The protein kinase regulated by RNA, PKR, plays an important function in innate immune response. The N-terminal includes a repeated domain that confers dsRNA-binding activity while the C-terminal confers the kinase activity. The best characterized substrate of PKR is the alpha-subunit of protein synthesis initiator 2 (eIF-2alpha(J02645:9606) ). When phosphorylated by PKR, eIF-2alpha leads to an inhibition of translation. Therefore, PKR is a key factor in the host antiviral response, through inhibition of protein synthesis during viral infection.

Viruses have evolved specific mechanisms to prevent the establishment of an antiviral state by inhibiting key components of the signaling pathway
