Glutathione S-transferase in yeast: induction of mRNA, cDNA cloning and expression in Escherichia coli.

Glutathione S-transferase Y-2 mRNA synthesis was induced in yeast Issatchenkia orientalis approximately 37-fold by cultivation with o-dinitrobenzene. A cDNA library complementary to poly (A)+RNA of I. orientalis grown with o-dinitrobenzene was screened by colony hybridization. Twenty positive clones were obtained from 6,000 clones and seven of twenty positive clones expressed glutathione S-transferase activity in E. coli. One of the expressing clones harboring plasmid pHT108 had 28 times more glutathione S-transferase activity induced by Isopropyl-beta-D-thio-galactopyranoside than a strain harboring plasmid pUC118. Expressed glutathione S-transferase Y-2 protein comigrated with yeast glutathione S-transferase Y-2 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis as detected by immunoblot analysis.