Identification of a tyrosine phosphatase involved in the response to mechanical injury in leaves of Ricinus communis.
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).
Laboratório de Química e Função de Proteínas e Peptídeos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes - RJ, Brazil.
Thiago Freitas
TF
de Souza
Alexandra Martins
AM
dos Santos Soares
Olga Lima Tavares
OL
Machado
D000595:Amino Acid Sequence; D002367:Ricinus communis / Q000201:enzymology / Q000502:physiology*; D018515:Plant Leaves / Q000201:enzymology / Q000502:physiology*; D018521:Plant Physiological Phenomena; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism*; D013314:Stress, Mechanical
D017027:Protein Tyrosine Phosphatases