Distribution of Glut1 in detergent-resistant membranes (DRMs) and non-DRM domains: effect of treatment with azide.
We have previously shown that the acute stimulation of glucose transport in Clone 9 cells in response to azide is mediated by activation of Glut1 and that stomatin, a Glut1-binding protein, appears to inhibit Glut1 function. In Clone 9 cells under basal conditions, approximately 38% of Glut1, approximately 70% of stomatin, and the bulk of caveolin-1 was localized in the detergent-resistant membrane (DRM) fraction; a significant fraction of Glut1 is also present in DRMs of 3T3-L1 fibroblasts and human red blood cells (RBCs). Acute exposure to azide resulted in 40 and 50% decreases in the content of Glut1 in DRMs of Clone 9 cells and 3T3-L1 fibroblasts, respectively, whereas the distribution of stomatin and caveolin-1 in Clone 9 cells remained unchanged. In addition, treatment of Clone 9 cells with azide resulted in a approximately 50% decrease in the content of Glut1 in the DRM fraction of plasma membranes. We conclude that 1) a significant fraction of Glut1 is localized in DRMs, and 2) treatment of cells with azide results in a partial redistribution of Glut1 out of the DRM fraction.
Rubin
Darrell
D
Department of Pathology, Case Western Reserve University, Cleveland, OH 44106-4951, USA.
Ismail-Beigi
Faramarz
F
D016475:3T3 Cells; D000818:Animals; D001386:Azides / Q000494:pharmacology*; D001798:Blood Proteins / Q000187:drug effects / Q000378:metabolism; D051242:Caveolin 1; D022461:Caveolins / Q000187:drug effects / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism*; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D051272:Glucose Transporter Type 1; D006801:Humans; D021962:Membrane Microdomains / Q000187:drug effects / Q000378:metabolism; D008565:Membrane Proteins; D051379:Mice; D009004:Monosaccharide Transport Proteins / Q000187:drug effects / Q000378:metabolism*; D017434:Protein Structure, Tertiary / Q000187:drug effects / Q000502:physiology; D011990:Receptors, Transferrin / Q000187:drug effects / Q000378:metabolism; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism
D001386:Azides; D001798:Blood Proteins; C495540:CAV1 protein, human; C495541:Cav1 protein, mouse; D051242:Caveolin 1; D022461:Caveolins; C488964:Stom protein, mouse; D051272:Glucose Transporter Type 1; D008565:Membrane Proteins; D009004:Monosaccharide Transport Proteins; D011990:Receptors, Transferrin; C495677:SLC2A1 protein, human; C036860:STOM protein, human; C495678:Slc2a1 protein, mouse; D005947:Glucose