Prolonged Insulin Stimulation Down-regulates GLUT4 through Oxidative Stress-mediated Retromer Inhibition by a Protein Kinase CK2-dependent Mechanism in 3T3-L1 Adipocytes

• Published in: The Journal of biological chemistry Vol. 289; no. 1; pp. 133 - 142
• Main Authors: Ma, Jinhui, Nakagawa, Yuko, Kojima, Itaru, Shibata, Hiroshi
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 03.01.2014; American Society for Biochemistry and Molecular Biology
• Subjects: 3T3 Cells; Adaptor Proteins, Vesicular Transport - genetics; Adaptor Proteins, Vesicular Transport - metabolism; Adipocyte; Adipocytes - cytology; Adipocytes - metabolism; Animals; Casein Kinase II - genetics; Casein Kinase II - metabolism; Cell Biology; Down-Regulation - drug effects; Down-Regulation - physiology; Gene Knockdown Techniques; Glucose Transporter Type 4 - genetics; Glucose Transporter Type 4 - metabolism; Glut4; Hypoglycemic Agents - metabolism; Hypoglycemic Agents - pharmacology; Insulin; Insulin - metabolism; Insulin - pharmacology; Intracellular Membranes - metabolism; Liposomes - metabolism; Membrane Trafficking; Mice; Microsomes - metabolism; Mitogen-Activated Protein Kinase 3 - genetics; Mitogen-Activated Protein Kinase 3 - metabolism; Oxidative Stress - drug effects; Oxidative Stress - physiology; Phosphatidylinositol 3-Kinases - genetics; Phosphatidylinositol 3-Kinases - metabolism; Phosphorylation - drug effects; Phosphorylation - physiology; Protein Transport - drug effects; Protein Transport - physiology; Proteolysis - drug effects; Retromer; Signal Transduction; Vesicular Transport Proteins - genetics; Vesicular Transport Proteins - metabolism; Membrane Trafficking; Adipocyte; Glut4; Signal Transduction; Insulin; Retromer
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M113.533240

Although insulin acutely stimulates glucose uptake by promotion of GLUT4 translocation from intracellular compartments to the plasma membrane in adipocytes and muscles, long term insulin stimulation causes GLUT4 depletion that is particularly prominent in the insulin-responsive GLUT4 storage compartment. This effect is caused mainly by accelerated lysosomal degradation of GLUT4, although the mechanism is not fully defined. Here we show that insulin acutely induced dissociation of retromer components from the low density microsomal membranes of 3T3-L1 adipocytes that was accompanied by disruption of the interaction of Vps35 with sortilin. This insulin effect was dependent on the activity of protein kinase CK2 but not phosphatidylinositol 3-kinase or extracellular signal-regulated kinase 1/2. Knockdown of Vps26 decreased GLUT4 to a level comparable with that with insulin stimulation for 4 h. Vps35 with a mutation in the CK2 phosphorylation motif (Vps35-S7A) was resistant to insulin-induced dissociation from the low density microsomal membrane, and its overexpression attenuated GLUT4 down-regulation with insulin. Furthermore, insulin-generated hydrogen peroxide was an upstream mediator of the insulin action on retromer and GLUT4. These results suggested that insulin-generated oxidative stress switches the GLUT4 sorting direction to lysosomes through inhibition of the retromer function in a CK2-dependent manner. Insulin down-regulates GLUT4 by accelerating degradation in lysosomes. Insulin through H2O2 production dissociates retromer from LDM membrane in a protein kinase CK2-dependent manner. Insulin switches GLUT4 traffic route toward lysosomes via retromer inhibition. This revealed a unique oxidative stress-mediated insulin signal cascade that regulates the fate of GLUT4.