The Plant Science Student Conference (PSSC) has been organised by students from the two Leibniz institutes, IPK and IPB, every year for the last 20 years. In this interview, Christina Wäsch (IPK) and Carolin Apel (IPB)…
Over 600 guests came to the IPB on July 4 for the Long Night of Sciences to learn lots of new things and put their knowledge to the test at our science quiz course. This year, our program was aimed equally at children and…
Our 10th Leibniz Plant Biochemistry Symposium on May 7 and 8 was a great success. This year's theme was new methods and research approaches in natural product chemistry. The excellent presentations on active substances and…
Hoehenwarter, W.; Thomas, M.; Nukarinen, E.; Egelhofer, V.; Röhrig, H.; Weckwerth, W.; Conrath, U.; Beckers, G. J. M.;Identification of Novel in vivo MAP Kinase Substrates in Arabidopsis thaliana Through Use of Tandem Metal Oxide Affinity ChromatographyMol. Cell. Proteomics12369-380(2013)DOI: 10.1074/mcp.M112.020560
Mitogen-activated protein kinase (MPK) cascades are important for eukaryotic signal transduction. They convert extracellular stimuli (e.g. some hormones, growth factors, cytokines, microbe- or damage-associated molecular patterns) into intracellular responses while at the same time amplifying the transmitting signal. By doing so, they ensure proper performance, and eventually survival, of a given organism, for example in times of stress. MPK cascades function via reversible phosphorylation of cascade components MEKKs, MEKs, and MPKs. In plants the identity of most MPK substrates remained elusive until now. Here, we provide a robust and powerful approach to identify and quantify, with high selectivity, site-specific phosphorylation of MPK substrate candidates in the model plant Arabidopsis thaliana. Our approach represents a two-step chromatography combining phosphoprotein enrichment using Al(OH)3-based metal oxide affinity chromatography, tryptic digest of enriched phosphoproteins, and TiO2-based metal oxide affinity chromatography to enrich phosphopeptides from complex protein samples. When applied to transgenic conditional gain-of-function Arabidopsis plants supporting in planta activation of MPKs, the approach allows direct measurement and quantification ex vivo of site-specific phosphorylation of several reported and many yet unknown putative MPK substrates in just a single experiment.