A large-scale protein phosphorylation analysis reveals novel phosphorylation motifs and phosphoregulatory networks in Arabidopsis

Xu Wang, Yangyang Bian, Kai Cheng, Li-Fei Gu, Mingliang Ye, Hanfa Zou, Samuel Sai-Ming Sun, Jun-Xian He
2013 Journal of Proteomics  
Large-scale protein phosphorylation analysis by MS is emerging as a powerful tool in plant signal transduction research. However, our current understanding of the phosphorylation regulatory network in plants is still very limited. Here, we report on a proteome-wide profiling of phosphopeptides in nine-day-old Arabidopsis (Arabidopsis thaliana) seedlings by using an enrichment method combining the titanium (Ti 4+ )-based IMAC and the RP-strong cation exchange (RP-SCX) biphasic trap column-based
more » ... nline RPLC. Through the duplicated RPLC-MS/MS analyses, we identified 5348 unique phosphopeptides for 2552 unique proteins. Among the phosphoproteins identified, 41% of them were first-time identified. Further evolutionary conservation and phosphorylation motif analyses of the phosphorylation sites discovered 100 highly conserved phosphorylation residues and identified 17 known and 14 novel motifs specific for Ser/Thr protein kinases. Gene ontology and pathway analyses revealed that many of the new identified phosphoproteins are important regulatory proteins that are involved in diverse biological processes, particularly in central metabolisms and cell signaling. Taken together, our results provided not only new insights into the complex phosphoregulatory network in plants but also important resources for future functional studies of protein phosphorylation in plant growth and development.
doi:10.1016/j.jprot.2012.10.018 pmid:23111157 fatcat:xiwpojsxbjdlxinjvh5ewjmm2e