PT  - JOURNAL ARTICLE
AU  - Dai, Weiwei
AU  - Panserat, Stéphane
AU  - Mennigen, Jan A.
AU  - Terrier, Frédéric
AU  - Dias, Karine
AU  - Seiliez, Iban
AU  - Skiba-Cassy, Sandrine
TI  - Post-prandial regulation of hepatic glucokinase and lipogenesis requires the activation of TORC1 signalling in rainbow trout (<em>Oncorhynchus mykiss</em>)
AID  - 10.1242/jeb.091157
DP  - 2013 Dec 01
TA  - The Journal of Experimental Biology
PG  - 4483--4492
VI  - 216
IP  - 23
4099  - http://jeb.biologists.org/content/216/23/4483.short
4100  - http://jeb.biologists.org/content/216/23/4483.full
SO  - J. Exp. Biol.2013 Dec 01; 216
AB  - To assess the potential involvement of TORC1 (target of rapamycin complex 1) signalling in the regulation of post-prandial hepatic lipid and glucose metabolism-related gene expression in trout, we employed intraperitoneal administration of rapamycin to achieve an acute inhibition of the TOR pathway. Our results reveal that rapamycin inhibits the phosphorylation of TORC1 and its downstream effectors (S6K1, S6 and 4E-BP1), without affecting Akt and the Akt substrates Forkhead-box Class O1 (FoxO1) and glycogen synthase kinase 3α/β (GSK 3α/β). These results indicate that acute administration of rapamycin in trout leads to the inhibition of TORC1 activation. No effect is observed on the expression of genes involved in gluconeogenesis, glycolysis and fatty acid oxidation, but hepatic TORC1 inhibition results in decreased sterol regulatory element binding protein 1c (SREBP1c) gene expression and suppressed fatty acid synthase (FAS) and glucokinase (GK) at gene expression and activity levels, indicating that FAS and GK activity is controlled at a transcriptional level in a TORC1-dependent manner. This study demonstrates for the first time in fish that post-prandial regulation of hepatic lipogenesis and glucokinase in rainbow trout requires the activation of TORC1 signalling. 4E-BP14E-binding protein 16PF1K6-phosphofructo-1-kinaseACLYATP citrate lyaseAktprotein kinase BCPT1carnitine palmitoyltransferase 1EF1αelongation factor-1 alphaFASfatty acid synthaseFBPasefructose 1,6-bisphosphataseFKBP1212-kDa FK506-binding proteinFoxO1forkhead-box class O1G6Paseglucose 6-phosphataseG6PDHglucose 6-phosphate dehydrogenaseGKglucokinaseGSK 3glycogen synthase kinase 3α/βHIF1ahypoxia inducible factor 1aHKhexokinaseHOAD3-hydroxyacyl-CoA dehydrogenasei.p.intraperitonealPEPCKphosphoenolpyruvate carboxykinasePKpyruvate kinaseS6ribosomal protein S6S6K1ribosomal protein S6 kinaseSREBP1csterol regulatory element binding protein 1cTORtarget of rapamycinTORCtarget of rapamycin complex