Amino Acid Starvation Has Opposite Effects on Mitochondrial and Cytosolic Protein Synthesis Mark A. Johnson Sara Vidoni Romina Durigon Sarah F. Pearce Joanna Rorbach Jiuya He Gloria Brea-Calvo Michal Minczuk Aurelio Reyes Ian J. Holt Antonella Spinazzola 10.1371/journal.pone.0093597 https://plos.figshare.com/articles/dataset/_Amino_Acid_Starvation_Has_Opposite_Effects_on_Mitochondrial_and_Cytosolic_Protein_Synthesis_/993471 <div><p>Amino acids are essential for cell growth and proliferation for they can serve as precursors of protein synthesis, be remodelled for nucleotide and fat biosynthesis, or be burnt as fuel. Mitochondria are energy producing organelles that additionally play a central role in amino acid homeostasis. One might expect mitochondrial metabolism to be geared towards the production and preservation of amino acids when cells are deprived of an exogenous supply. On the contrary, we find that human cells respond to amino acid starvation by <i>upregulating</i> the amino acid-consuming processes of respiration, protein synthesis, and amino acid catabolism in the mitochondria. The increased utilization of these nutrients in the organelle is not driven primarily by energy demand, as it occurs when glucose is plentiful. Instead it is proposed that the changes in the mitochondrial metabolism complement the repression of cytosolic protein synthesis to restrict cell growth and proliferation when amino acids are limiting. Therefore, stimulating mitochondrial function might offer a means of inhibiting nutrient-demanding anabolism that drives cellular proliferation.</p></div> 2014-04-09 03:36:24 Biochemistry Bioenergetics Energy-producing organelles enzymology enzymes metabolism Carbohydrate metabolism proteins amino acids protein synthesis Nucleic acids cell biology Cellular structures and organelles Molecular cell biology Metabolic disorders chemistry Chemical compounds acids organic acids organic chemistry starvation mitochondrial cytosolic