Cloning and characterization of the human PAX7 promoter.

PAX7, a member of the PAX transcription factor gene family, is normally expressed at high levels during development in the neural tube and in skeletal muscle precursor cells. Interestingly, PAX7 expression was also identified in tumor cells developing from these cell types. To date not much is known about the molecular mechanisms controlling the regulation of PAX7 expression. Therefore, we have cloned and sequenced part of the proximal 5'-flanking region of the human PAX7 gene. Computer-based sequence analysis identified putative binding sites for basic transcription factors. Analysis of a series of deletion constructs in different cell types suggested that a distal region containing several E-boxes might be involved in muscle-specific expression of PAX7, and that a distinct proximal region can enhance basal PAX7 expression in tumor cells.