Lee Stella Suyong, Bohrson Craig, Pike Alexandra Mims, Wheelan Sarah Jo, Greider Carol Widney
Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Predoctoral Training Program in Human Genetics and Molecular Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
Cell Rep. 2015 Nov 24;13(8):1623-32. doi: 10.1016/j.celrep.2015.10.035. Epub 2015 Nov 12.
Short telomeres induce a DNA damage response, senescence, and apoptosis, thus maintaining telomere length equilibrium is essential for cell viability. Telomerase addition of telomere repeats is tightly regulated in cells. To probe pathways that regulate telomere addition, we developed the ADDIT assay to measure new telomere addition at a single telomere in vivo. Sequence analysis showed telomerase-specific addition of repeats onto a new telomere occurred in just 48 hr. Using the ADDIT assay, we found that ATM is required for addition of new repeats onto telomeres in mouse cells. Evaluation of bulk telomeres, in both human and mouse cells, showed that blocking ATM inhibited telomere elongation. Finally, the activation of ATM through the inhibition of PARP1 resulted in increased telomere elongation, supporting the central role of the ATM pathway in regulating telomere addition. Understanding this role of ATM may yield new areas for possible therapeutic intervention in telomere-mediated disease.
短端粒会引发DNA损伤反应、细胞衰老和凋亡,因此维持端粒长度平衡对细胞活力至关重要。端粒酶添加端粒重复序列在细胞中受到严格调控。为了探究调控端粒添加的途径,我们开发了ADDIT检测法来测量体内单个端粒上新端粒的添加情况。序列分析表明,端粒酶特异性地在新端粒上添加重复序列仅在48小时内发生。使用ADDIT检测法,我们发现小鼠细胞中端粒添加新的重复序列需要ATM。对人类和小鼠细胞中的总体端粒进行评估表明,阻断ATM会抑制端粒延长。最后,通过抑制PARP1激活ATM导致端粒延长增加,支持了ATM途径在调控端粒添加中的核心作用。了解ATM的这一作用可能会为端粒介导的疾病带来新的可能治疗干预领域。