Figure 7.

Bnip3 reduces levels of both nuclear- and mitochondria-encoded proteins involved in mitochondrial respiration. Bax/Bak DKO MEFs were infected with adenoviruses encoding β-gal or Bnip3 for the indicated times and protein levels were analyzed by western blot analysis. (a) Increased levels of Bnip3 reduced the expression of both nuclear- (n) and mitochondrial (m)-encoded subunits in complex III and IV. The protein levels were restored to normal when Bnip3 levels were reduced 5 days after infection. (b) Bnip3 reduced the levels of subunits in complex V (ATP synthase), II, and I. (c) Downregulation of endogenous Bnip3 using siRNA for 72 h results in increased levels of both nuclear (n) and mitochondrial (m) encoded subunits in complex III and IV. (d) Mitochondrial proteins Tom20 and MnSOD were unchanged in response to Bnip3 in Bax/Bak DKO MEFs. (e) O₂ consumption in Bax/Bak DKO MEFs was assessed in a Seahorse (North Billerika, MA, USA) XF24 extracellular analyzer. The graph is a representative experiment showing rates of endogenous, state 4 (oligo), maximal uncoupler-stimulated (FCCP), and non-mitochondrial (Rot/Anti-A) respiration