Molecular and Genetic Analysis of the COP9 Complex, A Novel Light-Regulated Developmental Regulator in Arabidopsis

来自环境的信号被植物的特定调节受体感知，并与发育信号进行转导和整合，从而控制植物的生长发育。本研究的长期目标是通过拟南芥的光调节幼苗发育为模型系统，分析这些信号被转导和整合以调节植物发育的分子机制。发现了10个多效性COP/DET/FUS基因座，这些基因座突变后不能抑制黑暗环境下的光形态发生发育，导致暗生长的幼苗表型复制光照生长的兄弟姐妹。十个基因座之一的COP9基因座已被克隆，并被发现编码一种新的、普遍表达的23 kDa蛋白。结果表明，COP9是一个大的（560kDa）多亚基复合物中的一个亚基，该复合物是核定位的，其构象可能被光调制。结果表明，COP9复合体在介导光控制幼苗发育的网络联系中确定了一个步骤。为了进一步表征该复合体的结构及其在植物发育光调控网络中的功能作用，下一阶段的研究将集中在完成两个主要目标上：1)克隆该复合体的基因和亚基的生化特征；2)了解COP9复合体功能的生化和细胞基础及其与光调控网络中其他组分的分子相互作用。这项研究的完成将确定一个关键的调控复合体的性质，该复合体将光和其他可能的信号与幼苗发育联系起来，并可能为影响植物发育的光控制元件网络的调控组分之间的关系提供新的见解。* * *

9513366 Deng Signals from the environment are perceived by specific regulatory receptors in plants, and transduced and integrated with developmental signals to control growth and development. The long term goal of this research is to dissect the molecular mechanisms by which such signals are transduced and integrated to modulate plant development by using light-regulated seedling development of Arabidopsis thaliana as a model system. Ten pleiotropic COP/DET/FUS loci have been identified, which when mutated fail to suppress the photomorphogenic development in darkness and result in dark-grown seedlings phenocopying the light-grown siblings. One of the ten loci, COP9 locus, has been cloned and found to encode a novel, ubiquitously expressed 23 kDa protein. It was demonstrated that COP9 acts as a subunit in a large (560kDa) multiple subunit complex, which is nuclear localized and whose conformation is probably modulated by light. The results suggest that the COP9 complex defines a step in the nexus of the network mediating light control of seedling development. To further characterize the structure of the complex and its functional role in the network mediating light control of plant development, the next stage of investigation will focus on accomplishing two major goals: 1) cloning of the genes and biochemical characterization of the subunits of the complex and 2) understanding the biochemical and cellular basis of the function of the COP9 complex function and its molecular interaction with other components in the light regulatory network. %%% Accomplishment of the proposed investigation will ascertain the nature of a critical regulatory complex that links light and possibly other signals to seedling development and could provide novel insights into the relationships between regulatory components of the network of elements affecting light control of plant development. ***