PYR/PYL/RCAR family members are major in-vivo ABI1 protein phosphatase 2C-interacting proteins in Arabidopsis.
PYR/PYL/RCAR family members are major in-vivo ABI1 protein phosphatase 2C-interacting proteins in Arabidopsis.
复制标题
DOI：
10.1111/j.1365-313x.2009.04054.x
复制
发表时间：
2010-01
期刊：
影响因子：
--
通讯作者：
Schroeder JI
中科院分区：
文献类型：
--
作者：
Nishimura N;Sarkeshik A;Nito K;Park SY;Wang A;Carvalho PC;Lee S;Caddell DF;Cutler SR;Chory J;Yates JR;Schroeder JI
脱落酸（ABA）介导植物对非生物胁迫的抗性，并控制植物的发育过程。以ABI1为原型成员的a组pp2c是蛋白磷酸酶，在ABA信号转导的早期作为负调控因子发挥关键作用。由于冗余被认为限制了早期ABA信号的遗传解剖，为了鉴定冗余和早期ABA信号蛋白，我们采用了蛋白质组学方法。我们生成了yfp标记的ABI1拟南芥表达系，并通过ABI1复合物的质谱分析鉴定了体内ABI1相互作用蛋白。已知的ABA信号组分包括SnRK2蛋白激酶。我们证实了之前在酵母中的研究，现在发现ABI1在植物中与aba信号激酶OST1、SnRK2.2和SnRK2.3相互作用。有趣的是，在所有LC-MS/MS实验中，植物中最强大的ABI1相互作用蛋白是14种PYR/PYL/RCAR蛋白中的9种，这些蛋白最近被报道为aba结合信号转导蛋白，为拟南芥中PYR/PYL/RCAR与ABI1的体内相互作用提供了证据。ABI1-PYR1相互作用在ABA处理后5 min内被激活。有趣的是，相比之下，PYR1和SnRK2.3在ABA存在和不存在的情况下都能很好地共免疫沉淀。为了研究PYR/PYLs的生物学相关性，我们分析了pyr1/pyl1/pyl2/pyl4四重突变株，发现它们对aba诱导的气孔关闭和aba抑制气孔开放具有较强的不敏感性。这些发现表明，ABI1可以与拟南芥中几个PYR/PYL/RCAR家族成员相互作用，ABA在拟南芥中迅速刺激PYR1-ABI1相互作用，并表明新的SnRK2激酶-PYR/PYL/RCAR相互作用在PYR/PYL/RCAR介导的ABA信号传导模型中。
Abscisic acid (ABA) mediates resistance to abiotic stress and controls developmental processes in plants. The group-A PP2Cs, of which ABI1 is the prototypical member, are protein phosphatases that play critical roles as negative regulators very early in ABA signal transduction. Because redundancy is thought to limit the genetic dissection of early ABA signalling, to identify redundant and early ABA signalling proteins, we pursued a proteomics approach. We generated YFP-tagged ABI1 Arabidopsis expression lines and identified in vivo ABI1-interacting proteins by mass-spectrometric analyses of ABI1 complexes. Known ABA signalling components were isolated including SnRK2 protein kinases. We confirm previous studies in yeast and now show that ABI1 interacts with the ABA-signalling kinases OST1, SnRK2.2 and SnRK2.3 in plants. Interestingly, the most robust in planta ABI1-interacting proteins in all LC-MS/MS experiments were nine of the 14 PYR/PYL/RCAR proteins, which were recently reported as ABA-binding signal transduction proteins, providing evidence for in vivo PYR/PYL/RCAR interactions with ABI1 in Arabidopsis. ABI1–PYR1 interaction was stimulated within 5 min of ABA treatment in Arabidopsis. Interestingly, in contrast, PYR1 and SnRK2.3 co-immunoprecipitated equally well in the presence and absence of ABA. To investigate the biological relevance of the PYR/PYLs, we analysed pyr1/pyl1/pyl2/pyl4 quadruple mutant plants and found strong insensitivities in ABA-induced stomatal closure and ABA-inhibition of stomatal opening. These findings demonstrate that ABI1 can interact with several PYR/PYL/RCAR family members in Arabidopsis, that PYR1–ABI1 interaction is rapidly stimulated by ABA in Arabidopsis and indicate new SnRK2 kinase-PYR/PYL/RCAR interactions in an emerging model for PYR/PYL/RCAR-mediated ABA signalling.