Full-length cDNA Cloning and Expression Analysis of catalase Gene from Sea Cucumber (Apostichopus japonicus).

Studying the function and mechanism of immune-related genes can provide scientific reference for preventing and controlling diseases in sea cucumber (A. japonicus) culture. In this study, the full-length cDNA of catalase gene from A. japonicus was cloned and characterized for the first time, which was 1 885 bp including a 76 bp 5'-untranslated region (UTR), 1 503 bp ORF encoding 500 amino acids, and a 306 bp 3'-UTR; and the predicted molecular weight was 56.56 kDa. The result of amino acid sequence alignment showed that 75% amino acid sequence identity to the Catalase of Hyriopsis cumingii and Strongylocentrotus purpuratus. The peroxisomal targeting signal PTS2, NADPH binding residues, and heme-ligand binding signal sequences "RLFSYPDTH" were identified in the deduced amino acid sequence of Catalase from A. japonicus. Phylogenetic analysis suggested that the Catalase of A. japonicus was close to that of S. purpuratus in invertebrate cluster. Quantitative real-time PCR analysis showed that catalase gene was expressed in all the tested tissues including body wall, feet, coelomocyte, respiratory tree, muscle, intestine, and the highest expression level was found in intestine. The expression of catalase mRNA was up-regulated significant!)' in the coelomocytes at 4 h after LPS challenge. Those indicated that catalase gene was involved in the immune response to the bacteria challenge in A. japonicus. [ABSTRACT FROM AUTHOR]