270 results on '"Giorgio, Scita"'
Search Results
152. EC 3.4.22.53
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Toru Miki, Randa Hilal-Dandan, Laurence L. Brunton, Jean Sévigny, Kwok-On Lai, Nancy Y. Ip, Renping Zhou, Francesca Milanesi, Niels Volkmann, Giorgio Scita, Dorit Hanein, Jacques Pouysségur, Philippe Lenormand, Sonia Klinger, Sylvain Meloche, Karin Dahlman-Wright, and Chunyan Zhao
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- 2012
153. ESA1
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Toru Miki, Randa Hilal-Dandan, Laurence L. Brunton, Jean Sévigny, Kwok-On Lai, Nancy Y. Ip, Renping Zhou, Francesca Milanesi, Niels Volkmann, Giorgio Scita, Dorit Hanein, Jacques Pouysségur, Philippe Lenormand, Sonia Klinger, Sylvain Meloche, Karin Dahlman-Wright, and Chunyan Zhao
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- 2012
154. Ect2 (Epithelial Cell Transforming 2 Oncogene)
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Toru Miki, Randa Hilal-Dandan, Laurence L. Brunton, Jean Sévigny, Kwok-On Lai, Nancy Y. Ip, Renping Zhou, Francesca Milanesi, Niels Volkmann, Giorgio Scita, Dorit Hanein, Jacques Pouysségur, Philippe Lenormand, Sonia Klinger, Sylvain Meloche, Karin Dahlman-Wright, and Chunyan Zhao
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- 2012
155. Extracellular Regulated Kinase 1 and 2
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Toru Miki, Randa Hilal-Dandan, Laurence L. Brunton, Jean Sévigny, Kwok-On Lai, Nancy Y. Ip, Renping Zhou, Francesca Milanesi, Niels Volkmann, Giorgio Scita, Dorit Hanein, Jacques Pouysségur, Philippe Lenormand, Sonia Klinger, Sylvain Meloche, Karin Dahlman-Wright, and Chunyan Zhao
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- 2012
156. Ecto-ADPase
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Toru Miki, Randa Hilal-Dandan, Laurence L. Brunton, Jean Sévigny, Kwok-On Lai, Nancy Y. Ip, Renping Zhou, Francesca Milanesi, Niels Volkmann, Giorgio Scita, Dorit Hanein, Jacques Pouysségur, Philippe Lenormand, Sonia Klinger, Sylvain Meloche, Karin Dahlman-Wright, and Chunyan Zhao
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- 2012
157. Endocytic Receptor 180
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Toru Miki, Randa Hilal-Dandan, Laurence L. Brunton, Jean Sévigny, Kwok-On Lai, Nancy Y. Ip, Renping Zhou, Francesca Milanesi, Niels Volkmann, Giorgio Scita, Dorit Hanein, Jacques Pouysségur, Philippe Lenormand, Sonia Klinger, Sylvain Meloche, Karin Dahlman-Wright, and Chunyan Zhao
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- 2012
158. EphA3, Erythropoietin-Producing Hepatocellular Carcinoma Cell Receptor A3
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Toru Miki, Randa Hilal-Dandan, Laurence L. Brunton, Jean Sévigny, Kwok-On Lai, Nancy Y. Ip, Renping Zhou, Francesca Milanesi, Niels Volkmann, Giorgio Scita, Dorit Hanein, Jacques Pouysségur, Philippe Lenormand, Sonia Klinger, Sylvain Meloche, Karin Dahlman-Wright, and Chunyan Zhao
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- 2012
159. ETR ETA
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Toru Miki, Randa Hilal-Dandan, Laurence L. Brunton, Jean Sévigny, Kwok-On Lai, Nancy Y. Ip, Renping Zhou, Francesca Milanesi, Niels Volkmann, Giorgio Scita, Dorit Hanein, Jacques Pouysségur, Philippe Lenormand, Sonia Klinger, Sylvain Meloche, Karin Dahlman-Wright, and Chunyan Zhao
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- 2012
160. Extracellular Matrix Receptor II (ECMR II)
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Toru Miki, Randa Hilal-Dandan, Laurence L. Brunton, Jean Sévigny, Kwok-On Lai, Nancy Y. Ip, Renping Zhou, Francesca Milanesi, Niels Volkmann, Giorgio Scita, Dorit Hanein, Jacques Pouysségur, Philippe Lenormand, Sonia Klinger, Sylvain Meloche, Karin Dahlman-Wright, and Chunyan Zhao
