Amino Acid Homeostasis in Mammalian Cells with a Focus on Amino Acid Transport

Amino acid homeostasis is maintained by import, export, oxidation, and synthesis of nonessential amino acids, and by the synthesis and breakdown of protein. These processes work in conjunction with regulatory elements that sense amino acids or their metabolites. During and after nutrient intake, amino acid homeostasis is dominated by autoregulatory processes such as transport and oxidation of excess amino acids. Amino acid deprivation triggers processes such as autophagy and the execution of broader transcriptional programs to maintain plasma amino acid concentrations. Amino acid transport plays a crucial role in the absorption of amino acids in the intestine, the distribution of amino acids across cells and organs, the recycling of amino acids in the kidney, and the recycling of amino acids after protein breakdown.

Automated summary

Amino acid homeostasis is maintained through import, export, oxidation, and synthesis of nonessential amino acids, along with protein breakdown and synthesis, while regulatory elements sense amino acids or their metabolites. During and after nutrient intake, autoregulatory processes such as transport and oxidation of excess amino acids dominate, while amino acid deprivation triggers processes such as autophagy and broader transcriptional programs. Amino acid transport is crucial for absorption, distribution, and recycling across cells and organs, as well as after protein breakdown.