Cloning and Expression Analysis of c-Jun N-Terminal Kinase Gene in Portunus trituberculatus after Pathogenic Stress

Abstract:

The c-Jun N-terminal kinase (JNK) is a member of the mitogen-activated protein kinase superfamily, which plays an important role in cell proliferation, apoptosis, and immune stress. To further explore the immune defense mechanism of JNK in Portunus trituberculatus, the EST sequence of PtJNK was isolated from the transcriptome database of P. trituberculatus. In this study, the JNK gene of P. trituberculatus (PtJNK) was successfully cloned by RACE; measurements showed a cDNA length of 3240 bp and an open reading frame of 1380 bp. PtJNK consists of 459 amino acids, including a serine/threonine protein kinase (S-TKc) domain with a conserved Thr-Pro-Tyr (TPY) motif, which is a typical feature of the JNK gene family. The results of tissue expression and distribution show that the PtJNK gene is expressed in all tissues. Real-time PCR was used to detect the expression of PtJNK under different pathogenic stimuli. The results show that expression of the gene is significantly down-regulated after injection of Vibrio parahaemolyticus (P<0.05), while expression is significantly up-regulated when white spot syndrome virus is injected (P<0.05). To sum up, PtJNK gene is a widely expressed gene, and expression of the gene differs according to pathogen.