FIGURE 6.
Effect of UCP3 knockdown on mitochondrial and cytosolic [ATP]. HeLa cells were transiently transfected with the mitochondrial or the cytosolic ATP probes ATeammito or ATeamcyto, respectively, together with the indicated siRNA for 48 h. A, averaged [ATP]mit changes elicited by 100 μm histamine and inhibition of mitochondrial ATP synthesis with oligomycin A (10 μg/ml) in cells perfused with 10 mm glucose as metabolic substrate and after inhibition of glycolysis with 10 mm 2-deoxyglucose. B, upper panels, mitochondrial (left) and cytosolic (right) ATeam signals recorded at 535 nm. Left lower panel, statistical evaluation of the histamine-induced, oligomycin A-sensitive [ATP]mit changes. Bars are mean ± S.E. of n = 4 (44 cells) and n = 5 (59 cells) for Ctrl and UCP3 siRNA, respectively. Right lower panel, statistical evaluation of the histamine-induced, oligomycin A-sensitive [ATP]cyt changes. Bars are mean ± S.E. of n = 5 (60 cells) and n = 5 (64 cells) for Ctrl and UCP3 siRNA, respectively. [ATP]cyt changes were recorded by applying the same protocol as in A. *, p < 0.05. NS, not stimulated.