Family of glucose-transporter genes. Implications for glucose homeostasis and diabetes.
Glucose transport by facilitated diffusion is mediated by a family of tissue-specific membrane glycoproteins. At least four members of this gene family have been identified by cDNA cloning. The HepG2-type transporter is the most widely distributed of these proteins. It provides many cells with their basal glucose requirement for ATP production and the biosynthesis of sugar-containing macromolecules. The liver-type transporter is expressed in tissues from which a net release of glucose can occur and in beta-cells of pancreatic islets. A genetic defect resulting in reduced activity of this transporter could hypothetically lead to the two principal features of non-insulin-dependent diabetes mellitus, insulin resistance and relative hypoinsulinemia. The adipocyte/muscle transporter is expressed exclusively in tissues that are insulin sensitive with respect to glucose uptake. This protein is an excellent candidate for a highly specific genetic defect predisposing to insulin resistance.
Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri 63110.
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Mueckler
D003924:Diabetes Mellitus, Type 2 / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology; D005947:Glucose / Q000378:metabolism* / Q000502:physiology; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D009004:Monosaccharide Transport Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology
D009004:Monosaccharide Transport Proteins; D005947:Glucose