Nucleic acid recognition and antiviral activity of 1,4-substituted terphenyl compounds mimicking all faces of the HIV-1 Rev protein positively-charged \u03b1-helix

Cristina Medina-Trillo,José Gallego,Pablo Barrio,Daniel M. Sedgwick,Santos Fustero,Manuela Beltrán,Luis. M. Bedoya,José Alcamí,Ángela Moreno,Lidia Herrera

doi:10.1038/s41598-020-64120-2

Abstract

Small synthetic molecules mimicking the three-dimensional structure of α-helices may find applications as inhibitors of therapeutically relevant protein-protein and protein-nucleic acid interactions. However, the design and use of multi-facial helix mimetics remains in its infancy. Here we describe the synthesis and application of novel bilaterally substituted p-terphenyl compounds containing positively-charged aminoalkyl groups in relative 1,4 positions across the aromatic scaffold. These compounds were specifically designed to mimic all faces of the arginine-rich α-helix of the HIV-1 protein Rev, which forms deeply embedded RNA complexes and plays key roles in the virus replication cycle. Two of these molecules recognized the Rev site in the viral RNA and inhibited the formation of the RRE-Rev ribonucleoprotein complex, a currently unexploited target in HIV chemotherapy. Cellular assays revealed that the most active compounds blocked HIV-1 replication with little toxicity, and likely exerted this effect through a multi-target mechanism involving inhibition of viral LTR promoter-dependent transcription and Rev function. Further development of this scaffold may open new avenues for targeting nucleic acids and may complement current HIV therapies, none of which involve inhibitors interfering with the gene regulation processes of the virus.

Highlights

Small synthetic molecules mimicking the three-dimensional structure of α-helices may find applications as inhibitors of therapeutically relevant protein-protein and protein-nucleic acid interactions
The aminoalkyl side chains imitate the Arg residues of Rev. (B) Schematic overlay of a 1,4-bilaterally substituted terphenyl and a protein α-helix showing the mimicked residues. (C) Threedimensional view of the complex formed between subdomain IIB of the Rev Recognition Element (RRE) and the Rev[34–50] helix of the HIV-1 protein Rev[12]
The Rev[34–50] helix forms a high-affinity interaction with an internal loop located within subdomain IIB of the Rev Recognition Element (RRE) of the viral RNA (Fig. 1C)[11,12]. This interaction is essential for virus viability, as it triggers the cooperative incorporation of additional Rev molecules into the complex through interactions between Rev[34–50] helices and further sites on the RRE as well as protein-protein contacts[13], allowing nuclear export of unspliced or singly-spliced viral RNA molecules in the late phase of the virus cycle[14]

Summary

Introduction

Small synthetic molecules mimicking the three-dimensional structure of α-helices may find applications as inhibitors of therapeutically relevant protein-protein and protein-nucleic acid interactions. We describe the synthesis and application of novel bilaterally substituted p-terphenyl compounds containing positively-charged aminoalkyl groups in relative 1,4 positions across the aromatic scaffold These compounds were designed to mimic all faces of the arginine-rich α-helix of the HIV-1 protein Rev, which forms deeply embedded RNA complexes and plays key roles in the virus replication cycle. Two of these molecules recognized the Rev site in the viral RNA and inhibited the formation of the RRE-Rev ribonucleoprotein complex, a currently unexploited target in HIV chemotherapy. The most active compounds successfully inhibited the formation of both the RRE IIB- Rev[34–50] and full-length RRE-Rev complexes, and blocked HIV-1 replication with little cellular toxicity

Methods

Results

Conclusion