title: 6-Phosphofructo-2-kinase/fructose-2,6-bisphosphatase gene expression is regulated by diet composition and ration size in liver of gilthead sea bream, Sparus aurata.
abstract: Modulation of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (6PF-2-K/Fru-2,6-P(2)ase) gene expression by diet composition and ration size was studied in the liver of gilthead sea bream, Sparus aurata. From five different types of diet supplied to fish, those with either high carbohydrate/low protein or high carbohydrate/low lipid content stimulated 6PF-2-K/Fru-2,6-P(2)ase expression at the levels of mRNA, immunodetectable protein and kinase activity as well as promoting higher fructose-2,6-bisphosphate (Fru-2,6-P(2)) values. The expression of the bifunctional enzyme and Fru-2,6-P(2) levels showed also direct dependence on the quantity of diet supplied. These findings demonstrate for the first time nutritional regulation of 6PF-2-K/Fru-2,6-P(2)ase at mRNA level by diet composition and ration size and suggest that the carnivorous fish S. aurata can adapt its metabolism, by stimulation of liver glycolysis, to partial substitution of protein by carbohydrate in the diet. In addition, the expression of 6PF-2-K/Fru-2,6-P(2)ase can be used as an indicator of nutritional condition.
authors.affiliation: Departament de Bioquímica i Biologia Molecular, Facultat de Farmàcia, Universitat de Barcelona, Avda. Diagonal 643, 08028, Barcelona, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Metón
authors.forename: A
authors.initials: A
authors.lastname: Caseras
authors.forename: F
authors.initials: F
authors.lastname: Fernández
authors.forename: I V
authors.initials: IV
authors.lastname: Baanante
mesh_terms: D000818:Animals; D004032:Diet; D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D005508:Food Deprivation; D005786:Gene Expression Regulation; D008099:Liver / Q000201:enzymology; D010473:Perciformes / Q000235:genetics* / Q000378:metabolism; D025481:Phosphofructokinase-2; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis
chemical_list: D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D012333:RNA, Messenger; D017853:Phosphotransferases (Alcohol Group Acceptor); D025481:Phosphofructokinase-2; D010744:Phosphoric Monoester Hydrolases