Title
Normal expression of KCNJ11 is maintained by the G-quadruplex
Author
Jinjing Zhang, Jiaxing Wang, Fangyuan Li, Min Zhua, Shiqiang Wang, Qinghua Cui, Gu Yuan, Jiang Zhou, Ming Xu
Year
2019
Journal
International Journal of Biological Macromolecules
Abstract
MicroRNAs affect various pathological pathways by binding to multiple target mRNAs. Recently, it was reported that eukaryotic RNA G-quadruplexes were enriched in mRNA 3′-UTR, where microRNAs can also bind. To determine the roles of the G-quadruplex within mRNA 3′-UTR in microRNA binding sites, a bioinformatics approach was utilized to identify candidate microRNA target mRNAs with potential G-quadruplex formation. Circular dichroism spectrometry demonstrated the formation of RNA G-quadruplexes in vitro in candidate G-rich sequences. Mutated guanosines that are critical for G-quadruplex formation significantly decreased luciferase activities. Moreover, a G-quadruplex ligand TMPyP4 was used to destabilize the KCNJ11 RNA G-quadruplex in cardiomyocytes, resulting in binding of the microRNA to mRNA and subsequent suppression of KCNJ11 expression. In conclusion, our study showed that the G-quadruplex structure affects microRNA binding to its target mRNA. Thus, our study reveals a novel mechanism for G-quadruplex-dependent regulation of microRNA-mRNA interaction, which is essential to maintain normal gene expression.
Instrument
J-815
Keywords
Circular dichroism, G-quadruplex structure, RNA structure, Chemical stability, Biochemistry