Mechanisms of chromosome-scale signal propagation

染色体尺度信号传播机制

基本信息

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
项目类别：
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

项目摘要

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距离传递染色体断裂信号。DNA 双链断裂 (DSB) 会对基因组完整性造成危险，因为它们可能会导致染色体重排和突变。染色体不稳定，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急剧增加，就像放射治疗和多种形式的治疗一样。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，这是减数分裂 DSB 的一个关键特征。修复的本质是它在染色体水平上进行协调，使得一个 DSB 的修复决策以染色体自主的方式传输到同一条染色体上相距较远的 DSB。这种通讯发生的机制本质上是这样的。未知，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在减数分裂 DSB 形成后明显沿着减数分裂染色体传播的几个信号。这些信号构成通信装置的一部分，允许减数分裂细胞传达 DSB 修复决定。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 DSB 修复的动态进行分析。超分辨率显微镜，利用一种新颖的条件核损耗方法，可以对通常的多效性修复因子进行特定阶段的敲除。此外，还将使用细胞学、生物化学和细胞学来分析信号整合。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弥补主要的技术差距，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。