Bacterial effector modifies host messenger RNA to promote virulence.

FadA effector from Legionella pneumophila modifies host mRNA with NADPH-oxidase activity, increasing oxo 8 G modifications and promoting bacterial persistence in vivo.

• Why it matters: Understanding how bacterial effectors influence host RNA can reveal new mechanisms of infection and immune evasion, filling a gap in knowledge about post-transcriptional host manipulation.
• What they did: Researchers used RNA-interactome capture to identify effectors bound to host mRNA during infection, discovering FadA, which localizes to the nucleus and interacts with U-rich RNA motifs.
• The result: FadA's enzymatic activity leads to oxidative damage of host mRNA, suppresses cytokine responses, and enhances bacterial survival, suggesting a novel post-transcriptional strategy for bacterial virulence.