biostudies-literatureUnknown1(3)Mi ZRetinoic acid-inducible gene-I (RIG-I) functions as an intracellular pattern recognition receptor (PRR) that recognizes the 5'-triphosphate moiety of single-stranded RNA viruses to initiate the innate immune response. Previous studies have shown that Lys63-linked ubiquitylation is required for RIG-I activation and the downstream anti-viral type I interferon (IFN-I) induction. Herein we reported that, RIG-I was also modified by small ubiquitin-like modifier-1 (SUMO-1). Functional analysis showed that RIG-I SUMOylation enhanced IFN-I production through increased ubiquitylation and the interaction with its downstream adaptor molecule Cardif. Our results therefore suggested that SUMOylation might serve as an additional regulatory tier for RIG-I activation and IFN-I signaling.Protein & cell275-83https://www.ebi.ac.uk/biostudies/studies/S-EPMC4875083biostudies-literatureSUMOylation of RIG-I positively regulates the type I interferon signaling.PMC4875083Xiong YMi ZFu JTang HfalseSUMOylation of RIG-I positively regulates the type I interferon signaling.Retinoic acid-inducible gene-I (RIG-I) functions as an intracellular pattern recognition receptor (PRR) that recognizes the 5'-triphosphate moiety of single-stranded RNA viruses to initiate the innate immune response. Previous studies have shown that Lys63-linked ubiquitylation is required for RIG-I activation and the downstream anti-viral type I interferon (IFN-I) induction. Herein we reported that, RIG-I was also modified by small ubiquitin-like modifier-1 (SUMO-1). Functional analysis showed that RIG-I SUMOylation enhanced IFN-I production through increased ubiquitylation and the interaction with its downstream adaptor molecule Cardif. Our results therefore suggested that SUMOylation might serve as an additional regulatory tier for RIG-I activation and IFN-I signaling.2010-01-01T00:00:00Z2010 Mar2025-04-22T06:16:15.703Z2019-03-27T02:14:14ZS-EPMC48750832120397410.1007/s13238-010-0030-1