Arabidopsis Kleisin Proteins and Their Role in Chromosome Biology

在细胞分裂和有性繁殖过程中，染色体凝聚力在染色体分离中起着核心作用。除了控制姐妹染色单体的凝聚力外，粘附素蛋白对重组、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的表达。因此，粘附素蛋白对于生物体的生存是必不可少的。这个项目的目标是更好地了解姐妹染色单体凝聚力在植物有性繁殖过程中是如何调节的，并研究姐妹染色单体凝聚力的新方面。对酵母和动物系统的研究提供了关于粘附素复合体的整体结构的信息，以及对粘附素是如何建立和去除的见解。粘附素复合体的结构和调节的大部分方面是保守的。然而，在一些物种中发现了新的方面，这些方面为如何调控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仁的α-kleisin(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的作用。同样，SWI1是一种植物特有的蛋白质，在减数分裂过程中需要建立凝聚力。本项目中概述的实验将确定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(S)来阐明植物如何建立姐妹染色单体凝聚力。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凝聚力和参与这一基本过程的蛋白质的了解。植物染色体凝聚力的研究对植物育种和改良农业实践具有重要意义。该项目将帮助培训一批未来的博士后、研究生和本科生，包括参加与该项目相关的独立研究项目的在自然科学领域任职人数不足的学生。

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.