posted on 2016-08-10, 00:00authored byShuo-Bin Chen, Ming-Hao Hu, Guo-Cai Liu, Jin Wang, Tian-Miao Ou, Lian-Quan Gu, Zhi-Shu Huang, Jia-Heng Tan
The RNA G-quadruplex
is an important secondary structure formed
by guanine-rich RNA sequences. However, its folding studies have mainly
been studied in vitro. Accurate identification of
RNA G-quadruplex formation within a sequence of interest remains difficult
in cells. Herein, and based on the guanine-rich sequence in the 5′-UTR
of NRAS mRNA, we designed and synthesized the first
G-quadruplex-triggered fluorogenic hybridization (GTFH) probe, ISCH-nras1, for the unique visualization of
the G-quadruplexes that form in this region. ISCH-nras1 is made up of two parts: The first is a fluorescent light-up moiety
specific to G-quadruplex structures, and the second is a DNA molecule
that can hybridize with a sequence that is adjacent to the guanine-rich
sequence in the NRAS mRNA 5′-UTR. Further
evaluation studies indicated that ISCH-nras1 could directly
and precisely detect the targeted NRAS RNA G-quadruplex
structures, both in vitro and in cells. Thus, this GTFH probe was a useful tool for directly investigating the
folding of G-quadruplex structures within an RNA of interest and represents
a new direction for the design of smart RNA G-quadruplex probes.