Glutaredoxins are belongs to thioredoxin super family and possess thioredoxin catalytic motif. I n vertebrates, G rx1 and G rx2 consider as dithiol proteins whereas G rx3 and Grx5 are monothiols. According to previous studies, Grx2 perform critical functions in both development and redox homeostasis in fish. Therefore, HaGrx2 was characterized by bioinformatical, transcriptional and functional assays .
Insilico analysis was performed by CLC main work bench version 8.0. Tissue distribution and immune challenge experiment (LPS, Poly I:C, E.tarda and S.iniea) was conducted and performed q-PCR analysis. Further, FHM cell survival upon H2O2 stress was measured by MTT assay.
According to the insilico analysis, HaGrx2 possess typical glutaredoxin structure with CPYC thioredoxin active motif and showed highest identity (95.4%) with Grx2 from Hippocampus comes. HaGrx2 exhibit highest expression in skin and brain of healthy fish. Liver HaGrx2 showed significant upregulation toward poly I:C, E.tarda and S.iniea . Further, HaGrx2 exhibit significant antiapoptotic activity against H2O2.
Grx2 is an enzyme that regulate many cellular pathways. As it is a redox enzyme, directly regulates the redox signaling during oxidative stress conditions. Also, it is known as a redox switch for releasing mitochondrial ROS during innate immune responses. Further, it can regulate the mitochondrial energy producing complexes by deglutathionylation thus boost the metabolism and host defense mechanisms indirectly at normal and stress conditions. Therefore, Grx2 might play a vital role in cell survival, growth, proliferation and innate immune responses. Altogether, results in this study suggests that HaGrx2 actively involved in host innate immune responses as well as cell survival during oxidative stress conditions.