权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Biogenesis and Regulation of Human Telomerase

人类端粒酶的生物发生和调控

基本信息

批准号：
8463827
负责人：
Kathleen Collins
金额：
$ 36.17万
依托单位：
UNIVERSITY OF CALIFORNIA BERKELEY
依托单位国家：
美国
项目类别：
财政年份：
2004
资助国家：
美国
起止时间：
2004-09-30 至 2014-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8463827
关键词：
Address Affinity Chromatography Age Amino Acid Motifs Biochemical Biogenesis Biological Biological Assay Cell Cycle Cells Chromosomes Clinical Collaborations Complex DNA DNA biosynthesis DNA-Directed DNA Polymerase Data Defect Disease Dyskeratosis Congenita Embryo Environment Enzymes Epithelial Equilibrium Eukaryota Event Failure Funding Goals Growth Health Hematopoietic System Hereditary Disease Homeostasis Human In Vitro Inherited Knowledge Length Link Malignant Neoplasms Medical Methods Molecular Normal Cell Pancytopenia Pathway interactions Patients Pharmaceutical Preparations Physiological Process Proteins Publishing RNA RNA-Protein Interaction Recruitment Activity Regulation Ribonucleoproteins Somatic Cell Specificity Syndrome Telomerase Telomerase Inhibitor Telomerase RNA Component Tertiary Protein Structure Tissues Work anti-cancer therapeutic cancer cell cell growth regulation chromosome replication design human TERT protein human disease human tissue in vivo insight prevent reconstitution telomerase reverse transcriptase telomere

项目摘要

Telomerase elongates chromosome ends by addition of tandem telomeric repeats. This new DNA synthesis is required to balance the loss of DNA that is inherent in the incomplete replication of chromosome ends by conventional DNA polymerases. Single-celled eukaryotes constitutively activate telomerase and maintain a homeostasis of telomere length. Surprisingly, human somatic cells do not: they show progressive shortening of the telomeric repeat array with proliferation. Some human cells in the embryo, germline, epithelial tissues, and hematopoietic system have detectable levels of telomerase catalytic activity in cell lysates, but this level of activation is insufficient to prevent an overall loss of telomere length in all human tissues with age. Cumulative loss eventually produces a repeat array that is too short to protect the chromosome end, resulting in a forced exit from the cell cycle. Cancer cells dramatically up-regulate telomerase to permit indefinite growth. For this reason, telomerase inhibitors have great promise as broadly effective anti-cancer therapeutics. Telomerase activators may have equally significant application for expanding the renewal capacity of normal somatic cells with critically short telomeres arising from genetics, disease, age, or environment. The telomerase RNA subunit (TER) is expressed as a precursor that must be processed, folded, and assembled as a stable ribonucleoprotein (RNP) complex in order to accumulate to detectable level in vivo. This RNP then recruits telomerase reverse transcriptase (TERT) to generate the active enzyme. Collins lab efforts in previous funding periods have contributed pioneering insights about the endogenous pathway of human TER precursor processing and RNP assembly and discovered defects in the accumulation of mature telomerase RNP that underlie X-linked and autosomal dominant forms of the bone marrow failure syndrome dyskeratosis congenita. The Specific Aims of the next funding period address remaining gaps in knowledge about human telomerase RNP accumulation and catalytic activation in vivo. Aim 1 exploits methods of transient and stable TER expression in human cells to discover and characterize additional RNA motifs and proteins required for TER maturation and biological stability. Aim 2 applies Collins lab expertise in RNA-protein interaction assays and affinity purification to define the biochemical defects that underlie inherited human diseases of telomerase deficiency. Aim 3 investigates the assembly and activity of telomerase RNP with TERT. In vivo reconstitution methods will be combined with in vitro and in vivo activity assays to define TER motif functions in the catalytic cycle. The physiological specificity of RNA and protein domain interactions within the active RNP will be established. The long-term goal of these studies is to understand telomerase RNP assembly, catalytic activation, and cellular regulation in normal cells and disease and to exploit this understanding for improvement of human health.

端粒酶通过添加串联端粒重复序列延长染色体末端。这个新的DNA