First Author | Thompson WR | Year | 1991 |
Journal | J Biol Chem | Volume | 266 |
Issue | 33 | Pages | 22678-88 |
PubMed ID | 1939278 | Mgi Jnum | J:1898 |
Mgi Id | MGI:50422 | Doi | 10.1016/s0021-9258(18)54623-8 |
Citation | Thompson WR, et al. (1991) A MyoD1-independent muscle-specific enhancer controls the expression of the beta-myosin heavy chain gene in skeletal and cardiac muscle cells. J Biol Chem 266(33):22678-88 |
abstractText | The beta-cardiac myosin heavy chain is the major contractile protein expressed in two sarcomeric muscles of distinct embryologic origins, the ventricular myocardium and slow twitch skeletal muscle. Characterization of the cis-acting regulatory sequences of the human and the rat beta-MHC genes established that their expression in these two muscle types is controlled, at least in part, by common mechanisms involving a muscle-specific enhancer. This enhancer consists of distinct but cooperative subelements that interact with muscle-specific nuclear proteins. In contrast to other muscle-specific enhancers, the beta-MHC gene enhancer is unresponsive, directly or indirectly, to the muscle lineage-determining and muscle gene-transactivating helix-loop-helix factors MyoD and myogenin. A MyoD-binding site in the rat beta-MHC promoter is not required for transcriptional activity in skeletal and cardiac cells, but is necessary for activation in 10T1/2 and CV1 cells transfected with MyoD. In addition, this element is absent from the human beta-MHC promoter. Thus, MyoD and MyoD-related processes are neither required nor sufficient for the expression of the beta-MHC gene either in cardiac or skeletal muscle cells. These observations provide evidence for the existence of myogenic regulatory programs that precede and/or differ from those governed by known myogenic helix-loop-helix transactivators. |