title: Insulin stimulates actin comet tails on intracellular GLUT4-containing compartments in differentiated 3T3L1 adipocytes.
abstract: Incubation of isolated GLUT4-containing vesicles with Xenopus oocyte extracts resulted in a guanosine 5'-[gamma-thio]triphosphate (GTP gamma S) and sodium orthovanadate stimulation of actin comet tails. The in vitro actin-based GLUT4 vesicle motility was inhibited by both latrunculin B and a dominant-interfering N-WASP mutant, N-WASP/Delta VCA. Preparations of gently sheared (broken) 3T3L1 adipocytes also displayed GTP gamma S and sodium orthovanadate stimulation of actin comet tails on GLUT4 intracellular compartments. Furthermore, insulin pretreatment of intact adipocytes prior to gently shearing also resulted in a marked increase in actin polymerization and actin comet tailing on GLUT4 vesicles. In addition, the insulin stimulation of actin comet tails was completely inhibited by Clostridum difficile toxin B, demonstrating a specific role for a Rho family member small GTP-binding protein. Expression of N-WASP/Delta VCA in intact cells had little effect on adipocyte cortical actin but partially inhibited insulin-stimulated GLUT4 translocation. Taken together, these data demonstrate that insulin can induce GLUT4 vesicle actin comet tails that are necessary for the efficient translocation of GLUT4 from intracellular storage sites to the plasma membrane.
authors.affiliation: Department of Physiology and Biophysics, University of Iowa, Iowa City, Iowa 52242, USA.
authors.forename: M
authors.initials: M
authors.lastname: Kanzaki
authors.forename: R T
authors.initials: RT
authors.lastname: Watson
authors.forename: A H
authors.initials: AH
authors.lastname: Khan
authors.forename: J E
authors.initials: JE
authors.lastname: Pessin
mesh_terms: D000199:Actins / Q000737:chemistry / Q000378:metabolism*; D000256:Adenoviridae / Q000235:genetics / Q000378:metabolism; D017667:Adipocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D001426:Bacterial Proteins; D001427:Bacterial Toxins / Q000494:pharmacology; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D002460:Cell Line; D017930:Genes, Reporter; D051275:Glucose Transporter Type 4; D005964:Glucosyltransferases / Q000378:metabolism; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology*; D008845:Microinjections; D008856:Microscopy, Fluorescence; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D009124:Muscle Proteins; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D009865:Oocytes / Q000502:physiology; D021381:Protein Transport / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013844:Thiazoles / Q000494:pharmacology; D053778:Thiazolidines; D014020:Tissue Extracts / Q000737:chemistry; D022161:Transport Vesicles / Q000187:drug effects / Q000378:metabolism*; D014638:Vanadates / Q000494:pharmacology; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal; D014982:Xenopus laevis
chemical_list: D000199:Actins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D019086:Bridged Bicyclo Compounds, Heterocyclic; D051275:Glucose Transporter Type 4; D007328:Insulin; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; D009419:Nerve Tissue Proteins; D011993:Recombinant Fusion Proteins; D013844:Thiazoles; D053778:Thiazolidines; D014020:Tissue Extracts; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal; C031815:toxB protein, Clostridium difficile; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D014638:Vanadates; D005964:Glucosyltransferases; C037068:latrunculin B