Figure 6
From: Sequestration of ubiquitous dietary derived pigments enables mitochondrial light sensing
Mitochondrial CoQ10 photoreduction as potential mechanism to sense light.
Almost all of the cell’s redox reactions culminate to reduce coenzyme Q (CoQ10), shown in the schematic in its three oxidations states. I and II (Complexes I and II): transfer electrons from NADH and FADH2, respectively, to CoQ10 mGPDH (Mitochondrial glycerol-3-phosphate dehydrogenase): oxidizes glycerol-3-phosphate to dihydroxyacetone phosphate with concurrent reduction of flavin adenine dinucleotide (FAD) to FADH2 and transfers electrons to CoQ10 DHODH (Dihydroorotate Dehydrogenase): catalyzes the oxidation of dihydroorotate to orotate for de novo pyrimidine biosynthesis, using CoQ10 as an electron acceptor. ChDH (Choline dehydrogenase): oxidizes choline to glycine-betaine with CoQ10 serving as the primary electron acceptor. EFT (Electron-transferring-flavoprotein dehydrogenase): links the oxidation of fatty acids and some amino acids to oxidative phosphorylation by the oxidation of electron-transferring-flavoprotein using CoQ10 as an electron acceptor. The oxidation state of the mitochondrial CoQ10 pool can be used as a means of signal origin. We propose that dietary chlorophyll metabolites (green circle), such as PA, can enter the mitochondria, where they can absorb long wavelength light, resulting in the photoreduction of CoQ10, which could then propagate the input photonic energy via several potential pathways (wavy lines).
