title: Dynamin participates in focal extracellular matrix degradation by invasive cells.
abstract: The degradation of extracellular matrix (ECM) by matrix metalloproteases is crucial in physiological and pathological cell invasion alike. Degradation occurs at specific sites where invasive cells make contact with the ECM via specialized plasma membrane protrusions termed invadopodia. Herein, we show that the dynamin 2 (Dyn2), a GTPase implicated in the control of actin-driven cytoskeletal remodeling events and membrane transport, is necessary for focalized matrix degradation at invadopodia. Dynamin was inhibited by using two approaches: 1) expression of dominant negative GTPase-impaired or proline-rich domain-deleted Dyn2 mutants; and 2) inhibition of the dynamin regulator calcineurin by cyclosporin A. In both cases, the number and extension of ECM degradation foci were drastically reduced. To understand the site and mechanism of dynamin action, the cellular structures devoted to ECM degradation were analyzed by correlative confocal light-electron microscopy. Invadopodia were found to be organized into a previously undescribed ECM-degradation structure consisting of a large invagination of the ventral plasma membrane surface in close spatial relationship with the Golgi complex. Dyn2 seemed to be concentrated at invadopodia.
authors.affiliation: Department of Cell Biology and Oncology, Istituto di Ricerche Farmacologiche Mario Negri, Consorzio Mario Negri Sud, S. Maria Imbaro (Chieti), 66030 Italy.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Baldassarre
authors.forename: Arsenio
authors.initials: A
authors.lastname: Pompeo
authors.forename: Galina
authors.initials: G
authors.lastname: Beznoussenko
authors.forename: Claudia
authors.initials: C
authors.lastname: Castaldi
authors.forename: Salvatore
authors.initials: S
authors.lastname: Cortellino
authors.forename: Mark A
authors.initials: MA
authors.lastname: McNiven
authors.forename: Alberto
authors.initials: A
authors.lastname: Luini
authors.forename: Roberto
authors.initials: R
authors.lastname: Buccione
mesh_terms: D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology; D022081:Cell Surface Extensions / Q000378:metabolism*; D034285:Dynamin II / Q000235:genetics / Q000378:metabolism*; D005109:Extracellular Matrix / Q000378:metabolism*; D006801:Humans; D020782:Matrix Metalloproteinases / Q000378:metabolism*; D009361:Neoplasm Invasiveness; D011993:Recombinant Fusion Proteins / Q000378:metabolism
chemical_list: D011993:Recombinant Fusion Proteins; D020782:Matrix Metalloproteinases; D034285:Dynamin II