Protein Kinase, Interferon Inducible Double Stranded RNA Dependent Activator (PRKRA)

The double-stranded RNA (dsRNA)-activated protein kinase PKR is a mediator of the effects of interferon, particularly its antiviral activities. PKR has also been implicated in the onset of differentiation.The PACT cDNA encodes a deduced 313-amino acid polypeptide that contains 3 motifs resembling the dimerization motifs present in PKR and other dsRNA-binding proteins. Northern blot analysis revealed that PACT is expressed as a 2.0-kb mRNA in a variety of human cell lines.Northern blot analysis detected expression of RAX in all tissues tested. Western blot analysis showed a 35-kD protein expressed in cell lines derived from several mammalian species.PACT binds to both PKR and dsRNA. PACT activates PKR in a dsRNA-independent manner.