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- 2012
161. Epithelial to Mesenchymal Transition
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Toru Miki, Randa Hilal-Dandan, Laurence L. Brunton, Jean Sévigny, Kwok-On Lai, Nancy Y. Ip, Renping Zhou, Francesca Milanesi, Niels Volkmann, Giorgio Scita, Dorit Hanein, Jacques Pouysségur, Philippe Lenormand, Sonia Klinger, Sylvain Meloche, Karin Dahlman-Wright, and Chunyan Zhao
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- 2012
162. Epidermal Growth Factor Receptor Kinase Substrate 8
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Toru Miki, Randa Hilal-Dandan, Laurence L. Brunton, Jean Sévigny, Kwok-On Lai, Nancy Y. Ip, Renping Zhou, Francesca Milanesi, Niels Volkmann, Giorgio Scita, Dorit Hanein, Jacques Pouysségur, Philippe Lenormand, Sonia Klinger, Sylvain Meloche, Karin Dahlman-Wright, and Chunyan Zhao
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- 2012
163. LIN7 regulates the filopodia and neurite promoting activity of IRSp53
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Valeria Padovano, Ilaria Ferrari, Arianna Crespi, Grazia Pietrini, Paola Adele Lonati, Giorgio Scita, Andrea Disanza, and Diego Fornasari
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Scaffold protein ,Neurite ,Cell Survival ,Octoxynol ,Cellular differentiation ,Amino Acid Motifs ,Vesicular Transport Proteins ,Nerve Tissue Proteins ,Biology ,Cell Line ,Mice ,03 medical and health sciences ,0302 clinical medicine ,Neurites ,Animals ,Humans ,Gene silencing ,Pseudopodia ,030304 developmental biology ,2. Zero hunger ,0303 health sciences ,Membrane Proteins ,Cell Differentiation ,Cell Biology ,Fusion protein ,Protein Structure, Tertiary ,Cell biology ,Protein Transport ,Solubility ,Cell culture ,Ectopic expression ,Filopodia ,030217 neurology & neurosurgery ,Protein Binding - Abstract
The insulin receptor substrate protein of 53 kDa (IRSp53) is crucially involved in the formation of filopodia and neurites through mechanisms that have only partially been clarified. We have investigated the role of the small scaffold protein LIN7, which interacts with IRSp53. We found that formation of actin-filled protrusions in neuronal NSC34 cells and neurites in neuroblastoma N2A cells depends on motifs mediating the LIN7:IRSp53 association, as both the coexpression of LIN7 with IRSp53 or the expression of the L27-IRSp53 chimera (a fusion protein between IRSp53 and the LIN7L27 domain for plasma membrane protein complexes association) prevented actin-deficient protrusions induced by overexpressed IRSp53, and enhanced the formation of actin-filled protrusions. The regulatory role of LIN7 in IRSp53-mediated extension of filopodia in neuronal N2A cells was demonstrated by live-cell imaging experiments. Moreover, LIN7 silencing prevented the extension of filopodia and neurites, induced by ectopic expression of IRSp53 or serum starvation, respectively, in undifferentiated and differentiated N2A cells. The expression of full-length IRSp53 or the LIN7ΔPDZ mutant lacking the domain for association with IRSp53 was unable to restore neuritogenesis in LIN7-silenced cells. Conversely, defective neuritogenesis could be rescued by the expression of RNAi-resistant full-length LIN7 or chimeric L27-IRSp53. Finally, LIN7 silencing prevented the recruitment of IRSp53 in Triton X-100-insoluble complexes, otherwise occurring in differentiated cells. Collectively these data indicate that LIN7 is a novel regulator of IRSp53, and that the association of these proteins is required to promote the formation of actin-dependent filopodia and neurites.
