#Id: 1622
#Unit 4. Cell Communication and Cell Signaling
IFN-α or -β activates IFNAR to recruit and activate specific JAKs (JAK1 and Tyk2), which then activate specific STATs induce expression of three genes, Protein kinase R (PKR), which inhibits viral (and cellular) protein synthesis by inhibiting the elongation factor eIF2α; 2’,5’-oligoadenlyate A synthetase, which activates the ribonuclease RNase L that degrades viral mRNA; and Mx proteins, which inhibit both the transcription of viral genes into mRNAs and the assembly of virus particles.