Figure 1.

Proteasome Activity in Skeletal Muscle during Muscle Regeneration

(A) Time course for CTX treatment and tissue harvesting.

(B) Chymotrypsin-like and trypsin-like proteasome activities (relative to those in intact tissue) in tibialis anterior (TA) muscles at 3, 7, and 14 days after injury are shown. Data represent means ± SEM (t test: ^∗p < 0.05, ^∗∗p < 0.01, ^∗∗∗p < 0.001 versus intact; n = 3–5 per group). IU, international units.

(C) Immunoblotting analysis of ubiquitin in the TA muscles at 3, 7, and 14 days post injury. Data represent means ± SEM (t test: ^∗∗∗p < 0.001 versus intact; n = 3–5 per group).

(D) Time course analysis of satellite cells at 3 days after injury.

(E) Chymotrypsin-like and trypsin-like proteasome activities (relative to those in intact satellite cells) in satellite cells sorted from TA muscles at 3 days post injury. Data represent means ± SEM (t test: ^∗∗∗p < 0.001 versus intact satellite cells; n = 4–5 per group). IU, international units.

See also Figures S1.