Regulation of human telomerase

人端粒酶的调节

• 批准号: 10623683
• 负责人: JIYUE ZHU
• 金额: $ 38.25万
• 依托单位: WASHINGTON STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-01 至 2028-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10623683
• 关键词: Aging; Alleles; Applications Grants; Bacterial Artificial Chromosomes; Cell Differentiation process; Cell Proliferation; Cell Survival; Chromatin; Chromosomes; Clustered Regularly Interspaced Short Palindromic Repeats; Compensation; DNA; Degenerative Disorder; Development; Disease; Distal; Elements; Elongation by Telomerase; Engineering; Enhancers; Enzymes; Funding; Gene Activation; Genes; Genetic Transcription; Genomics; Goals; HDAC4 gene; Homeostasis; Human; Introns; Laboratories; Malignant Neoplasms; Mediating; Methods; Molecular; Mus; Play; Pluripotent Stem Cells; Predisposition; RNA-Directed DNA Polymerase; Regulation; Regulatory Element; Reporter; Reporting; Repression; Role; Site; Somatic Cell; Specific qualifier value; TERT gene; Techniques; Telomerase; Transcriptional Regulation; age related; cancer cell; human disease; improved; in vivo; innovation; mouse model; recombinase; telomere; tool; transcription factor

Abstract Our long-term goal is to decipher the molecular mechanisms of telomerase regulation and telomere homeostasis during development. Telomerase elongates telomeres to compensate for their loss during cell proliferation. Its regulation is critical for human aging and susceptibilities to cancer and many age-related degenerative diseases. The TERT gene, encoding the human telomerase reverse transcriptase, is regulated primarily at the level of transcription. It is highly expressed in pluripotent stem cells, but stringently repressed in most somatic cells. Recent progresses on telomerase regulation in cancer cells have greatly improved our understanding of TERT gene activation during cancer development. However, the mechanisms of its repression in most differentiated cells and expression in certain somatic cells remain to be elucidated. Regulation of transcription during development and differentiation often involves distal elements and chromatin reorganization. We previously reported that the endogenous TERT gene was embedded in a condensed chromatin domain and stringently repressed in a histone deacetylase-dependent manner in somatic cells. To identify distal regulatory sequences required for establishing the repressive chromatin of the TERT locus and to understand its regulation in vivo, our laboratory has developed two innovative technical platforms in the past decade. The first is recombinase-mediated BAC targeting or RMBT method, for targeted integration of single-copy BAC reporters into specified chromosomal sites. This technique, together with the new CRISPR-mediated gene editing, enables us to study distal regulatory elements of the TERT gene in their genomic contexts. Consequently, we have discovered that a polymorphic tandem DNA repeat in intron 2 (VNTR2-1) functions as an enhancer for TERT transcription. In addition, we have engineered a humanized mTert allele (hmTert) for studying human-specific telomerase regulation in mice. In the next funding period, we plan to use these tools and focus on the following three directions: (1) Identify transcription factors that regulate TERT gene via VNTR2-1; (2) Identify key distal regulatory elements responsible for TERT repression; and (3) Study the roles of these distal elements in regulating telomere homeostasis in vivo using our mouse model with humanized telomeres. In short, using our unique tools, we will address some of the fundamental mechanisms critical to telomerase regulation and telomere homeostasis in humans, and ultimately telomere-associated human diseases.

抽象的 我们的长期目标是破译端粒酶调控和端粒的分子机制 发育过程中的稳态。端粒酶延长端粒以补偿细胞分裂过程中端粒的损失 增殖。它的调节对于人类衰老和癌症以及许多与年龄相关的疾病的易感性至关重要 退行性疾病。编码人类端粒酶逆转录酶的 TERT 基因受到调控 主要是在转录水平。它在多能干细胞中高度表达，但在 大多数体细胞。癌细胞端粒酶调控的最新进展极大地改善了我们的研究 了解癌症发展过程中 TERT 基因激活。然而，其抑制机制 在大多数分化细胞中的表达以及在某些体细胞中的表达仍有待阐明。监管 发育和分化过程中的转录通常涉及远端元件和染色质重组。 我们之前报道过，内源性TERT基因嵌入在一个浓缩的染色质结构域中，并且 在体细胞中以组蛋白脱乙酰酶依赖性方式受到严格抑制。确定远端监管 建立 TERT 位点的抑制性染色质并了解其调节所需的序列 在vivo方面，我们实验室在过去十年中开发了两个创新技术平台。第一个是 重组酶介导的 BAC 靶向或 MBT 方法，用于单拷贝 BAC 报告基因的靶向整合 进入指定的染色体位点。该技术与新的 CRISPR 介导的基因编辑相结合，使 我们研究 TERT 基因在其基因组环境中的远端调控元件。因此，我们有 发现内含子 2 (VNTR2-1) 中的多态性串联 DNA 重复序列可作为 TERT 的增强子 转录。此外，我们还设计了一个人源化 mTert 等位基因 (hmTert)，用于研究人类特异性 小鼠端粒酶调节。在下一个资助期内，我们计划使用这些工具并重点关注以下方面 三个方向：（1）通过VNTR2-1鉴定调节TERT基因的转录因子； (2) 识别关键远端 负责 TERT 抑制的调控元件； (3) 研究这些远端元件在 使用我们的具有人源化端粒的小鼠模型调节体内端粒稳态。简而言之，使用我们的 独特的工具，我们将解决一些对端粒酶调节至关重要的基本机制 人类端粒稳态，以及最终与端粒相关的人类疾病。