id author title date pages extension mime words sentences flesch summary cache txt cord-343221-e29of29o Kindler, Eveline Early endonuclease-mediated evasion of RNA sensing ensures efficient coronavirus replication 2017-02-03 .txt text/plain 7896 423 51 Specifically, we show that genetically engineered mutants of mouse hepatitis virus (MHV) and human coronavirus 229E (HCoV-229E), respectively, that encode an EndoU active-site substitution known to abolish nucleolytic activity, were severely attenuated and elicited an immediate and simultaneous activation of host cell dsRNA sensors. The severe attenuation of MHV H277A and HCoV-229E H250A replication in wild-type murine and human macrophages, respectively, precluded the use of primary macrophages to assess the sensitivity of EndoU-deficient coronaviruses to IFN-I pre-treatment. Our data suggest that direct restriction of replication of EndoU-deficient coronaviruses is mediated by RNase L-mediated RNA degradation and inhibition of host cell translation through activation of PKR. Notably, also in this case Xrn1 is required to further process the de-capped mRNAs. Our data show that early during coronavirus infection the EndoU activity conceptually fulfils the same task, namely the removal of dsRNA that would otherwise trigger host cell dsRNA responses, such as IFN-β expression and activation of PKR and OAS/RNase L. ./cache/cord-343221-e29of29o.txt ./txt/cord-343221-e29of29o.txt