovine GABA_A Receptor α1-subunit cDNA in Murine Erythroleukaemia Cells

Abstract

A plasmid vector has been constructed by insertion of the cDNA encoding the α1 subunit of the bovine GABA_A receptor into the LCR/MEL expression vector pNV1 downstream of the human globin locus control region between the promoter and the second intron of the β-globin gene to produce pNVGABAα. This plasmid was transfected into murine erythroleukernia (MEL) cells using electroporation to obtain recombinant cells. Parental and recombinant cells were tested by both RNA dot blot and electrophysiological analysis for the the presence of bovine GABA_A receptor α1 subunit mRNA. Parental MEL cells did not express GABA-gated chloride channels but recombinant cells were sensitive to pressure-applied GABA. The GABA responses reversed at the equilibrium potential predicted for chloride ions. These results show that the al subunit of the bovine GAE3AA receptor inserts in the plasma membrane of the MEL cells and forms homo-oligomeric chloride channels that are gated by GABA. Our studies suggest, therefore, that the LCR/MEL system can be used for the expression of neurotransmitter receptor genes.