Retinoic acid-inducible gene I (RIG-I) is a cytosolic viral RNA receptor. Upon viral infection, the protein recognizes and then recruits adapter protein mitochondrial antiviral signaling (MAVS) protein, initiating the production of interferons and proinflammatory cytokines to establish an antiviral state. In the present study, we identify zinc finger protein 205 (ZNF205) which associates with RIG-I and promotes the Sendai virus (SeV)-induced antiviral innate immune response. Overexpression of ZNF205 facilitates interferon-beta (IFN-β) introduction, whereas ZNF205 deficiency restricts its introduction. Mechanistically, the C-terminal zinc finger domain of ZNF205 interacts with the N-terminal tandem caspase recruitment domains (CARDs) of RIG-I; this interaction markedly promotes K63 ubiquitin-linked polyubiquitination of RIG-I, which is crucial for RIG-I activation. Thus, our results demonstrate that ZNF205 is a positive regulator of the RIG-I-mediated innate antiviral immune signaling pathway.
Keywords: RIG-I; RLR signaling; ZNF205; ubiquitination.