I-mf, a Novel Myogenic Repressor, Interacts with Members of the MyoD Family

• Published in: Cell Vol. 86; no. 5; pp. 731 - 741
• Main Authors: Chen, C.-M.Amy, Kraut, Norbert, Groudine, Mark, Weintraub, Harold
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 06.09.1996
• Subjects: 3T3 Cells; Amino Acid Sequence; Animals; Bacterial Proteins - genetics; Cell Nucleus - metabolism; Cloning, Molecular; Cytoplasm - chemistry; DNA - metabolism; DNA, Complementary - genetics; Embryo, Mammalian - chemistry; Gene Expression Regulation, Developmental - physiology; Mice; Molecular Sequence Data; Muscles - embryology; MyoD Protein - analysis; MyoD Protein - metabolism; Myogenic Regulatory Factors - genetics; Myogenic Regulatory Factors - metabolism; Recombinant Fusion Proteins; RNA, Messenger - analysis; Serine Endopeptidases - genetics; Transcriptional Activation - physiology
• ISSN: 0092-8674; 1097-4172
• DOI: 10.1016/S0092-8674(00)80148-8

During embryogenesis, cells from the ventral and dorsal parts of the somites give rise to sclerotome and dermomyotome, respectively. Dermomyotome contains skeletal muscle precursors that are determined by the MyoD family of myogenic factors. We have isolated a novel myogenic repressor, I-mf ( I nhibitor of M yoD f amily), which is highly expressed in the sclerotome. In contrast, MyoD family members are concentrated in the dermomyotome. We demonstrate that I-mf inhibits the transactivation activity of the MyoD family and represses myogenesis. I-mf associates with MyoD family members and retains them in the cytoplasm by masking their nuclear localization signals. I-mf can also interfere with the DNA binding activity of MyoD family members. We postulate that I-mf plays an important role in the patterning of the somite early in development.