PARAMIR · Investigating micro-RNA Dynamics using Paramagnetic NMR Spectroscopy

Over the last decades, new discoveries have revealed an ever-increasing diversity of RNA functions, profoundly modifying the conceptual framework of molecular biology. This is the case of micro-RNAs (miRNA), a fascinating class of small non-coding RNA that play essential roles in RNA induced gene silencing and are estimated to target up to 60% of protein-coding genes in humans.RNA functional diversity is often triggered by conformational changes, so capturing the dynamics of these molecules is key to a precise understanding of their function, which in turn is essential to control their activity. Nuclear Magnetic Resonance (NMR) spectroscopy is extremely well suited to investigate dynamical processes. However, the sparsity of measureable NMR data in a RNA sample represents a major bottleneck, preventing so far an accurate description of RNA conformational fluctuations.This project aims to overcome this barrier by developing paramagnetic NMR for RNA. By chemically modifying an RNA, I will introduce paramagnetic tags to strategic positions so as to acquire NMR data from otherwise silent substrate. Adequate computational and analytical models will be developed to decode the experimental data into an atomic-level description of dynamics.These goals require a leap forward with respect to today’s approaches. I propose to achieve this by combining innovative sample preparation strategies and NMR experiments, high magnetic fields, and MD simulations. With these methods, I will enable the determination of the dynamic landscape of let-7, the first miRNA discovered in humans, involved in cell proliferation and differentiation and oncogenesis.This project will yield a broadly applicable method for the structural and dynamic characterization of RNA with unprecedented details. This knowledge will improve our fundamental biochemical and biophysical conception of RNA, opening new avenues for bioengineering and establishing the bases for rational RNA-oriented drug discovery.