CircRNA-encoded protein fine-tunes ROS homeostasis and engages conserved JAK-STAT antiviral defenses in <i>Drosophila</i>.

ABSTRACT: Multicellular organisms rely on multilayered immune systems to defend against pathogen invasion. In Drosophila melanogaster, the primary antiviral barrier is RNA interference (RNAi). However, many viruses encode suppressors that disable RNAi, forcing hosts to activate complementary defense strategies. One such strategy involves the circular RNA circZfh1, which encodes the protein CRAV. CRAV is essential for activating the JAK-STAT pathway and providing antiviral protection when RNAi is neutralized. However, the molecular mechanism linking CRAV expression to upd3 induction and JAK-STAT activation remains unclear. Here, we show that CRAV directly interacts with the Ca²⁺-binding domain of the NADPH oxidase Nox, enhancing its enzymatic activity. This interaction promot

SUBMITTER: Guo D 

PROVIDER: S-EPMC12817946 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature