title: Mechanisms through which sulfur amino acids control protein metabolism and oxidative status.
abstract: Amino acids regulate protein synthesis and breakdown (i.e., protein turnover) and consequently protein deposition, which corresponds to the balance between the two processes. Elucidating the mechanisms involved in such regulation is important from fundamental and applied points of view since it can provide a basis to optimize amino acid requirements and to control protein mass, body composition and so forth. Amino acids, which have long been considered simply as precursors of protein synthesis, are now recognized to exert other significant influences; that is, they are precursors of essential molecules, act as mediators or signal molecules and affect numerous functions. For example, amino acids act as mediators of metabolic pathways in the same manner as certain hormones. Thus, they modulate the activity of intracellular protein kinases involved in the regulation of metabolic pathways such as mRNA translation. We provide here an overview of the roles of amino acids as regulators of protein metabolism, by focusing particularly on sulfur amino acids. The potential importance of methionine as a "nutrient signal" is discussed in the light of recent findings. Emphasis is also placed on mechanisms controlling oxidative status since sulfur amino acids are involved in the synthesis of intracellular antioxidants (glutathione, taurine etc.) and in the methionine sulfoxide reductase antioxidant system.
authors: INRA, UR83 Recherches Avicoles, Nouzilly, France.
authors: Sonia
authors: S
authors: Métayer
authors: Iban
authors: I
authors: Seiliez
authors: Anne
authors: A
authors: Collin
authors: Sophie
authors: S
authors: Duchêne
authors: Yves
authors: Y
authors: Mercier
authors: Pierre-André
authors: PA
authors: Geraert
authors: Sophie
authors: S
authors: Tesseraud
mesh_terms: D000603:Amino Acids, Sulfur / Q000378:metabolism*; D003545:Cysteine / Q000378:metabolism; D006710:Homocysteine / Q000378:metabolism; D008954:Models, Biological; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D014176:Protein Biosynthesis; D011506:Proteins / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D000603:Amino Acids, Sulfur; D011506:Proteins; D006710:Homocysteine; D003545:Cysteine