IFIH1 Protein, Human (His)

IFIH1 protein, as an innate immune receptor, functions as a cytoplasmic sensor for viral nucleic acids, playing a pivotal role in detecting viral infections and initiating a cascade of antiviral responses. It is essential for inducing type I interferons and pro-inflammatory cytokines in response to viral stimuli. IFIH1 recognizes ligands such as mRNA lacking 2'-O-methylation at their 5' cap and long double-stranded RNA (>1 kb). Upon ligand binding, it associates with mitochondria antiviral signaling protein (MAVS/IPS1), activating the IKK-related kinases TBK1 and IKBKE, which phosphorylate interferon regulatory factors (IRF3 and IRF7), leading to the transcription of antiviral immunological genes, including interferons IFN-alpha and IFN-beta. The protein is responsible for detecting various viruses, including members of the Picornaviridae family, such as encephalomyocarditis virus (EMCV), mengo encephalomyocarditis virus (ENMG), rhinovirus, and SARS-CoV-2. IFIH1 is also involved in antiviral signaling against viruses with a double-stranded DNA genome, like vaccinia virus. Furthermore, it contributes to innate immune signaling amplification by recognizing RNA metabolites generated during virus infection by ribonuclease L (RNase L). Additionally, IFIH1 may enhance natural killer cell function and participate in growth inhibition and apoptosis in various tumor cell lines.