First molluscan theta-class Glutathione S-Transferase: Identification, cloning, characterization and transcriptional analysis post immune challenges

摘要: Glutathione S-Transferases (GSTs) are multifunctional cytosolic isoenzymes, distinctly known as phase II detoxification enzymes. GSTs play a significant role in cellular defense against toxicity and have been identified nearly all organisms studied to date, from bacteria mammals. In this study, we full-length cDNA of the theta class GST Ruditapes philippinarum (RpGSTθ), an important commercial edible molluscan species. RpGSTθ was cloned recombinant protein expressed, order study its biochemical characteristics determine physiological activities. The comprised ORF 693 bp, encoding 231 amino acids with predicted molecular mass 27 kDa isoelectric point 8.2. Sequence analysis revealed that possessed characteristic conserved domains GST_N family, Class Theta subfamily (PSSM: cd03050) GST_C_family Super family cl02776). Phylogenetic showed evolutionarily linked other homologues. expressed Escherichia coli BL21(DE3) cells purified enzyme high activity substrates like CDNB 4-NBC. dependent peroxidase GST, investigated cumene hydroperoxide substrate affirmed antioxidant property rRpGSTθ. By quantitative PCR, found be ubiquitously tissues examined, highest levels occurring gills, mantle, hemocytes. Since may act enzymes mediate immune defense, effects pathogen associated pattern, lipopolysaccharide intact Vibrio tapetis challenge on gene transcription were studied. Furthermore, expression changes induced by challenges similar those manganese superoxide dismutase (RpMnSOD). To our knowledge, is first reported, immune-related Manila clam provide insights into potential therapeutic targets for protecting aquaculture