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- 2012
164. Endothelin Type A Receptor
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Toru Miki, Randa Hilal-Dandan, Laurence L. Brunton, Jean Sévigny, Kwok-On Lai, Nancy Y. Ip, Renping Zhou, Francesca Milanesi, Niels Volkmann, Giorgio Scita, Dorit Hanein, Jacques Pouysségur, Philippe Lenormand, Sonia Klinger, Sylvain Meloche, Karin Dahlman-Wright, and Chunyan Zhao
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- 2012
165. Endothelin Receptor Type A
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Toru Miki, Randa Hilal-Dandan, Laurence L. Brunton, Jean Sévigny, Kwok-On Lai, Nancy Y. Ip, Renping Zhou, Francesca Milanesi, Niels Volkmann, Giorgio Scita, Dorit Hanein, Jacques Pouysségur, Philippe Lenormand, Sonia Klinger, Sylvain Meloche, Karin Dahlman-Wright, and Chunyan Zhao
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- 2012
166. ETFR-1
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Toru Miki, Randa Hilal-Dandan, Laurence L. Brunton, Jean Sévigny, Kwok-On Lai, Nancy Y. Ip, Renping Zhou, Francesca Milanesi, Niels Volkmann, Giorgio Scita, Dorit Hanein, Jacques Pouysségur, Philippe Lenormand, Sonia Klinger, Sylvain Meloche, Karin Dahlman-Wright, and Chunyan Zhao
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- 2012
167. EBP50 (Ezrin-Radixin-Moesin-Binding Phosphoprotein 50 kDa)
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Toru Miki, Randa Hilal-Dandan, Laurence L. Brunton, Jean Sévigny, Kwok-On Lai, Nancy Y. Ip, Renping Zhou, Francesca Milanesi, Niels Volkmann, Giorgio Scita, Dorit Hanein, Jacques Pouysségur, Philippe Lenormand, Sonia Klinger, Sylvain Meloche, Karin Dahlman-Wright, and Chunyan Zhao
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- 2012
168. Epidermal Growth Factor Receptor Pathway Substrate 8
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Toru Miki, Randa Hilal-Dandan, Laurence L. Brunton, Jean Sévigny, Kwok-On Lai, Nancy Y. Ip, Renping Zhou, Francesca Milanesi, Niels Volkmann, Giorgio Scita, Dorit Hanein, Jacques Pouysségur, Philippe Lenormand, Sonia Klinger, Sylvain Meloche, Karin Dahlman-Wright, and Chunyan Zhao
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- 2012
169. Eps8 (Epidermal Growth Factor Receptor Pathway Substrate 8)
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Toru Miki, Randa Hilal-Dandan, Laurence L. Brunton, Jean Sévigny, Kwok-On Lai, Nancy Y. Ip, Renping Zhou, Francesca Milanesi, Niels Volkmann, Giorgio Scita, Dorit Hanein, Jacques Pouysségur, Philippe Lenormand, Sonia Klinger, Sylvain Meloche, Karin Dahlman-Wright, and Chunyan Zhao
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- 2012
170. Endothelin A Receptor (ETAR)
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Toru Miki, Randa Hilal-Dandan, Laurence L. Brunton, Jean Sévigny, Kwok-On Lai, Nancy Y. Ip, Renping Zhou, Francesca Milanesi, Niels Volkmann, Giorgio Scita, Dorit Hanein, Jacques Pouysségur, Philippe Lenormand, Sonia Klinger, Sylvain Meloche, Karin Dahlman-Wright, and Chunyan Zhao
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- 2012
171. ESR2, Estrogen Receptor Beta, ERbeta
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Toru Miki, Randa Hilal-Dandan, Laurence L. Brunton, Jean Sévigny, Kwok-On Lai, Nancy Y. Ip, Renping Zhou, Francesca Milanesi, Niels Volkmann, Giorgio Scita, Dorit Hanein, Jacques Pouysségur, Philippe Lenormand, Sonia Klinger, Sylvain Meloche, Karin Dahlman-Wright, and Chunyan Zhao
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- 2012
172. ETA Type Endothelin Receptor
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Toru Miki, Randa Hilal-Dandan, Laurence L. Brunton, Jean Sévigny, Kwok-On Lai, Nancy Y. Ip, Renping Zhou, Francesca Milanesi, Niels Volkmann, Giorgio Scita, Dorit Hanein, Jacques Pouysségur, Philippe Lenormand, Sonia Klinger, Sylvain Meloche, Karin Dahlman-Wright, and Chunyan Zhao
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- 2012
173. ESR1, Estrogen Receptor Alpha, ERalpha
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Toru Miki, Randa Hilal-Dandan, Laurence L. Brunton, Jean Sévigny, Kwok-On Lai, Nancy Y. Ip, Renping Zhou, Francesca Milanesi, Niels Volkmann, Giorgio Scita, Dorit Hanein, Jacques Pouysségur, Philippe Lenormand, Sonia Klinger, Sylvain Meloche, Karin Dahlman-Wright, and Chunyan Zhao
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- 2012
174. Erk3 and Erk4
