Figure 3.

Screening for transcription factor binding (TFB) activity during intestinal epithelial cell (IEC) differentiation. A: Changes in junction protein composition as the cells undergo differentiation. B: Left: TF DNA binding activity was assayed in nuclear lysates from 2- and 12-day-old confluent IEC monolayers using a TF/DNA binding array. The array assaying nuclear lysate from nondifferentiated (day 2) IECs is shown in green and the array with differentiated lysate (day 12) is overlaid in red to show differential binding activity of distinct TFs. Right: Two separate probes containing hepatocyte nuclear factor 4α (HNF-4α) binding motifs show increased TFB in differentiated IECs. C:In silico analysis was used to identify potential TFB sites on the CLDN7 promoter. D: The array and in silico data were cross-referenced to identify potential regulators of CLDN7 during IEC differentiation.