SET8 turnover is accelerated after UV damage, and SET8 is degraded after UV. (A) U2-OS cells were treated with increasing amounts of UV damage and processed for immunoblotting 3 h after treatment as indicated. (B) U2-OS cells were treated with a fixed dose of UV, harvested at the indicated time points, and processed for immunoblotting. (C and D) Proteasomal inhibition blocks SET8 degradation. (C) U2-OS cells were treated with UV alone or a combination of UV and MG132 for 1 h. Cells were processed for immunoblotting and quantitative PCR as indicated. Data are represented as mean + SD. (D) U2-OS cells were infected with an HA-SET8–expressing virus and seeded onto coverslips. Cells were treated with MG132, UV, or a combination 6 h before fixation and harvest. Coverslips were processed for immunofluorescence with the indicated antibodies. The remaining cells were processed for immunoblotting with the indicated antibodies. Bars, 10 µm. (E) UV treatment accelerates degradation of SET8. U2-OS cells were synchronized using aphidicolin and release into S phase, where they were treated with cycloheximide or a combination of cycloheximide and UV as indicated. Cells were processed for immunoblotting with the indicated antibodies.