Roles of S100A1 and S100A10 from hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀) in immune response to Vibrio infection

The S100 proteins are highly conserved EF-hand calcium-binding proteins found only in vertebrates. In the current study, two S100 genes (S100A1 and S100A10) were successfully identified and characterized from hybrid grouper Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀. The deduced S100A10 protein contained two EF-hand domains, and S100A1 only possessed the N-terminal EF-hand. Phylogenetic analysis revealed that S100A1 and S100A10 from hybrid grouper were evolutionarily closely related to their counterparts in other selected vertebrates. Quantitative real-time PCR results revealed that the transcripts of S100A1 and S100A10 mRNA were ubiquitously distributed in all the examined tissues. After Vibrio alginolyticus infection, the expression of S100A1 and S100A10 in the spleen increased significantly. Moreover, overexpression of S100A1 and S100A10 could not only regulate the expression of interleukin 8 (IL-8), IL-10, and IL-16 in the head kidney, liver, and spleen, change the activities of acid phosphatase, catalase, lysozyme, and superoxide dismutase in serum, but also reduce the promoter activities of interferon 3 and nuclear factor kappa-B in vitro. Taken together, this study indicated that S100A1 and S100A10 participate in the immune response of hybrid grouper against bacterial infection.