Uncovering the Role of Exo1 in Meiotic Recombination

揭示 Exo1 在减数分裂重组中的作用

• 批准号: 10547751
• 负责人: Lisette Payero
• 金额: $ 3.92万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-06 至 2024-07-05
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10547751
• 关键词: Alleles; Aneuploidy; Binding; Catalytic Domain; Cell division; Chimeric Proteins; Chromosomes; Competence; Couples; Cruciform DNA; DNA; DNA Binding; DNA Binding Domain; Data; Defect; Dissection; Ensure; Excision; Failure; Frequencies; Genetic; Genetic Crossing Over; Genetic Recombination; Genetic Screening; Genetic Variation; Germ Cells; Homologous Gene; Human; Infertility; Length; Location; Measures; Meiosis; Meiotic Recombination; Mismatch Repair; Modeling; Mutation; Pathway interactions; Pattern; Peptides; Phenotype; Play; Process; Production; Proteins; Resolution; Role; Saccharomycetales; Specificity; Spontaneous abortion; Spottings; Structure; Testing; Work; Yeasts; alpha helix; egg; endonuclease; experimental study; follow-up; genetic information; genome-wide; insight; mutant; novel; nuclease; recruit; repaired; scaffold; segregation

PROJECT SUMMARY Meiosis is a specialized form of cell division that results in the formation of gametes. Meiotic recombination is a crucial step in this process during which homologous chromosomes physically interact and exchange genetic information. The final recombination DNA intermediate in this process is the double Holliday Junction (dHJ). A major question in the meiosis field is the mechanism through which dHJs are resolved in a biased manner to create crossover products between homologs. Mlh1-Mlh3, the nuclease responsible for resolving the majority of dHJs in budding yeast, does not appear to be intrinsically capable of recognizing and cleaving dHJs in a biased manner. This observation combined with genetic screens revealing a wide variety of crossover promoting factors indicates that other proteins may interact at the dHJ to promote biased resolution. Here I aim to interrogate Exo1, a crossover promoting factor with well-established roles as a nuclease in homology directed repair (HDR) and mismatch repair (MMR). Interestingly, despite playing an important role in crossover formation previous work shows that catalytically deficient exo1 mutants do not suffer reductions in crossover frequencies, suggesting a meiotic role for Exo1 that is independent of its nuclease activity. Here, I will investigate the mechanism through which Exo1 promotes the formation of crossovers. I hypothesize that Exo1 acts as a scaffold at the dHJ to stabilize and orient Mlh1-Mlh3 through direct interaction with both the DNA and Mlh1. Additionally, I will follow up on my recent work indicating a pro-CO activity of Exo1 independent of Mlh1 Mlh3 functions that acts upstream of resolution. This work will provide insight into long-standing questions in the meiosis field and open up exciting new paths for future research.

项目概要 减数分裂是细胞分裂的一种特殊形式，导致配子的形成。减数分裂重组是 这一过程中的关键步骤，在此过程中同源染色体发生物理相互作用并交换遗传信息 信息。此过程中最终的重组 DNA 中间体是双霍利迪连接点 (dHJ)。一个 减数分裂领域的主要问题是 dHJ 以偏向方式解决的机制 在同系物之间创建交叉产品。 Mlh1-Mlh3，负责解决大多数问题的核酸酶 芽殖酵母中的 dHJ，似乎本质上不具备识别和切割 dHJ 的能力。 带有偏见的方式。这一观察结果与遗传筛选相结合，揭示了多种交叉 促进因子表明其他蛋白质可能在 dHJ 处相互作用以促进偏倚分辨率。我的目标是这里 询问 Exo1，一种交叉促进因子，具有作为同源核酸酶的明确作用 定向修复（HDR）和错配修复（MMR）。有趣的是，尽管在跨界中发挥着重要作用 先前的工作表明，催化缺陷的 exo1 突变体不会减少交叉 频率，表明 Exo1 的减数分裂作用与其核酸酶活性无关。在这里，我将 研究 Exo1 促进交叉形成的机制。我假设Exo1 作为 dHJ 处的支架，通过与 DNA 和 DNA 直接相互作用来稳定和定向 Mlh1-Mlh3 Mlh1。此外，我将跟进我最近的工作，表明 Exo1 的亲 CO 活性独立于 Mlh1 Mlh3 的功能作用于解析的上游。这项工作将深入了解长期存在的问题 减数分裂领域，并为未来的研究开辟令人兴奋的新路径。