title: Ready, set, internalize: mechanisms and regulation of GLUT4 endocytosis.
abstract: The facilitative glucose transporter GLUT4, a recycling membrane protein, is required for dietary glucose uptake into muscle and fat cells. GLUT4 is also responsible for the increased glucose uptake by myofibres during muscle contraction. Defects in GLUT4 membrane traffic contribute to loss of insulin-stimulated glucose uptake in insulin resistance and Type 2 diabetes. Numerous studies have analysed the intracellular membrane compartments occupied by GLUT4 and the mechanisms by which insulin regulates GLUT4 exocytosis. However, until recently, GLUT4 internalization was less well understood. In the present paper, we review: (i) evidence supporting the co-existence of clathrin-dependent and independent GLUT4 internalization in adipocytes and muscle cells; (ii) the contrasting regulation of GLUT4 internalization by insulin in these cells; and (iii) evidence suggesting regulation of GLUT4 endocytosis in muscle cells by signals associated with muscle contraction.
authors.affiliation: Program in Cell Biology, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, Canada, M5G 1X8.
authors.forename: Costin N
authors.initials: CN
authors.lastname: Antonescu
authors.forename: Michelangelo
authors.initials: M
authors.lastname: Foti
authors.forename: Nathalie
authors.initials: N
authors.lastname: Sauvonnet
authors.forename: Amira
authors.initials: A
authors.lastname: Klip
mesh_terms: D017667:Adipocytes / Q000166:cytology / Q000378:metabolism; D000818:Animals; D002966:Clathrin / Q000378:metabolism; D004705:Endocytosis; D051275:Glucose Transporter Type 4 / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000378:metabolism; D032342:Muscle Cells / Q000166:cytology / Q000378:metabolism
chemical_list: D002966:Clathrin; D051275:Glucose Transporter Type 4; D007328:Insulin