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(申请人提供)：这个项目的总体目标是确定细胞如何跨越大的染色体距离传递染色体断裂信号。DNA双链断裂(DSB)是对基因组完整性的危险侮辱，因为它们可能导致染色体重排和染色体不稳定，这两者都与癌症进展和出生缺陷密切相关。在多个DSB同时发生的情况下，基因组不稳定的风险被显著放大，就像放射治疗和多种形式的化疗一样。然而，至少在某些情况下，单元能够有效地协调多个并发DSB的修复。最突出的例子是减数分裂，当生殖细胞在它们的大多数基因组中引入数百个程序化的DSB时。减数分裂DSB修复的一个关键特征是它在染色体水平上是协调的，这样一个DSB上的修复决定以染色体自主的方式传递到发生在同一染色体上很远的DSB上。这种交流发生的机制基本上是未知的，但将为细胞如何应对大规模的染色体侮辱提供重要的新见解。对有性生殖酵母菌的减数分裂DNA损伤信号的初步分析表明，在减数分裂DSB形成后，有几个信号似乎明显地沿着减数分裂染色体传播。我们推测，这些信号构成了允许减数分裂细胞传达DSB修复决定的通讯装置的一部分。这些信号有几种不同的形式，包括蛋白质磷酸化的传播和染色体结构的变化，并表现出时间和空间上的差异，这表明它们可能传达减数分裂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，将利用一种新的条件性核耗竭方法，利用一种新的条件性核耗竭方法，分析染色体信号和DSB修复的动力学，该方法允许对通常具有多效性的修复因子进行阶段特异性击倒。此外，信号整合将通过细胞学、生化和修复中间产物的物理分析进行分析。最后，该提案将通过开发一种在整个基因组中绘制DSB修复中间体的方法来弥合一项重大的技术差距。总之，这些分析将提供对染色体信号传播控制DNA修复的机制的初步见解，并为理解导致出生缺陷和癌症的DSB修复错误开辟新的途径。