Auxin-Binding Protein 1 is a negative regulator of the SCFTIR1/AFB pathway
Auxin-Binding Protein 1 is a negative regulator of the SCFTIR1/AFB pathway
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DOI：
10.1038/ncomms3496
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发表时间：
2013-09-01
影响因子：
16.6
通讯作者：
Perrot-Rechenmann, Catherine
中科院分区：
文献类型：
--
作者：
Tromas, Alexandre;Paque, Sebastien;Perrot-Rechenmann, Catherine
生长素是一种主要的植物激素，控制植物生长和发育的大部分方面。生长素由两类不同的受体感知：运输抑制剂反应1（TIR 1，或生长素相关的F盒（AFB））和生长素/吲哚-3-乙酸（AUX/IAA）共受体，控制对生长素的转录反应，以及生长素结合蛋白1（ABP 1），控制各种生长和发育过程。迄今为止，ABP 1的作用模式仍然知之甚少，其与TIR 1/AFB-AUX/IAA共受体的功能相互作用仍然难以捉摸。在这里，我们结合联合收割机遗传和生物化学的方法来深入了解这两个途径的整合。我们发现，ABP 1是基因上游的TIR 1/AFB; ABP 1敲低导致增强降解AUX/IAA阻遏物，独立于其对内吞作用，通过SCFTIR 1/AFB E3泛素连接酶途径。SCF泛素依赖性通路的正、负调控可能是紧密控制细胞凋亡介导的反应的共同机制。
Auxin is a major plant hormone that controls most aspects of plant growth and development. Auxin is perceived by two distinct classes of receptors: transport inhibitor response 1 (TIR1, or auxin-related F-box (AFB)) and auxin/indole-3-acetic acid (AUX/IAA) coreceptors, that control transcriptional responses to auxin, and the auxin-binding protein 1 (ABP1), that controls a wide variety of growth and developmental processes. To date, the mode of action of ABP1 is still poorly understood and its functional interaction with TIR1/AFB-AUX/IAA coreceptors remains elusive. Here we combine genetic and biochemical approaches to gain insight into the integration of these two pathways. We find that ABP1 is genetically upstream of TIR1/AFBs; ABP1 knockdown leads to an enhanced degradation of AUX/IAA repressors, independently of its effects on endocytosis, through the SCFTIR1/AFB E3 ubiquitin ligase pathway. Combining positive and negative regulation of SCF ubiquitin-dependent pathways might be a common mechanism conferring tight control of hormone-mediated responses.