RESUMO
BACKGROUND: TPA Induced Sequence 7 acts as a transcriptional co-regulator controlling the expression of genes involved in differentiation of various cell types, including skeletal myoblasts. We and others have shown that TIS7 regulates adult myogenesis through MyoD, one of the essential myogenic regulatory factors. RESULTS: Here, we present data identifying ICln as the specific, novel protein downstream of TIS7 controlling myogenesis. We show that TIS7/ICln epigenetically regulate myoD expression controlling protein methyl transferase activity. In particular, ICln regulates MyoD expression via its interaction with PRMT5 by an epigenetic modification that utilizes symmetrical di-methylation of histone H3 on arginine 8. We provide multiple evidences that TIS7 directly binds DNA, which is a functional feature necessary for its role in transcriptional regulation. CONCLUSION: We present here a molecular insight into TIS7-specific control of MyoD gene expression and thereby skeletal muscle differentiation.
Assuntos
Diferenciação Celular/fisiologia , Proteínas Imediatamente Precoces/metabolismo , Proteínas de Membrana/metabolismo , Animais , Diferenciação Celular/genética , Células Cultivadas , Células HEK293 , Humanos , Proteínas Imediatamente Precoces/genética , Immunoblotting , Proteínas de Membrana/genética , Camundongos , Desenvolvimento Muscular/genética , Desenvolvimento Muscular/fisiologia , Músculo Esquelético/citologia , Músculo Esquelético/metabolismo , Proteína MyoD/genética , Proteína MyoD/metabolismo , Ligação Proteica , Reação em Cadeia da Polimerase em Tempo Real , Ressonância de Plasmônio de Superfície , Transcrição Gênica/genéticaRESUMO
Regulation and assembly of the flagellar type III secretion system is one of the most investigated and best understood regulational cascades in molecular biology. Depending on the host organism, flagellar morphogenesis requires the interplay of more than 50 genes. Direct secretion of heterologous proteins to the supernatant is appealing due to protection against cellular proteases and simplified downstream processing. As Escherichia coli currently remains the predominant host organism used for recombinant prokaryotic protein expression, the generation of a strain that exhibits inducible flagellar secretion would be highly desirable for biotechnological applications. Here, we report the first engineered Escherichia coli mutant strain featuring flagellar morphogenesis upon addition of an external inducer. Using FlgM as a sensor for direct secretion in combination with this novel strain may represent a potent tool for significant improvements in future engineering of an inducible type III secretion for heterologous proteins.
