Transient expression of a winged-helix protein, MNF-beta, during myogenesis.
A novel winged-helix transcription factor, MNF-beta, is expressed coincidentally with cell cycle withdrawal and differentiation of skeletal myogenic cells. MNF-beta is closely related to the myocyte nuclear factor (MNF) protein previously described (now termed MNF-alpha), but expression of the two isoforms is differentially regulated, and they exhibit distinctive functional properties with respect to DNA binding in vitro and transcriptional regulatory activity in transient-transfection assays. A DNA sequence motif binding MNF-beta with high affinity was selected from a library of random oligonucleotides and was found to be similar to but distinct from the cognate binding site for HNF-3beta, a more distantly related winged-helix protein. The temporal pattern of MNF-beta expression and the presence of MNF binding motifs within conserved promoter elements of several genes that modulate cell cycle progression support a working hypothesis that MNF proteins may modulate proliferation of myogenic precursor cells during development and muscle regeneration.
Yang
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Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas 75235-8573, USA.
Bassel-Duby
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Williams
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D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002478:Cells, Cultured; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D019143:Evolution, Molecular; D051858:Forkhead Transcription Factors; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D024510:Muscle Development; D010449:Peptide Mapping; D011401:Promoter Regions, Genetic; D051381:Rats; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; C495879:FOXK1 protein, human; D051858:Forkhead Transcription Factors; C497672:Foxk1 protein, mouse; D014157:Transcription Factors; D004247:DNA