Palmitoylation acts as a checkpoint for MAVS aggregation to promote antiviral innate immune responses

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Abstract

Upon RNA virus infection, the signaling adaptor MAVS forms functional prion-like aggregates on the mitochondrial outer membrane, which serve as a central hub that links virus recognition to downstream antiviral innate immune responses. Multiple mechanisms regulating MAVS activation have been revealed; however, the checkpoint governing MAVS aggregation remains elusive. Here, we demonstrated that the palmitoylation of MAVS at cysteine 79 (C79), which is catalyzed mainly by the palmitoyl S-acyltransferase ZDHHC12, was essential for MAVS aggregation and antiviral innate immunity upon viral infection in macrophages. Notably, the systemic lupus erythematosus–associated mutation MAVS C79F was associated with defective palmitoylation, resulting in low type I interferon (IFN) production. Accordingly, Zdhhc12 deficiency apparently impaired RNA virus–induced type I IFN responses, and Zdhhc12-deficient mice were highly susceptible to lethal viral infection. These findings reveal a previously unknown mechanism by which the palmitoylation of MAVS is a checkpoint for its aggregation during viral infection to ensure timely activation of antiviral defense.

Authors

Liqiu Wang, Mengqiu Li, Guangyu Lian, Shuai Yang, Jing Cai, Zhe Cai, Yaoxing Wu, Jun Cui