Human PKR Synthetic Peptide. PKR is a 68 kDa protein and an IFN-induced serine/threonine protein kinase consisting of two N-terminal RNA-binding regulatory domains and a functional C-terminal serine/threonine protein kinase domain. Activated by dsRNA produced during viral infections, PKR plays a key role in IFN induced-innate antiviral response, virus-induced apoptosis, cell growth & differentiation. Upon activation, PKR gets autophosphorylated and catalyzes the phosphorylation of elF2 alpha subunit, which leads to an inhibition of protein synthesis. PKR induces apoptosis by up-regulating Fas expression and mediates FADD/Caspase-8 death signaling pathway. Upon viral infection, it functions as a dual protein, sequentially activating both cel