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Toru Miki, Randa Hilal-Dandan, Laurence L. Brunton, Jean Sévigny, Kwok-On Lai, Nancy Y. Ip, Renping Zhou, Francesca Milanesi, Niels Volkmann, Giorgio Scita, Dorit Hanein, Jacques Pouysségur, Philippe Lenormand, Sonia Klinger, Sylvain Meloche, Karin Dahlman-Wright, and Chunyan Zhao
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- 2012
175. Endothelin Receptor ETA
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Toru Miki, Randa Hilal-Dandan, Laurence L. Brunton, Jean Sévigny, Kwok-On Lai, Nancy Y. Ip, Renping Zhou, Francesca Milanesi, Niels Volkmann, Giorgio Scita, Dorit Hanein, Jacques Pouysségur, Philippe Lenormand, Sonia Klinger, Sylvain Meloche, Karin Dahlman-Wright, and Chunyan Zhao
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- 2012
176. E-NTPDase Family
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Toru Miki, Randa Hilal-Dandan, Laurence L. Brunton, Jean Sévigny, Kwok-On Lai, Nancy Y. Ip, Renping Zhou, Francesca Milanesi, Niels Volkmann, Giorgio Scita, Dorit Hanein, Jacques Pouysségur, Philippe Lenormand, Sonia Klinger, Sylvain Meloche, Karin Dahlman-Wright, and Chunyan Zhao
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- 2012
177. Retinoic acid and beta-carotene inhibit fibronectin synthesis and release by fibroblasts; antagonism to phorbol ester
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Giorgio Scita and George Wolf
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Cancer Research ,Cell ,Retinoic acid ,Tretinoin ,Biology ,Mice ,chemistry.chemical_compound ,medicine ,Animals ,Drug Interactions ,Fibroblast ,Cells, Cultured ,Mice, Inbred C3H ,General Medicine ,Fibroblasts ,beta Carotene ,Carotenoids ,Molecular biology ,In vitro ,Fibronectins ,Fibronectin ,medicine.anatomical_structure ,Mechanism of action ,Biochemistry ,chemistry ,biology.protein ,Tetradecanoylphorbol Acetate ,Tumor promotion ,medicine.symptom ,medicine.drug - Abstract
Previous work from our and other laboratories has shown that tumor promoters stimulated the loss of fibronectin (FN) from the cell surface of fibroblasts in culture; retinoic acid (RA) appeared to counteract this loss. We have now studied the action of RA and carotenoids on FN synthesis and release. Using mouse fibroblasts (C3H/10T1/2 cells), we found that RA inhibited release of FN into the medium in a time- and concentration-dependent manner (e.g. 90% inhibition in 48 h with 1 x 10(-6) M RA). RA caused inhibition of synthesis, as well as a time- and concentration-dependent decrease in FN mRNA. A second phenomenon we observed was the greatly increased binding of FN to the surface of the cells, both in dimeric and multimeric forms, caused by RA treatment. RA produced a striking inhibition of the 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-stimulated FN release from the cell surface usually associated with tumor promotion. We postulate that the combined action of RA in causing decreased FN synthesis and increased FN binding to the cell surface is the reason for the apparent antagonism of RA to the TPA-stimulated release of FN. Surprisingly, beta-carotene (BC) and canthaxanthin (a non-provitamin A carotenoid) also inhibited the release of FN from these cells. The action of BC was specific, in that an antioxidant carotenoid (trans-methyl-bixin) and lycopene were inactive. BC also inhibited FN synthesis and thus inhibited the TPA-stimulated release of FN, similar to RA, but to a lesser extent. BC had no effect on the binding of FN to the cell surface.
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- 1994
178. From filopodia to synapses: the role of actin-capping and anti-capping proteins
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Elisabetta, Menna, Giuliana, Fossati, Giorgio, Scita, and Michela, Matteoli
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Neurons ,Neuronal Plasticity ,Actin Capping Proteins ,Synapses ,Pseudopodia ,Receptors, AMPA ,Receptors, N-Methyl-D-Aspartate ,Actins - Abstract
Actin-capping and anti-capping proteins are crucial regulators of actin dynamics. Recent studies have indicated that these proteins may be heavily involved in all stages of synaptogenesis, from the emergence of filopodia, through neuritogenesis and synaptic contact stabilization, to the structural changes occurring at the synapse during potentiation phenomena. In this review, we focus on recent evidence pointing to an active role of actin-capping and anti-capping proteins in orchestrating the processes controlling neuronal connectivity and plasticity.
