%0 Journal Article %A Yoshiaki Kamiyama %A Misaki Hirotani %A Shinnosuke Ishikawa %A Fuko Minegishi %A Sotaro Katagiri %A Fuminori Takahashi %A Mika Nomoto %A Kazuya Ishikawa %A Yutaka Kodama %A Yasuomi Tada %A Daisuke Takezawa %A Scott C. Peck %A Kazuo Shinozaki %A Taishi Umezawa %T SNF1-related protein kinase 2 directly regulate group C Raf-like protein kinases in abscisic acid signaling %D 2020 %R 10.1101/2020.02.04.933978 %J bioRxiv %P 2020.02.04.933978 %X A phytohormone abscisic acid (ABA) has a major role in abiotic stress responses in plants, and subclass III SNF1-related protein kinase 2 (SnRK2) mediates ABA signaling. In this study, we identified Raf36, a group C Raf-like protein kinase in Arabidopsis, as an interacting protein with SnRK2. A series of reverse genetic and biochemical analyses revealed that Raf36 negatively regulates ABA responses and is directly phosphorylated by SnRK2s. In addition, we found that Raf22, another C-type Raf-like kinase, functions partially redundantly with Raf36 to regulate ABA responses. Comparative phosphoproteomic analysis using Arabidopsis wild-type and raf22raf36-1 plants identified proteins that are phosphorylated downstream of Raf36 and Raf22 in planta. Together, these results reveal a novel subsection of ABA-responsive phosphosignaling pathways branching from SnRK2. %U https://www.biorxiv.org/content/biorxiv/early/2020/02/04/2020.02.04.933978.full.pdf