The P Protein of Spring Viremia of Carp Virus Negatively Regulates the Fish Interferon Response by Inhibiting the Kinase Activity of TANK-Binding Kinase 1

Abstract

TBK1 is a pivotal phosphokinase that activates host IFN production to defend against viral infection; thus, it is a potential target for viruses to negatively regulate IFN response and facilitate viral evasion. We report that the SVCV P protein functions as a decoy substrate for cellular TBK1, leading to the reduction of IRF3 phosphorylation and suppression of IFN expression. These findings reveal a novel immune evasion mechanism of SVCV.