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- 2011
179. The signaling adaptor Eps8 is an essential actin capping protein for dendritic cell migration
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Andrea Disanza, Changsong Yang, Andrea Palamidessi, Tatyana Svitkina, Giorgio Scita, Emanuela Frittoli, Gianluca Matteoli, Elisa Mazzini, Luigi Maddaluno, and Maria Rescigno
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Actin Capping Proteins ,T-Lymphocytes ,Immunology ,Arp2/3 complex ,Dermatitis, Contact ,Article ,EPS8 ,03 medical and health sciences ,Actin remodeling of neurons ,Mice ,0302 clinical medicine ,Cell Movement ,Immunology and Allergy ,Animals ,Cytoskeleton ,Dendritic cell migration ,Cells, Cultured ,030304 developmental biology ,Adaptor Proteins, Signal Transducing ,Cell Proliferation ,Mice, Knockout ,0303 health sciences ,Antigen Presentation ,biology ,Signal transducing adaptor protein ,Actin remodeling ,Dendritic Cells ,Actin cytoskeleton ,Flow Cytometry ,Cell biology ,Mice, Inbred C57BL ,Cytoskeletal Proteins ,Infectious Diseases ,030220 oncology & carcinogenesis ,biology.protein ,Signal Transduction - Abstract
SummaryDendritic cells (DCs) flexibly adapt to different microenvironments by using diverse migration strategies that are ultimately dependent on the dynamics and structural organization of the actin cytoskeleton. Here, we have shown that DCs require the actin capping activity of the signaling adaptor Eps8 to polarize and to form elongated migratory protrusions. DCs from Eps8-deficient mice are impaired in directional and chemotactic migration in 3D in vitro and are delayed in reaching the draining lymph node (DLN) in vivo after inflammatory challenge. Hence, Eps8-deficient mice are unable to mount a contact hypersensitivity response. We have also shown that the DC migratory defect is cell autonomous and that Eps8 is required for the proper architectural organization of the actin meshwork and dynamics of cell protrusions. Yet, Eps8 is not necessary for antigen uptake, processing, and presentation. Thus, we have identified Eps8 as a unique actin capping protein specifically required for DC migration.
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- 2011
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180. The Eps8/IRSp53/VASP Network Differentially Controls Actin Capping and Bundling in Filopodia Formation
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Elisabetta Menna, Francesca Milanesi, Giorgio Scita, Nir S. Gov, Federico Vaggi, Andrea Disanza, Pier Paolo Di Fiore, Michela Matteoli, and Andrea Ciliberto
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QH301-705.5 ,Immunoblotting ,Nerve Tissue Proteins ,macromolecular substances ,Biology ,Hippocampus ,Models, Biological ,EPS8 ,Protein filament ,Cellular and Molecular Neuroscience ,Molecular Cell Biology ,Genetics ,Humans ,Pseudopodia ,Biology (General) ,Molecular Biology ,Ecology, Evolution, Behavior and Systematics ,Actin ,Cytoskeleton ,Adaptor Proteins, Signal Transducing ,Regulatory Networks ,Neurons ,Ecology ,Histocytochemistry ,Microfilament Proteins ,Intracellular Signaling Peptides and Proteins ,Computational Biology ,Reproducibility of Results ,Microfilament Protein ,Actin cytoskeleton ,Phosphoproteins ,Cellular Structures ,Actins ,Cell biology ,Actin Cytoskeleton ,Computational Theory and Mathematics ,Modeling and Simulation ,Lamellipodium ,Filopodia ,Cell Adhesion Molecules ,Metabolic Networks and Pathways ,Research Article ,HeLa Cells ,Signal Transduction - Abstract
There is a body of literature that describes the geometry and the physics of filopodia using either stochastic models or partial differential equations and elasticity and coarse-grained theory. Comparatively, there is a paucity of models focusing on the regulation of the network of proteins that control the formation of different actin structures. Using a combination of in-vivo and in-vitro experiments together with a system of ordinary differential equations, we focused on a small number of well-characterized, interacting molecules involved in actin-dependent filopodia formation: the actin remodeler Eps8, whose capping and bundling activities are a function of its ligands, Abi-1 and IRSp53, respectively; VASP and Capping Protein (CP), which exert antagonistic functions in controlling filament elongation. The model emphasizes the essential role of complexes that contain the membrane deforming protein IRSp53, in the process of filopodia initiation. This model accurately accounted for all observations, including a seemingly paradoxical result whereby genetic removal of Eps8 reduced filopodia in HeLa, but increased them in hippocampal neurons, and generated quantitative predictions, which were experimentally verified. The model further permitted us to explain how filopodia are generated in different cellular contexts, depending on the dynamic interaction established by Eps8, IRSp53 and VASP with actin filaments, thus revealing an unexpected plasticity of the signaling network that governs the multifunctional activities of its components in the formation of filopodia., Author Summary Cells move and interact with the environment by forming migratory structures composed of self organized polymers of actin. These protrusions can be flat and short surfaces, the lamellipodia, or adopt an elongated, finger-like shape called filopodia. In this article, we analyze the ‘computation’ performed by cells when they opt to form filopodia. We focus our attention on some initiators of filopodia that play an essential role due to their interaction with the cell membrane. We analyze the formation of these filopodia initiators in different genotypes, thus providing a way to rationalize the behaviors of different cells in terms of tendency to form filopodia. Our results, based on the combination of experimental and computational approaches, suggest that cells have developed molecular networks that are extremely flexible in their capability to follow the path leading to filopodia formation. In this sense the role of an element of the network, Eps8, is paradigmatic, as this protein can both induce or inhibit the formation of filopodia depending on the cellular context.
