RESUMEN
Retinoic acid-inducible gene I (RIG-I) is a pattern recognition receptor and is involved in the innate immune response against RNA viruses infection. Here, we demonstrate that the Ras-GTPase-activating protein SH3-domain-binding protein 1 (G3BP1) serves as a positive regulator of the RIG-I-mediated signaling pathway. G3BP1-deficient cells inhibited RNA virus-triggered induction of downstream antiviral genes. Furthermore, we found that G3BP1 inhibited the replication of Sendai virus and vesicular stomatitis virus, indicating a positive regulation of G3BP1 to cellular antiviral responses. Mechanistically, G3BP1 formed a complex with RNF125 and RIG-I, leading to decreased RNF125 via its auto-ubiquitination; thus, promoting expression of RIG-I. Overall, the results suggest a novel mechanism for G3BP1 in the positive regulation of antiviral signaling mediated by RIG-I.
Asunto(s)
Proteína 58 DEAD Box/genética , ADN Helicasas/genética , Proteínas de Unión a Poli-ADP-Ribosa/genética , ARN Helicasas/genética , Proteínas con Motivos de Reconocimiento de ARN/genética , Infecciones por Virus ARN/genética , Ubiquitina-Proteína Ligasas/genética , Proteína 58 DEAD Box/inmunología , Regulación de la Expresión Génica/inmunología , Interacciones Huésped-Patógeno/genética , Interacciones Huésped-Patógeno/inmunología , Humanos , Inmunidad Innata/genética , Infecciones por Virus ARN/inmunología , Infecciones por Virus ARN/virología , Virus ARN/genética , Virus ARN/inmunología , Virus ARN/patogenicidad , Receptores Inmunológicos , Receptores de Reconocimiento de Patrones/genética , Transducción de Señal , Ubiquitina-Proteína Ligasas/inmunología , Ubiquitinación/genética , Ubiquitinación/inmunología , Replicación Viral/genéticaRESUMEN
Transcription factor IRF3-mediated type I interferon induction plays a role in antiviral innate immunity. However, mechanisms for the control and regulation of IRF3 nuclear import remain largely unknown. We have identified DEAD box polypeptide 56 (DDX56) as a negative regulator of virus-triggered IFN-ß induction. Overexpression of DDX56 suppressed nuclear translocation of IRF3 via disrupting the IRF3-IOP5 interaction, whereas knockdown or knockout of DDX56 had the opposite effect. In addition, the interaction between DDX56 and IRF3 increased during viral infection. We further found that the D166 site of DDX56 was essential for inhibiting IRF3 import into the nucleus. Our findings suggest that DDX56 regulates antiviral innate immunity by inhibiting the nuclear translocation of IRF3, revealing a novel mechanism of the DDX56-mediated innate antiviral response.This article has an associated First Person interview with the first author of the paper.