G-quadruplex Structure in miRNA / 中国生物化学与分子生物学报

ABSTRACT

G-quadruplex (G4) is a non-canonical nucleic acid secondary structure composed of guanine-rich DNA or RNA sequences. In the past few decades, researchers have focused on the G-rich sequences in gene promoter region, UTR, telomere and other common gene functional regions, to understand the relationship between their structure and function. In recent years, due to the in-depth study of non-coding RNA in diseases, G-rich sequences in non-coding RNA, especially miRNA, have attracted more attention. G-rich sequence has been involved in all physiological processes of miRNA synthesis, from primary miRNA (pri-miRNA), precursor miRNA (pre-miRNA) to mature miRNA: the dynamic balance formed between the G-quadruplex and the RNA stem-loop structure affects the maturation process of primary and precursor miRNA, causing the change of mature miRNA and the complementary pairing between miRNA and mRNA. This review focused on the dynamic changes between G4 and hairpin structure, and expounded the role of G-rich sequence in pri-miRNA, pre-miRNA, mature miRNA and mRNA. The important role of G-quadruplex in the maturation and function of miRNA was also discussed. It was concluded that the changes of external regulatory factors such as ionic conditions (K+, Mg +, K+ + Mg, Li +Mg +, etc) and G-quadruplex ligand molecules (destabilizer TMPyP4, etc) could regulate the balance between G-quadruplex and stem-loop structure, thus modulating the functions of miRNA. This review may help providing ideas and directions for the study of G-quadruplex function and regulation.