Fig. 1: Amino acids in metabolic pathways.
From: Amino acids in cancer
Metabolic reprogramming is a staple of cancer cell growth and proliferation. Both essential and nonessential amino acids (EAAs and NEAAs) support altered metabolism by serving as energy sources, biosynthetic molecules, and mediators of redox balance. Amino acids produce metabolic intermediates, such as acetyl-CoA, that sustain energy synthesis through the citric acid cycle. Amino acids also provide building blocks for nucleotide synthesis and lipogenesis that are critical to a cell’s ability to grow and develop. To circumvent the effects of oxidative stress, amino acids can regulate redox balance through their production of glutathione. Furthermore, EAA catabolism contributes to the generation of NEAAs through chemical reactions, including those mediated by transaminases. Amino acids are in green, and other metabolites are in red. Orange represents transporters. Yellow boxes signify enzymes. SHMT1 serine hydroxymethyltransferase, cytosolic, BCAT branched-chain amino acid transaminase, mitochondrial, BCAA branched-chain amino acid (valine, leucine, isoleucine), BCKA branched-chain ketoacid, GOT1 aspartate transaminase, cytosolic (AST), GLS glutaminase, GS glutamine synthetase (cytosolic and mitochondrial), ASNS asparagine synthetase, PRODH pyrroline-5-carboxylate dehydrogenase, PYCR pyrroline-5-carboxylate reductase, P5C pyrroline-5-carboxylate, GSH glutathione, Gly glycine, Ser serine, Met methionine, Met cycle methionine cycle, Gln glutamine, Cys cysteine, Glu glutamate, Asp aspartate, Pro proline, Asn asparagine, Arg arginine, PRPP phosphoribosyl pyrophosphate, acetyl-coA acetyl-coenzyme A, α-KG alpha-ketoglutaric acid, OAA oxaloacetic acid, LAT1 large-neutral amino acid transporter 1, SLC25A44 solute carrier family 25 member 44, GLUT glucose transporter, TCA cycle the tricarboxylic acid (also known as the citric acid cycle).
