a1 1 INRA, UR83 Recherches Avicoles, F-37380 Nouzilly, France
a2 2 INRA, UMR1067 Nutrition Aquaculture et Génomique, F-64 310 St Pée-sur-Nivelle, France
Protein synthesis is affected when an insufficient level of sulfur amino acids is available. This defect may originate from dietary amino acid deficiency and/or excessive amino acid utilisation for other purposes such as the synthesis of glutathione and acute-phase proteins during catabolic stress. Sulfur amino acids are recognised to exert other significant functions since they are precursors of essential molecules, are involved in the methylation process, participate in the control of oxidative status, and may act as mediators affecting metabolism and cell functions. Despite this increased understanding of the role of sulfur amino acids, many questions still remain unanswered due to the complexity of the mechanisms involved. Moreover, surprising effects of dietary sulfur amino acids have been reported, with the development of disorders in cases of both deficiency and excess. These findings indicate the importance of defining adequate levels of intake and providing a rationale for nutritional advice. The aim of the present review is to provide an overview on the roles of sulfur amino acids as regulators of nutrient metabolism and cell functions, with emphasis placed on the implications for nutrition.
(Received June 18 2008)
(Revised October 27 2008)
(Accepted October 28 2008)
(Online publication December 15 2008)
Abbreviations: ATF4, activating transcription factor 4; CHOP, CCAAT/enhancer binding protein homologous protein; CpG, cytosine-guanine dinucleotide