Evidence against protein kinase B as a mediator of contraction-induced glucose transport and GLUT4 translocation in rat skeletal muscle

FEBS Lett. 1998 Apr 3;425(3):472-4. doi: 10.1016/s0014-5793(98)00293-2.

Abstract

Both insulin and muscle contraction stimulate glucose transport activity. However, contraction stimulation does not involve the insulin signalling intermediate phosphatidylinositol 3-kinase (PI 3-kinase). Protein kinase B (PKB) has recently been identified as a direct downstream target of PI 3-kinase in the insulin signalling pathway. We have examined here whether the two stimuli share PKB as a convergent step in separate signalling pathways. Insulin stimulates both glucose transport, GLUT4 cell-surface content and PKB activity (by 4-6-fold above basal) in a wortmannin-sensitive manner in in vitro incubated rat soleus muscles. By contrast, muscle contraction, which stimulates glucose transport and the cell surface content of GLUT4 by 3-fold above basal levels, had no effect on PKB activity. These data demonstrate that PKB is not a mediator of contraction-induced glucose transport and GLUT4 translocation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3-O-Methylglucose / pharmacokinetics
  • Affinity Labels / metabolism
  • Androstadienes / pharmacology
  • Animals
  • Azides / metabolism
  • Biological Transport / drug effects
  • Disaccharides / metabolism
  • Glucose / pharmacokinetics*
  • Glucose Transporter Type 4
  • Glycosides
  • Insulin / pharmacology
  • Male
  • Monosaccharide Transport Proteins / metabolism*
  • Muscle Contraction / physiology*
  • Muscle Proteins*
  • Muscle, Skeletal / metabolism*
  • Phosphatidylinositol 3-Kinases / metabolism
  • Propylamines*
  • Protein Serine-Threonine Kinases*
  • Proto-Oncogene Proteins / physiology*
  • Proto-Oncogene Proteins c-akt
  • Rats
  • Rats, Wistar
  • Signal Transduction / physiology
  • Wortmannin

Substances

  • Affinity Labels
  • Androstadienes
  • Azides
  • Disaccharides
  • Glucose Transporter Type 4
  • Glycosides
  • Insulin
  • Monosaccharide Transport Proteins
  • Muscle Proteins
  • Propylamines
  • Proto-Oncogene Proteins
  • Slc2a4 protein, rat
  • 2-N-(4-(1-azitrifluoroethyl)benzoyl)-1,3-bis-(mannos-4-yloxy)-2-propylamine
  • 3-O-Methylglucose
  • Protein Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt
  • Glucose
  • Wortmannin