The long-term objective of the studies described in this proposal is to understand the mechanisms of biosynthesis and regulation of the mammalian facilitated diffusion glucose transporter (GT). These investigations are of medical significance because of the importance of the GT in the control of glucose homeostasis, the disruption of which is a consequence of several disease states, most notably the hyperglycemia and insulin-resistance observed in noninsulin-dependent diabetes. Moreover, the GT has proven to be an interesting model to study the mechanism of biosynthesis of multi-spanning membrane transport proteins. To achieve this objective, the specific aims of this proposal are: 1) To detemine the levels of control of GT activity in mouse 3T3 adipocytes in response to insulin, sulfonyl ureas, and modulation of glucose levels. Antibodies and a cDNA clone will be used to measure levels of GT activity, steady-state protein, rate of synthesis, mRNA, and gene transcription. 2) To transfect the human GT cDNA into 3T3 adipocytes and determine the subcellular distribution of the transfected protein in response to insulin. Site-directed mutagenesis of th cDNA clone prior to transfection will be used to identify putative translocation and targeting signals in the protein. 3) To clone and charaterize the human GT gene. 4) To use site-directed mutagenesis of a full-length GT cDNA clone in conjunction with fusion-protein constructions to identify and define informational amino acid sequences within the protein required for proper insertion into microsomal vesicles in in vivo translation/translocation systems.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK038495-04
Application #
3237875
Study Section
Physiological Chemistry Study Section (PC)
Project Start
1987-04-01
Project End
1992-03-31
Budget Start
1990-04-01
Budget End
1991-03-31
Support Year
4
Fiscal Year
1990
Total Cost
Indirect Cost
Name
Washington University
Department
Type
Schools of Medicine
DUNS #
062761671
City
Saint Louis
State
MO
Country
United States
Zip Code
63130
Roach, William; Plomann, Markus (2007) PACSIN3 overexpression increases adipocyte glucose transport through GLUT1. Biochem Biophys Res Commun 355:745-50
Murata, Haruhiko; Hresko, Richard C; Mueckler, Mike (2003) Reconstitution of phosphoinositide 3-kinase-dependent insulin signaling in a cell-free system. J Biol Chem 278:21607-14
Osman, Abdullah A; Saito, Mitsuyoshi; Makepeace, Carol et al. (2003) Wolframin expression induces novel ion channel activity in endoplasmic reticulum membranes and increases intracellular calcium. J Biol Chem 278:52755-62
Hresko, Richard C; Murata, Haruhiko; Mueckler, Mike (2003) Phosphoinositide-dependent kinase-2 is a distinct protein kinase enriched in a novel cytoskeletal fraction associated with adipocyte plasma membranes. J Biol Chem 278:21615-22
Murata, Haruhiko; Hruz, Paul W; Mueckler, Mike (2002) Indinavir inhibits the glucose transporter isoform Glut4 at physiologic concentrations. AIDS 16:859-63
Buse, Maria G; Robinson, Katherine A; Marshall, Bess A et al. (2002) Enhanced O-GlcNAc protein modification is associated with insulin resistance in GLUT1-overexpressing muscles. Am J Physiol Endocrinol Metab 283:E241-50
Hruz, Paul W; Murata, Haruhiko; Qiu, Haijun et al. (2002) Indinavir induces acute and reversible peripheral insulin resistance in rats. Diabetes 51:937-42
Hresko, Richard C; Mueckler, Mike (2002) Identification of pp68 as the Tyrosine-phosphorylated Form of SYNCRIP/NSAP1. A cytoplasmic RNA-binding protein. J Biol Chem 277:25233-8
Hresko, R C; Mueckler, M (2000) A novel 68-kDa adipocyte protein phosphorylated on tyrosine in response to insulin and osmotic shock. J Biol Chem 275:18114-20
Murata, H; Hruz, P W; Mueckler, M (2000) The mechanism of insulin resistance caused by HIV protease inhibitor therapy. J Biol Chem 275:20251-4

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