Research Paper Volume 7, Issue 10 pp 776—787

Figure 3. Caspase-like activity is decreased in 20S complexes but not in 26S/30S complexes of aged mice. (A) Native gel analysis of proteasome complexes with activity overlay for the chymotrypsin-like (CT-L) proteasome activity in lung tissue lysates from young and aged C57Bl/6 mice and (B) quantification thereof. (C) Native gel analysis with activity overlay for the caspase-like (C-L) proteasome activity and (D) quantification thereof. The appearance of 20S double bands is possibly due to the binding of alternative proteasome regulators such as PA28 family members [57]. Bar graphs show mean+SEM. (E) Western blot analysis for lysin-48 (K48) linked polyubiquitinated proteins in lung tissue lysates from young and aged C57Bl/6 mice. Detection of β-actin was used as a loading control. (F) Luciferase activity in lung tissue of young and aged FVB-luc reporter mice. n = 6-7+SEM.