Peroxiredoxins (Prxs) are a group of evolutionarily conserved selenium-independent thiol-specific antioxidant proteins. In this study, the peroxiredoxin-4 (CiPrx4) gene from grass carp was identified and characterized. The full-length of CiPrx4 is 1339 bp, encoding 260 amino acids that contain two peroxiredoxin signature motifs and two GVL motifs. CiPrx4 belongs to the typical 2-Cys subfamily and shows the highest homology with Prx4 from Cyprinus carpio (95.4%). CiPrx4 mRNA was constitutively expressed in all tested tissues and was upregulated by grass carp reovirus and pathogen-associated molecular pattern (PAMP) stimulation. CiPrx4 was localized in the cytoplasm and co-localized with the endoplasmic reticulum. The purified CiPrx4 protein protected DNA from degradation in a dose-dependent manner. Moreover, the overexpression of CiPrx4 in Escherichia coli and fish cells showed apparent antioxidant and antiviral activities. Collectively, the results of the present study provide new insights for further understanding the functions of Prx4 in teleost fish.

Peroxiredoxins (Prxs) 是一组进化上保守的不依赖硒的硫醇特异性抗氧化蛋白。本研究对草鱼的过氧化还原蛋白4 ( CiPrx4 ) 基因进行了鉴定和表征。CiPrx4的全长为1339 bp，编码260个氨基酸，包含两个过氧化还原蛋白特征基序和两个GVL基序。CiPrx4 属于典型的 2-Cys 亚家族，与Cyprinus carpio的 Prx4 同源性最高（95.4%）。CiPrx4mRNA 在所有受试组织中组成型表达，并被草鱼呼肠孤病毒和病原体相关分子模式 (PAMP) 刺激上调。CiPrx4 定位在细胞质中并与内质网共定位。纯化的 CiPrx4 蛋白以剂量依赖性方式保护 DNA 免受降解。此外，CiPrx4 在大肠杆菌和鱼细胞中的过表达显示出明显的抗氧化和抗病毒活性。总的来说，本研究的结果为进一步了解 Prx4 在硬骨鱼中的功能提供了新的见解。