| First Author | Black BL | Year | 1995 |
| Journal | J Biol Chem | Volume | 270 |
| Issue | 7 | Pages | 2889-92 |
| PubMed ID | 7852366 | Mgi Jnum | J:22937 |
| Mgi Id | MGI:70806 | Doi | 10.1074/jbc.270.7.2889 |
| Citation | Black BL, et al. (1995) The mouse MRF4 promoter is trans-activated directly and indirectly by muscle-specific transcription factors. J Biol Chem 270(7):2889-92 |
| abstractText | MRF4 is a member of the basic helix-loop-helix (bHLH) family of muscle-specific transcription factors, which also includes MyoD, myogenin, and myf5. The myocyte enhancer binding factor 2 (MEF2) proteins also serve as important muscle-specific transcription factors. In addition to activating the expression of many muscle-specific structural genes, various members of these two classes of proteins activate their own expression and the expression of each other in a complex transcriptional network that results in the establishment and maintenance of the muscle phenotype. To begin to determine how the expression of MRF4 is regulated by other muscle-specific transcription factors, we have isolated a region of the MRF4 gene that confers muscle-specific expression and have analyzed this promoter region for cis-acting elements involved in trans-activation by the myogenic bHLH and MEF2 transcription factors. Here, we show that in 10T1/2 fibroblasts the MRF4 promoter is trans-activated by myogenin, MyoD, myf5, and by the MEF2 factors, but that MRF4 does not activate expression of its own promoter. Myogenin activated the MRF4 promoter directly by an E box-dependent mechanism, while MEF2 factors activated the promoter through an indirect pathway. The E box-dependent regulation of the MRF4 promoter is in contrast to the regulation of the myogenin and MyoD promoters and may represent a mechanism for the differential expression of these factors during myogenesis. |
