EXPRESSION OF A BOVINE GABA(A), RECEPTOR ALPHA-1-SUBUNIT CDNA IN MURINE ERYTHROLEUKEMIA-CELLS

A plasmid vector has been constructed by insertion of the cDNA encodin g the al subunit of the bovine GABA, receptor into the LCR/MEL express ion vector pNV1 downstream of the human globin locus control region be tween the promoter and the second intron of the beta-globin gene to pr oduce pNVGABA alpha. This plasmid was transfected into murine erythrol eukemia (MEL) cells using electroporation to obtain recombinant cells. Parental and recombinant cells were tested by both RNA dot blot and e lectrophysiological analysis for the the presence of bovine GABA(A) re ceptor alpha 1 subunit mRNA. Parental MEL cells did not express GABA-g ated chloride channels but recombinant cells were sensitive to pressur e-applied GABA. The GABA responses reversed at the equilibrium potenti al predicted for chloride ions. These results show that the al subunit of the bovine GABA(A) receptor inserts in the plasma membrane of the MEL cells and forms homo-oligomeric chloride channels that are gated b y GABA. Our studies suggest, therefore, that the LCR/MEL system can be used for the expression of neurotransmitter receptor genes.