University of Dundee

"2'-O-Methylation (Nm) Prevent tRNA Endonucleolytic Cleavage and Regulates RNA Silencing in Drosophila"

Event Date: 
Thursday, October 24, 2019 - 14:00 to 15:00
Event Location: 
Sir Kenneth and Lady Noreen Murray Seminar Room School of Life Sciences, Discovery Centre (CTIR 2.84)
Dr Jens Januschke
Event Speaker: 
Dr Clément Carré
Institut de Biologie Sorbonne Université
Event Type: 
2’-O-methylation (Nm) represents one of the most common RNA modifications. Nm affects RNA structure and function with crucial roles in various RNA-mediated processes ranging from RNA silencing, translation, self versus non-self recognition to viral defense mechanisms. Here, we identify two novel Nm methyltransferases (Nm-MTases) in Drosophila melanogaster (CG7009 and CG5220) as functional orthologs of yeast TRM7 and human FTSJ1, respectively. Genetic knockout studies together with MALDI-TOF mass spectrometry and RiboMethSeq mapping revealed that CG7009 is responsible for methylating the wobble position in tRNAPhe, tRNATrp and tRNALeu, while subsequently, CG5220 methylates position C32 in the same tRNAs and targets also additional tRNAs. CG7009 or CG5220 mutant animals were viable and fertile but exhibited various phenotypes such as life span reduction, small RNA pathways dysfunction and increased sensitivity to RNA virus infections. Our results provide the first detailed characterization of two TRM7 family members in Drosophila and uncover a molecular link between enzymes catalysing Nm at specific tRNAs and small RNA-induced gene silencing pathways.