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

Authors：Cheng, Chang-Hong^*; Zhang, Shu-Fei; Ma, Hong-Ling; Liu, Guang-Xin; Fan, Si-Gang; Deng, Yi-Qin; Jiang, Jian-Jun; Feng, Juan; Guo, Zhi-Xun^*

Source：Fish and Shellfish Immunology, 2023, 135: 108674.

DOI：10.1016/j.fsi.2023.108674

• Scylla paramamosain
• Oxidative stress
• Ammonia stress
• CYP2

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.