DNA sequences involved in transcriptional regulation of the mouse beta-globin promoter in murine erythroleukemia cells.

We have developed a transient assay in murine erythroleukemia (MEL) cells to analyze the cis-acting sequence requirements for transcriptional regulation of the mouse beta-major-globin promoter. From deletion analysis, a fragment of the promoter region, from -106 to +26 relative to the RNA cap site, was found to be sufficient for regulated transcription in MEL cells following induction of differentiation by dimethyl sulfoxide. Single-base mutational analysis of this 132-base-pair promoter fragment identified three sequence elements required for transcription in MEL cells. These are the ATATAA sequence at -31 to -26, the CCAATC sequence between -77 and -72, and the GCCACACCC sequence between -95 and -87. In addition, we found a requirement for sequences adjacent to the CCAAT and ATATAA consensus motifs. Point mutations within the promoter did not abolish transcriptional regulation following induction of differentiation by dimethyl sulfoxide. However, mutations that resulted in reduced transcription levels in uninduced MEL cells gave similarly decreased levels in induced MEL cells.