Determining the role of TCAB1 in shaping telomerase function

确定 TCAB1 在塑造端粒酶功能中的作用

基本信息

批准号：
9366667
负责人：
STEVEN E ARTANDI
金额：
$ 44.83万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-15 至 2022-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9366667
关键词：
Adopted Affect Aging Binding Binding Proteins Bioinformatics Biological Assay Catalysis Catalytic Domain Cell Aging Cell Nucleus Cells Complement Complex Core Protein Development Disease Elements Embryo Engineering Enzymes Evolution Fibroblasts Functional disorder Genetic Polymorphism Germ Cells Germ-Line Mutation Holoenzymes Human Impairment Incidence Investigation Knockout Mice Messenger RNA Molecular Conformation Morbidity - disease rate Mus Mutation Pathway interactions Patients Pattern Phenotype Population Process Proteins Pseudouridine RNA RNA Folding RNA Splicing RNA-Directed DNA Polymerase Recruitment Activity Reproducibility Role Series Shapes Structure Susceptibility Gene Telomerase Telomerase RNA Component Telomere Maintenance Telomere Shortening Untranslated RNA crosslinking and immunoprecipitation sequencing embryonic stem cell genome-wide human tissue in vivo mutant protein complex scaffold single molecule telomere trafficking transcriptome sequencing

项目摘要

Abstract Impaired maintenance of telomeres by telomerase causes cellular senescence and underlies many aging-related diseases in humans. Furthermore, telomere shortening is one of the most reproducible hallmarks of aging in human tissues, suggesting that telomere dysfunction contributes broadly to aging phenotypes in people. The human telomerase enzyme is comprised of a catalytic core – the telomerase reverse transcriptase (TERT) and the telomerase RNA component (TERC) – but also depends upon other holoenzyme proteins that bind the H/ACA element within TERC. During evolution, vertebrate telomerase hijacked this H/ACA sequence from other ancient non-coding RNAs, bringing the dyskerin core protein complex, which recognizes the H/ACA element, and TCAB1, which binds the CAB box element, into the telomerase holoenzyme. Telomerase function is critically dependent upon a series of steps, including assembly of the enzyme, trafficking within the nucleus, recruitment to telomeres and finally catalytic extension of telomeres. Each of these steps is poorly understood in humans and each step can be disrupted by germline mutations in patients with telomere diseases. The dyskerin complex is required for assembly and stability of telomerase. We identified TCAB1 as a protein that interacts with dyskerin and showed that TCAB1 binds the CAB box element common to TERC and to all small Cajal body RNAs (scaRNAs). We previously showed that TCAB1 is required for localization of telomerase in Cajal bodies, required for telomere maintenance and is important in recruitment to telomeres. We recently made the surprising finding that TCAB1 is also critical for telomerase catalytic activity and that TCAB1 is required for proper TERC conformation. Telomerase and other RNPs depend on an RNA molecule that needs to fold in a precise conformation, and this correct conformation represents one of countless potential structures. In this proposal, we pursue the hypothesis that TCAB1 is essential in shaping the telomerase RNA, and that this activity of TCAB1 is conserved in the splicing RNA pathway. We propose that the principal advantages conferred upon telomerase by adopting an H/ACA RNA fate is facilitating assembly and proper folding of TERC, and that numerous downstream steps depend upon this proper folding. We will pursue the following aims: (1) To understand how telomerase catalytic function depends upon TCAB1 (2) To determine how TCAB1 influences telomerase trafficking and recruitment (3) To determine how TCAB1 loss affects scaRNA function and RNA splicing.

抽象的端粒酶维持端粒的维持受损会导致细胞感应和基础人类中许多与衰老有关的疾病。此外，端粒缩短是最多的人体组织衰老的可再现标志，表明端粒功能障碍在人们的衰老表型中广泛贡献。人端粒酶是完成催化核 - 端粒酶逆转录酶（TERT）和端粒酶 RNA成分（TERC） - 但也取决于其他全酶蛋白 TERC中的H/ACA元素。在进化过程中，脊椎动物端粒酶劫持了此H/ACA 来自其他古老的非编码RNA的序列，带来了Dyskerin核心蛋白复合物，识别h/aca元素和将驾驶室盒元素绑定到的TCAB1中端粒酶全酶。端粒酶函数在一系列步骤中至关重要，包括酶的组装，核内的贩运，招募端粒和最后，端粒的催化扩展。这些步骤中的每个步骤在人类中都很了解端粒疾病患者的种系突变可能会破坏每个步骤。这端粒酶的组装和稳定性需要障碍蛋白复合物。我们将TCAB1确定为与Dyskerin相互作用并表明TCAB1结合CAB Box元件的蛋白质 TERC和所有小的Cajal身体RNA（Scarnas）共有。我们以前表明 TCAB1是端粒体中端粒酶定位所必需的，端粒需要维护，对于招募端粒很重要。我们最近感到惊讶发现TCAB1对于端粒酶催化活性也至关重要，并且TCAB1对于适当的TERC构象。端粒酶和其他RNP取决于RNA分子需要以精确的构象折叠，而这种正确的构象代表无数的潜在结构。在此提案中，我们提出了这样的假设，即TCAB1是塑造端粒酶RNA的必不可少的，并且TCAB1的这种活性在剪接RNA途径。我们建议，主要优势由采用H/ACA RNA命运正在促进装配和适当的TERC折叠，并且许多下游步骤取决于这种正确的折叠。我们将追求以下目的：（1）了解端粒酶催化功能如何取决于TCAB1（2）确定TCAB1如何影响端粒酶运输和招聘（3）来确定如何 TCAB1损失会影响Scarna功能和RNA剪接。