caa a22 4500 475771303 CHVBK 20180406123618.0 cr unu---uuuuu 170329e20000901xx s 000 0 eng 10.1007/s001250051501 doi (NATIONALLICENCE)springer-10.1007/s001250051501 Impaired phosphorylation and insulin-stimulated translocation to the plasma membrane of protein kinase B/Akt in adipocytes from Type II diabetic subjects [Elektronische Daten] [E. Carvalho, B. Eliasson, C. Wesslau, U. Smith] Aims/hypothesis. To examine protein kinase B/Akt distribution and phosphorylation in response to insulin in different subcellular fractions of human fat cells from healthy subjects and subjects with Type II (non-insulin-dependent) diabetes mellitus. Methods. We prepared subcellular fractions of plasma membranes (PM), low density microsomes and cytosol and examined gene and protein expression as well as serine and threonine phosphorylation in response to insulin. Results. Protein kinase B/Akt mRNA as well as total protein kinase B/Akt protein in whole-cell lysate and cytosol were similar in both groups. Insulin increased protein kinase B/Akt translocation to the the plasma membrane about twofold [(p < 0.03) in non-diabetic cells but this effect was impaired in diabetic cells (∼ 30 %; p > 0.1)]. In both groups, protein kinase B/Akt threonine phosphorylation considerably increased in low density microsomes and cytosol whereas serine phosphorylation was predominant in the plasma membrane. Phosphatidylinositol-dependent kinase 1, which partially activates and phosphorylates protein kinase B/Akt on the specific threonine site, was predominant in cytosol but it was also recovered in low density microsomes. Serine phosphorylation in response to insulin was considerably reduced (50-70 %; p < 0.05) in diabetic cells but threonine phosphorylation was less reduced (∼ 20 %). Wortmannin inhibited these effects of insulin supporting a role for PI3-kinase activation. Conclusion/interpretation. Insulin stimulates a differential subcellular pattern of phosphorylation of protein kinase B/Akt. Furthermore, insulin-stimulated translocation of protein kinase B/Akt to the plasma membrane, where serine phosphorylation and full activation occurs, is impaired in Type II diabetes. Threonine phosphorylation was much less reduced. This discrepancy may be related to differential activation of phosphatidylinositol 3-kinase in the different subcellular compartments and phosphatidylinositol-dependent kinase 1 having high affinity for phosphatidylinositol phosphate 3. [Diabetologia (2000) 43: 1107-1115] Springer-Verlag Berlin Heidelberg, 2000 Keywords PKB/Akt nationallicence PI3-kinase nationallicence insulin action nationallicence Type II diabetes nationallicence GLUT-4 nationallicence Carvalho E. The Lundberg Laboratory for Diabetes Research, Department of Internal Medicine, Gothenburg University, Sahlgrenska University Hospital, Gothenburg, Sweden, SE aut Eliasson B. The Lundberg Laboratory for Diabetes Research, Department of Internal Medicine, Gothenburg University, Sahlgrenska University Hospital, Gothenburg, Sweden, SE aut Wesslau C. The Lundberg Laboratory for Diabetes Research, Department of Internal Medicine, Gothenburg University, Sahlgrenska University Hospital, Gothenburg, Sweden, SE aut Smith U. The Lundberg Laboratory for Diabetes Research, Department of Internal Medicine, Gothenburg University, Sahlgrenska University Hospital, Gothenburg, Sweden, SE aut https://doi.org/10.1007/s001250051501 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s001250051501 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Carvalho E. The Lundberg Laboratory for Diabetes Research, Department of Internal Medicine, Gothenburg University, Sahlgrenska University Hospital, Gothenburg, Sweden, SE aut NATIONALLICENCE 700 1- Eliasson B. The Lundberg Laboratory for Diabetes Research, Department of Internal Medicine, Gothenburg University, Sahlgrenska University Hospital, Gothenburg, Sweden, SE aut NATIONALLICENCE 700 1- Wesslau C. The Lundberg Laboratory for Diabetes Research, Department of Internal Medicine, Gothenburg University, Sahlgrenska University Hospital, Gothenburg, Sweden, SE aut NATIONALLICENCE 700 1- Smith U. The Lundberg Laboratory for Diabetes Research, Department of Internal Medicine, Gothenburg University, Sahlgrenska University Hospital, Gothenburg, Sweden, SE aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer