HEK293 cells were seeded at 5 × 105 cells per well in six-well plates. Cells were transfected with 500 ng of pDM128 (Rev reporter plasmid), 30 ng of Rev expression plasmid, 300 ng of DDX3X expression plasmid and 500 ng of TBK1 expression plasmid. All samples were normalized for DNA content using an empty plasmid. Cells were harvested 24 h post-transfection and CAT levels were analysed by ELISA (Roche) according to the manufacturer's instructions.
(B) HEK293 cells were transfected with the reporter plasmid pDM128 and constant amounts of Rev DDX3X wt or K230A and TBK1 wt or K38M were added as indicated. CAT expression was measured 24 h post-transfection by ELISA (Roche).