title: Cysteine-independent Catalase-like Activity of Vertebrate Peroxiredoxin 1 (Prx1).
abstract: Peroxiredoxins (Prxs) are a ubiquitous family of antioxidant proteins that are known as thioredoxin peroxidases. Here we report that Prx1 proteins from Tetraodon nigroviridis and humans also possess a previously unknown catalase-like activity that is independent of Cys residues and reductants but dependent on iron. We identified that the GVL motif was essential to the catalase (CAT)-like activity of Prx1 but not to the Cys-dependent thioredoxin peroxidase (POX) activity, and we generated mutants lacking POX and/or CAT activities for individually delineating their functional features. We discovered that the TnPrx1 POX and CAT activities possessed different kinetic features in reducing H2O2. The overexpression of wild-type TnPrx1 and mutants differentially regulated the intracellular levels of reactive oxygen species and p38 phosphorylation in HEK-293T cells treated with H2O2. These observations suggest that the dual antioxidant activities of Prx1 may be crucial for organisms to mediate intracellular redox homeostasis.
authors.affiliation: From the College of Life Sciences, Zhejiang University and Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Hangzhou 310058, China and.
authors.forename: Cen-Cen
authors.initials: CC
authors.lastname: Sun
authors.affiliation: From the College of Life Sciences, Zhejiang University and Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Hangzhou 310058, China and.
authors.forename: Wei-Ren
authors.initials: WR
authors.lastname: Dong
authors.affiliation: From the College of Life Sciences, Zhejiang University and Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Hangzhou 310058, China and.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhao
authors.affiliation: From the College of Life Sciences, Zhejiang University and Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Hangzhou 310058, China and.
authors.forename: Li
authors.initials: L
authors.lastname: Nie
authors.affiliation: From the College of Life Sciences, Zhejiang University and Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Hangzhou 310058, China and xianglx@zju.edu.cn.
authors.forename: Li-Xin
authors.initials: LX
authors.lastname: Xiang
authors.affiliation: From the College of Life Sciences, Zhejiang University and Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Hangzhou 310058, China and the Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas 77843 gzhu@cvm.tamu.edu.
authors.forename: Guan
authors.initials: G
authors.lastname: Zhu
authors.affiliation: From the College of Life Sciences, Zhejiang University and Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Hangzhou 310058, China and shaojz@zju.edu.cn.
authors.forename: Jian-Zhong
authors.initials: JZ
authors.lastname: Shao
keywords: catalase; hydrogen peroxide; peroxidase; peroxiredoxin; signaling