title: Cooperation between myogenic regulatory factors and SIX family transcription factors is important for myoblast differentiation.
abstract: Precise regulation of gene expression is crucial to myogenesis and is thought to require the cooperation of various transcription factors. On the basis of a bioinformatic analysis of gene regulatory sequences, we hypothesized that myogenic regulatory factors (MRFs), key regulators of skeletal myogenesis, cooperate with members of the SIX family of transcription factors, known to play important roles during embryonic skeletal myogenesis. To this day little is known regarding the exact molecular mechanism by which SIX factors regulate muscle development. We have conducted a functional genomic study of the role played by SIX1 and SIX4 during the differentiation of skeletal myoblasts, a model of adult muscle regeneration. We report that SIX factors cooperate with the members of the MRF family to activate gene expression during myogenic differentiation, and that their function is essential to this process. Our findings also support a model where SIX factors function not only 'upstream' of the MRFs during embryogenesis, but also 'in parallel' to them during myoblast differentiation. We have identified new essential nodes that depend on SIX factor function, in the myogenesis regulatory network, and have uncovered a novel way by which MRF function is modulated during differentiation.
authors.affiliation: Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Faculty of Medicine, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada.
authors.forename: Yubing
authors.initials: Y
authors.lastname: Liu
authors.forename: Alphonse
authors.initials: A
authors.lastname: Chu
authors.forename: Imane
authors.initials: I
authors.lastname: Chakroun
authors.forename: Uzma
authors.initials: U
authors.lastname: Islam
authors.forename: Alexandre
authors.initials: A
authors.lastname: Blais
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002460:Cell Line; D016678:Genome; D018398:Homeodomain Proteins / Q000378:metabolism* / Q000502:physiology; D006801:Humans; D051379:Mice; D024510:Muscle Development / Q000235:genetics*; D032448:Myoblasts, Skeletal / Q000166:cytology / Q000378:metabolism*; D018006:Myogenic Regulatory Factors / Q000378:metabolism*; D015534:Trans-Activators / Q000378:metabolism* / Q000502:physiology; D015533:Transcriptional Activation
chemical_list: D018398:Homeodomain Proteins; D018006:Myogenic Regulatory Factors; C490947:Six1 protein, mouse; C098490:Six4 protein, mouse; D015534:Trans-Activators