Figure 1.

Interrelationships among components of the 1-carbon metabolism pathway (Methionine cycle, Folate cycle, and Transsulfuration pathway). 5-Mthf, 5-methyl-tetrahydrofolate; AMD1, adenosylmethionine decarboxylase 1; ARG, arginase; B₁₂, cobalamin; B₂, riboflavin; B₆, Pyridoxal 5′-phosphate; CBS, cystathionine beta-synthase; dc-SAM, decarboxylated S-adenosylmethionine; DHFR, dihydrofolate reductase; DNMT, DNA methyltransferase; dTMP, thymidine monophosphate; dUMP, deoxyuridine monophosphate; FTCD, formimidoyltransferase cyclodeaminase; GNMT, glycine N-methyltransferase; MAT, methionine adenosyltransferase; MTHFR, methylenetetrahydrofolate reductase; MTRR, 5-methyltetrahydrofolate-homocysteine methyltransferase reductase; ODC1, ornithine decarboxylase 1; PEMT, phosphatidylethanolamine N-methyltransferase; SAHH, S-adenosyl-homocysteine hydrolase; SHMT, serine hydroxymethyltransferase; SMS, spermine synthase; SRM, spermidine synthase; TDH, threonine dehydrogenase; THF, tetrahydrofolate; TYMS, thymidylate synthetase.