title: The type III TGFβ receptor regulates filopodia formation via a Cdc42-mediated IRSp53-N-WASP interaction in epithelial cells.
abstract: Cell adhesion and migration are tightly controlled by regulated changes in the actin cytoskeleton. Previously we reported that the TGFβ (transforming growth factor β) superfamily co-receptor, TβRIII (type III TGFβ receptor; also known as βglycan), regulates cell adhesion, migration and invasion, and suppresses cancer progression, in part, through activation of the small GTPase Cdc42 (cell division cycle 42), and Cdc42-dependent alterations to the actin cytoskeleton. In the present study we demonstrate that TβRIII specifically promotes filopodial formation and extension in MCF10A and HMEC (human mammary epithelial cell) mammary epithelial cells. Mechanistically, cell-surface TβRIII and Cdc42 co-localize to filopodial structures and co-complex in a β-arrestin2-dependent, and a TβRI/TβRII-independent manner. The β-arrestin2-mediated interaction between TβRIII and Cdc42 increases complex formation between the Cdc42 effectors IRSp53 with N-WASP (neuronal Wiskott-Aldrich syndrome protein) to increase filopodial formation. We demonstrate a function link between filopodial structures and epithelial cell adhesion as regulated by the TβRIII-Cdc42 interaction. The present studies identify TβRIII as a novel regulator of IRSp53/N-WASP via Cdc42 to regulate filopodial formation and cell adhesion.
authors.affiliation: Department of Medicine, Division of Medical Oncology, Duke University Medical Center, Durham, NC 27708, U.S.A.
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Oh
authors.forename: Erik H
authors.initials: EH
authors.lastname: Knelson
authors.forename: Gerard C
authors.initials: GC
authors.lastname: Blobe
authors.forename: Karthikeyan
authors.initials: K
authors.lastname: Mythreye
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D002461:Cell Line, Transformed; D004847:Epithelial Cells / Q000378:metabolism; D006801:Humans; D042361:Mammary Glands, Human / Q000166:cytology / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D011485:Protein Binding / Q000502:physiology; D011554:Pseudopodia / Q000502:physiology*; D051381:Rats; D053782:Transforming Growth Factor beta3 / Q000502:physiology*; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal / Q000378:metabolism*; D020764:cdc42 GTP-Binding Protein / Q000502:physiology*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C503229:Baiap2 protein, rat; D009419:Nerve Tissue Proteins; C509046:Tgfb3 protein, rat; D053782:Transforming Growth Factor beta3; C495770:Wasl protein, rat; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal; D020764:cdc42 GTP-Binding Protein