Methylation of the mRNA 5’ cap by methyltransferases enables efficient translation and avoids recognition by innate immune factors. We analyze SARS-CoV-2 lacking its 2’-O-methyltransferases Nsp16. We identified a dual role for the 2’-O-methyltransferase Nsp16 during SARS–CoV-2 replication in avoiding efficient recognition by the RNA sensor MDA5 and in shielding its RNA from interferon-induced antiviral responses, thereby identifying Nsp16 as potential candidate for therapeutic intervention
Mobile genetic elements have significantly shaped our genomic landscape. LINE-1 retroelements are the only autonomously active elements left in the human genome and new insertions can have detrimental consequences. We demonstrate that the antiviral restriction factor TRIM5α senses and blocks LINE-1 retroelements.

Invited by Florence Margottin-Goguet.