Global Discovery of Covalent Modulators of Ribonucleoprotein Granules

Abstract

Stress granules (SGs) and processing-bodies (PBs, P-bodies) are ubiquitous and widely studied ribonucleoprotein (RNP) granules involved in cellular stress response, viral infection, and the tumor microenvironment. While proteomic and transcriptomic investigations of SGs and PBs have provided insights into molecular composition, chemical tools to probe and modulate RNP granules remain lacking. Herein, we combine an immunofluorescence (IF)-based phenotypic screen with chemoproteomics to identify sulfonyl-triazoles (SuTEx) capable of preventing or inducing SG and PB formation through liganding of tyrosine (Tyr) and lysine (Lys) sites in stressed cells. Liganded sites were enriched for RNA-binding and protein–protein interaction (PPI) domains, including several sites found in RNP granule-forming proteins. Among these, we functionally validate G3BP1 Y40, located in the NTF2 dimerization domain, as a ligandable site that can disrupt arsenite-induced SG formation in cells. In summary, we present a chemical strategy for the systematic discovery of condensate-modulating covalent small molecules.

Stress Granule Core Protein-Derived Peptides Inhibit Assembly of Stress Granules and Improve Sorafenib Sensitivity in Cancer Cells

“…It also raises the significance of the development of SG inhibitors. Although efforts have been paid to screen SG inhibitors from compound library screens [33][34][35][36][37], these SG inhibitors are limited by specificity or SG-inhibiting efficacy. The design of compounds based on the SG core protein-mediated SG assembly mechanism and viral anti-SG strategies that afford us opportunities to learn are still lacking [38].…”