Diffusion-ordered spectroscopy and saturation transfer difference NMR spectroscopy studies of selective interactions between ELAV protein fragments and an mRNA target

The crucial role of post-transcriptional processes in the control of gene expression
opened a new route to translate basic mechanisms into clinical medicine. In this
contest, ELAV proteins represent a family of well-characterized proteins that bind
mRNA. Interestingly, preliminary data bode well that the ELAV-mediated mRNA
stabilization is a mechanism relevant to Alzheimer Disease. Herein we analyzed four
peptides, belonging to RNA Recognition Motif of ELAVs, in presence of a mRNA
fragment from Tumor Necrosis Factor α, by NMR techniques with the final aim to get
insight into the interaction mechanism. Saturation Transfer Difference and Diffusion
Order NMR experiments showed that appropriate mixtures of peptides (and not each
peptide individually) bind effectively to the biological target. DOSY technique was
applied here for the first time to study mRNA:peptides complexes. For each peptide the
3D structure was also determined by NOE analysis supported by molecular dynamics
simulations