Ch4 — Metf

SAM acts as a "prosperity signal." When cellular SAM levels are high (indicating sufficient methyl donors), SAM allosterically inhibits MTHFR. This shuts down the production of 5-methyl-THF, effectively pausing the remethylation of homocysteine. Consequently, homocysteine is shunted toward the transsulfuration pathway to produce glutathione, enhancing antioxidant defenses.

Understanding MET-F C4 has led to specific therapeutic strategies: metf ch4

Global hypomethylation is a hallmark of cancer. In MET-F C4 dysfunction, low SAM levels or high SAH levels lead to passive DNA demethylation. This can activate proto-oncogenes. Conversely, specific hypermethylation of tumor suppressor gene promoters is also observed, driven by aberrant SAM utilization. Furthermore, cancer cells often upregulate SHMT to fuel one-carbon metabolism, making the MET-F axis a target for chemotherapy (e.g., Methotrexate targeting folate metabolism). SAM acts as a "prosperity signal