Ubiquitin (UB) is an 8.6 IcDa peptide involved in targeting of cellular proteins for degradation by an ATP-dependent degrading enzyme complex. Ubiquitinization of skeletal muscle proteins is increased with muscle injury Using Western blot we examined the Ubiquitinization of skeletal muscle proteins in 60 day old dystrophic (dy) 129 ReJ mice Dystrophic muscle showed greater levels of UB conjugated proteins (CUB) in the 10-50 kDa range and higher levels of free Ub (FUB) when compared to normal muscle (NORM). When dy animals were treated with rhIGF-I for 30 days (10 ug/day s.c.), the total amount of CUB and FUB was increased compared to NORM CUB CUB CUB FUB Group (10-50 kDa) f50-205 kOal (total) (total) dy 4.6±0.531.6±2.9 35.9±3.1 201±0.8IGFdy 5.5±0.539.9±3.9 45.3±4.325.3±05NORM 1.7±0.3 28,6±2.0 30.1±2.3 15,1±1.3 (values are units/50 ug protein,p<0.05,p<0.01 vs NORM, n=5 per group.) In summary, dystrophic muscle exhibits increased ubiqutinization of selected proteins along with increased levels of FUB. IGF-I increases Ubiquitinization of a number of muscle proteins while increasing levels of FUB Increased Ubiquitinization of proteins with IGF-I may be involved in the increased turnover of muscle proteins we observed in dy mice treated with IGF-I-.
|Original language||English (US)|
|State||Published - Dec 1 1996|
ASJC Scopus subject areas
- Molecular Biology