Modulation of Plant Transcription Factor Function by Small Molecules

该项目的目标是揭示一种新型反馈调节（一种小化学分子可以调节自身生产的机制）的见解，该机制由分子与控制该分子生产的主蛋白质调节剂的结合介导。该项目将有助于博士后研究员的科学和专业发展，并将为从事研究的本科生提供研究经验。该项目包括在定量生物化学夏季实践研讨会的发展，这将有利于本科生和研究生，博士后研究人员，和初级教师。在玉米中，R蛋白是一种转录因子，激活基因编码的酶的类黄酮生物合成途径的紫色花青素色素的转录。 初步数据表明，类黄酮分子的R，通过一个特定的蛋白质结构域（ACT域）的结合，调节蛋白质-蛋白质相互作用和DNA结合能力的R蛋白，从而导致差异识别的启动子中的基因参与类黄酮途径。 该模型的实验测试将：1）建立R与已被鉴定为与ACT结合的类黄酮相互作用的体内结果; 2）研究ACT-小分子结构-功能关系，通过定义哪些其他小分子与ACT结合，鉴定与小分子相互作用相关的ACT残基，并确定该结果对于其他植物转录因子中的ACT结构域的普遍性;和3）通过将遗传资源与细胞方法相结合以研究在何处和哪些相互作用发生，在存在和不存在类黄酮或其他小分子的情况下。 这项工作有望揭示一种新型的反馈调节机制（代谢物结合调节负责配体合成的转录因子），这可以作为其他小代谢物如何调节自身合成的模型。该项目由生物科学理事会（分子和细胞生物科学部的遗传机制计划;综合有机体系统部的植物基因组研究计划）和数学和物理科学理事会（化学部的生命过程化学计划）共同资助。

The goal of this project is to reveal insights into a novel type of feedback regulation (a mechanism by which a small chemical molecule can regulate its own production) mediated by the binding of a molecule to the master protein regulator controlling the production of that molecule. The project will contribute to the scientific and professional development of postdoctoral fellows and will provide research experiences for undergraduate students in research. The project includes the development of a Summer Practical Workshop in Quantitative Biochemistry, which will benefit both undergraduate and graduate students, postdoctoral researchers, and junior faculty.In corn, the R protein is a transcription factor that activates transcription of genes encoding enzymes in the flavonoid biosynthetic pathway for purple anthocyanin pigments. Preliminary data suggest that binding of flavonoid molecules to R, through a specific protein domain (the ACT domain), modulates the protein-protein interactions and the DNA-binding abilities of the R protein, leading in turn to differential recognition of promoters in the genes involved in the flavonoid pathway. Experimental tests of this model will: 1) Establish the in vivo consequences of the interaction of R with flavonoids that have been identified to bind to the ACT; 2) Investigate ACT-small molecule structure-function relationships, by defining which other small molecules bind to the ACT, identifying the ACT residues relevant for the small molecule interaction, and establishing how general the results are for ACT domains in other plant transcription factors; and 3) Analyze in vivo the dynamic associations controlled by the ACT domain of R, by combining genetic resources with cellular approaches to investigate where and which interactions occur, in the presence and absence of flavonoids or other small molecules. The work is expected to reveal a new type of feedback regulatory mechanism (metabolite binding regulating a transcription factor responsible for synthesis of the ligand), which could serve as a model for how other small metabolites might regulate their own synthesis. This project is co-funded by the Directorate for Biological Sciences (Genetic Mechanisms Program in the Division of Molecular and Cellular Biosciences; Plant Genome Research Program in the Division of Integrative Organismal Systems) and by the Directorate for Mathematics and Physical Sciences (Chemistry of Life Processes Program in the Division of Chemistry).