Identification and cloning of a γ3 subunit splice variant of the human GABAA receptor

Abstract cDNA sequences encoding two forms of the GABA A γ3 receptor subunit were cloned from human hippocampus. The nucleotide sequences differ by the absence (γ3S) or presence (γ3L) of 18 bp located in the presumed intracellular loop between transmembrane region (TM) III and IV. The extra 18 bp in the γ3L subunit generates a consensus site for phosphorylation by protein kinase C (PKC). Analysis of human genomic DNA encoding the γ3 subunit reveals that the 18 bp insert is contiguous with the upstream proximal exon.