Regulation of the myoblast-specific expression of the human beta-enolase gene.
The muscle-specific beta-enolase gene is expressed in proliferating adult myoblasts as well as in differentiated myotubes. Through deletion-transfection analysis, we identified a 79-base pair enhancer from the beta-enolase gene that leads to high level expression of a reporter gene in myoblasts, but not in fibroblasts. Following myoblast differentiation into myotubes, the activity of the enhancer declined, indicating that beta-enolase gene expression in myotubes is mediated by other regulators, possibly the myogenic helix-loop-helix family of transcription factors. Electrophoretic mobility shift assays indicated that proteins present in myoblast nuclear extracts specifically bind to the 3' half of the 79-base pair enhancer. This region contains an ets DNA-binding motif which is required not only for high level activity in myoblasts, but also for repressing activity in fibroblasts. Furthermore, the beta-enolase myoblast-specific enhancer shows limited similarity to the myoblast-specific enhancer associated with the human desmin gene, suggesting that gene expression in adult myoblasts may be coordinately regulated.
Department of Medicine, University of Arkansas for Medical Sciences, Little Rock.
J M
JM
Taylor
J D
JD
Davies
C A
CA
Peterson
D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation; D002478:Cells, Cultured; D004247:DNA; D004268:DNA-Binding Proteins / Q000378:metabolism; D004742:Enhancer Elements, Genetic; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009132:Muscles / Q000166:cytology / Q000201:enzymology*; D010751:Phosphopyruvate Hydratase / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid; D012689:Sequence Homology, Nucleic Acid
D004268:DNA-Binding Proteins; D004247:DNA; D010751:Phosphopyruvate Hydratase