Étudiant-chercheur étoile October 2012

Guillaume Desnoyers

PhD student in Biochemistry
Université de Sherbrooke

Award-winning publication: Noncanonical repression of translation initiation through small RNA recruitment of the RNA chaperone Hfq

Published in: Genes & Development, 2012 26: 726-739


"We characterized a new gene regulation mechanism in the E. coli bacteria that involves bacterial small RNAs (ribonucleic acids)—newly discovered molecules that play a crucial role in bacterial stress adaptation. Bacterial small RNAs act post-transcriptionally to regulate mRNA (messenger ribonucleic acid) translation by competing directly with the binding of ribosomes (cellular particles made of RNA and proteins involved in protein synthesis). Our work describes an alternative model by which a small RNA may repress translation by guiding regulatory proteins on an mRNA to modulate expression."

This basic research describes the strategies used by enterobacteria to colonize hosts. The small RNAs enable the bacteria to adapt to the stress of the infected host's changing conditions by modifying their gene expression. Several bacterial small RNA are involved in virulence, especially in E. coli and Salmonella, which, every year, cause millions of cases of food poisoning worldwide. Several bacterial strains are growing resistant to antibiotics, and a better understanding of the mechanisms of action of these small RNA could lead to the development of a new generation of antibiotics.