STRUCTURE & FUNCTION OF BASE MODIFICATIONS IN SUBTELOMERIC & TELOMERIC DNA

结构

• 批准号: 7355192
• 负责人: Woodring Erik Wright
• 金额: $ 0.42万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-02-01 至 2007-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7355192
• 关键词: STRUCTURE; FUNCTION; BASE; MODIFICATIONS; SUBTELOMERIC

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Normal human cells have a limited capacity to proliferate, a process termed replicative aging. Increasing evidence has implicated telomeres, the structures that cap the ends of the chromosomes, as the molecular clock that counts the number of times the cell has divided. The mechanism of lagging-strand DNA synthesis prevents DNA polymerase from replicating the DNA all the way to the 5'''' end of a linear chromosome, leaving a 3'''' overhang and causing the chromosomes to shorten every time a cell divides. Human telomeres are composed of many kilobases of the repetitive sequence TTAGGG that, together with telomere-binding proteins, prevent the cell from recognizing the end of the chromosome as a DNA break needing repair. Cellular senescence may occur when some of the telomeres have shortened sufficiently to induce a DNA damage signal. Cancer cells escape the proliferative limits of replicative aging by up-regulating the expression of telomerase, an enzyme capable of adding telomere repeats to the ends of the chreomsomes and maintaining their length. Using methods for identifying the presence of modified nucleotides in subtelomeric DNA, for purifying telomeres (based on the presence of the 3'''' G-rich overhang) that yields a greater than 1000-fold enrichment in a single step, for determining the size of the overhangs, and for measuring telomere sizes in interphase nuclei. These advances will permit us to pursue the following goals: (1) To understand the structure and function of base modifications in subtelomeric/telomeric DNA; (2) to determine what regulates the rate of telomere shortening; and (3) To define when and where chells with short telomeres accumulate in vivo in humans. The overall goal is to manipulate rates of telomere shortening, with obvious applications in developing therapeutics for aging and cancer. LC/MS and LC/MS/MS methods will be implemented and applied to analyzing samples for modified nucleobases.

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子弹和调查员（PI）可能已经从其他NIH来源获得了主要资金，因此可以在其他清晰的条目中代表。列出的机构适用于该中心，这不一定是调查员的机构。正常的人类细胞具有有限的增殖能力，该过程称为复制衰老。越来越多的证据暗示了端粒，即覆盖染色体末端的结构，因为分子时钟计算了细胞分裂的次数。 The mechanism of lagging-strand DNA synthesis prevents DNA polymerase from replicating the DNA all the way to the 5'''' end of a linear chromosome, leaving a 3'''' overhang and causing the chromosomes to shorten every time a cell divides.人端粒由重复序列的许多千倍酶组成，它们与端粒结合蛋白一起阻止细胞识别染色体的末端，因为DNA断裂需要修复。当一些端粒缩短以诱导DNA损伤信号时，可能会发生细胞衰老。癌细胞通过上调端粒酶的表达来避免复制衰老的增殖限制，端粒酶的表达能够在Chreomomesomes的末端添加端粒重复并保持其长度。使用方法来识别亚电体DNA中修饰的核苷酸的存在，以净化端粒（基于3''''g-rich unhang的存在），在单个步骤中产生大于1000倍的富集，以确定超悬垂的大小，并测量触形型中的触形尺寸。这些进步将使我们能够实现以下目标：（1）了解亚端粒/端粒DNA中基础修饰的结构和功能； （2）确定是什么调节端粒缩短速率； （3）定义何时何地，在人体中，端粒较短的Chell在体内积聚。总体目标是操纵端粒缩短速率，并在开发衰老和癌症的治疗剂方面有明显的应用。 LC/MS和LC/MS/MS方法将被实施，并应用于分析改良核碱基的样品。