title: Destabilization of fructose 1,6-bisphosphatase-Z-line interactions is a mechanism of glyconeogenesis down-regulation in vivo.
abstract: Although it is well known that insulin controls the synthesis of glycogen from non-carbohydrates by down-regulating expression of several glyconeogenic enzymes, a mechanism of short-term inhibition of glyconeogenesis remains unknown. In recent years, we have shown that in skeletal muscle, fructose 1,6-bisphosphatase (FBPase) is a part of the hypothetical glyconeogenic complex located on sarcomeric Z-line. Here, we show that inhibition of glycogen synthase kinase-3 causes disruption of the FBPase-Z-line interactions and reduction of muscle glycogen content in vivo. The normal, striated pattern of muscle FBPase localization is also disturbed by insulin treatment but preserved when insulin is applied together with Akt inhibitor. We suggest that destabilization of FBPase-Z-line interaction is a universal cellular mechanism of glyconeogenesis down-regulation, allowing for preferential utilization of glucose for insulin-stimulated muscle glycogen synthesis.
authors.affiliation: Department of Animal Molecular Physiology, Wroclaw University, Cybulskiego 30, 50-205 Wroclaw, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Gizak
authors.forename: Jakub
authors.initials: J
authors.lastname: Mazurek
authors.forename: Marta
authors.initials: M
authors.lastname: Wozniak
authors.forename: Ewa
authors.initials: E
authors.lastname: Maciaszczyk-Dziubinska
authors.forename: Dariusz
authors.initials: D
authors.lastname: Rakus
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D015536:Down-Regulation; D005632:Fructose / Q000378:metabolism; D006597:Fructose-Bisphosphatase / Q000378:metabolism*; D005943:Gluconeogenesis / Q000187:drug effects / Q000502:physiology*; D005947:Glucose / Q000378:metabolism*; D006003:Glycogen / Q000378:metabolism*; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism; D007328:Insulin / Q000494:pharmacology; D008297:Male; D018482:Muscle, Skeletal / Q000201:enzymology*; D010766:Phosphorylation; D021381:Protein Transport; D051381:Rats; D017208:Rats, Wistar; D012518:Sarcomeres / Q000378:metabolism; D015027:Zebrafish / Q000378:metabolism*
chemical_list: D007328:Insulin; D005632:Fructose; D006003:Glycogen; D038362:Glycogen Synthase Kinase 3; D006597:Fructose-Bisphosphatase; D005947:Glucose; D002118:Calcium