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- 2011
181. The catalytic class I(A) PI3K isoforms play divergent roles in breast cancer cell migration
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Simone M. Schoenwaelder, Giorgio Scita, Andrea Palamidessi, Ernst Reichmann, Shaun P. Jackson, Alexandre Arcaro, Olivier E. Pardo, and Angela De Laurentiis
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Gene isoform ,Epithelial-Mesenchymal Transition ,Down-Regulation ,P70-S6 Kinase 1 ,Breast Neoplasms ,Biology ,P110α ,Cell Line ,Transforming Growth Factor beta1 ,03 medical and health sciences ,Mice ,0302 clinical medicine ,Cell Movement ,Tumor Cells, Cultured ,Animals ,Humans ,Protein kinase B ,PI3K/AKT/mTOR pathway ,Cytoskeleton ,030304 developmental biology ,Adaptor Proteins, Signal Transducing ,Cell Line, Transformed ,0303 health sciences ,Mammary Neoplasms, Experimental ,Cell migration ,Epithelial Cells ,Cell Biology ,Cell biology ,Class Ia Phosphatidylinositol 3-Kinase ,Isoenzymes ,Cytoskeletal Proteins ,Genes, ras ,P110δ ,030220 oncology & carcinogenesis ,Immunology ,Female ,Transforming growth factor ,Signal Transduction - Abstract
Transforming growth factor-β (TGFβ) plays an important role in breast cancer metastasis. Here phosphoinositide 3-kinase (PI3K) signalling was found to play an essential role in the enhanced migration capability of fibroblastoid cells (FibRas) derived from normal mammary epithelial cells (EpH4) by transduction of oncogenic Ras (EpRas) and TGFβ1. While expression of the PI3K isoform p110δ was down-regulated in FibRas cells, there was an increase in the expression of p110α and p110β in the fibroblastoid cells. The PI3K isoform p110β was found to specifically contribute to cell migration in FibRas cells, while p110α contributed to the response in EpH4, EpRas and FibRas cells. Akt, a downstream targets of PI3K signalling, had an inhibitory role in the migration of transformed breast cancer cells, while Rac, Cdc42 and the ribosomal protein S6 kinase (S6K) were necessary for the response. Together our data reveal a novel specific function of the PI3K isoform p110β in the migration of cells transformed by oncogenic H-Ras and TGF-β1.
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- 2010
182. Secretory and endo/exocytic trafficking in invadopodia formation: the MT1-MMP paradigm
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Emanuela Frittoli, Giorgio Scita, Andrea Palamidessi, and Andrea Disanza
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Metalloproteinase ,Histology ,Proteolytic enzymes ,Cell Biology ,General Medicine ,Biology ,Matrix metalloproteinase ,Pericellular proteolysis ,Cell Membrane Structures ,Pathology and Forensic Medicine ,Cell biology ,Extracellular Matrix ,Extracellular matrix ,Protein Transport ,Invadopodia ,Matrix Metalloproteinase 14 ,Animals ,Humans ,Cell Surface Extensions ,Signalling pathways ,Secretory pathway - Abstract
Invadopodia are actin-rich, adhesive protrusions that extend into and remodel the extracellular matrix. They are associated with high levels of pericellular proteolysis and correlate with the invasive capacity of a variety of tumour cells. Invadopodia have, thus, been proposed to recapitulate key events of the metastatic process. Although our understanding of the patho-physiology of invadopodia is still in its infancy, the molecular components and signalling pathways leading to their formation have received increasing attention. Recent studies have revealed that diverse membrane polarized secretory and endo/exocytic trafficking pathways converge at these structures for the delivery, in a temporally controlled and spatially confined manner, of key proteolytic enzymes. Here, we will focus our attention on MT1-MMP, a paradigmatic metalloprotease that is primarily responsible for the proteolytic activity of invadopodia. We propose that the biosynthetic/secretory pathway might be critical for the polarized delivery of MT1-MMP to invadopodia that form as "default response" whenever cells have to deal with extracellular matrix (ECM) of variable composition and stiffness. Conversely, "inducible" endo/exocytic trafficking routes might primarily control the delivery of MT1-MMP to invadopodia when cells need to respond in a fast and transient manner to soluble motogenic factors, rather than the insoluble ECM.
