NF1 nonsense suppression by targeted pseudouridylation

ABOUT THE PROJECT

A significant proportion (≈20%) of NF1 mutations are nonsense mutations that result in a PTC (premature translation termination codon) in the coding region. Consequently, a substantial fraction of PTC-containing NF1 mRNA is degraded by the cellular NMD (nonsense-mediated mRNA decay) surveillance pathway. Τhe small remaining fraction of un-degraded PTC-containing NF1 mRNA (escaped from NMD) is translated into protein, but the translation terminates prematurely at the PTC, thus generating a truncated and non-functional neurofibromin protein in the cell. Hence, nonsense mutations usually cause the most severe form of Neurofibromatosis type 1 (NF1) disease. In this application, we propose to fully develop a novel approach, namely site-specific RNA pseudouridylation (U-to-Ψ conversion) directed by box H/ACA RNA, to target NF1 PTCs, thereby suppressing NMD and promoting PTC-readthrough to restore the production of full-length functional neurofibromin protein in the cell.