The N-terminal-most (NTM) domain of Myrf is required for transcriptional activity. (A) The auto-cleavage scheme of Myrf. (B) The transcriptional activity of wild-type Myrf N-terminal fragment was compared with that of mutant ones by luciferase assay. The luciferase activity of pcDNA3 was set to 1, and the reported values are means and standard errors. *p < 0.001 by two-tailed unpaired Student’s t test with Bonferroni correction. The luciferase assay samples were subsequently analysed by Western blot to examine protein expression levels. The grouping of blots cropped from different parts of the same gel is indicated by dividing lines. The full blots are shown in Supplementary Figure 1A. (C) The 17-base pair long Myrf motif that is recognized by the homo-trimer of Myrf N-terminal fragments. (D) DNA pulldown assay showed that Myrf-ΔN30 N-terminal fragment correctly distinguishes the Myrf motif (WT) from a decoy version (MU). The full blot is shown in Supplementary Figure 1B. (E) The subcellular localization of Myrf N-terminal fragment was determined by immunofluorescence in Oli-neu cells. A representative example is shown for each Myrf construct, and quantitative analysis is shown below the images. Scale bar, 10 µm. Myrf-ΔNLS N-terminal fragment is frequently found outside of the nucleus compared with the wild-type one (*p ≈ 0 by cumulative binomial distribution with Bonferroni correction). IB: immunoblotting.