FIGURE 1.

PmitoK_ATP functioning and modulation in durum wheat mitochondria (DWM). PmitoK_ATP catalyzes the electrophoretic K⁺ uptake across the inner membrane toward the matrix, so lowering membrane potential; the cooperation between PmitoK_ATP and the K⁺/H⁺ antiporter allows a K⁺ cycle able to dissipate also ΔpH, the second component of the proton motive force generated by the respiratory chain. ATP inhibits the channel while free fatty acids (FFAs), acyl-CoAs and superoxide anion activate it. The reducing equivalent flux through the respiratory chain to molecular oxygen and the coupled proton ejection into the intermembrane space are also indicated. The topology of ATP, FFAs, acyl-CoAs and ROS interaction with PmitoK_ATP is not considered. SH₂, reduced substrates; S, oxidized substrates; i.m.m., inner mitochondrial membrane.