title: Phosphorylation and stabilization of Arabidopsis MAP kinase phosphatase 1 in response to UV-B stress.
abstract: MAP kinase phosphatases (MKPs) are important regulators of the activation levels and kinetics of MAP kinases. This is crucial for a large number of physiological processes during development and growth, as well as interactions with the environment, including the response to ultraviolet-B (UV-B) stress. Arabidopsis MKP1 is a key regulator of MAP kinases MPK3 and MPK6 in response to UV-B stress. However, virtually nothing is presently known about the post-translational regulation of plant MKPs in vivo. Here, we provide evidence that MKP1 is a phosphoprotein in vivo and that MKP1 accumulates in response to UV-B stress. Moreover, proteasome inhibitor experiments suggest that MKP1 is constantly turned-over under non-stress conditions and that MKP1 is stabilized upon stress treatment. Stress-responsive phosphorylation and stabilization of MKP1 demonstrate the post-translational regulation of a plant MKP in vivo, adding an additional regulatory layer to MAP kinase signaling in plants.
authors.affiliation: Department of Botany and Plant Biology, University of Geneva, Sciences III, CH-1211 Geneva 4, Switzerland.
authors.forename: Marina A
authors.initials: MA
authors.lastname: González Besteiro
authors.forename: Roman
authors.initials: R
authors.lastname: Ulm
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D054638:Dual Specificity Phosphatase 1 / Q000737:chemistry / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects*; D020935:MAP Kinase Signaling System; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010641:Phenotype; D010766:Phosphorylation; D010940:Plant Proteins / Q000378:metabolism; D030821:Plants, Genetically Modified; D011499:Protein Processing, Post-Translational; D015398:Signal Transduction; D014466:Ultraviolet Rays
chemical_list: D029681:Arabidopsis Proteins; D010940:Plant Proteins; C436293:MPK6 protein, Arabidopsis; D020928:Mitogen-Activated Protein Kinases; D054638:Dual Specificity Phosphatase 1