DNAJC3: Proteins and Enzymes

The 58-kDa inhibitor of the interferon-induced double-stranded RNA-activated protein kinase (PKR) is a cellular protein that is activated during influenza virus infection to down-regulate the activity of PKR. The 58-kDa inhibitor of the interferon-induced double-stranded RNA-activated protein kinase (PKR) is a cellular protein that is activated during influenza virus infection to down-regulate the activity of PKR (1). The P58 protein inhibits both the autophosphorylation of PKR and the phosphorylation of the PKR natural substrate, the alpha subunit of eukaryotic initiation factor eIF-2. Sequence analysis revealed that P58 is a member of the tetratricopeptide family of proteins (2). Also, like other J-domain proteins, P58 stimulated the ATPase activity of Hsc70. Taken together, data suggests that P58 is a co-chaperone, possibly directing hsp/Hsc70 to refold, and thus inhibit kinase function (3).