Molecular identification of cytokine inducible SH-2 containing protein (CISH) gene from common carp Cyprinus carpio and its expression pattern

Abstract:

Janus kinase-signal transducers and activators of transcription (JAK-STAT) signaling pathway is one of the most important ubiquitous cell signaling pathways in animals. In vertebrates, it is mainly involved in regulating the expression and secretion of many cytokines. The members of the suppressor of cytokine signaling (SOCS) family are the important JAK-STAT pathway inhibitory factors. Cytokine-induced SH-2 containing protein (CISH) is one known family members of SOCS, with its main function involved in regulating the signaling of interleukin-2. In this study, the full-length cDNA sequence of Cyprinus carpio CISH with the length of 1 685 bp was cloned. The open reading frame (ORF) was 666 bp in length and encoded 221 amino acids. The molecular weight of the deduced protein was 24.91 ku. C. carpio CISH possesses typical SOCS family structure, with three functional domains including N region, central SH2 domain and C terminal SOCS box domain, the latter two being conservatively present in CISH proteins of other bony fish. The phylogenetic analysis showed that the common carp CISH was the closest to CISHs of grass carp and zebrafish, which also belong to Cyprinidae. The results showed that the mRNA expression level of C. carpio CISH in blood was the highest, and the lowest expression level in liver. After being stimulated by Aeromonas hydrophila, the expression of C. carpio CISH in blood was up-regulated significantly at 24 h, and returned to the normal level at 48 h, suggesting that it may play an important role in the process of the resistance to bacterial infection.