Molecular Analysis of the rbcS Multigene Family

转录调控是植物红血球基因家族发育和器官特异性表达的重要调控步骤。在植物基因中，RBCS启动子是最具顺式作用的DNA序列元件和调控因子的启动子之一。相比之下，人们对将监管组成部分整合到发展计划中的了解要少得多。以番茄为模型系统，我们已经证明了每个RBC启动子的时间和器官特异性活性与DNA结合蛋白与特定DNA序列之间复杂相互作用的变化有关，这些DNA序列在启动子区域之间是共享的或唯一的。在番茄果实中，从幼果到成熟果实的过渡过程中，除一个外，所有的RBC启动子DNA-蛋白质复合体都消失了。这项提议将研究DNA-蛋白质相互作用中控制发育差异和器官特异性差异的机制。该项目将专注于五种不同的DNA结合蛋白，它们具有独特的结合特性。通过实验确定这些蛋白质在红细胞转录调控中的功能，并确定这些蛋白质在不同器官和果实发育过程中的表达是如何调节的。这一方法将为植物发育过程中调控DNA结合蛋白的机制提供新的和重要的见解。

Transcriptional regulation is an important control step in the developmental and organ-specific expression of the rbcS gene family in plants. Among plant genes, the rbcS promoter is one of the best characterized for cis-acting DNA sequence elements and transacting factors. In contrast, much less is known about the integration of the regulatory components into the developmental program. Using tomato as a model system, we have shown that the temporal and organ-specific activity of each rbcS promoter is correlated with changes in the complex interaction of DNA-binding proteins with specific DNA sequences that are shared or unique among the promoter regions. In tomato fruit, all but one of the rbcS promoter DNA-protein complexes disappear during the transition from young to ripening fruit. This proposal will investigate the mechanisms that control the developmental and organ-specific differences in DNA-protein interactions. The project will focus on five different DNA-binding proteins with unique binding characteristics. Experiments are presented to establish the function of the proteins in rbcS transcriptional control and to determine how the expression of the proteins is regulated in different organs and during fruit development. %%% This approach will provide novel and important insights into the mechanisms that control regulatory DNA-binding proteins during plant development.