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- 2010
183. Bidirectional Crosstalk between Actin Dynamics and Endocytosis
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Giorgio Scita and Pier Paolo Di Fiore
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biology ,Profilin ,Endocytic cycle ,biology.protein ,Arp2/3 complex ,Actin remodeling ,macromolecular substances ,Receptor-mediated endocytosis ,MDia1 ,Actin-binding protein ,biological phenomena, cell phenomena, and immunity ,Microfilament ,Cell biology - Abstract
Publisher Summary This chapter covers the cell biology evidence establishing the significance of actin dynamics for the correct execution of endocytosis and emphasizes the molecular connections between the endocytic and actin machineries. It also describes results showing how endocytosis itself controls various forms of actin dynamics, especially those required for the spatial restriction of signaling events. The minimal requirement to support cycles of actin polymerization and depolymerization have been identified through in vitro reconstitution experiments. These experiments showed that five different types of purified proteins are sufficient to generate forces for motility, including de novo actin nucleators and their regulators (Arp2/3 complex and N-WASP), actin severing/depolymerizing factors, barbed end cappers, and an ATP-actin monomeric binding protein (profilin). In mammalian cells, critical components of the actin dynamics machinery such as the Arp2/3 complex, N-WASP, and the capping protein Eps8 are also transiently recruited to clathrin-positive endocytic sites, and their ablation impairs clathrin mediated endocytosis to various extents. Rab5 is a master regulator of endocytosis and endosomal dynamics. Rab5, however, is also involved in the control of actin dynamics. This dual function is underscored by a complex system of regulation, in which several activators of Rab5 (including the GEFs RIN1, Rabex-5, and Alsin) are also involved in the control of actin dynamics. RIN1 is an effector of Ras and binding to Ras enhances the Rab5 specific GEF activity of RIN1 that mediates EGFR mediated Rab5 activation via Ras in vivo. A more direct way of achieving Rab5 activation by surface receptors is through Rabex-5 that possesses two ubiquitin binding domains, which bind ubiquitinated proteins including EGFR.
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- 2010
184. Endocytic Control of Actin-based Motility
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Andrea Disanza, Flavia Troglio, Emanuela Frittoli, Chiara Giuliani, Giorgio Scita, Francesca Milanesi, and Andrea Palamidessi
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Endocytic cycle ,Extracellular ,Actin remodeling ,Motility ,Biology ,Endocytosis ,Cell-substrate adhesion ,Actin cytoskeleton ,Actin ,Cell biology - Abstract
Endocytosis and recycling are emerging as essential components of the wiring enabling cells to perceive extracellular signals and resolve them in a temporally and spatially controlled fashion, directly influencing not only the duration and intensity of the signaling output, but also its correct location. One process, which requires the precise resolution of spatial information, is actin-based cell motility. This is achieved by coordinating membrane traffic, cell substrate adhesion, and actin remodeling in order to generate propulsive forces responsible for the formation of a diverse set of polarized migratory protrusions, the first steps of cell locomotion. Here, we will discuss how prototypical endocytic molecules control actin dynamics, frequently by linking the core machinery of actin polymerization to the plasma membrane. We will further discuss how endocytosis and recycling ensure spatial restriction of signaling to actin dynamics, thus enabling cells to migrate in response to different extracellular stimuli and in diverse microenvironments adopting diverse motile strategies, which have important implications in relevant physiological and pathological processes, first and foremost cancer cell invasion and dissemination.
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- 2010
185. Molecular basis for the dual function of Eps8 on actin dynamics: bundling and capping
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Maria Grazia Malabarba, Stefano Confalonieri, Niels Volkmann, Pier Paolo Di Fiore, HongJun Liu, Dorit Hanein, Nina Offenhäuser, Emilie Perlade, Marie-France Carlier, Francesca Milanesi, Maud Hertzog, Klemens Rottner, Larnele Hazelwood, Sebastiano Pasqualato, Jennifer Block, Andrea Disanza, Christophe Le Clainche, Alessio Maiolica, Giorgio Scita, and IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, Milan, Italy.
