These results suggest that PACT plays an important role in potentiating RIG-I function to produce type I IFNs in order to restrict arenavirus replication and that viral NP RNase activity is essential for optimal viral replication by suppressing PACT-induced RIG-I activation.<b>IMPORTANCE</b> We report here a new role of the nucleoproteins of arenaviruses that can block type I IFN production via their specific inhibition of the cellular protein sensors of virus infection (RIG-I and PACT).
Taken together, our findings reveal a new facet of the host-IAV interaction in which the interplay between PACT and IAV polymerase affects the outcome of viral infection and antiviral response.-Chan, C.-P., Yuen, C.-K., Cheung, P.-H. H., Fung, S.-Y., Lui, P.-Y., Chen, H., Kok, K.-H., Jin, D.-Y.