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The Integrin Alpha6beta4 Functions In Carcinoma Cell Migration On Laminin-1 By Mediating The Formation And Stabilization Of Actin-Containing Motility Structures, Isaac Rabinovitz, Arthur M. Mercurio
The Integrin Alpha6beta4 Functions In Carcinoma Cell Migration On Laminin-1 By Mediating The Formation And Stabilization Of Actin-Containing Motility Structures, Isaac Rabinovitz, Arthur M. Mercurio
Arthur M. Mercurio
Functional studies on the alpha6beta4 integrin have focused primarily on its role in the organization of hemidesmosomes, stable adhesive structures that associate with the intermediate filament cytoskeleton. In this study, we examined the function of the alpha6beta4 integrin in clone A cells, a colon carcinoma cell line that expresses alpha6beta4 but no alpha6beta1 integrin and exhibits dynamic adhesion and motility on laminin-1. Time-lapse videomicroscopy of clone A cells on laminin-1 revealed that their migration is characterized by filopodial extension and stabilization followed by lamellae that extend in the direction of stabilized filopodia. A function-blocking mAb specific for the alpha6beta4 integrin …
Adam12 Induces Actin Cytoskeleton And Extracellular Matrix Reorganization During Early Adipocyte Differentiation By Regulating Beta1 Integrin Function, Nobuko Kawaguchi, Christina Sundberg, Marie Kveiborg, Behzad Moghadaszadeh, Meena Asmar, Nikolaj Dietrich, Charles Kumar Thodeti, Finn C. Nielsen, Peter Moller, Arthur M. Mercurio, Reidar Albrechtsen, Ulla M. Wewer
Adam12 Induces Actin Cytoskeleton And Extracellular Matrix Reorganization During Early Adipocyte Differentiation By Regulating Beta1 Integrin Function, Nobuko Kawaguchi, Christina Sundberg, Marie Kveiborg, Behzad Moghadaszadeh, Meena Asmar, Nikolaj Dietrich, Charles Kumar Thodeti, Finn C. Nielsen, Peter Moller, Arthur M. Mercurio, Reidar Albrechtsen, Ulla M. Wewer
Arthur M. Mercurio
Changes in cell shape are a morphological hallmark of differentiation. In this study we report that the expression of ADAM12, a disintegrin and metalloprotease, dramatically affects cell morphology in preadipocytes, changing them from a flattened, fibroblastic appearance to a more rounded shape. We showed that the highest levels of ADAM12 mRNA were detected in preadipocytes at the critical stage when preadipocytes become permissive for adipogenic differentiation. Furthermore, as assessed by immunostaining, ADAM12 was transiently expressed at the cell surface concomitant with the reduced activity of beta1 integrin. Co-immunoprecipitation studies indicated the formation of ADAM12/beta1 integrin complexes in these preadipocytes. Overexpression …
The Activation Dependent Adhesion Of Macrophages To Laminin Involves Cytoskeletal Anchoring And Phosphorylation Of The Alpha 6 Beta 1 Integrin, Leslie M. Shaw, Jeanne M. Messier, Arthur M. Mercurio
The Activation Dependent Adhesion Of Macrophages To Laminin Involves Cytoskeletal Anchoring And Phosphorylation Of The Alpha 6 Beta 1 Integrin, Leslie M. Shaw, Jeanne M. Messier, Arthur M. Mercurio
Arthur M. Mercurio
Macrophages require activation with either PMA (Mercurio, A. M., and L. M. Shaw. 1988. J. Cell Biol. 107:1873-1880) or interferon-gamma (Shaw, L. M., and A. M. Mercurio. 1989. J. Exp. Med. 169:303-308) to adhere to a laminin substratum. In the present study, we identified an integrin laminin receptor on macrophages and characterized cellular changes that occur in response to PMA activation that facilitate laminin adhesion. A monoclonal antibody (GoH3) that recognizes the integrin alpha 6 subunit (Sonnenberg, A., H. Janssen, F. Hogervorst, J. Calafat, and J. Hilgers. 1987. J. Biol. Chem. 262:10376-10383) specifically inhibited adhesion to laminin-coated surfaces. This antibody …
Tlr4, Ethanol, And Lipid Rafts: A New Mechanism Of Ethanol Action With Implications For Other Receptor-Mediated Effects, Gyongyi Szabo, Angela Dolganiuc, Qun Dai, Stephen Pruett
Tlr4, Ethanol, And Lipid Rafts: A New Mechanism Of Ethanol Action With Implications For Other Receptor-Mediated Effects, Gyongyi Szabo, Angela Dolganiuc, Qun Dai, Stephen Pruett
Gyongyi Szabo
Ethanol (EtOH) is the most widely abused substance in the United States, and it contributes to well-documented harmful (at high dosages) and beneficial (at low dosages) changes in inflammatory and immune responses. Lipid rafts have been implicated in the regulation and activation of several important receptor complexes in the immune system, including the TLR4 complex. Many questions remain about the precise mechanisms by which rafts regulate the assembly of these receptor complexes. Results summarized in this review indicate that EtOH acts by altering the LPS-induced redistribution of components of the TLR4 complex within the lipid raft and that this is …
Supervillin Reorganizes The Actin Cytoskeleton And Increases Invadopodial Efficiency, Jessica Lynn Crowley, Tara C. Smith, Zhiyou Fang, Norio Takizawa, Elizabeth J. Luna
Supervillin Reorganizes The Actin Cytoskeleton And Increases Invadopodial Efficiency, Jessica Lynn Crowley, Tara C. Smith, Zhiyou Fang, Norio Takizawa, Elizabeth J. Luna
Elizabeth J. Luna
Tumor cells use actin-rich protrusions called invadopodia to degrade extracellular matrix (ECM) and invade tissues; related structures, termed podosomes, are sites of dynamic ECM interaction. We show here that supervillin (SV), a peripheral membrane protein that binds F-actin and myosin II, reorganizes the actin cytoskeleton and potentiates invadopodial function. Overexpressed SV induces redistribution of lamellipodial cortactin and lamellipodin/RAPH1/PREL1 away from the cell periphery to internal sites and concomitantly increases the numbers of F-actin punctae. Most punctae are highly dynamic and colocalize with the podosome/invadopodial proteins, cortactin, Tks5, and cdc42. Cortactin binds SV sequences in vitro and contributes to the formation …