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（由申请人提供）：该项目的总体目标是确定细胞如何跨大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，而这两者都与癌症进展以及出生缺陷密切相关。在同时发生多个 DSB 的情况下，基因组不稳定的风险会显着放大，例如放疗和多种形式的化疗。然而，至少在某些情况下，细胞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，此时生殖细胞在其大部分基因组中引入数百个编程的 DSB。减数分裂 DSB 修复的一个关键特征是它在染色体水平上进行协调，这样一个 DSB 的修复决策就会以染色体自主的方式传递到同一条染色体上相距很远的 DSB。这种通讯发生的机制基本上是未知的，但将为细胞如何应对大规模染色体损伤提供重要的新见解。对有性生殖酵母酿酒酵母中减数分裂 DNA 损伤信号的初步分析揭示了一些信号，这些信号似乎在减数分裂 DSB 形成后沿着减数分裂染色体明显传播。我们假设这些信号构成了通信装置的一部分，允许减数分裂细胞传达 DSB 修复决策。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差异，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，将通过遗传学和超分辨率显微镜分析染色体信号传导和 DSB 修复的动态，利用一种新颖的条件核耗竭方法，该方法允许对通常的多效性修复因子进行特定阶段的敲低。此外，将使用修复中间体的细胞学、生物化学和物理分析来分析信号整合。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缩小主要的技术差距。总之，这些分析将为控制 DNA 修复的染色体信号传播机制提供初步见解，并为了解导致先天缺陷和癌症的 DSB 修复错误开辟新途径。