Fig. 4. SARS-CoV-2 ORF6 or NSP13 expression is sufficient to cause CHK1 loss.
a, Immunofluorescence (IF) images of Huh7 cells expressing Strep-tagged SARS-CoV-2 ORF6 or NSP13 fixed 48 h post-transfection and stained for DDR markers; GFP was used as control; staining with anti-Strep-tag was used to label transfected cells; nuclei were stained with DAPI. Scale bar, 10 μm. b, The histograms show the percentage of CHK1- or RRM2-expressing cells among the transfected ones (Strep-Tag+) as determined in a; n = 3 independent experiments (n = 4 for GFP-expressing cells in RRM2 analysis). The dot plots show the number of γH2AX or pRPAS4/8 foci in the samples described in a. c, Representative immunoblots of whole cell lysates from Huh7 cells transfected with plasmids encoding for HA-tagged SARS-CoV-2 ORF6, or Strep-tagged SARS-CoV-2 NSP13, or empty vector (EV) as a control. Where present, dashed lines indicate where the blot was cropped. d, Quantification of protein levels shown in c; values are the mean ± s.e.m. of four independent experiments and shown as relative to the control sample (EV). Source numerical data and unprocessed blots are available in source data.