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

了解细胞机制如何读取基因组以使细胞存活是生物学研究的一个主要焦点。细胞机制的一种特殊酶包含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的重复的原因或单个重复的特定功能目前尚不清楚。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。这种方法的开发和应用将与日本岛根大学医学院的Hiroaki Kato博士合作进行，他是细胞机制控制基因表达的专家。从这项工作中获得的结果将推动进一步了解蛋白质重复序列在健康和患病细胞中基因表达过程中的作用。转录周期的进展是由RNA聚合酶II的c端结构域的七肽重复密切调节的。这些重复序列在酵母中有26个，在人类中有52个，它们在翻译后被修饰以募集额外的蛋白质复合物到转录位点。该项目将研究重复序列的特定延伸，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进入裂变酵母菌模式生物的途径，以补充以前对出芽酵母的研究。基于芽殖酵母的研究方法，将在裂变酵母中建立一个新的RNA聚合酶II研究系统。然后，该系统将应用于研究异染色质沉默期间的重复特异性蛋白质募集。存在于裂变酵母中（并与高等真核生物共享）但不存在于出芽酵母中的途径。这种比较方法将揭示c端重复序列在调节RNA聚合酶II活性中的额外空间机制。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).