Farnesyl pyrophosphate (FPP),is an intermediate in the HMG-CoA reductase pathway used by organisms in the biosynthesis of terpenes, terpenoids, and sterols. It is used in the synthesis of CoQ (part of the electron transport chain), as well as being the immediate precursor of squalene (via the enzyme squalene synthase), dehydrodolichol diphosphate (a precursor of dolichol, which transports proteins to the ER lumen for N-glycosylation), and geranylgeranyl pyrophosphate (GGPP). The above reactions are inhibited by bisphosphonates. Statin-induced rhabdomyolysis is due to the depletion of farnesyl-PPi, which leads to a depletion of CoQ in the electron transport chain of mitochondria, an organelle that is found in great numbers in myocytes. Farnesyl pyrophosphate synthase catalyzes sequential condensation reactions of dimethylallyl pyrophosphate with 2 units of 3-isopentenyl pyrophosphate to form farnesyl pyrophosphate,.
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