title: Aluminum fluoride stimulates surface protrusions in cells overexpressing the ARF6 GTPase.
abstract: To study the effector function of the ADP- ribosylation factor (ARF) 6 GTP-binding protein, we transfected HeLa cells with wild-type, epitope-tagged ARF6. Previously shown to indirectly activate the ARF1 GTPase, aluminum fluoride (AIF) treatment of ARF6-transfected cells resulted in a redistribution of both ARF6 and actin to discrete sites on the plasma membrane, which became increasingly protrusive over time. The effects of AIF were reversible, specific to cells transfected with wild-type ARF6, and resembled the cellular protrusions observed in cells expressing the GTPase defective mutant of ARF6. Importantly, the protrusions observed in cells transfected with ARF6 were distinct from the enhanced stress fibers and membrane ruffles observed in cells transfected with RhoA and Rac1, respectively. In cells forming protrusions, there was an apparent stimulation of macropinocytosis and membrane recycling within the protrusive structures. In contrast, no block in transferrin uptake or alteration of the distribution of clathrin AP-2 complexes was detected in these cells. The AIF-induced, ARF6- dependent formation of protrusive structures was blocked by cytochalasin D and inhibitors of the lipoxygenase pathway. These observations support a novel role for the ARF6 GTPase in modeling the plasma membrane and underlying cytoskeleton.
authors.affiliation: Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
authors.forename: H
authors.initials: H
authors.lastname: Radhakrishna
authors.forename: R D
authors.initials: RD
authors.lastname: Klausner
authors.forename: J G
authors.initials: JG
authors.lastname: Donaldson
mesh_terms: D020823:ADP-Ribosylation Factor 1; D000089982:ADP-Ribosylation Factor 6; D020727:ADP-Ribosylation Factors; D000199:Actins / Q000378:metabolism; D017607:Aluminum Compounds / Q000494:pharmacology*; D016718:Arachidonic Acid / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000032:analysis; D002462:Cell Membrane / Q000187:drug effects* / Q000378:metabolism; D002966:Clathrin / Q000032:analysis; D051356:Cortactin; D015638:Cytochalasin D / Q000494:pharmacology; D005459:Fluorides / Q000494:pharmacology*; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D020558:GTP Phosphohydrolases / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D018260:Gelsolin / Q000032:analysis; D006367:HeLa Cells; D006801:Humans; D016859:Lipoxygenase Inhibitors / Q000494:pharmacology; D009637:Masoprocol / Q000494:pharmacology; D008565:Membrane Proteins / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D008840:Microfilament Proteins / Q000032:analysis; D009154:Mutation; D010741:Phospholipases A / Q000037:antagonists & inhibitors; D010873:Pinocytosis; D011505:Protein-Tyrosine Kinases / Q000032:analysis; D011554:Pseudopodia / Q000187:drug effects; D014162:Transfection; D014168:Transferrin / Q000378:metabolism; D020744:rac GTP-Binding Proteins; D020742:rhoA GTP-Binding Protein
chemical_list: D000089982:ADP-Ribosylation Factor 6; D000199:Actins; D017607:Aluminum Compounds; D015815:Cell Adhesion Molecules; D002966:Clathrin; D051356:Cortactin; D018260:Gelsolin; D016859:Lipoxygenase Inhibitors; D008565:Membrane Proteins; D008840:Microfilament Proteins; D014168:Transferrin; D015638:Cytochalasin D; D016718:Arachidonic Acid; D009637:Masoprocol; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human; D010741:Phospholipases A; C097313:ADP-ribosylation factor related proteins; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins; D020823:ADP-Ribosylation Factor 1; D020727:ADP-Ribosylation Factors; C000715348:ARF6 protein, human; D020744:rac GTP-Binding Proteins; D020742:rhoA GTP-Binding Protein; D005459:Fluorides; C032311:aluminum fluoride