Glutathione S-transferase Ya subunit gene: identification of regulatory elements required for basal level and inducible expression.

The function of the 5'-flanking region of a rat glutathione S-transferase Ya subunit structural gene has been examined in homologous and heterologous cells. By using the 5'-flanking region of the Ya subunit gene fused to the structural gene encoding chloramphenicol acetyltransferase, we have identified two cis-acting regulatory elements in the upstream region of the Ya gene. One element is required for maximum basal level expression in homologous cells, whereas maximum basal level expression in homologous cells, whereas the second element is required for inducible expression of the Ya gene by planar aromatic compounds such as beta-naphthoflavone.

Sequence analysis and regulation of rat liver glutathione S-transferase mRNAs.

We have utilized polysomal immunoadsorption techniques to purify the rat liver glutathione S-transferase mRNAs. Using the purified mRNAs as template, cDNA clones complementary to the Ya, Yb1, and Yc mRNAs have been constructed. The cDNA clones have been utilized in RNA blot hybridization and nuclear run-off assays to demonstrate that the Ya and Yb mRNAs are elevated 8 and 5-fold, respectively by phenobarbital; whereas the Yc mRNA is elevated only 2.

Structural analysis of a rat liver glutathione S-transferase Ya gene.

We have isolated and characterized a complete structural gene encoding a rat liver glutathione S-transferase (glutathione transferase; EC 2.5.1.

Multiplicity of glutathione S-transferase genes in the rat and association with a type 2 Alu repetitive element.

Southern blot analysis of rat genomic DNA using glutathione S-transferase Ya and Yc cDNA probes was employed to estimate the size of the Ya/Yc multigene family. A minimum of five to seven Ya/Yc genes were detected; at least two of these are Yc genes. The presence of multiple genes was further supported by the isolation of three nonoverlapping genomic clones from a rat EcoRI library that hybridized to a Ya cDNA clone, pGTB38.