The African swine fever virus (ASFV) employs sophisticated strategies to promote viral replication in the host; however, the underlying mechanisms remain incompletely understood. Here, we demonstrated that the ASFV encoded pE199L protein acts as a potential mitophagy receptor that disrupted innate immunity through structural mimicry. The pE199L protein localized to mitochondria via its C terminal hydrophobic domain (155-199 aa) and induced mitochondrial fission by promoting DNM1L/Drp1 phosphorylation. Importantly, pE199L contained three LC3-interacting regions (LIRs: W35-I38, F157-L160, F193-L196) that directed autophagic degradation of key immune adaptors. Specifically, pE199L mediated mitophagic clearance of TBK1 (the CGAS-STING1 pathway) and MAVS (the RLR-MAVS pathway), thereby inhibiting type I interferon production and enhancing viral replication. This dual degradation mechanism was confirmed through rescue experiments using autophagy inhibitors and functional assays with LIR mutants. We identifted pE199L as the first canonical mitophagy receptor encoded by ASFV, unveiling a novel immune evasion strategy and a potential target for antiviral vaccine development.
Li et al. (Mon,) studied this question.