Genetics of telomerase in C. elegans

线虫端粒酶的遗传学

基本信息

批准号：
7583603
负责人：
SHAWN CAMERON AHMED
金额：
$ 28.76万
依托单位：
UNIV OF NORTH CAROLINA CHAPEL HILL
依托单位国家：
美国
项目类别：
财政年份：
2002
资助国家：
美国
起止时间：
2002-08-01 至 2013-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7583603
关键词：
Animals Aplastic Anemia Biochemical Biology Caenorhabditis elegans Cell Cycle Chromosomes Cloning Co-Immunoprecipitations Complex DNA Damage DNA Double Strand Break DNA Interstrand Crosslinking DNA Repair DNA crosslink Defect Development Diagnosis Disease Event Evolution Genes Genetic Genetic Epistasis Genetic Recombination Genetic Screening Genomic Instability Goals Hereditary Disease Human Hypersensitivity Ligation Light Malignant Neoplasms Maps Mediating Minority Modeling Molecular Analysis Molecular Structure Mutate Mutation Nature Nematoda Nonhomologous DNA End Joining Organism Pathway Analysis Pathway interactions Preparation Process Proteins Pulmonary Fibrosis Recruitment Activity Research Research Project Grants Resolution Role Somatic Cell Southern Blotting System Telomerase Telomere Shortening Testing Yeasts comparative genomic hybridization human disease in vivo insight mutant novel nuclease protein folding public health relevance repaired research study response telomere tumor

项目摘要

DESCRIPTION (provided by applicant): Telomerase reverse transcribes telomere repeats onto chromosome termini. The long- term goal of this project is to develop the nematode C. elegans as a system for the study of telomerase and telomere biology. C. elegans possesses holocentric chromosomes that facilitate genetic isolation of initial end-to-end chromosome fusion events that occur when telomerase is deficient. Isolation and analysis of end-to-end fusions from various genetic backgrounds will provide unprecedented insight into their genesis and may reveal unexpected functions of some DNA damage response proteins that interact with normal telomeres. Genetic screens have identified four proteins that are required for telomerase to function at telomeres in yeast, whereas our forward genetic screens indicate that 10 or more proteins are required in C. elegans and perhaps in other multicellular organisms. One model in the field suggests that telomeres may be sensed as DNA double-strand breaks prior to recruitment of telomerase. However, we have determined that the MRT-1 nuclease, which facilitates DNA interstrand crosslink repair, is required for telomerase to act at C. elegans telomeres. Thus, telomerase may be recruited to telomeres via a pathway that can respond to DNA interstrand crosslinks. We suspect that this hypothesis may be relevant to telomere evolution and plan to test this possibility using genetic and biochemical approaches. In addition, we shall identify and characterize four new mutations that result in deficiency for telomerase activity in vivo in C. elegans (279, 222g, 36f and 3211e). Finally, further mutant screens will be performed in an effort to saturate for genes required for telomerase activity in vivo. Telomerase only acts at telomeres for a fleeting moment during the cell cycle, so the powerful genetics of C. elegans may help to identify the suite of genes responsible for telomerase activity in vivo in multicellular organisms. PUBLIC HEALTH RELEVANCE Deficiency for telomerase causes lethal human hereditary disorders such as aplastic anemia, dyskeritosis congenita and pulmonary fibrosis: genes that mutate to cause these human diseases may be defined by this research project. Given that most cancers express telomerase whereas most normal somatic cells do not, our studies may also help to define proteins and/or pathways that may be useful targets for treatment of a wide variety of cancers. Finally, this project may define recombination intermediates and pathways that are relevant to telomere-induced genome instability, which may promote tumor development.

描述（由申请人提供）：端粒酶将端粒重复转录到染色体末端。该项目的长期目标是开发线虫秀丽隐杆线虫作为端粒酶和端粒生物学研究的系统。线虫拥有全着丝粒染色体，有助于端粒酶缺陷时发生的初始端到端染色体融合事件的遗传分离。对来自不同遗传背景的端到端融合的分离和分析将为对其起源提供前所未有的见解，并可能揭示一些与正常端粒相互作用的 DNA 损伤反应蛋白的意想不到的功能。遗传筛选已鉴定出端粒酶在酵母端粒上发挥作用所需的四种蛋白质，而我们的正向遗传筛选表明，秀丽隐杆线虫以及其他多细胞生物体中可能需要 10 种或更多蛋白质。该领域的一种模型表明，在端粒酶募集之前，端粒可能会被感知为 DNA 双链断裂。然而，我们已经确定，端粒酶作用于线虫端粒需要 MRT-1 核酸酶来促进 DNA 链间交联修复。因此，端粒酶可能通过一条能够响应 DNA 链间交联的途径被募集到端粒上。我们怀疑这一假设可能与端粒进化有关，并计划使用遗传和生化方法测试这种可能性。此外，我们将鉴定和表征导致秀丽隐杆线虫体内端粒酶活性缺陷的四种新突变（279、222g、36f 和 3211e）。最后，将进行进一步的突变体筛选，以期饱和体内端粒酶活性所需的基因。端粒酶仅在细胞周期中短暂地作用于端粒，因此秀丽隐杆线虫强大的遗传学可能有助于识别多细胞生物体内负责端粒酶活性的一组基因。公共卫生相关性端粒酶缺乏会导致致命的人类遗传性疾病，例如再生障碍性贫血、先天性角化不良和肺纤维化：该研究项目可能会定义导致这些人类疾病的突变基因。鉴于大多数癌症表达端粒酶，而大多数正常体细胞不表达端粒酶，我们的研究也可能有助于定义可能成为治疗多种癌症的有用靶点的蛋白质和/或途径。最后，该项目可能会定义与端粒诱导的基因组不稳定性相关的重组中间体和途径，这可能会促进肿瘤的发展。