Showing papers on "MYF5 published in 1990"

Transcriptional activation domain of the muscle-specific gene-regulatory protein myf5

Abstract: The human muscle determination factor myf5, like MyoD and other members of the family of skeletal muscle-specific regulatory proteins, contains a highly conserved putative helix-loop-helix domain. In MyoD this motif is required for the initiation of myogenesis in C3H mouse 10T1/2 fibroblasts and other non-muscle cells as well as for transcriptional activation of muscle genes. High affinity DNA binding of MyoD to regulatory DNA elements in muscle genes requires the formation of heterodimers with ubiquitous helix-loop-helix proteins such as E12 or E47. To investigate the potential of myf5 as a transcription factor, we have fused the GAL4 DNA-binding domain to various parts of the myf5 protein and analysed the transactivation of a GAL4 reporter plasmid. Here we report that myf5 contains an intrinsic transcriptional activation domain which is distinct from the helix-loop-helix motif. The predominant transactivating effect is associated with the C-terminal half of the myf5 molecule. High-affinity sequence-specific DNA binding of myf5 also requires hetero-oligomeric association with the enhancer-binding protein E12 to confer muscle-specific transactivation.

Localized expression of a myogenic regulatory gene, qmf1, in the somite dermatome of avian embryos.

Abstract: qmf1 is a quail myogenic regulatory gene that is transcribed in skeletal myoblasts and differentiated muscle and shows sequence homology to MyoD1 and Myf5. We used the qmf1 transcript as an in situ hybridization marker for determined myogenic cells to study myogenic lineages in developing embryos. We present evidence for the temporal and spatial regulation of qmf1 mRNA expression and slow cardiac troponin C (TnC), fast skeletal troponin T (TnT), and alpha-cardiac actin contractile protein mRNA expression in the somite myotome and limb buds. Our results show that qmf1 is a marker for myogenic lineages during both somite formation and limb development and that qmf1 mRNAs, but not contractile protein mRNAs, localize in dorsal medial lip (DML) cells of the somite dermatome. We propose that the DML is a site of myogenic lineage determination.