Yu Zhen, Hendricks Amber L, Cowan James A
Department of Chemistry and Biochemistry, Ohio State University, Columbus, OH 43210, USA.
iScience. 2021 May 29;24(6):102661. doi: 10.1016/j.isci.2021.102661. eCollection 2021 Jun 25.
G-quadruplex structures are associated with various biological activities, while evidence is essential to confirm the formation of G-quadruplexes inside cells. Most conventional agents that recognize G-quadruplex, including antibodies and small-molecule G-quadruplex ligands, either stabilize the G-quadruplex or prevent G-quadruplex unfolding by helicase, thereby artificially increasing the G-quadruplex levels in cells. Unambiguous study of G-quadruplexes at natural cellular levels requires agents that do not enhance the stability of G-quadruplex. Herein, we report the first example of nonperturbative chemical nucleases that do not influence the stability of G-quadruplex telomeric DNA but can selectively cleave G-quadruplex DNA over duplex DNA. These chemical nucleases can be readily taken up by cells and promote selective cleavage of telomeric DNA with low levels of nonselective DNA cleavage of other regions of the genome. The cleavage of G-quadruplex telomeric DNA by nonperturbative chemical nucleases confirms the formation of G-quadruplex telomeric DNA in live cells.
G-四链体结构与多种生物学活性相关，而确认细胞内G-四链体的形成需要证据。大多数识别G-四链体的传统试剂，包括抗体和小分子G-四链体配体，要么稳定G-四链体，要么通过解旋酶阻止G-四链体解折叠，从而人为提高细胞内G-四链体水平。在天然细胞水平上对G-四链体进行明确研究需要不增强G-四链体稳定性的试剂。在此，我们报道了首例不影响G-四链体端粒DNA稳定性但能选择性切割G-四链体DNA而非双链DNA的非干扰性化学核酸酶。这些化学核酸酶可轻易被细胞摄取，并促进端粒DNA的选择性切割，同时对基因组其他区域的非选择性DNA切割水平较低。非干扰性化学核酸酶对G-四链体端粒DNA的切割证实了活细胞中G-四链体端粒DNA的形成。
