Structure and expression of a cluster of glutathione S-transferase genes from a marine fish, the plaice (Pleuronectes platessa)

Abstract

Glutathione S-transferases are involved in the detoxification of reactive electrophilic compounds, including intracellular metabolites, drugs, pollutants and pesticides. A cluster of three glutathione S-transferase genes, designated GSTA, GSTA1 and GSTA2, was isolated from the marine flatfish, plaice (Pleuronectes platessa). GSTA and GSTA1 code for protein products with 76% amino acid identity. GSTA2 appears to contain a single nucleotide deletion which would render any product non-functional. All of these genes consist of six exons of similar sizes and greater than 70% nucleotide identity, and are interrupted by five introns of differing sizes. GSTA and GSTA1 mRNAs were present in a range of tissues, while GSTA2 mRNA was not detected. Expression of GSTA mRNA was increased in plaice intestine and spleen by pretreatment with b-naphthoflavone, and expression of both GSTA and GSTA1 mRNAs was increased in plaice liver and gill by pretreatment with the peroxisome-proliferating agent perfluoro-octanoic acid.