Transcriptional regulation of the mouse interleukin-2 receptor β chain gene by Ets and Egr-1

To clarify the mechanisms and factors involved in the regulation of mouse IL-2Rβ gene expression, we isolated the 5′-flanking region of IL-2Rβ gene and investigated the promoter activity. Here we elucidated the positive regulatory regions, the most potent of which are located between −50 to −30 bp and −164 to −135 bp. These regions contain a potentially functional Ets and Egr-1-binding sites whose mutations abrogate promoter activity. Data from electrophoretic mobility shift assay indicate that Ets and Egr-1, but not Sp1, bind to the positive regulatory regions, −50 to −30 bp and −164 to −135 bp, respectively. Furthermore, recruitment of Ets and Egr-1 at endogenous IL-2Rβ promoter segments in an IL-2-dependent F7 cells was verified by the chromatin immunoprecipitation assay. This study for the first time delineates the molecular mechanisms underlying regulation of mouse IL-2Rβ gene transcription by Ets family proteins, partially with Egr-1, and thereby further elucidates the molecular basis of lymphocyte activation and differentiation.