One-carbon Metabolism

As a family of enzyme cofactors, folate is a B-vitamin carries and chemically activates one-carbon units for biosynthesis of formate, formaldehyde, and methanol. One-carbon metabolism is a metabolic network widely existing in the cytoplasm, mitochondria, and nucleus. They are the interdependent and indespensible biosynthetic pathways in these organs. One-carbon metabolism in the cytoplasm is required for polyamine synthesis and methylation reactions of a wide range of molecules such as phospholipids, neurotransmitters, proteins and numerous other small molecules. In the mitochondria, the one-carbon metabolism is also needed for a large number of reactions, such as the interconversion of serine and glycine, the metabolism of choline, purines, and histidine and the synthesis of formylated methionyl-tRNA. Besides, the one-carbon metabolism in the mitochondria provides most of the one-carbon units used for metabolism in cytoplasm. In the nucleus of certain cell types, the folate-dependent de novo thymidylate biosynthesis pathway is shown to exist, which is indicated by increasing evidence.