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This Article Full Text Full Text (PDF) Supplemental Figures and Tables All Versions of this Article: 295/1/R329    most recent 00146.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Seiliez, I. Articles by Tesseraud, S. Search for Related Content PubMed PubMed Citation Articles by Seiliez, I. Articles by Tesseraud, S.

COMPARATIVE AND EVOLUTIONARY PHYSIOLOGY

An in vivo and in vitro assessment of TOR signaling cascade in rainbow trout (Oncorhynchus mykiss)

¹INRA, UMR1067 Nutrition Aquaculture et Génomique, F-64310 Saint-Pée-sur-Nivelle, France; ²INRA, UR1037 Station Commune de Recherches en Ichtyophysiologie Biodiversité et Environnement, Campus de Beaulieu, Rennes, France; ³Departament de Fisiologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; and ⁴Institut National de la Recherche Agronomique, UR83 Recherches Avicoles, Nouzilly, France

Submitted 28 February 2008 ; accepted in final form 17 April 2008

In mammals, feeding promotes protein accretion in skeletal muscle through a stimulation of the insulin- and amino acid- sensitive mammalian target of rapamycin (mTOR) signaling pathway, leading to the induction of mRNA translation. The purpose of the present study was to characterize both in vivo and in vitro the activation of several major kinases involved in the mTOR pathway in the muscle of the carnivorous rainbow trout. Our results showed that meal feeding enhanced the phosphorylation of the target of rapamycin (TOR), PKB, p70 S6 kinase, and eIF4E-binding protein-1, suggesting that the mechanisms involved in the regulation of mRNA translation are well conserved between lower and higher vertebrates. Our in vitro studies on primary culture of trout muscle cells indicate that insulin and amino acids regulate TOR signaling and thus may be involved in meal feeding effect in this species as in mammals. In conclusion, we report here for the first time in a fish species, the existence and the nutritional regulation of several major kinases involved in the TOR pathway, opening a new area of research on the molecular bases of amino acid utilization in teleosts.

feeding; signaling; protein synthesis; muscle; fish