FIGURE 7.
A model of Rybp/YY1-miR-29 regulatory circuitry in skeletal myogenesis. The model depicts the role of the Rybp/YY1-miR-29 regulatory circuitry in myogenic differentiation. In myoblast, a repressive complex containing YY1/Rybp/Ezh2/HDAC4 binds to the promoter region of miR-29, leading to the trimethylation of histone lysine 27 and subsequent silencing of miR-29 transcription. Upon myogenesis starts, the recruitment of the MyoD/serum response factor activating complex and the displacement of the repressive complex lead to the activation of miR-29, which in turns targets both Rybp and YY1 to ensure the progress of myogenic differentiation. Straight line, promoter/enhancer region of mmu-miR-29b/c with arrow denotes TSS; CCAT, YY1 binding element; E-box, MyoD binding site; Me, methylation of histone lysine 27; Ac, acetylation of histones.