biostudies-literatureMurali ANIAID NIH HHS15825-33https://www.ebi.ac.uk/biostudies/studies/S-EPMC2414291biostudies-literatureUnknown283(23)RNA recognition receptors are important for detection of and response to viral infections. RIG-I and MDA5 are cytoplasmic DEX(D/H) helicase proteins that can induce signaling in response to RNA ligands, including those from viral infections. LGP2, a homolog of RIG-I and MDA5 without the caspase recruitment domain required for signaling, plays an important role in modulating signaling by MDA5 and RIG-I, presumably through heterocomplex formation and/or by serving as a sink for RNAs. Here we demonstrate that LGP2 can be coexpressed with RIG-I to inhibit activation of the NF-kappaB reporter expression and that LGP2 protein produced in insect cells can bind both single- and double-stranded RNA (dsRNA), with higher affinity and cooperativity for dsRNA. Electron microscopy and image reconstructiThe Journal of biological chemistryStructure and function of LGP2, a DEX(D/H) helicase that regulates the innate immunity response.PMC24142911R01AI073335Murali ALi XKao CCRanjith-Kumar CTLi PHolzenburg ABhardwaj KfalseStructure and function of LGP2, a DEX(D/H) helicase that regulates the innate immunity response.RNA recognition receptors are important for detection of and response to viral infections. RIG-I and MDA5 are cytoplasmic DEX(D/H) helicase proteins that can induce signaling in response to RNA ligands, including those from viral infections. LGP2, a homolog of RIG-I and MDA5 without the caspase recruitment domain required for signaling, plays an important role in modulating signaling by MDA5 and RIG-I, presumably through heterocomplex formation and/or by serving as a sink for RNAs. Here we demonstrate that LGP2 can be coexpressed with RIG-I to inhibit activation of the NF-kappaB reporter expression and that LGP2 protein produced in insect cells can bind both single- and double-stranded RNA (dsRNA), with higher affinity and cooperativity for dsRNA. Electron microscopy and image reconstructi2008-01-01T00:00:00Z2008 Jun2026-05-01T16:55:22.976Z2019-03-27T00:15:24ZS-EPMC24142911841126910.1074/jbc.m80054220010.1074/jbc.M800542200