FIG. 1.

Cellular substrates of the E1b55K/E4orf6 complex are degraded independently of one another during adenovirus infection. (A) Degradation of cellular proteins over a time course of Ad5 infection. U2OS cells were infected with WT Ad5 (MOI of 25), and lysates were harvested at the indicated times postinfection for analysis by immunoblotting with specific antibodies. GAPDH served as a loading control. Protein levels were compared to those in mock-infected cells (M). (B) Independent degradation of p53, the MRN complex, and DNA ligase IV. Cell lines with mutant p53 (Saos2), Mre11 (A-TLD1), or DNA-PKcs (FUS9) were infected with WT Ad5 (MOIs of 25, 100, and 25, respectively). Lysates were prepared at 24 to 48 hpi and analyzed by immunoblotting for the indicated proteins. +, present; −, absent. (C) Mre11 may be the degradation target within the MRN complex. IMR90, A-TLD3, A-TLD1, or NBS cells were either mock treated (M) or infected with WT Ad5 (Ad; MOI of 75). Cells were harvested at 24 to 48 hpi, and lysates were analyzed by immunoblotting for the indicated proteins. Ku70 served as a loading control.