Characterization and expression analysis of granzyme B like gene in half smooth tongue sole (Cynoglossus semilaevis)

Abstract:

Granzyme B is an indispensable mediator of the immune inflammatory response, which can induce apoptosis of target cells by activating caspase 3. In this study, we cloned the full-length cDNA of Cynoglossus semilaevis granzyme B-like gene (CsGzmBl) and analyzed its sequence characteristics and expression levels. The full-length cDNA of CsGzmBl was 923 bp, containing a 49 bp 5ʹUTR, 94 bp 3ʹUTR, and 780 bp ORF regions encoding 259 amino acid proteins with 19 amino acid signal peptides. The genome structure of CsGzmBl is highly conserved and consists of five exons and four introns. The CsGzmBl protein possesses two N-terminal glycosylation sites, a catalytic triad “His63Asp112Ser207,” a “PHSRPYMA” domain, and six conserved cysteines. qRT-PCR indicated that CsGzmBl was expressed in different tissues of healthy C. semilaevis adults, with the highest expression in the spleen, followed by that in the head kidney, kidney, liver, and gills, with the lowest expression in muscle. After infection with Vibrio harveyi, CsGzmBl was up-regulated to varying degrees in six immune-related tissues (spleen, intestine, liver, skin, gills, and kidneys) at different time points compared to the control group at 0 h. These results indicate that CsGzmBl plays an important role in the immune response of C. semilaevis against V. harveyi infection.