Investigating telomerase dynamics in live cells at a single-molecule level

在单分子水平上研究活细胞中的端粒酶动力学

• 批准号: 10753326
• 负责人: Pascal Chartrand
• 金额: $ 42.36万
• 依托单位: SLOAN-KETTERING INST CAN RESEARCH
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2027-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10753326
• 关键词: Address; Aging; Bacteriophages; Base Pairing; Biochemical; Biology; Catalytic Domain; Cell Aging; Cell Nucleus; Cell Proliferation; Cells; Cellular biology; Chromosomal Stability; Chromosomes; Crowding; Cytoplasmic Granules; DNA; Data; Development; Engineering; Ensure; Enzymes; Eukaryotic Cell; Future; Genetic; Goals; Human; Image; Label; Length; Ligation; Light; Link; Longevity; MS2 coat protein; Maintenance; Malignant Neoplasms; Mechanics; Membrane; Methodology; Organelles; Phase; Photobleaching; Physiological; Prevention; Process; Proteome; Proteomics; RNA; RNA-Directed DNA Polymerase; Regulation; Ribonucleoproteins; Role; System; TEL1 Gene; Telomerase; Telomerase RNA Component; Telomere Maintenance; Testing; Tumor Suppression; Untranslated RNA; Visualization; Work; Yeasts; cancer cell; cancer therapy; cell fixing; cell growth regulation; design; experimental study; fluorophore; genetic approach; genome integrity; image visualization; imaging modality; innovation; molecular imaging; novel; photoactivation; prevent; recruit; single molecule; stem; superresolution imaging; telomere; trafficking

Abstract: Eukaryotic cells solve the end-replication and end-protection problems through the addition of telomere sequences to the ends of chromosomes. Proper regulation of telomere length is critical for genome integrity, regulation of cellular lifespan, aging, and cancer. Over the years, genetic and biochemical studies have shed an enormous amount of light on how this process is controlled. However, the cell biology of this process in the crowded nucleus remains poorly understood, and the timing, dynamics, and spatial coordination of telomere extension are unknown. To address these gaps in our understanding, we will exploit the MS2 tagging system and Halo-fluorophore to visualize single molecules of endogenous telomerase in live cells. Here, we will decipher discrete and critical steps as hTR traffics from Cajal bodies to telomeres. Contrary to earlier FISH data in fixed cells, our preliminary data using diffraction-limited and super-resolution imaging modalities combined with single-molecule FISH show that hTR is broadly distributed throughout the nucleus. At telomeres, we show that following TPP1-driven recruitment, stable interactions are established between the enzyme and its substrate by RNA:DNA base pairing. Our goal is to apply photoactivation and photobleaching experiments to test the role of the catalytic subunit, hTERT, in the gating of hTR between the Cajal bodies and telomeres. In addition, we will engineer a short telomere to depict telomerase dynamics at critical telomeres that need to be elongated. Lastly, we will perform a proximity-based labeling and purification methodology to investigate the factors that control key steps of telomerase trafficking to short telomeres. All in all, our innovative approach offers a detailed view of the precise mechanics of telomere extension at physiological timescales and opens many future avenues for the study of the link between telomere maintenance and aging as well as cancer.

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