Essential role of the Cytochrome P450 2 (CYP2) in the mud crab Scylla paramamosain antioxidant defense and immune responses

Cytochrome P450 (CYPs) enzymes are one of the critical detoxification enzymes, playing a key role in antiox-idant defense. However, the information of CYPs cDNA sequences and their functions are lacked in crustaceans. In this study, a novel full-length of CYP2 from the mud crab (designated as Sp-CYP2) was cloned and charac-terized. The coding sequence of Sp-CYP2 was 1479 bp in length and encoded a protein containing 492 amino acids. The amino acid sequence of Sp-CYP2 comprised a conserved heme binding site and chemical substrate binding site. Quantitative real-time PCR analysis revealed that Sp-CYP2 was ubiquitously expressed in various tissues, and it was highest in the heart followed by the hepatopancreas. Subcellular localization showed that Sp-CYP2 was prominently located in the cytoplasm and nucleus. The expression of Sp-CYP2 was induced by Vibrio parahaemolyticus infection and ammonia exposure. During ammonia exposure, ammonia exposure can induce oxidative stress and cause severely tissue damage. Knocking down Sp-CYP2 in vivo can increase malondialdehyde content and the mortality of mud crabs after ammonia exposure. All these results suggested that Sp-CYP2 played a crucial role in the defense against environmental stress and pathogen infection in crustaceans.

Automated summary

A novel cytochrome P450 enzyme, Sp-CYP2, was cloned and characterized in the mud crab. Sp-CYP2 was found to be widely expressed in various tissues, with the highest expression in the heart and hepatopancreas. Its expression was induced by ammonia exposure and infection of Vibrio parahaemolyticus. Knocking down Sp-CYP2 increased oxidative stress and mortality in mud crabs, suggesting its crucial role in defense against environmental stress and pathogen infection in crustaceans.