title: Phosphorylation of insulin receptor substrate-1 serine 307 correlates with JNK activity in atrophic skeletal muscle.
abstract: c-Jun NH(2)-terminal kinase (JNK) has been shown to negatively regulate insulin signaling through serine phosphorylation of residue 307 within the insulin receptor substrate-1 (IRS-1) in adipose and liver tissue. Using a rat hindlimb suspension model for muscle disuse atrophy, we found that JNK activity was significantly elevated in atrophic soleus muscle and that IRS-1 was phosphorylated on Ser(307) prior to the degradation of the IRS-1 protein. Moreover, we observed a corresponding reduction in Akt activity, providing biochemical evidence for the development of insulin resistance in atrophic skeletal muscle.
authors.affiliation: Department of Pharmacology, University of North Carolina, Chapel Hill 27599-7365, USA. thomas_hilder@med.unc.edu
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Hilder
authors.forename: Janet C L
authors.initials: JC
authors.lastname: Tou
authors.forename: Richard E
authors.initials: RE
authors.lastname: Grindeland
authors.forename: Charles E
authors.initials: CE
authors.lastname: Wade
authors.forename: Lee M
authors.initials: LM
authors.lastname: Graves
mesh_terms: D000818:Animals; D001284:Atrophy / Q000378:metabolism*; D004789:Enzyme Activation; D005260:Female; D051275:Glucose Transporter Type 4; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D006614:Hindlimb / Q000473:pathology; D055504:Insulin Receptor Substrate Proteins; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009004:Monosaccharide Transport Proteins / Q000378:metabolism; D009124:Muscle Proteins; D018482:Muscle, Skeletal / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology*; D010750:Phosphoproteins / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D010768:Phosphoserine / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D051381:Rats; D017207:Rats, Sprague-Dawley; D011972:Receptor, Insulin / Q000378:metabolism; D012694:Serine / Q000378:metabolism*
chemical_list: D051275:Glucose Transporter Type 4; D055504:Insulin Receptor Substrate Proteins; C526296:Irs1 protein, rat; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; D010750:Phosphoproteins; D011518:Proto-Oncogene Proteins; C495694:Slc2a4 protein, rat; D010768:Phosphoserine; D012694:Serine; D011972:Receptor, Insulin; C494920:Akt1 protein, rat; D000071679:Glycogen Synthase Kinase 3 beta; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D038362:Glycogen Synthase Kinase 3