Biogenesis and Regulation of Human Telomerase

人类端粒酶的生物发生和调控

• 批准号: 8762004
• 负责人: Kathleen Collins
• 金额: $ 37.36万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-30 至 2018-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8762004
• 关键词: Antineoplastic Agents; Aplastic Anemia; Biochemical; Biogenesis; Biological; Cause of Death; Cell Cycle; Cell division; Cell physiology; Cells; Chromatin; Chromosomes; Collaborations; DNA; DNA-Directed DNA Polymerase; Disease; Failure; Funding; Genetic; Genome; Genome Stability; Goals; Growth; Health; Hematopoietic Stem Cell Transplantation; Holoenzymes; Homeostasis; Human; In Vitro; Individual; Knowledge; Length; Link; Maintenance; Malignant Neoplasms; Mediating; Molecular; Normal Cell; Pancytopenia; Pathway interactions; Patients; Physiological; Pluripotent Stem Cells; Population; Primates; Principal Investigator; Proteins; Publishing; Pulmonary Fibrosis; RNA; RNA-Directed DNA Polymerase; Reagent; Regulation; Research; Ribonucleoproteins; Rodent; Role; Short Tandem Repeat; Somatic Cell; Structure; System; Systems Analysis; Telomerase; Telomerase Inhibitor; Telomere Maintenance; Telomere Shortening; Tissue Transplantation; Tissues; anti-cancer therapeutic; base; cell growth regulation; crosslink; design; embryonic stem cell; exhaust; human embryonic stem cell; improved; in vivo; innovation; insight; mouse model; neoplastic cell; programs; public health relevance; reconstitution; telomere; tissue regeneration

DESCRIPTION (provided by applicant): Telomerase is a unique reverse transcriptase that protects genome stability by adding simple- sequence repeats to chromosome termini. Some terminal telomeric repeats are eroded with each cell division due to incomplete DNA-templated DNA polymerase synthesis. By copying its integral RNA template, telomerase can extend a chromosome end to compensate for proliferation-linked repeat loss. Human pluripotent stem cells have active telomerase and therefore long-term renewal capacity, but most human somatic cells lack telomerase function and therefore have limited renewal. Patients with human telomerase deficiencies that cause bone marrow failure, aplastic anemia and pulmonary fibrosis have accelerated telomere shortening causative for tissue failures. Opposite this effect is the telomerase reactivation that underlies the proliferative immortality of almost all human cancers. The long-term objective of research funded by this RO1 is to understand the biochemical and cellular basis of human telomerase ribonucleoprotein (RNP) biogenesis, catalytic activation and regulation in normal cells and disease, and to exploit this understanding for the improvement of human health. Knowledge of human telomerase function and regulation has direct relevance for improvements of human health, for example in designing improved hematopoietic stem cell transplantation for bone marrow failure patients. It will also enable screens for telomerase inhibitors that could be highly effective anti-cancer agents. Studies in mouse models are unable to substitute for studies using human cells due to differences in telomerase structure, telomeric chromatin and telomere length regulation in rodents versus primates. Research in the next funding period will provide fundamental gains in knowledge about how the cellular human telomerase holoenzyme engages telomeres. All three Aims expand results and experimental systems established in the current funding period. Aim 1 studies define the roles and regulations of telomerase-telomere association through the telomere protein TPP1. Embryonic stem cells are the only known human cells that physiologically maintain telomere length homeostasis, so in collaboration with the Hockemeyer lab they will be used for genetic approaches to understand telomerase recruitment and catalytic activation by TPP1. Aim 2 studies use an innovative, redirected telomerase holoenzyme assembly pathway to resolve the functions of H/ACA and Cajal body proteins in telomere elongation versus initial telomerase RNP biogenesis. Aim 3 studies exploit approaches including in vivo protein-RNA crosslinking and in vitro reconstitution to define the biochemical mechanisms of individual steps of telomerase regulation.

描述(由申请人提供)： 端粒酶是一种独特的逆转录酶，通过在染色体末端增加简单序列重复来保护基因组的稳定性。由于DNA模板DNA聚合酶合成不完全，一些末端端粒重复序列在每次细胞分裂时被侵蚀。通过复制其完整的RNA模板，端粒酶可以延长染色体末端，以补偿与增殖相关的重复序列丢失。人类多能干细胞具有活性的端粒酶，因此具有长期更新能力，但大多数人类体细胞缺乏端粒酶功能，因此更新有限。人类端粒酶缺乏导致骨髓衰竭、再生障碍性贫血和肺纤维化的患者加速了端粒缩短，从而导致组织衰竭。与这种效应相反的是端粒酶的重新激活，它是几乎所有人类癌症增殖永生的基础。这项由RO1资助的研究的长期目标是了解人类端粒酶核糖核蛋白(RNP)在正常细胞和疾病中的生物发生、催化激活和调节的生化和细胞基础，并利用这一理解来改善人类健康。对人类端粒酶功能和调控的了解直接关系到人类健康的改善，例如在为骨髓衰竭患者设计改进的造血干细胞移植方面。它还将使筛选可能是高效抗癌药物的端粒酶抑制剂成为可能。由于啮齿动物和灵长类动物在端粒酶结构、端粒染色质和端粒长度调节方面的差异，在小鼠模型中的研究无法取代使用人类细胞的研究。下一个资助期的研究将提供关于细胞内人类端粒酶全酶如何与端粒结合的基础知识。所有这三个目标都是扩大在当前供资期间建立的成果和实验系统。目的1研究通过端粒蛋白TPP1确定端粒酶-端粒结合的作用和调节。胚胎干细胞是唯一已知的在生理上维持端粒长度动态平衡的人类细胞，因此与霍克迈尔实验室合作，它们将被用于遗传学方法，以了解端粒酶招募和TPP1的催化激活。目的2研究利用一种创新的、重定向的端粒酶全酶组装途径来解决H/ACA和Cajal小体蛋白在端粒延长与端粒酶RNP初始生物发生中的作用。目的3项研究利用体内蛋白质-RNA交联法和体外重组法来确定端粒酶调节各个步骤的生化机制。