FIGURE 3.

Rybp is down-regulated during C2C12 myogenesis concomitant with YY1. A, C2C12 myoblasts were induced to differentiate in differentiation medium (DM) for 0, 2, 4, or 6 days. Total proteins were extracted and used for Western blotting for Rybp, YY1, and MyHC. GAPDH was used as a loading control. B, primary myoblasts were induced to differentiate in DM for 0, 2, and 4 days. Total proteins were extracted and used for Western blotting analysis for Rybp, YY1, α-Actin, Troponin, and MyHC. α-Tubulin was used as a loading control. C, C2C12 cells were stained for Rybp (red) and YY1 (green) by IF. The merged signals of Rybp and YY1 are yellow. DAPI staining indicates the nuclei. Bars = 50 μm. D, protein lysates were extracted from C2C12 myoblasts and subjected to co-IP assay using antibodies against YY1 or Rybp. E and F, total RNAs were extracted from the indicated mouse tissues, and the expression levels of Rybp and Yy1 mRNAs were measured by qRT-PCR and normalized with GAPDH. Data are represented as mean ± S.D. G, expression levels of Rybp or Yy1 in muscle tissue or primary myoblasts were measured by qRT-PCR.