Identification of important regulatory region of Th-POK

CD4+ and CD8+ T cells develop from CD4+CD8+ thymocytes. Although it has been
reported that expression of the transcription factor Th-POK is important for CD4+ T cell
development, the detailed mechanism regulating Th-POK expression is still obscure. By
comparing the promoter regions of the Th-POK gene between human and mouse, I
found that the region 3600 base pairs (bps) upstream from the transcription initiation
site of the Th-POK gene was highly conserved. To identify the important element(s) regulating
Th-POK expression in CD4+ T cells, I investigated the promoter activity of this region
using a luciferase assay in the human T cell line Jurkat. I identified a positive regulatory
element in this region 22 bps in length located 600 bp upstream from the transcription
initiation site. This 22 bp element had a consensus binding sequence for SAP-1,
which is encoded by the Elk4 gene and is activated by the Erk pathway. These data suggest
that the 22 bp element might positively regulate Th-POK expression through Erk-
SAP-1 signaling.

The journal of medical investigation : http://medical.med.tokushima-u.ac.jp/jmi/index.html