Modulation of GDP-dissociation inhibitor protein membrane retention by the cellular redox state in adipocytes.
Small GTPases of the Rab family play a key role in the regulation of vesicular transport in eukaryotic cells. As they cycle on and off membranes, Rab proteins rely on the escort services of the GDP-dissociation inhibitor (GDI) proteins. While specific recognition of Rab-GDI complexes by membrane targets is suggested, the mechanisms underlying the subsequent GDI release into the cytosol remain unknown. In this study, we demonstrate that modulations of the cellular redox status in intact rat fat cells, 3T3-L1 adipocytes in culture, and other cultured cell types result in rapid, effective, dose-dependent, and selective membrane dynamics of GDI-1 and -2, membrane retention under reduced redox state, or dissociation under oxidized conditions. GDI retention on adipocyte membranes is associated with a complete arrest of insulin-induced translocation of GLUT4 glucose transporters onto plasma membrane. Together, these data suggest, first, that following Rab delivery to membranes, GDI release is promoted by a shift in the redox state and, second, that arrest of GDIs on membranes inhibits intracellular membrane trafficking events.
Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.
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Chinni
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Brenz
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Shisheva
D016475:3T3 Cells; D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D017667:Adipocytes / Q000737:chemistry*; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D002458:Cell Fractionation; D002462:Cell Membrane / Q000737:chemistry; D003600:Cytosol / Q000737:chemistry; D019204:GTP-Binding Proteins / Q000032:analysis*; D051275:Glucose Transporter Type 4; D020730:Guanine Nucleotide Dissociation Inhibitors; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology; D008297:Male; D051379:Mice; D009004:Monosaccharide Transport Proteins / Q000032:analysis; D009124:Muscle Proteins; D016877:Oxidants / Q000494:pharmacology; D010084:Oxidation-Reduction; D011506:Proteins / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D055765:Shc Signaling Adaptor Proteins; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1
D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D000975:Antioxidants; C086796:GDP dissociation inhibitor 1; C098085:Gdi2 protein, mouse; D051275:Glucose Transporter Type 4; D020730:Guanine Nucleotide Dissociation Inhibitors; D007328:Insulin; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; D016877:Oxidants; D011506:Proteins; D055765:Shc Signaling Adaptor Proteins; C528034:Shc1 protein, mouse; C528035:Shc1 protein, rat; C495693:Slc2a4 protein, mouse; C495694:Slc2a4 protein, rat; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D006861:Hydrogen Peroxide; D019204:GTP-Binding Proteins