NSP1 inhibits IFN-β induction irrespective of IRF3 degradation.

<p><b>A)</b> HEK293 cells were transfected with FLAG-MAVS and pcD-OSU-NSP1 vector in order to assess the MAVS mediated inhibition of IRF3 phosphorylation. Cell lysates were analyzed for pIRF3, IRF3, Anti-His, Anti-FLAG and GAPDH specific antibodies. <b>B)</b> Fold change of IFN-β transcripts was assessed in cells overexpressing human TBK1 and pFLAG-MAVS vectors, in presence or absence of pcD-NSP1. The data shown are means ± the SD (n = 3). * Significantly different in comparison to human TBK1 and NSP1 transfected and pFLAG-MAVS untransfected condition. P<0.05 <b>C)</b> Activation of IRF3 was assessed in absence or presence of pcD-NSP1 in cells transfected with TBK1 and FLAG-MAVS. <b>D)</b> Association of MAVS with TBK1 was studied by Co-IP in presence or absence of pcD-NSP1 in cells overexpressing TBK1 and MAVS. The MAVS degradation was controlled by proteosomal inhibitor MG132 Results reveal reduced interaction between MAVS-TBK1 in presence of NSP1.