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: 10386110
• 负责人: Lisette Payero
• 金额: $ 3.82万
• 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/10386110
• 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; 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; base; 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.

项目摘要 减数分裂是细胞分裂的一种特殊形式，导致配子的形成。减数分裂重组是一种 同源染色体相互作用和交换遗传信息的过程中的关键步骤 信息.在这个过程中，最终的重组DNA中间体是双霍利迪连接（dHJ）。一 减数分裂领域的一个主要问题是dHJ以偏向的方式分解的机制， 在同类产品之间创造交叉产品。Mlh 1-Mlh 3，负责解析大多数 在芽殖酵母中的dHJ，似乎并不固有地能够识别和切割dHJ在芽殖酵母中。 有偏见的方式。这一观察与遗传筛选相结合，揭示了各种各样的交叉 促进因子表明其他蛋白质可能在dHJ处相互作用以促进有偏差的分辨率。我瞄准这里 询问Exo 1，一种交叉促进因子，作为同源性核酸酶具有公认的作用， 定向修复（HDR）和错配修复（MMR）。有趣的是，尽管在跨界中扮演着重要角色， 以前的工作表明，催化缺陷exo 1突变体不会减少交叉 频率，这表明Exo 1的减数分裂作用是独立于其核酸酶活性。来，我来 研究Exo 1促进交叉形成的机制。我假设exo 1 作为dHJ处的支架，通过与DNA的直接相互作用来稳定和定向Mlh 1-Mlh 3， Mlh 1.此外，我将继续我最近的工作，表明一个亲CO活动的exo 1独立于Mlh 1 mlh 3的功能，作用于上游的决议。这项工作将提供洞察长期存在的问题， 减数分裂领域，并为未来的研究开辟了令人兴奋的新途径。