title: Greater filamin C, GSK3α, and GSK3β serine phosphorylation in insulin-stimulated isolated skeletal muscles of calorie restricted 24 month-old rats.
abstract: Moderate calorie restriction (CR) can improve insulin-stimulated Akt phosphorylation and glucose uptake in muscles from 24 month-old rats, but the specific Akt substrates linking CR-effects on Akt to glucose uptake and other cellular processes are uncertain. We probed CR's influence on site-specific phosphorylation of five Akt substrates (AS160(Ser588), TBC1D1(Thr596), FLNc(Ser2213), GSK3α(Ser21), and GSK3β(Ser9)) in predominantly fast-twitch (epitrochlearis) and predominantly slow-twitch (soleus) muscles. We observed no CR-effect on phosphorylation of AS160(Ser588) or TBC1D1(Thr596), but there was a CR-induced increase in insulin-stimulated FLNc(Ser2213), GSK3α(Ser21), and GSK3β(Ser9) phosphorylation for both muscles. These results indicate that CR does not uniformly affect insulin-mediated phosphorylation of Akt substrates in fast- or slow-twitch muscles from 24 month-old rats.
authors.affiliation: Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109-2214, USA.
authors.forename: Donel A
authors.initials: DA
authors.lastname: Sequea
authors.forename: Naveen
authors.initials: N
authors.lastname: Sharma
authors.forename: Edward B
authors.initials: EB
authors.lastname: Arias
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Cartee
mesh_terms: D000818:Animals; D031204:Caloric Restriction; D003285:Contractile Proteins / Q000378:metabolism*; D064448:Filamins; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D007004:Hypoglycemic Agents / Q000378:metabolism*; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D008840:Microfilament Proteins / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D051381:Rats; D012694:Serine / Q000378:metabolism
chemical_list: D003285:Contractile Proteins; D064448:Filamins; D007004:Hypoglycemic Agents; D007328:Insulin; D008840:Microfilament Proteins; D012694:Serine; D000071679:Glycogen Synthase Kinase 3 beta; C000605508:Gsk3b protein, rat; D038362:Glycogen Synthase Kinase 3; C448021:glycogen synthase kinase 3 alpha