Myogenin and the SWI/SNF ATPase Brg1 maintain myogenic gene expression at different stages of skeletal myogenesis
Authors
Ohkawa, YasuyukiYoshimura, Saori
Higashi, Chiduru
Marfella, Concetta G. A.
Dacwag, Caroline S.
Tachibana, Taro
Imbalzano, Anthony N.
Student Authors
Concetta G. A. MarfellaUMass Chan Affiliations
Department of Cell BiologyDocument Type
Journal ArticlePublication Date
2007-03-02Keywords
Animals; Cell Line; Chromosomal Proteins, Non-Histone; DNA Helicases; Embryo, Mammalian; *Gene Expression Regulation, Developmental; Mice; Muscle Development; Muscle, Skeletal; MyoD Protein; Myogenin; Nuclear Proteins; Promoter Regions (Genetics); Transcription FactorsCell Biology
Life Sciences
Medicine and Health Sciences
Metadata
Show full item recordAbstract
Many studies have examined transcriptional regulation during the initiation of skeletal muscle differentiation; however, there is less information regarding transcriptional control during adult myogenesis and during the maintenance of the differentiated state. MyoD and the mammalian SWI/SNF chromatin-remodeling enzymes containing the Brg1 ATPase are necessary to induce myogenesis in cell culture models and in developing embryonic tissue, whereas myogenin and Brg1 are critical for the expression of the late genes that induce terminal muscle differentiation. Here, we demonstrate that myogenin also binds to its own promoter during the late stages of embryonic muscle development. As is the case during embryonic myogenesis, MyoD and Brg1 co-localize to the myogenin promoter in primary adult muscle satellite cells. However, in mature myofibers, myogenin and Brg1 are preferentially co-localized to the myogenin promoter. Thus, the myogenin promoter is occupied by different myogenic factors at different times of myogenesis. The relevance of myogenin in the continued expression from its own promoter is demonstrated in culture, where we show that myogenin, in the absence of MyoD, is capable of maintaining its own expression by recruiting the Brg1 ATPase to modify promoter chromatin structure and facilitate myogenin expression. Finally, we utilized in vivo electroporation to demonstrate that Brg1 is required for the continued production of the myogenin protein in newborn skeletal muscle tissue. These findings strongly suggest that the skeletal muscle phenotype is maintained by myogenin and the continuous activity of Brg1-based SWI/SNF chromatin-remodeling enzymes.Source
J Biol Chem. 2007 Mar 2;282(9):6564-70. Epub 2006 Dec 27. Link to article on publisher's siteDOI
10.1074/jbc.M608898200Permanent Link to this Item
http://hdl.handle.net/20.500.14038/34263PubMed ID
17194702Related Resources
Link to article in PubMedae974a485f413a2113503eed53cd6c53
10.1074/jbc.M608898200