FIGURE 7.

The double acetylation mimetic of Lys-19 and Lys-26 (K19Q/K26Q) decreases the pyruvate-dependent cellular oxygen consumption rate. A, H9c2 cells were placed in medium containing pyruvate as the sole nutrient source, and the OCR was measured as described under “Experimental Procedures.” CHC (0.1 mm) was added just prior to the beginning of the experiment as indicated. OCR measurements taken were basal (1), post-oligomycin (2), post-FCCP (3), and post-antimycin A (4). B, the maximal OCR was calculated as the post-FCCP OCR minus the post-oligomycin OCR (n = 4). C, wild type Myc-MPC2 and RR and QQ Myc-tagged MPC2 were expressed in H9c2 cells. A representative Western blot (WB) is shown indicating protein expression levels. D and E, the effects of exogenously expressed Myc-MPC2 on OCR (D) and maximal (Max) OCR (E) were evaluated. F, a schematic representation of the proposed transmembrane domains and topology of MPC2 (adapted from Ref. 36) and relative positions of Lys-19 and Lys-26. IMM, inner mitochondrial membrane; IMS, intermembrane space. n = 4; *, p < 0.05, unpaired Student's t test. Error bars are the standard deviation.