Investigating the Molecular Architecture of the Synaptonemal Complex and its Role in Crossover Formation.

项目摘要 在有性繁殖的生物体中，稳定基因组的遗传依赖于减数分裂， 从二倍体细胞产生单倍体配子的分裂。这一过程中的缺陷导致染色体异常 数字，也被称为非整倍体，这是不育和发育障碍的主要原因， 唐氏综合症。减数分裂期间染色体的成功分离需要同源染色体配对，突触， 并形成交叉。突触的过程是由一种蛋白质结构的形成所定义的，这种蛋白质结构被称为突触。 联会复合体（SC），它将两个同源物连接在一起，并作为交叉的支架 重组SC由两个平行的染色质相关的轴向元件和一个中心的延伸组成。 由横向元件组成的区域，其以类似拉链的方式连接同源物。尽管其结构 由于大多数真核生物的保守性，对SC组装及其调控机制知之甚少。 功能协调发展的本研究的目的是利用线虫C. elegans作为模式生物。C.秀丽线虫至少由四个卷曲螺旋组成 蛋白质SYP-1、SYP-2、SYP-3和SYP-4，它们的组装是相互依赖的。我最近 发现了SC的两个新组件，SYP-5和SYP-6，它们彼此同源， 突触中的冗余角色在目标1中，我将扩展这些发现，并确定高度 SYP-5/6的保守的无序C-末端。最近的证据在C。elegans表明SC具有液体状 特性，从而使远程信号转导介导染色体范围的交叉控制。我 我将研究SYP-5/6的C-末端尾部是否有助于SC和交叉的这种动态行为 调控在目的2中，我将使用SYP蛋白复合物确定SC的生化特性 从C.以及重组蛋白质。我来确定化学计量和蛋白质- SC组分之间的蛋白质相互作用，并决定其形成的倾向和要求 聚合物或液体状液滴。总体而言，这项工作将为SC的基本原则提供关键见解 组织及其功能，这将广泛应用于包括人类在内的物种。通过工作 在本申请中，我将学习遗传学，细胞生物学和蛋白质生物化学的关键实验技能。 结合国家的最先进的研究环境，优秀的培训教师，和职业发展 约翰霍普金斯大学是一个理想的地方，以促进我的发展成为一个独立的科学家。

Project Summary In sexually reproducing organisms, inheritance of a stable genome relies on meiosis, a specialized cell division that produces haploid gametes from a diploid cell. Defects in this process lead to abnormal chromosome numbers, also known as aneuploidy, and this is a major cause of infertility and developmental disorders such as Down Syndrome. Successful segregation of chromosomes during meiosis requires that homologs pair, synapse, and form crossovers. The process of synapsis is defined by the formation of a proteinaceous structure called the synaptonemal complex (SC), which links two homologs together and serves as a scaffold for crossover recombination. The SC consists of two parallel stretches of chromatin-associated axial elements and a central region comprised of transverse elements, which connect homologs in a zipper-like fashion. Despite its structural conservation across most eukaryotes, little is known about the mechanisms governing SC assembly and its functions. The goal of this proposal is to determine the structure and functions of the SC using the nematode C. elegans as a model organism. The transverse elements in C. elegans are comprised of at least four coiled-coil proteins, SYP-1, SYP-2, SYP-3, and SYP-4, which are interdependent for their assembly. I have recently discovered two new components of the SC, SYP-5 and SYP-6, which are paralogous to each other and play redundant roles in synapsis. In Aim 1, I will extend these findings and determine the significance of highly conserved disordered C-termini of SYP-5/6. Recent evidence in C. elegans suggests that the SC has liquid-like properties, thereby enabling long-range signal transduction to mediate a chromosome-wide crossover control. I will examine whether the C-terminal tails of SYP-5/6 contribute to this dynamic behavior of the SC and crossover regulation. In Aim 2, I will determine the biochemical characteristics of the SC using the SYP protein complexes purified from C. elegans as well as the recombinant proteins. I will determine the stoichiometry and protein- protein interactions among the SC components and determine their propensity and requirements to form polymers or liquid-like droplets. Overall, this work will provide key insights into the fundamental principles of SC organization and its functions, which will be broadly applied across species, including humans. Through the work proposed in this application, I will learn key experimental skills in genetics, cell biology, and protein biochemistry. Combined with the state-of-the-art research environment, excellent training faculty, and career development programs, Johns Hopkins University is an ideal place to foster my development into an independent scientist.