STING M284 variant (human, recombinant)

STING M284 variant (human, recombinant) contains amino acids 138-379 of the wild-type variant (R232) with a methionine substituted for arginine at position 284. 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-κB and transcription of immunomodulatory genes, including type I interferon (IFN). 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. The SNP variant H232 is found at a 13.7% frequency. The R284M mutation in STING is associated with constitutive activation of downstream signaling. It increases the propensity of STING to dimerize and associate with the kinase TBK1, enhancing the ability of STING to activate IRF3 and NF-κB and induce a type I IFN response. However, the R284M mutation occurs outside of the dimerization region between positions 153-177, so rather than a direct effect on dimerization, it is predicted to promote or inhibit binding of a cellular factor that stabilizes or impairs STING dimerization.