mTOR pathway inhibition stimulates pharmacologically induced nonsense suppression

Abstract

A large number of human genetic diseases result from premature termination codons (PTCs) caused by splicing defects, insertions, deletions or point mutations also termed nonsense mutations. Nonsense mutations are the source of various genetic diseases, ranging from rare neuro-metabolic disorders to relatively common inheritable cancer syndromes and muscular dystrophies. Over the years, a wide spectrum of studies has shown that certain antibiotics and other synthetic molecules can act as nonsense mutation suppressors, by inducing readthrough of the stop-codon leading to the expression of a full-length protein. Unfortunately, most readthrough-inducing agents have limited effects and are toxic. Thus, efforts are made to improve the clinical outcome of nonsense mutation suppressors. Here we show that the mTOR pathway is involved in antibiotic-mediated readthrough of nonsense mutations at the level of protein translation initiation. We demonstrate that inhibition of the mTOR translation-initiation-controlling eIF4E branch induces antibiotic-mediated nonsense mutation readthrough, paving the way to the development of a novel therapeutic strategy for enhancing the restoration of these disease-causing mutated transcripts.