Fig. 1.
Fast-to-slow isoform switches of both thick- and thin-filament proteins in soleus muscle of 3-mo-old genetically modified mice with Gsα deficiency in skeletal muscle (MGsKO). A: glycerol-SDS gel was employed to identify myosin heavy chain (MHC) isoforms, and regular SDS-PAGE/Western blots using anti-troponin I (TnI) monoclonal antibody (MAb) TnI-1, anti-slow and cardiac troponin T (TnT) MAb CT3, and anti-fast TnT MAb T12 were used to identify troponin isoforms. The results showed increases in MHC I, slow TnI, and slow TnT, accompanied by decreases in MHC IIx, fast TnI, and fast TnT in MGsKO soleus muscle compared with age-matched controls. MLC, myosin light chain. B: the fast-to-slow isoform changes in thick- and thin-filament proteins were quantified using densitometry analysis. Values are means ± SE; n = 5 mice each in control and MGsKO groups. *P < 0.05, **P < 0.01 vs. control in Student's t-test.