Evolution of Telomere End Protection

端粒末端保护的演变

基本信息

批准号：
8531703
负责人：
Robert Anthony Hom
金额：
$ 5.22万
依托单位：
UNIVERSITY OF COLORADO
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-09-01 至 2014-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8531703
关键词：
Address Aging Binding Biochemical Biological Assay Candida albicans Cell Cycle Cell Cycle Arrest Chromosomes Collaborations Complex Cyclin B DNA DNA Binding DNA Damage DNA Footprint DNA biosynthesis DNA-Binding Proteins Data Electrophoretic Mobility Shift Assay Event Evolution Functional disorder Genetic Genome Stability Genomic Instability Genomics Homologous Gene Human Human Genome In Vitro Institutes Knowledge Lead Link Maintenance Malignant Neoplasms Modeling Molecular Nature Nucleoproteins Oligonucleotides Oncogenic Play Point Mutation Proteins Regulation Resolution Role Saccharomyces cerevisiae Saccharomyces cerevisiae Proteins Saccharomycetales Sampling Solutions Specificity Structure System Techniques Telomere Maintenance Testing Time TimeLine Work X-Ray Crystallography Yeast Model System Yeasts cancer prevention cancer type genome-wide human DNA human disease in vivo insight mutant novel prevent protein function replication factor A response telomere

项目摘要

Genomic instability is a common feature that can be found in most cancer types. Protection of chromosome ends is provided by nucleoprotein structures called telomeres. Telomeric DNA is composed of a highly conserved 3' single-stranded overhang. When unprotected, this overhang initiates lethal DNA damage responses that can cause end-to-end fusion, degradation, and cell cycle arrest. Besides cancer, telomere dysfunctions can lead to various human diseases and degenerative aging. The proposed studies will use standard biochemical, biophysical, and structural techniques to investigate how telomere end protection has evolved. Strong evidence suggests that Cdc13, Stn1, and Ten1 proteins form a trimeric complex that protect telomeric ends in yeast. However, a direct interaction between these three proteins has never been observed, and this has lead to contradicting views on how these proteins function. Recently, similar complexes have been found in humans that do not appear to play a role in the capping of telomeric DNA. We wish to evolutionary track the roles of Cdc13, Stn1, and Ten1 through different species, in order to better understand what functions certain complexes play in telomere end protection. In Aim 1, we will elucidate for the first time in vitro if Cdc13, Stn1, and Ten1 interact with each other. The structure of this complex in several species will be determined to elucidate how these proteins play a role in end-protection. Aim 2 will track how the DNA binding protein Cdc13, and its subunits Stn1 and Ten1, has evolved in their recognition of telomeric DNA. A large sample of Cdc13 proteins will be tested for their ability to bind telomeric DNA. The collected data will provide insight on how telomeric end protection from yeast had evolved into complexes with more genomic wide functions found in humans. The biochemical and structural nature of this work will provide evidence for the first time if Cdc13, Stn1, and Ten1 interact. We will also elucidate how the recognition of telomeric DNA has changed over time from different species. This in vitro data will provide a novel connection of how end-protection has evolved.

基因组不稳定性是在大多数癌症类型中都可以找到的常见特征。染色体末端的保护由称为端粒的核蛋白结构提供。端粒DNA由高度保守的3'单链悬垂组成。如果没有保护，这种悬垂会引起致命的DNA损伤反应，可能导致端到端融合，降解和细胞周期停滞。除癌症外，端粒功能障碍还会导致各种人类疾病和退化性衰老。拟议的研究将使用标准的生化，生物物理和结构技术来研究端粒终端保护的发展。有力的证据表明，CDC13，STN1和TEN1蛋白会形成一种三聚体络合物，可保护端粒末端。但是，这三种蛋白质之间的直接相互作用从未被观察到，这导致对这些蛋白质如何发挥作用矛盾。最近，在人类中发现了类似的复合物，这些复合物似乎在端粒DNA的上限中没有作用。我们希望通过不同的物种进化跟踪CDC13，STN1和TEN1的作用，以便更好地了解某些功能在端粒端保护中的功能。在AIM 1中，如果CDC13，STN1和TEN1相互相互作用，我们将首次在体外阐明。该络合物在几种物种中的结构将被确定，以阐明这些蛋白质如何在末端保护中发挥作用。 AIM 2将跟踪DNA结合蛋白CDC13及其亚基STN1和TEN1的识别如何在其端体DNA识别中发展。将测试大量CDC13蛋白的样本，以结合端粒DNA的能力。收集到的数据将提供有关酵母中端粒端保护如何发展为具有人类基因组广泛功能的复合物的见解。如果CDC13，STN1和TEN1相互作用，这项工作的生化和结构性质将首次提供证据。我们还将阐明端粒DNA的识别如何随着时间的流逝而变化。该体外数据将提供一种新颖的联系，说明末端保护的发展方式。