EAPSI: Discovering Novel Functions of Protein Repeats Critical to Gene Expression

了解基因组是如何被细胞机器读取以使细胞存活的是生物学研究的一个主要重点。细胞器的一种特殊酶含有一个对基因表达至关重要的高度重复结构的不寻常区域。然而，具有如此多相同结构或单个重复的特定功能的重复的原因目前尚不清楚。该项目将开发新的遗传工具来研究这些重复序列在控制基因表达中的作用。这一方法的开发和应用将与日本岛根大学医学院的加藤博昭博士合作进行，加藤博明博士是细胞机械控制基因表达的专家。这项工作的结果将推动进一步了解蛋白质重复在健康和患病细胞的基因表达中的作用。整个转录周期的进展受到RNA聚合酶II C末端结构域的七肽重复序列的严格调控。这些重复序列在酵母中为26个，在人类中为52个，经过翻译后修饰，将更多的蛋白质复合体招募到转录位点。这个项目将研究特定的重复序列，以了解相同的蛋白质重复序列是否在招募蛋白质因子方面具有独特的功能。与加藤博士的合作将提供获得分裂酵母模式生物的途径，以补充之前对萌芽酵母的研究。一种基于发芽酵母方法的研究RNA聚合酶II的新系统将在裂解酵母中开发。然后，该系统将被应用于研究异染色质沉默过程中重复特定蛋白的募集？在分裂酵母中存在的一种途径(与高等真核生物共有)，但在萌芽酵母中不存在。这种比较方法将揭示C末端结构域重复在调节RNA聚合酶II活性方面的额外空间机制。NSF EAPSI奖是与日本科学促进会(JSPS)合作资助的。

Understanding how the genome is read by the cellular machinery to allow the cell to survive is a major focus of biological research. One specific enzyme of the cellular machinery contains an unusual region of highly repetitive structure critical to gene expression. However the reason for having so many repetitions of the same structure or the specific function of individual repeats is currently unknown. This project will develop novel genetic tools to investigate the role of these repeats in controlling gene expression. The development and application of this approach will be performed in collaboration with Dr. Hiroaki Kato of the Shimane University School of Medicine in Japan, an expert in the control of gene expression by the cellular machinery. Results obtained from this work will drive further understanding of the role of protein repeats during gene expression in both healthy and sick cells. Progress through the transcription cycle is tightly regulated by the heptad repeats of the C-terminal domain of RNA polymerase II. These repeats, numbering 26 in yeast and 52 in humans, are post-translationally modified to recruit additional protein complexes to the site of transcription. This project will investigate specific stretches of repeats to understand if identical protein repeats can have unique functions in recruiting protein factors. Collaboration with Dr. Kato will provide access to the fission yeast model organism to complement previous studies in budding yeast. A new system for studying RNA polymerase II based upon a method used in budding yeast will be developed in fission yeast. The system will then be applied to study repeat-specific protein recruitment during heterochromatin silencing ? a pathway present in fission yeast (and shared with higher eukaryotes) but absent in budding yeast. This comparative approach will uncover additional spatial mechanisms of the C-terminal domain repeats in regulating the activity of RNA polymerase II. This NSF EAPSI award is funded in collaboration with the Japan Society for the Promotion of Science (JSPS).