Isolation and characterization of the human glutathione S-transferase A2 subunit gene.

We have isolated and characterized a second human liver glutathione S-transferase (GST) subunit gene. The nucleotide sequence of this gene indicates that it encodes the alpha class subunit A2, with a coding region of about 13 kb. Using reverse transcription assays it could be shown that the A2 subunit gene is expressed in human liver and HepG2 cells. The transcription initiation site has been determined by primer extension analysis. A "TATA"-sequence was found 26 nucleotides upstream from the transcription start site. A comparison of the structure of the A2 subunit gene with that of the A1 subunit gene shows significant sequence identity between the two genes. Southern blot analysis of restriction endonuclease digests of human DNA indicates that there may be several more human alpha class GST genes.