One-Carbon Metabolism Links Nutrition Intake to Embryonic Development via Epigenetic Mechanisms

Figure 1

The interplay between one-carbon metabolism (OCM) and epigenetic modifications. Methionine and folate cycles are entwined and contribute to the methyl group transfers that may cause epigenetic changes in cells. Methionine is initially converted into SAM, and then, SAM actively contributes the methyl group to DNA, proteins, and other metabolites, via reactions catalyzed by substrate-specific methyltransferases. SAH, a byproduct generated from the methylation cycles, is subsequently reversibly cleaved into Hcy. Methionine can be regenerated via the process of folate cycle, which involves remethylation of Hcy by 5-methyl-THF to form methionine in the presence of vitamin B₁₂ as a cofactor. SAM: S-adenosyl methionine; SAH: S-adenosyl homocysteine; Hcy: homocysteine; THF: tetrahydrofolic acid; 5,10-methyl-THF: 5,10-methylate tetrahydrofolic acid; 5-methyl-THF: 5-methylate tetrahydrofolic acid; B₁₂: vitamin B₁₂; B₂: vitamin B₂; MS: methionine synthase; DMG: dimethylglycine.