Mechanisms of chromosome-scale signal propagation

染色体尺度信号传播机制

• 批准号: 8888653
• 负责人: Andreas Hochwagen
• 金额: $ 30.07万
• 依托单位: NEW YORK UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-03-01 至 2019-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8888653
• 关键词: Animal Model; Biochemistry; Biology; Cell Nucleus; Cells; Centromere; Chromosomal Breaks; Chromosomal Instability; Chromosome Pairing; Chromosome Structures; Chromosomes; Communication; Congenital Abnormality; Coupled; Cytology; DNA Damage; DNA Double Strand Break; DNA Repair; Data; Development; Distant; Double Strand Break Repair; Engineering; Ensure; Environment; Excision; Exhibits; Genetic Crossing Over; Genetic Recombination; Genome; Genomic Instability; Genomics; Germ Cells; Goals; Homologous Gene; Human; Infertility; Lesion; Link; Malignant Neoplasms; Maps; Measures; Mediating; Meiosis; Meiotic Recombination; Methods; Microscopy; Molecular; Nuclear; Outcome; Pattern; Phosphoric Monoester Hydrolases; Phosphorylation; Process; Production; Prophase; Proteins; Radiation therapy; Recruitment Activity; Regulation; Research; Resolution; Risk; Role; Saccharomyces cerevisiae; Signal Transduction; Sister Chromatid; Site; Source; Staging; Structure; Synaptonemal Complex; Testing; Time; Yeasts; base; cancer risk; chemotherapy; coping; egg; genetic analysis; genome integrity; genome-wide; insight; knock-down; novel; prevent; programs; public health relevance; repaired; research study; response; segregation; sperm cell; tumor progression

 DESCRIPTION (provided by applicant): The overall goal of this project is to determine how cells communicate chromosome break signals across large chromosomal distances. DNA double-strand breaks (DSBs) are dangerous insults to genome integrity because of their potential to cause chromosome rearrangements and chromosome instability, both of which are strongly associated with cancer progression as well as birth defects. The risk of genome instability is dramatically amplified in situations where multiple DSBs occur at the same time, as is the case with radiotherapy and many forms of chemotherapy. However, at least under certain circumstances, cells are able to efficiently orchestrate the repair of multiple concurrent DSBs. The most prominent example is meiosis, when germ cells introduce hundreds of programmed DSBs across most of their genomes. A key feature of meiotic DSB repair is that it is coordinated at a chromosomal level, such that repair decisions at one DSB are transmitted in a chromosome- autonomous way to DSBs that occurred a large distance away on the same chromosome. The mechanism by which such communication occurs is essentially unknown, but would provide important new insights into how cells cope with massive chromosomal insults. Preliminary analysis of meiotic DNA damage signaling in the sexually reproducing yeast Saccharomyces cerevisiae revealed several signals that appeared to visibly propagate along meiotic chromosomes following meiotic DSB formation. We hypothesize that these signals form part of the communication apparatus that allows meiotic cells to communicate DSB repair decisions. The signals take several different forms, including propagation of protein phosphorylation and changes in chromosome structure, and exhibit temporal and spatial differences, suggesting that they may communicate different aspects of the meiotic DSB repair process. To determine the meiotic roles of these signals, the dynamics of chromosomal signaling and DSB repair will be analyzed by genetics and super resolution microscopy, taking advantage of a novel conditional nuclear depletion approach that allows stage-specific knock-downs of the often pleiotropic repair factors. In addition, signal integration will be analyzed usig cytology, biochemistry, and physical analysis of repair intermediates. Finally, the proposal will close a major technological gap with the development of a method to map DSB repair intermediates across the entire genome. Together, these analyses will provide first insights into the mechanisms of chromosomal signal propagation controlling DNA repair, and open new avenues for understanding the errors in DSB repair that cause birth defects and cancer.

 描述（由适用提供）：该项目的总体目标是确定细胞如何在大染色体距离上传达染色体断裂信号。 DNA双链断裂（DSB）是对基因组完整性的危险侮辱，因为它们有可能引起染色体重排和染色体不稳定性，这两者都与癌症进展以及先天缺陷密切相关。基因组不稳定性的风险显然是减数分裂DSB修复的关键特征，是它在染色体水平上进行协调，因此，一个DSB处的维修决策以染色体自主的方式传输到在同一染色体上发生较大距离的DSB。这种交流发生的机制本质上是未知的，但将提供有关细胞如何应对大规模染色体损伤的重要新见解。对酿酒酵母的性繁殖酵母糖酵母中的减数分裂DNA损伤信号传导的初步分析显示，几个信号在减数分裂DSB形成后似乎沿减数分裂染色体显着地传播。我们假设这些信号构成了通信设备的一部分，该信号使减数分裂细胞可以传达DSB修复决策。信号采用几种不同的形式，包括蛋白质磷酸化的传播以及染色体结构的变化以及暴露的临时和空间差异，表明它们可能传达了减数分裂DSB修复过程的不同方面。为了确定这些信号的减数分裂作用，将通过遗传学和超级分辨率显微镜分析染色体信号传导和DSB修复的动力学，利用一种新型的条件核部署方法，该方法允许经常进行Pleiotiotiotiotiotiotiotiotropic修复因子的阶段特异性敲除。此外，将分析信号积分的USIG细胞学，生物化学和修复中间体的物理分析。最后，该提案将通过开发绘制整个基因组的DSB修复中间体的方法的发展来缩小主要技术差距。总之，这些分析将首先了解控制DNA修复的染色体信号传播机制，并开放新的途径，以理解导致先天缺陷和癌症的DSB修复中的误差。