Identification of a Tyrosine Phosphatase Involved in the Response to Mechanical Injury in Leaves of Ricinus Communis

Thiago      Freitas de Souza; Alexandra      Martins dos Santos Soares; Olga      Lima Tavares Machado

doi:10.2174/092986611794328654

Abstract

Plants defend themselves against biotic or abiotic stress by triggering intracellular signaling pathways that regulate gene expression and responses to the offending agent. Phosphorylation and dephosphorylation represent major mechanisms for the regulation of plant defense pathways. Therefore, MAP kinases and phosphatases have been the focus of many studies in this area. This study identified three phosphatase activities, namely RcPPase I, II and III. Wounding increased the activity levels of RcPPase III, while the activities of RcPPase I and II remained constant compared to the control. N-terminal partial amino acid sequence, biochemical characterization with use of specific substrates and inhibitors indicated that the RcPPase III belong to the family of tyrosine phosphatases (PTPs).

Keywords: Cell signaling, plant defense, protein phosphatases, Ricinus communis, wounding, MAP kinases, hormones jasmonate, mitogen-activated protein kinase (MAPK), metal ion-dependent (PPM), tyrosine-specific PTPs, dual-specificity PTPs (DsPTPs), MAPKs, electrophoresis reagents, polyvinylpolypirrolidone, Wound-Inducible Phosphatase, Native Electrophoresis, Coomassie Blue, Phosphatase Activities, MAPK regulation pathways, P-Ser, P-Tyr, Activities of RcPPase, SDS-PAGE, IITQHREFARL, Glycine max, Arabidopsis, high osmolarity, high salinity, threonine, tyrosine residues, protein tyrosine phosphatases (PTPs), serine-threonine phosphatases (PSTPs), stress-activated MAPK (SAMK), wound-activated MAPK, p-NPP, Cantaridine, cyclosporine A, microcystinCell signaling, plant defense, protein phosphatases, Ricinus communis, wounding, MAP kinases, hormones jasmonate, mitogen-activated protein kinase (MAPK), metal ion-dependent (PPM), tyrosine-specific PTPs, dual-specificity PTPs (DsPTPs), MAPKs, electrophoresis reagents, polyvinylpolypirrolidone, Wound-Inducible Phosphatase, Native Electrophoresis, Coomassie Blue, Phosphatase Activities, MAPK regulation pathways, P-Ser, P-Tyr, Activities of RcPPase, SDS-PAGE, IITQHREFARL, Glycine max, Arabidopsis, high osmolarity, high salinity, threonine, tyrosine residues, protein tyrosine phosphatases (PTPs), serine-threonine phosphatases (PSTPs), stress-activated MAPK (SAMK), wound-activated MAPK, p-NPP, Cantaridine, cyclosporine A, microcystin