title: Identification of an important site for function of the type 2C protein phosphatase ABI2 in abscisic acid signalling in Arabidopsis.
abstract: It is known that the clade A protein phosphatase 2Cs (PP2Cs), including ABI1 and ABI2 and other PP2C members, are key players that function directly downstream of the PYR/PYL/RCAR abscisic acid (ABA) receptors. Here, identification of a crucial site for function of ABI2 protein phosphatase in ABA signalling is reported. It was observed that a calcium-dependent protein kinase (CDPK) phosphorylation site-like motif (CPL) in the ABI2 molecule is required for the interactions of ABI2 with the two members of the ABA receptors PYL5 and PYL9 and with a downstream protein kinase SnRK2.6, and for the catalytic activity of ABI2 in vitro, as well as for the response of ABI2 to the ABA receptors PYL5/PYL9 in relation to the ABA receptor-induced inhibition of the ABI2 phosphatase activity. Further, genetic evidence was provided to demonstrate that this CPL is required for the function of ABI2 to mediate ABA signalling. These data reveal that this CPL is an important site necessary for both the phosphatase activity of ABI2 and the functional interaction between ABI2 and PYL5/9 ABA receptors, providing new information to understand primary events of ABA signal transduction.
authors: College of Biological Sciences, China Agricultural University, Beijing 100094, China.
authors: Hai-Li
authors: HL
authors: Sun
authors: Xiao-Jing
authors: XJ
authors: Wang
authors: Wei-Hua
authors: WH
authors: Ding
authors: Sai-Yong
authors: SY
authors: Zhu
authors: Rui
authors: R
authors: Zhao
authors: Yi-Xie
authors: YX
authors: Zhang
authors: Qi
authors: Q
authors: Xin
authors: Xiao-Fang
authors: XF
authors: Wang
authors: Da-Peng
authors: DP
authors: Zhang
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology*; D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins; D008969:Molecular Sequence Data; D010749:Phosphoprotein Phosphatases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D020798:Two-Hybrid System Techniques
chemical_list: D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; C540972:RCAR1 protein, Arabidopsis; D000040:Abscisic Acid; C106443:ABI2 protein, Arabidopsis; D010749:Phosphoprotein Phosphatases