Figure 1.
Roles of PKR in the cell. PKR is latent in healthy cells and upon pathogen infection interferons are produced, which upregulate PKR. These pathogens release their RNAs, which promote PKR dimerization and autophosphorylation. PKR autophosphorylates eukaryotic initiation factor 2α (eIF2α), which leads to inhibition of protein synthesis and apoptosis. PKR is inactivated by smaller RNAs, potentially from self- or non-self.