Figure 5.

Prediction of transcription factors that regulate Egfr and the effect of nine predicted transcription factors on the Egfr promoter with bidirectional activity.

(A) Workflow for screening potential transcription factors (TFs) that regulate Egfr expression. (B) Predicted TF binding loci within the rat Egfr promoter. (C) TF-mediated activation or repression of Egfr reporter activity using dual-luciferase assays. The reporters and effectors were co-expressed in 293T cells, and both REN and LUC activity were measured. The relative LUC activities normalized to the REN activities are shown. Results are presented as the mean ± SD from three independent experiments, each with three replicates. *P < 0.05 (one-way analysis of variance followed by the Dunnett multiple comparison test). (D) Three potential conserved transcription factors of Egfr in humans, mice, and rats. The star (*) indicates support from ChIP-seq data in humans. (E) Relative mRNA expression of six candidate TFs at embryonic days 18 (E18d) and postnatal week 1 (P1w) and 8 (P8w) was compared with the expression at embryonic day 13 (E13d). Expression levels of target genes were normalized to Gapdh. Data are expressed as means ± SEM (n = 3).