G-quadruplex from precursor miR-1587 modulated its maturation and function.

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• Precursor microRNAs (miRNAs) with G-quadruplex forming sequences can influence Dicer-mediated cleavage.
• G-quadruplex structures are implicated in regulating miRNA production and function.

Purpose of the Study:

• To investigate the role of G-quadruplex formation in human precursor miR-1587 maturation and function.
• To explore how modulating G-quadruplex structures affects miRNA expression and target gene regulation.

Main Methods:

• Transfection of human precursor miR-1587 with varying solution conditions (e.g., K+, TMPyP4).
• Confirmation of G-quadruplex formation using Circular Dichroism (CD) and UV melting.
• Quantification of miR-1587 expression via Q-RT-PCR.
• Assessment of target gene inhibition (TAGLN, NCOR1) using Q-RT-PCR and Western blot.
• Elucidation of molecular mechanisms using dual-luciferase assays.

Main Results:

• G-quadruplex formation in precursor miR-1587 inhibited its maturation, leading to reduced miR-1587 expression.
• Destabilization of G-quadruplex structures increased miR-1587 expression.
• Modulation of G-quadruplex structures altered miR-1587's inhibitory effect on target genes (TAGLN, NCOR1).
• The observed changes in miRNA expression and function were attributed to G-quadruplex structure transformation.

Conclusions:

• G-quadruplex structures play a critical role in miRNA biosynthesis and function.
• Modulating the molecular conformation of G-rich precursor miRNAs can alter their function.
• This study provides a novel approach to control miRNA activity by targeting G-quadruplex structures.