miR-29 in Myoblast Conversion to Myofibroblast Figure 5. Smad3 suppresses miR-29 promoter through inhibiting MyoD binding and enhancing YY1 recruitment. (A) Schematic illustration of proximal promoter region of mmu-miR-29b/c primary transcript. The arrow denotes the Transcriptional Start Site (TSS). Predicted Smad3 (S), MyoD (M) and YY1 (Y) binding sites were displayed. The location of each site was indicated below. (B) C2C12 myoblasts were untreated or treated with TGF-b for 12 hrs at which time chromatins were collected for ChIP assays using antibodies against MyoD or IgG as controls. PCR assays PLoS ONE | www.plosone.org 9 March 2012 | Volume 7 | Issue 3 | e33766