Quantitative phosphoproteomics identifies SnRK2 protein kinase substrates and reveals the effectors of abscisic acid action

• DOI: 10.1073/pnas.1308974110
• Publication Date: 2013-06-18T03:05:44Z
• Authors: Pengcheng Wang; Liang Xue; Giorgia Batelli; Shinyoung Lee; Yueh-Ju Hou; Michael J. Van Oo...; Huiming Zhang; W. Andy Tao; Jian-Kang Zhu
• Keywords: Phosphoproteomics

Sucrose nonfermenting 1 (SNF1)-related protein kinase 2s (SnRK2s) are central components of abscisic acid (ABA) signaling pathways. The snrk2.2/2.3/2.6 triple-mutant plants nearly completely insensitive to ABA, suggesting that most the molecular actions ABA triggered by SnRK2s-mediated phosphorylation substrate proteins. Only a few proteins SnRK2s known. To identify additional and provide insight into we used quantitative phosphoproteomics compare global changes in phosphopeptides WT triple mutant seedlings response treatment. Among 5,386 unique phosphorylated peptides identified this study, found can increase 166 decrease 117 seedlings. In mutant, 84 peptides, representing 58 proteins, could not be phosphorylated, or was increased under vitro assays suggest serve as substrates SnRK2s. SnRK2 include involved flowering time regulation, RNA DNA binding, miRNA epigenetic signal transduction, chloroplast function, many other cellular processes. Consistent with regulators, flowered significantly earlier than WT. These results shed new light on role kinases downstream effectors action, improve our understanding plant responses adverse environments.