title: Purification and characterization of ZmRIP1, a novel reductant-inhibited protein tyrosine phosphatase from maize.
abstract: Protein tyrosine phosphatases (PTPases) have long been thought to be activated by reductants and deactivated by oxidants, owing to the presence of a crucial sulfhydryl group in their catalytic centers. In this article, we report the purification and characterization of Reductant-Inhibited PTPase1 (ZmRIP1) from maize (Zea mays) coleoptiles, and show that this PTPase has a unique mode of redox regulation and signaling. Surprisingly, ZmRIP1 was found to be deactivated by a reductant. A cysteine (Cys) residue (Cys-181) near the active center was found to regulate this unique mode of redox regulation, as mutation of Cys-181 to arginine-181 allowed ZmRIP1 to be activated by a reductant. In response to oxidant treatment, ZmRIP1 was translocated from the chloroplast to the nucleus. Expression of ZmRIP1 in Arabidopsis (Arabidopsis thaliana) plants and maize protoplasts altered the expression of genes encoding enzymes involved in antioxidant catabolism, such as At1g02950, which encodes a glutathione transferase. Thus, the novel PTPase identified in this study is predicted to function in redox signaling in maize.
authors.affiliation: College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
authors.forename: Bingbing
authors.initials: B
authors.lastname: Li
authors.forename: Yanxia
authors.initials: Y
authors.lastname: Zhao
authors.forename: Liyan
authors.initials: L
authors.lastname: Liang
authors.forename: Huibo
authors.initials: H
authors.lastname: Ren
authors.forename: Yu
authors.initials: Y
authors.lastname: Xing
authors.forename: Lin
authors.initials: L
authors.lastname: Chen
authors.forename: Mingzhu
authors.initials: M
authors.lastname: Sun
authors.forename: Yuanhua
authors.initials: Y
authors.lastname: Wang
authors.forename: Yu
authors.initials: Y
authors.lastname: Han
authors.forename: Haifeng
authors.initials: H
authors.lastname: Jia
authors.forename: Conglin
authors.initials: C
authors.lastname: Huang
authors.forename: Zhongyi
authors.initials: Z
authors.lastname: Wu
authors.forename: Wensuo
authors.initials: W
authors.lastname: Jia
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D001152:Arsenicals / Q000494:pharmacology; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism; D002736:Chloroplasts / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D003545:Cysteine / Q000378:metabolism; D004229:Dithiothreitol / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010940:Plant Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D017354:Point Mutation; D021381:Protein Transport / Q000187:drug effects; D017027:Protein Tyrosine Phosphatases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D011523:Protoplasts / Q000378:metabolism; D015398:Signal Transduction; D003313:Zea mays / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics
chemical_list: D001152:Arsenicals; D010940:Plant Proteins; C029341:oxophenylarsine; D005982:Glutathione Transferase; D017027:Protein Tyrosine Phosphatases; D003545:Cysteine; D004229:Dithiothreitol