Fig. 2.

Increased nuclear YAP with repeated isometric contractions in vivo is dependent on dystrophin. A: muscle homogenates were fractionated into nuclear and cytoplasmic components. Confirmation of effective nuclear/cytoplasmic fractionation was confirmed with absence of GAPDH expression in nuclear fraction, and absence of lamin A/C expression in cytoplasmic fraction. B and C: representative Western blots showing fold-change in cytoplasmic and nuclear YAP protein expression in WT and mdx muscles with or without isometric loading, relative to the unloaded conditions. The cropped blot in each panel is from a single gel and single exposure of 2 contiguous lanes. Densitometry measures were normalized to GAPDH and lamin A/C for cytoplasmic and nuclear fractions, respectively. Values are means ± SD for TA muscles from 3 animals/genotype and loading condition. Although both nuclear and cytoplasmic YAP increase significantly in WT muscles after loading, no change is observed in mdx muscles after loading (*P < 0.05). A t-test was performed to determine statistical differences between control (no-load) and loaded conditions for WT and mdx muscles.