Figure 4: A virus-specific RNA-protein interaction protects viral RNA from Nsp1-dependent host shutoff.
A) Scheme of the coronavirus 5′ leader sequence with proposed 2D structures of SL1 from SARS-CoV-2, MERS-CoV and HuCoV-OC43 shown below. SL1 from different β-CoVs shows remarkable sequence variability. B-E) Nsp1-dependent host shutoff or translation boost in HEK293T cells transiently expressing Nsp1 from the indicated viruses and FLuc reporters carrying the indicated 5′ UTRs. NLuc was co-transfected as an internal control. N=6, error bars = SD. F) Western blot of whole cell lysate (top, antibody: anti-GFP), and Northern blot of total RNA from HEK293T cells transiently expressing SARS-CoV-2 Nsp1 wild-type or the indicated mutants and a GFP reporter. Probes are against GFP and U6 spliceosomal RNA.