Research Paper Volume 11, Issue 19 pp 8433—8462

Brain pyrimidine nucleotide synthesis and Alzheimer disease

Figure 1. Oxidative phosphorylation system (OXPHOS) and biochemical pathways for pyrimidine nucleotide synthesis. OM, IMS, IM, and M code for mitochondrial outer membrane, intermembrane space, mitochondrial inner membrane, and mitochondrial matrix, respectively; ETC, electron transport chain; CI, CIII, CIV, CV and Cyt c code for respiratory complexes I, III, IV, ATP synthase and cytochrome c, respectively; Q, coenzyme Q10; NADH and NAD+, reduced and oxidized forms of nicotinamide adenine dinucleotide; H+, protons; e-, electrons; ADP, ATP and Pi, adenosine diphosphate, adenosine triphosphate, and inorganic phosphate; H2O, water; O2, oxygen; CAD, carbamoyl phosphate synthetase, aspartate transcarbamylase, dihydroorotase; DHODH, dihydroorotate dehydrogenase; UMPS, uridine monophosphate synthase; HCO3-, bicarbonate; Gln, glutamine; Asp, aspartate; DHO, dihydroorotate; O, orotate; PRPP, phosphoribosyl 5’-pyrophosphate; UMP, uridine monophosphate; CMP, cytidine monophosphate; CTP, cytidine triphosphate; UCK2, uridine cytidine kinase 2.