The cDNA Cloning and Expression Analysis of p38 MAPK Gene of Fenneropenaeus chinensis

Abstract:

In this study we employed the RACE method to sequence the full-length cDNA of p38 MAPK gene of Fenneropenaeus chinensis for the first time and named it as Fcp38. The full-length cDNA sequence contained 1563 bp, including a 122-bp 5'-UTR, a 343-bp 3'-UTR, and a 1098-bp open reading frame (ORF) that encoded 365 amino acid residues. The isoelectric point (pI) of this peptide was 5.68, and the molecular mass was 41.77 kDa. Homology analysis revealed that the amino acid sequence of Fcp38 was highly similar to the p38 MAPK sequences in other species. The sequence similarity reached 98% between F. chinensis and Litopenaeus vannamei and Marsupenaeus japonicus. Fcp38 had a conserved Thr-Gly-Tyr (TGY) motif, a substrate-binding site Ala-Thr-Arg-Trp (ATRW), and an ED (ERK docking) motif. This structure played a critical role in the interaction between p38 MAPK and other molecules. The phylogenetic analysis showed that p38 of F. chinensis was in the same branch with L. vannamei and M. japonicus. The expression of Fcp38 gene in different tissues was also analyzed with quantitative real-time PCR. The results showed that Fcp38 existed in all the tested tissues including the intestine, gill, stomach, heart, hepatopancreas, muscles and hemocytes, and the expression was the highest in muscles. Real-time PCR analysis showed that ammonia-N stress significantly up-regulated the expression of Fcp38 in the muscles, hemocytes, gill, heat, intestine and stomach, and that there was a spatiotemporal pattern for the expression of Fcp38. These results implied that Fcp38 might play an important role in the response to the environmental stresses