cDNA cloning and characterization of peroxiredoxin gene from the swimming crab Portunus trituberculatus.

摘要

Peroxiredoxin is a superfamily of antioxidative proteins that play important roles in protecting organisms against the toxicity of reactive oxygen species (ROS). In this study, a peroxiredoxin gene was cloned from the swimming crab Portunus trituberculatus by using rapid amplification of cDNA ends (RACE) approaches. The full-length cDNA of the Prx was of 1306 bp, containing a 5' untranslated region (UTR) of 54 bp, a 3' UTR of 654 bp with a poly (A) tail, and an open reading frame (ORF) of 597 bp encoding a polypeptide of 198 amino acids with the predicted molecular weight of 21.9 kDa. The conserved Prx domain and the signature of peroxidase catalytic center identified in Prx suggested that the Prx belonged to the 2-Cys Prx subgroup. Sequence comparison showed that Prx of P. trituberculatus shared 96%, 82%, 81%, 80% and 71% identity with that of crustacean Scylla paramamosain, Litopenaeus vannamei, Fenneropenaeus indicus, Fenneropenaeus chinensis and mammalians Homo sapiens, respectively. Quantitative real-time RT-PCR analysis revealed that P. trituberculatus Prx transcript was strongly detected in muscle, hepatopancreas, heart, stomach, intestine, gill, ovary and haemocytes. The expression level of Prx transcripts both in haemocytes and hepatopancreas increased in the first 3 h after Vibrio alginolyticus challenging, as the bacterial infection progressed, the challenged decreased to levels significantly lower than control. These facts indicate that Prx is potentially involved in the acute response against invading bacteria in P. trituberculatus.