Grass Carp Prx 3 Elevates Host Antioxidant Activity and Induces Autophagy to Inhibit Grass Carp Reovirus (GCRV) Replication.

Peroxiredoxins are a family of antioxidant proteins that protect cells from oxidative damage caused by reactive oxygen species (ROS). Herein, the peroxiredoxin 3 gene from grass carp (), named , was cloned and analyzed. The full-length cDNA of is 1068 bp long, with a 753 bp open reading frame (ORF) that contains a thioredoxin-2 domain, two peroxiredoxin signature motifs, and two highly conserved cysteine residues. was ubiquitously expressed in all the tested tissues, while its expression level was altered significantly after exposure to grass carp reovirus (GCRV) and pathogen-associated molecular patterns (PAMPs). was localized in the mitochondria of transfected cells and concentrated in the nucleus after poly (I:C) treatment. Transformation of into enhanced host resistance to HO and heavy metals. Purified recombinant proteins could protect DNA against oxidative damage. Overexpression of in fish cells reduced intracellular ROS, increased cell viability, and decreased cell apoptosis caused by HO stimulation and GCRV infection. Further study indicated that induced autophagy to inhibit GCRV replication in fish cells. Collectively, these results imply that grass carp Prx3 elevates host antioxidant activity and induces autophagy to inhibit GCRV replication.