Regulation of Telomere Maintenance in Fission Yeast

裂殖酵母端粒维持的调控

• 批准号: 10795564
• 负责人: Toru Nakamura
• 金额: $ 3.46万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10795564
• 关键词: Affect; Aging; Applications Grants; Binding; Cell Proliferation; Chromosomes; Collaborations; Complex; DNA Damage; DNA Repair; DNA biosynthesis; DNA-Directed DNA Polymerase; Defect; Disease; Dissociation; Ensure; Eukaryotic Cell; Fission Yeast; Future; Goals; Human; Knowledge; Laboratories; Maintenance; Malignant Neoplasms; Modeling; Mutation; Nature; Organism; Pattern; Phosphorylation; Play; Proteins; Regulation; Research Project Grants; Role; Site; Structure; Sumoylation Pathway; Telomerase; Telomere Maintenance; Tissues; age related; effective therapy; experimental study; genome integrity; human disease; insight; interest; preservation; prevent; protein complex; recruit; response; telomere; treatment strategy; tumor

Project Summary/Abstract Our laboratory is interested in understanding how eukaryotic cells ensure the maintenance of telomeres, the natural ends of linear eukaryotic chromosomes. Evolutionarily conserved shelterin and CST (CTC1/Cdc13-STN1-TEN1) complexes play essential roles in telomerase recruitment and protection of telomeres against DNA repair and checkpoint factors. Stable maintenance of telomeres is critical to preserve genomic integrity and prevent the accumulation of undesired mutations that might lead to tumor formation. Regulation of telomere structures and telomerase also affect cell proliferation and tissue maintenance in aging organisms. Therefore, basic mechanistic studies investigating how telomere and DNA damage response proteins collaborate in proper telomere maintenance should provide critical insights necessary to help devise more effective treatment strategies against tumors or other age-related diseases. Our proposed research projects utilize the fission yeast Schizosaccharomyces pombe. Fission yeast telomeres serve as a good model for human telomeres since proteins involved in telomere maintenance are highly conserved between fission yeast and humans. Studies from our lab and others have provided detailed insights into how fission yeast shelterin and Stn1-Ten1 ensure stable maintenance of telomeres in fission yeast. Those include findings that (1) Tel1ATM/Rad3ATR-dependent phosphorylation of the shelterin subunit Ccq1 on Thr93 promotes telomerase recruitment by promoting interaction between Ccq1 and the telomerase subunit Est1, and (2) SUMOylation of another shelterin subunit Tpz1TPP1 on Lys242 facilitates Stn1-Ten1 recruitment to telomeres and limits telomere extension. Evolutionarily conserved "TEL patch" residues within Tpz1 have also been found to promote telomerase activation and recruitment, further highlighting the well- conserved nature of telomere regulation by fission yeast and mammalian shelterin. Our analyses of temporal binding patterns for DNA polymerases, telomerase, shelterin, and Stn1 found that shelterin subunits Rap1 and Poz1 and the Stn1-Ten1 complex promote timely dissociation of telomerase from telomeres by promoting recruitment of Pola to complete lagging strand synthesis at telomeres. For the current grant application, our proposed experiments will (1) identify and characterize the underlying regulatory mechanism(s) that allow Ccq1 and Poz1 to promote Pola-dependent telomere protection (Aim 1), (2) identify new interaction partners of Stn1-Ten1 complex and characterize their contributions to recruitment/retention of Stn1-Ten1 complex at telomeres and non-telomeric sites (Aim 2), and (3) investigate how regulation of TERRA vs. poly(A)+TERRA expression modulates Stn1-Ten1-Pola recruitment at telomeres (Aim 3).

项目摘要/摘要 我们的实验室有兴趣了解真核细胞如何确保维护 端粒，线性真核染色体的自然末端。进化保守的庇护所和 CST（CTC1/CDC13-STN1-TEN1）复合物在端粒募集和 保护端粒免受DNA修复和检查点因子的保护。端粒的稳定维护是 保持基因组完整性和防止可能不希望的突变的积累至关重要 导致肿瘤形成。端粒结构和端粒酶的调节也会影响细胞增殖 和衰老生物的组织维护。因此，基础机械研究研究了如何 端粒和DNA损伤响应蛋白在适当的端粒维护中进行合作 提供必要的关键见解，以帮助制定针对肿瘤的更有效的治疗策略或 其他与年龄有关的疾病。我们提出的研究项目利用裂变酵母 精神分裂症pombe。裂变酵母端粒是人类端粒的良好模型 由于参与端粒维护的蛋白质在裂变酵母和 人类。 我们实验室和其他人的研究提供了有关裂变酵母庇护所和如何的详细见解 STN1-TEN1确保在裂变酵母中稳定维护端粒。这些包括（1）的发现 Thr93上庇护素亚基CCQ1的Tel1ATM/Rad3ATR依赖性磷酸化促进 通过促进CCQ1与端粒酶亚基EST1和 （2）在Lys242上的另一个庇护所TPZ1TPP1的Sumoylation促进STN1-TEN1的招聘 端粒和限制端粒扩展。 TPZ1中的进化保守的“ TEL Patch”残基 还发现可以促进端粒酶激活和募集，进一步强调了良好 通过裂变酵母和哺乳动物庇护所对端粒调节的保守性质。我们的分析 DNA聚合酶，端粒酶，庇护素和STN1的时间结合模式发现庇护所 亚基RAP1和POZ1以及STN1-TEN1复合物及时促进端粒酶的分离 端粒通过促进Pola的招募来完成端粒的滞后链合成。为了 当前的赠款应用程序，我们提出的实验将（1）识别和表征基础 允许CCQ1和POZ1促进依赖Pola的端粒保护的监管机制 （AIM 1），（2）确定STN1-TEN1复合物的新互动伙伴并表征其贡献 招募/保留端粒和非层次位点的STN1-TEN1复合物（AIM 2）和（3） 研究如何调节Terra与Poly（A）+Terra表达如何调节STN1-TEN1-POLA 在端粒招募（AIM 3）。