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.

Two FERONIA-Like Receptor Kinases Regulate Apple Fruit Ripening by Modulating Ethylene Production

“…Fluorescence was observed 3 days after transformation using a confocal laser-scanning microscope (Fluoview FV1000, Olympus). Maize ( Zea mays ) protoplast isolation and transformation were carried out according to a protocol described by Sheen et al ( 1995 ), with minor modifications (Li et al, 2012 ). The primers used are listed in Supplemental Table S4 .…”

VvWRKY8 represses stilbene synthase genes through direct interaction with VvMYB14 to control resveratrol biosynthesis in grapevine

“…It was first isolated in 1939 from roots of white hellebore ( Veratrum grandiflorum ) (Takaoka, 1939), and then in 1964 from roots of Japanese knotweed ( Polygonum cuspidatum ) (Nonomura et al , 1963). In 1974, it was characterized as a phytoalexin in the leaves of Vitaceae (Langcake and Pryce, 1976). The production of this phytoalexin is stimulated when Vitaceae are exposed to fungal infections, ozone, injury, wounding, and UV-C irradiation (Langcake and Pryce, 1976).…”

“…In 1974, it was characterized as a phytoalexin in the leaves of Vitaceae (Langcake and Pryce, 1976). The production of this phytoalexin is stimulated when Vitaceae are exposed to fungal infections, ozone, injury, wounding, and UV-C irradiation (Langcake and Pryce, 1976). Grapevine ( Vitis ) is currently the main source of supply of Res worldwide because of its extensive cultivation and high production efficiency (Weiskirchen and Weiskirchen, 2016).…”

Maize protein phosphatase gene family: identification and molecular characterization

“…Although recent advances in higher plants, only a small portion of the members in this family have been found to be components of signaling pathway in maize. This include, ZmPP2Ca (ZmPP8), which is involved in the signal transduction in regulating response to drought stress [ 17 ]; ZmPP2C2 (ZmPP159), which plays a positive role in tobacco cold resistance [ 18 ]; ZmPP2C (ZmPP76), which is implicated in Arabidopsis stress signal transduction [ 19 ]; ZMPP2 (ZmPP138), which was selected as a candidate for the catalytic subunit of phospho-pyruvate dehydrogenase phosphatase (PDP) [ 20 ]; ZmRIP1 (ZmPP1), which acts as a chloroplast-to-nucleus signaling messenger, and is confirmed to function in maize redox signaling [ 21 ]; ZmPP1 (ZmPP65), whose function and regulation might be very similar to that of mammalian PPs [ 22 ].…”