Fig. 4
From: Emerging roles of the Protein Phosphatase 1 (PP1) in the context of viral infections
PP1 is a negative regulator of the TLR pathway and is recruited by viruses to impair TLR signaling. PP1:GADD34 holoenzyme counteracts the activation of TAK1 and IKK, two crucial kinases in the TLR cascade. In resting cells, IKK is maintained in an inactive state by the PP1:GADD34:CUEDC2 complex. Upon viral infection, PP1 avoids the excessive activation of IRF3 and IRF7 and limits IFN-α/β expression. HSV-1 γ34.5 and enteroviruses (EV71, PV, CVA, and CVB) protein 2C recruit PP1 to dephosphorylate IKKβ and inhibit NF-κB activation. Figure created with BioRender.com