PSMB8 and infection: After 24 h of infection with siRNA-control or siRNA-Psmb8 and under the stimulation of H/R, immunoblotting with an antibody against ubiquitin (Ub) or Drp1 showed that knockdown of Psmb8 by siRNA-Psmb8 dramatically increased Drp1 ubiquitination and protein levels compared with those of the siRNA-control (Fig. 7A).