title: Mechanistic insights into the regulation of circular dorsal ruffle formation.
abstract: Growth factor stimulations induce dynamic changes in the cytoskeleton beneath the plasma membrane. Among them is the formation of membrane ruffles organized in a circular array, called 'circular dorsal ruffles' (CDRs). Physiological functions of CDRs include downregulation of cell growth by desensitizing the signalling from growth factor receptors as well as rearrangement of adhesion sites at the onset of cell migration. For the formation of CDRs, not only the activators of actin polymerization, such as N-WASP and the Arp2/3-complex, but also membrane deforming proteins with BAR/F-BAR domains are necessary. Small GTPases are also involved in the formation of CDRs by controlling intracellular trafficking through endosomes. Moreover, recent analyses of another circular cytoskeletal structure, podosome rosettes, have revealed common molecular features shared with CDRs. Among them, the roles of PI3-kinase and phosphoinositide 5-phosphatase may hold the key to the induction of these circular structures.
authors.affiliation: Division of Membrane Biology, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Kobe 650-0017, Japan. titoh@med.kobe-u.ac.jp
authors.forename: Toshiki
authors.initials: T
authors.lastname: Itoh
authors.forename: Junya
authors.initials: J
authors.lastname: Hasegawa
mesh_terms: D051376:Actin-Related Protein 2-3 Complex / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D002462:Cell Membrane / Q000201:enzymology / Q000378:metabolism* / Q000648:ultrastructure; D003599:Cytoskeleton / Q000201:enzymology / Q000378:metabolism* / Q000648:ultrastructure; D006801:Humans; D008954:Models, Biological; D058539:Phosphatidylinositol 3-Kinase; D010744:Phosphoric Monoester Hydrolases; D015398:Signal Transduction; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal / Q000737:chemistry / Q000378:metabolism; D000099182:Phosphoinositide 5-Phosphatases
chemical_list: D051376:Actin-Related Protein 2-3 Complex; D058539:Phosphatidylinositol 3-Kinase; D010744:Phosphoric Monoester Hydrolases; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal; D000099182:Phosphoinositide 5-Phosphatases; C495771:WASL protein, human