Structure and Dynamics of the Synaptonemal Complex

描述(由申请人提供)： 项目摘要/摘要在减数分裂前期，配对染色体之间的同源性识别与沿着染色体对(突触)长度的蛋白质支架--联会复合体(SC)的组装相协调。同源重组在组装的SC的背景下进行，许多同源重组事件依赖于SC进行适当的分布和/或完成。我们的实验室研究了SC的结构以及SC组装如何与减数分裂前期染色体事件相协调。最近我们证明，在酿酒酵母中，即使在染色体完全突触之后，至少有一些SC成分在减数分裂前期仍保持动态。此外，我们发现，与SC上的其他位点相比，重组位点保持着不同的SC动态。此外，我们的初步研究表明，定位于SC结构的SUMO与卷曲卷曲的ZIP1蛋白在减数分裂染色体上组装SC具有相互依赖的关系。通过使用超分辨光学显微镜进行开创性的成像研究，我们还发现SUMO定位于ZIP1N末端，位于SC结构的中心。最后，该实验室已经分离出ZIP1等位基因，这些等位基因在染色体上组装，独立于规范的调节器。每个ZIP1等位基因代表ZIP1末端C端的单一氨基酸替换，并可能揭示ZIP1组装机制的某些方面。这项资助计划的目的是1)使用我们已建立的遗传和显微工具来定义SC内所有已知突触蛋白的分子结构和动力学，以及2)分离突触起始蛋白和ZIP1的点突变等位基因，以确定每个蛋白质在突触和其他减数分裂前期染色体事件中的分子特征。

DESCRIPTION (provided by applicant): Project Summary/Abstract During meiotic prophase, homology recognition between partner chromosomes is coordinated with the assembly of a proteinaceous scaffold, the synaptonemal complex (SC), along the length of the chromosome pair (synapsis). Interhomolog recombination progresses within the context of assembled SC, and many interhomolog recombination events rely on SC for their proper distribution and/or completion. Our lab investigates SC structure and how SC assembly is coordinated with meiotic prophase chromosomal events. Recently we demonstrated that In S. cerevisiae, at least some components of the SC remain dynamic during meiotic prophase, even after chromosomes are fully synapsed. Moreover we found that recombination sites maintain a different SC dynamic as compared to other sites on the SC. Furthermore, our preliminary studies show that SUMO, which localizes to SC structures, has a mutually dependent relationship with the coiled-coil Zip1 protein to assemble SC on meiotic chromosomes. With pioneering imaging studies using super-resolution light microscopy, we have also shown that SUMO localizes to Zip1 N termini, at the center of SC structure. Finally, the lab has isolated zip1 alleles that assemble on chromosomes independent of canonical regulators. Each zip1 allele represents a single amino acid substitution at the extreme C terminus of Zip1 and may reveal aspects of the mechanism underlying Zip1 assembly. The purpose of this grant proposal is to 1) use our established genetic and microscopy tools to define the molecular architecture and dynamics of all known synapsis proteins within the SC, and 2) to isolate point mutant alleles of synapsis initiation proteins and Zip1 in order to identif molecular features of each protein responsible for their function in synapsis and other meiotic prophase chromosomal events.