Biochemical Characterization of Arabidopsis Complexes Containing CONSTITUTIVELY PHOTOMORPHOGENIC1 and SUPPRESSOR OF PHYA Proteins in Light Control of Plant Development[W]
Biochemical Characterization of Arabidopsis Complexes Containing CONSTITUTIVELY PHOTOMORPHOGENIC1 and SUPPRESSOR OF PHYA Proteins in Light Control of Plant Development[W]
复制标题
DOI：
10.1105/tpc.107.056580
复制
发表时间：
2008-09
期刊：
影响因子：
--
通讯作者：
Danmeng Zhu;Alexander Maier;Jae-Hoon Lee;S. Laubinger;Y. Saijo;Haiyang Wang;Li-jia Qu;U. Hoecker-U.-Hoeck
中科院分区：
文献类型：
--
作者：
Danmeng Zhu;Alexander Maier;Jae-Hoon Lee;S. Laubinger;Y. Saijo;Haiyang Wang;Li-jia Qu;U. Hoecker-U.-Hoeck
COP 1（CONSTITUTIVELY PHOMOPHOGENIC 1）和四个部分冗余SPA（SUPPLYOR OF PHYA）蛋白协同工作，通过靶向关键转录因子和光敏色素A，通过26 S蛋白酶体降解，抑制拟南芥中的光形态建成。在这里，我们报告了详细的SPA-COP 1复合物的生化特性。这四种内源性SPA蛋白可以在体内与COP 1形成稳定的复合物，而与光照条件无关，但在不同组织和光照条件下表现出不同的表达谱。SPA蛋白可以自缔合或彼此相互作用，形成SPA-COP 1复合物的异质组，其中确切的SPA蛋白组成根据单个SPA蛋白的丰度而变化。四种SPA蛋白可以分为两个功能组，这取决于它们的相互作用亲和力，它们对伸长下胚轴5降解的调节，以及它们对COP 1蛋白积累的相反作用。主要SPA蛋白中的功能丧失突变可能导致整体SPA-COP 1 E3连接酶活性显著降低，导致部分组成型光形态发生表型。因此，这项研究提供了一个深入的SPA-COP 1 E3连接酶复合物的生物化学观点，并提供了新的见解的分子基础上，其独特的作用，在植物发育的光控制。
COP1 (for CONSTITUTIVELY PHOTOMORPHOGENIC1) and the four partially redundant SPA (for SUPPRESSOR OF PHYA) proteins work in concert to repress photomorphogenesis in Arabidopsis thaliana by targeting key transcription factors and phytochrome A for degradation via the 26S proteasome. Here, we report a detailed biochemical characterization of the SPA-COP1 complexes. The four endogenous SPA proteins can form stable complexes with COP1 in vivo regardless of light conditions but exhibit distinct expression profiles in different tissues and light conditions. The SPA proteins can self-associate or interact with each other, forming a heterogeneous group of SPA-COP1 complexes in which the exact SPA protein compositions vary depending on the abundance of individual SPA proteins. The four SPA proteins could be divided into two functional groups depending on their interaction affinities, their regulation of ELONGATED HYPOCOTYL5 degradation, and their opposite effects on COP1 protein accumulation. Loss-of-function mutations in a predominant SPA protein may cause a significant reduction in the overall SPA-COP1 E3 ligase activity, resulting in a partial constitutive photomorphogenic phenotype. This study thus provides an in-depth biochemical view of the SPA-COP1 E3 ligase complexes and offers new insights into the molecular basis for their distinct roles in the light control of plant development.