Figure 2.

Detection of activating transcription factor 3 (ATF3) as a candidate TF. A, Motif analysis for activated enhancer regions. Among 10 260 activated enhancer regions, the top 3000 regions with highly expressed H3K27ac signal were extracted and subjected to de novo motif analysis. Top 5 significant motifs and candidate TFs, ATF3, JUN, JUNB, FOSL2, and BATF, are shown. B, Expression of genes neighboring the top 5 motifs. Neighboring genes were significantly upregulated in Epstein‐Barr virus (EBV)‐infected MKN7 cells (MKN7_EB). C, Relative expression levels of candidate TFs in MKN7_EB. While ATF3, TEAD2, and RUNX3 were clearly upregulated in MKN7_EB, other candidate TFs were not. D, Expression of genes in EBV‐infected GES1 cells. ATF3 was confirmed to be upregulated after EBV infection, whereas TEAD2 and RUNX3 were not. E, ATF3 protein level in cytoplasm and nucleus. Western blot showed ATF3 localized in nucleus, and expressed at higher levels in MKN7_EB cells. Open and closed boxes indicate relative ratio of the intensity of ATF3 to that of lamin A in the nucleus in MKN7_WT and MKN7_EB cells, respectively (n = 3). Values are shown as the mean ± SD