Rational Design of L-RNA Aptamer-Peptide Conjugate for Efficient Cell Uptake and G-quadruplex-Mediated Gene Control

29 Dec 2023

Published on Angewandte Chemie (29 Dec 2023)

Author(s): Dr. Kun Zhang, Qichang Nie, Prof. Dr. Terrence Chi-Kong Lau, Prof. Dr. Chun Kit Kwok

Abstract

RNA G-quadruplexes (D-rG4s) are prevalent in the transcriptome and play crucial regulatory roles in various biological processes. Recently, L-RNA aptamers have been reported to recognize functional rG4s with a strong binding affinity and specificity. However, owing to the poor cell penetration capacity of L-RNA aptamers, their biological applications are currently limited. Herein, we rationally design an L-RNA aptamer-peptide conjugate, Tamra_Ahx_R8_L-Apt.4-1c, which can efficiently translocate into the cytosol and target the rG4 of interest. Notably, we demonstrate diverse regulatory roles of Tamra_Ahx_R8_L-Apt.4-1c on rG4 motif present in different regions of mRNAs and further expand the application in different cell lines. Our novel and biocompatible conjugate enhances the cellular uptake of the L-RNA aptamer, and our robust strategy enables non-canonical RNA structures to be targeted by L-RNA aptamers for gene control in cells.

We present a novel strategy for transporting L-RNA aptamers that target rG4s into the cytosol using cell-penetrating peptides (CPPs). Polyarginine residues (R8) were covalently attached to the L-aptamer by click chemistry and the first L-RNA aptamer-CPP conjugate (Tamra_Ahx_R8_L-Apt.4-1c) was generated. Our study demonstrates that Tamra_Ahx_R8_L-Apt.4-1c functions as an effective tool for regulating rG4-mediated gene expression.