Fig. 3: Luciferase assay to measure proteins produced from frameshifting.
a Schematic of dual-luciferase constructs used to compare frameshift products. In the no-repeat control, NLuc was fused in frame with FLuc as a single open reading frame. In the readthrough control, NLuc was placed in the same frame between FLuc and GR-(GGGGCC)70. In the no-repeat frameshift control, NLuc was placed in the +1 or in the +2 frame, with stop codon placed in the FLuc frame before NLuc. In the repeat frameshift construct, the GR frame of (GGGGCC)70 was placed in frame with FLuc. b–d Normalized frameshift products of different reporters in 293T (b), U-2 OS (c) and SH-SY5Y (d) cells, respectively. All constructs were transiently transfected into cells for 24 h. NLuc signals were normalized to FLuc in each sample. The no-repeat frameshift is normalized by no-repeat control, and the repeat frameshift is normalized by the readthrough control. Data were reported as mean ± SEM from three or four biological replicates. Statistical analysis using two-tailed t-test. 293T: frame+1, ****P = 0.000016; frame+2, ****P = 0.00007. U-2 OS: frame+1, ****P = 0.000021; frame+2, ***P = 0.00014. SH-SY5Y: frame+1, ****P = 0.000019; frame+2, **P = 0.0059.
