Protein kinase R (PKR) is an intracellular stress-sensing protein that is able to detect and respond to viral infections. While PKR is able to sense and respond to a variety of signals, dsRNA is a well-characterized ligand. dsRNA produced during viral replication binds to PKR and induces a conformational change, dimerization, and exposure of the catalytic autophosphorylation site (1). Once in this active form PKR is able to phosphorylate substrates to regulate cell growth and stress responses.
