Arabidopsis Kleisin Proteins and Their Role in Chromosome Biology

染色体内聚在细胞分裂和有性生殖过程中对染色体分离起着核心作用。除了控制姐妹染色单体内聚外，内聚蛋白对重组、染色体结构和稳定性、DNA损伤的修复至关重要，并可能有助于控制基因表达。因此，黏结蛋白对生物体的生存能力至关重要。本项目的目的是更好地了解姐妹染色单体内聚在植物有性生殖过程中是如何调节的，并研究姐妹染色单体内聚的新方面。对酵母和动物系统的研究提供了有关黏结蛋白复合物整体结构的信息，以及对黏结蛋白如何建立和去除的见解。内聚物的结构和调节的大多数方面是保守的。然而，在一些物种中发现了新的方面，这些方面为如何调节这一基本过程提供了重要的新见解。例如，拟南芥含有一种优先定位于核核的α -柔素（SYN3），这表明它在控制核糖体DNA （rDNA）结构和/或表达方面发挥了特殊作用。同样，SWI1也是植物在减数分裂过程中建立内聚所必需的一种特异性蛋白。本项目概述的实验将确定SYN3如何控制rDNA结构，并通过确定SWI1和CTF7在减数分裂中的作用来阐明植物如何建立姐妹染色单体内聚。在模式生物拟南芥中的实验结果将提供新的见解，并扩大我们对姐妹染色单体内聚和参与这一重要过程的蛋白质的认识。植物染色体内聚的研究对植物育种和改进农业生产具有重要意义。该项目将帮助培养一批未来的博士后、研究生和本科水平的科学家，包括在物理科学领域代表性不足的学生，他们将参与与该项目相关的独立研究项目。

Chromosome cohesion plays a central role in chromosome segregation during both cell division and sexual reproduction. In addition to controlling sister chromatid cohesion, cohesin proteins are critical for recombination, chromosome structure and stability, the repair of DNA lesions and may help control gene expression. Therefore, cohesin proteins are essential for the viability of organisms. The goal of this project is to better understand how sister chromatid cohesion is regulated during sexual reproduction in plants and to investigate novel aspects of sister chromatid cohesion. Studies in yeast and animal systems have provided information on the overall structure of the cohesin complex as well as insights into how cohesin is established and removed. Most aspects of the structure and regulation of cohesin complexes are conserved. However, novel aspects have been identified in some species and these are providing important new insights into how this essential process is regulated. For example, Arabidopsis contains an alpha-kleisin (SYN3) that is preferentially localized in the nucleolus, suggesting it has evolved a specialized role in controlling ribosomal DNA (rDNA) structure and/or expression. Likewise, SWI1 is a plant-specific protein that is required to establish cohesion during meiosis. Experiments outlined in this project will determine how SYN3 functions in controlling rDNA structure, and elucidate how plants establish sister chromatid cohesion by determining the role(s) of SWI1 and CTF7 in meiosis. Results from experiments in the model organism Arabidopsis will provide new insights and expand our knowledge of sister chromatid cohesion and the proteins involved in this essential process. Studies on chromosome cohesion in plants have many important implications for plant breeding and improving agricultural practices. This project will help train a number of future scientists at the postdoctoral, graduate and undergraduate levels, including students underrepresented in the physical sciences who will participate in independent research projects associated with this project.