Red-Light-Dependent Interaction of phyB with SPA1 Promotes COP1-SPA1 Dissociation and Photomorphogenic Development in Arabidopsis
Red-Light-Dependent Interaction of phyB with SPA1 Promotes COP1-SPA1 Dissociation and Photomorphogenic Development in Arabidopsis
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DOI：
10.1016/j.molp.2014.11.025
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发表时间：
2015-03-02
期刊：
影响因子：
27.5
通讯作者：
Yang, Hong-Quan
中科院分区：
文献类型：
--
作者：
Lu, Xue-Dan;Zhou, Chuan-Miao;Yang, Hong-Quan
拟南芥光敏色素（phyA-phyE）是一种光感受器，主要感受红光和远红光。光敏色素通过信号传导途径促进光照射后的光形态发生发育，该信号传导途径涉及PIF（光敏色素相互作用因子）的快速降解和COP 1（组成性光形态发生1）核积累的抑制，分别通过与PIF和COP 1的物理相互作用。phyA和phyB，两个最好的特点光敏色素，调节植物光形态建成主要在远红光和红光下，分别。植物色素A1的供应者SPA 1（SupplementorofPhytochromeA 1）与COP 1相互作用，促进COP 1的活性，抑制光形态建成。在这里，我们报告，在红光下的phyB促进光形态建成的机制涉及直接的物理和功能之间的相互作用红光激活phyB和SPA 1。我们发现SPA 1在PHYB基因下游起作用，抑制红光下的光形态建成。在酵母和拟南芥中的蛋白质相互作用的研究表明，光活化的phyB抑制协会的SPA 1与COP 1，这是介导的，至少部分，通过红光依赖的相互作用的phyB与SPA 1。此外，我们表明，phyA物理相互作用与SPA 1在PFR形式依赖的方式，SPA 1的下游的PHYA的行为，以调节光形态发生在远红光。本研究提供了一个遗传和生物化学模型，光激活phyB如何抑制COP 1-SPA 1复合物的活性，通过直接与SPA 1的相互作用，促进光形态建成在红光。
Arabidopsis phytochromes (phyA-phyE) are photoreceptors dedicated to sensing red/far-red light. Phytochromes promote photomorphogenic developments upon light irradiation via a signaling pathway that involves rapid degradation of PIFs (PHYTOCHROME INTERACTING FACTORS) and suppression of COP1 (CONSTITUTIVE PHOTOMORPHOGENIC 1) nuclear accumulation, through physical interactions with PIFs and COP1, respectively. Both phyA and phyB, the two best characterized phytochromes, regulate plant photomorphogenesis predominantly under far-red light and red light, respectively. It has been demonstrated that SPA1 (SUPPRESSOR OF PHYTOCHROME A 1) associates with COP1 to promote COP1 activity and suppress photomorphogenesis. Here, we report that the mechanism underlying phyB-promoted photomorphogenesis in red light involves direct physical and functional interactions between red-light-activated phyB and SPA1. We found that SPA1 acts genetically downstream of PHYB to repress photomorphogenesis in red light. Protein interaction studies in both yeast and Arabidopsis demonstrated that the photoactivated phyB represses the association of SPA1 with COP1, which is mediated, at least in part, through red-light-dependent interaction of phyB with SPA1. Moreover, we show that phyA physically interacts with SPA1 in a Pfr-form-dependent manner, and that SPA1 acts downstream of PHYA to regulate photomorphogenesis in far-red light. This study provides a genetic and biochemical model of how photoactivated phyB represses the activity of COP1-SPA1 complex through direct interaction with SPA1 to promote photomorphogenesis in red light.