STING R224 variant (human recombinant) contains amino acids 138-379 of the wild-type variant (R232) with lysine 224 substituted with arginine. Stimulator of interferon genes (STING) is a component of the innate immune response that binds to cyclic dinucleotides, which are bacterial second messengers, lEAding to activation of NF-B and transcription of immunomodulatory genes, including type I interferon (IFN).1,2,3,4 The R232 variant of STING is the most common variant in the human population, found at a frequency of 57.9% in the 1000 Genome Project.5 The SNP variant H232 is found at a 13.7% frequency. The K224R mutation prevents ubiquitination of STING at position K224, a process which is essential for efficient cytosolic DNA-mediated signaling.6 Therefore, this mutation disrupts optimal STING trafficking, which inhibits TBK1-mediated IRF3 activation but not NF-B activation.Technical InformationSynonymsEndoplasmic Reticulum Interferon StimulatorStimulator of Interferon GenesTMEM173Purity70% estimated by SDS-PAGESourceN-terminally Histidine-tagged human STING R232, K224R mutant purified from E. coliAmino Acids138-379 (N-terminal truncation)MW28.8 kDaFormulation50 mM HEPES, pH 8.0, 150 mM sodium chloride, and 10% glycerol