In this project, we introduce an integrative approach that leads to the identification of several effective YB-1 inhibitors in the low micromolar range selected computationally and validated in vitro by NMR spectroscopy and in cells using the MT bench assay. Here, the MT bench was adapted to score small molecules targeting RBP interactions with endogenous mRNA in cells. The MT bench assays can notably fill the gap between in vitro and functional assays by probing whether the interaction of a selected RBP with mRNAs is affected in a cellular context but not that of other RBPs. Our results validated the reliability of the MT bench assay in detecting and scoring YB-1 interactions with mRNA in 96-well plates (SSMD >8). The results presented here, show that the physics-based in silico approach allowed the identification of 22 potential hits that we subsequently tested in vitro by nuclear magnetic resonance (NMR) spectroscopy and in cells using the adapted MT bench assay by scoring the interaction of YB-1 with mRNA in the cytoplasm. Of these 22 potential YB-1 inhibitors, 15 compounds were found to bind YB-1 in vitro and 11 of them were found to efficiently interfere with the interaction of YB-1 with mRNA in cells at low micromolar concentrations; and with a notable specificity when compared with two other RBPs, Human antigen R (HuR) and fused in sarcoma (FUS). The potency of the selected compounds was further demonstrated by in depthMD and NMR analyses. The results also validate that theMT bench allows to score RBP-specific interactions robustly and automatically with endogenous mRNAs by using high-resolution HCS imagers.
Interestingly, compound P1, an FDA-approved poly(ADP-ribose) polymerase 1 (PARP-1) inhibitor, was found to interact with YB-1 with higher selectivity compared to the other hits. The efficiency of P1 in targeting RPIs and interfering with YB-1 cellular functions was then challenged with functional assays. Together, these results demonstrate the validity of our integrative approach and the efficacy of the MT bench assay that critically complements tional and structural approaches to identify compounds targeting RPIs in cells.
The project results were disseminated in scientific publications and were also deposited in open access repositories (bioRxiv). All of them include reference to EU funding:
1- K El Hage*, et al. Targeting RNA:Protein Interactions with an Integrative Approach Leads to the Identification of Potent YB-1 Inhibitors. bioRxiv. 2022.
https://doi.org/10.1101/2022.04.08.487452(odnośnik otworzy się w nowym oknie)This paper is under review at eLife.
2- K Budkina, et al. YB-1 unwinds mRNA secondary structures in vitro and negatively regulates stress granule assembly in HeLa cells. Nucleic acids research 2021, 49 (17) : 10061-10081.
https://doi.org/10.1093/nar/gkab748(odnośnik otworzy się w nowym oknie) 3- A Samsonova, et al. Lin28, a major translation reprogramming factor, gains access to YB-1-packaged mRNA through its cold-shock domain. Communications Biology, 2020, 4(1) :1-16.
https://doi.org/10.1038/s42003-021-01862-3(odnośnik otworzy się w nowym oknie)The results were also disseminated in international conferences and workshops:
1) The ISQBP President’s meeting 2022 in Innsbruck, Austria “The International Society of
Quantum Biology and Pharmacology”. The researcher gave an oral contribution on the first day of the meeting entitled “Targeting RNA:Protein Interactions using an integrative approach: Identification of potent YB-1 inhibitors.”; and the talk was tweeted on social media.
2) EMBO: Advances and challenges in BioMolecular Simulations (18-21 October 2021, Virtual). The researcher presented a Poster.
3) The ISQBP President’s meeting 2021 (29 June - 1st July 2021, Virtual). The researcher presented a Poster.
4) 2021 Virtual Workshop on free energy methods in drug design (June 15-June 17). The researcher presented a Poster.