FIGURE 1.

Brief summary of 1-carbon metabolism and DNA methylation. BER, base excision repair enzymes; BHMT, betaine-homocysteine S-methyltransferase; DHF, dihydrofolate; DMG, dimethylglycine; DNMT, DNA methyltransferase; MTHFR, methylenetetrahydrofolate reductase; MTR, methionine synthase; SAH, S-adenosylhomocysteine; SAM, S-adenosylmethionine; SHMT, serine hydroxymethyltransferase; TDG, thymine DNA glycosylase; TET, ten-eleven translocation methylcytosine dioxygenase enzymes; THF, tetrahydrofolate.