One-Carbon Metabolism

One-carbon metabolism is a network of interconnected biochemical pathways that transfer single carbon units (as methyl, methylene, or formyl groups) between molecules. These reactions are essential for numerous cellular processes, including the synthesis of DNA and RNA (nucleotide biosynthesis), amino acid homeostasis, epigenetic regulation via methylation, redox balance, and energy metabolism. The pathway is primarily divided into two main arms: the Folate Cycle, involving tetrahydrofolate (THF), and the Methionine Cycle, involving S-adenosylmethionine (SAM). A third related pathway is the trans-sulfuration pathway. Disruptions in one-carbon metabolism are implicated in several diseases, including neural tube defects, cancer progression, and cardiovascular disease.