- Subjects
Models, Molecular ,QH301-705.5 ,Cell Biology/Developmental Molecular Mechanisms ,Arp2/3 complex ,Plasma protein binding ,macromolecular substances ,Biochemistry ,General Biochemistry, Genetics and Molecular Biology ,Mass Spectrometry ,EPS8 ,03 medical and health sciences ,Biochemistry/Protein Chemistry ,Cell Biology/Cytoskeleton ,Humans ,Actin-binding protein ,Biology (General) ,Cytoskeleton ,Actin ,030304 developmental biology ,Adaptor Proteins, Signal Transducing ,Helix bundle ,0303 health sciences ,General Immunology and Microbiology ,biology ,General Neuroscience ,030302 biochemistry & molecular biology ,Biochemistry/Chemical Biology of the Cell ,Intracellular Signaling Peptides and Proteins ,Actin remodeling ,Cell Biology ,Actins ,3. Good health ,Cell biology ,Microscopy, Electron ,biology.protein ,Thermodynamics ,General Agricultural and Biological Sciences ,Research Article ,Protein Binding - Abstract
The unusual dual functions of the actin-binding protein EPS8 as an actin capping and actin bundling factor are mapped to distinct structural features of the protein and to distinct physiological activities in vivo., Actin capping and cross-linking proteins regulate the dynamics and architectures of different cellular protrusions. Eps8 is the founding member of a unique family of capping proteins capable of side-binding and bundling actin filaments. However, the structural basis through which Eps8 exerts these functions remains elusive. Here, we combined biochemical, molecular, and genetic approaches with electron microscopy and image analysis to dissect the molecular mechanism responsible for the distinct activities of Eps8. We propose that bundling activity of Eps8 is mainly mediated by a compact four helix bundle, which is contacting three actin subunits along the filament. The capping activity is mainly mediated by a amphipathic helix that binds within the hydrophobic pocket at the barbed ends of actin blocking further addition of actin monomers. Single-point mutagenesis validated these modes of binding, permitting us to dissect Eps8 capping from bundling activity in vitro. We further showed that the capping and bundling activities of Eps8 can be fully dissected in vivo, demonstrating the physiological relevance of the identified Eps8 structural/functional modules. Eps8 controls actin-based motility through its capping activity, while, as a bundler, is essential for proper intestinal morphogenesis of developing Caenorhabditis elegans., Author Summary One of the key components of the cytoskeleton of cells is actin, which allows cells to move. Actin-based motility is involved in many biological processes, such as intestinal development, intracellular trafficking and cell migration. Actin monomers are individual building blocks that can be linked together to form actin filaments. Numerous actin-binding proteins are involved in controlling the higher order architecture and dynamics of these actin filaments within cells. For example, actin capping proteins regulate actin dynamics by controlling the number of growing filament ends, and actin cross-linking or bundling proteins determine how to organize these filaments into higher order structures. The protein Eps8 is capable of capping as well as bundling actin filaments. However, the structural basis of this dual role of Eps8 remains unknown. In this study, we use a combination of techniques to unravel the molecular and structural basis of Eps8 interactions with actin filaments. We show that distinct structural modules of Eps8 are responsible for capping versus bundling activity, and we determine the contributions of these modules in vitro and in vivo. At the functional level, we find that Eps8 regulates actin-based motility and cellular trafficking through its capping activity, whereas Eps8-mediated bundling is essential for intestinal morphogenesis.
- Published
- 2010
186. Recycling of vitamin E in human low density lipoproteins
- Author
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Lester Packer, Trudy M. Forte, Giorgio Scita, Elena Serbinova, and Valerian E. Kagan
- Subjects
Antioxidant ,Linolenic Acids ,Ultraviolet Rays ,medicine.medical_treatment ,Radical ,Lipoxygenase ,QD415-436 ,Ascorbic Acid ,Oxidative phosphorylation ,Biochemistry ,Scavenger ,chemistry.chemical_compound ,Endocrinology ,Dihydrolipoic acid ,medicine ,Humans ,Vitamin E ,Chromans ,Thioctic Acid ,biology ,Electron Spin Resonance Spectroscopy ,Drug Synergism ,Free Radical Scavengers ,Cell Biology ,beta Carotene ,Ascorbic acid ,Carotenoids ,Lipoproteins, LDL ,chemistry ,biology.protein ,lipids (amino acids, peptides, and proteins) ,Lipid Peroxidation - Abstract
Oxidative modification of low density lipoproteins (LDL) and their unrestricted scavenger receptor-dependent uptake is believed to account for cholesterol deposition in macrophage-derived foam cells. It has been suggested that vitamin E that is transported by LDL plays a critical role in protecting against LDL oxidation. We hypothesize that the maintenance of sufficiently high vitamin E concentrations in LDL can be achieved by reducing its chromanoxyl radicals, i.e., by vitamin E recycling. In this study we demonstrate that: i) chromanoxyl radicals of endogenous vitamin E and of exogenously added alpha-tocotrienol, alpha-tocopherol or its synthetic homologue with a 6-carbon side-chain, chromanol-alpha-C6, can be directly generated in human LDL by ultraviolet (UV) light, or by interaction with peroxyl radicals produced either by an enzymic oxidation system (lipoxygenase + linolenic acid) or by an azo-initiator, 2,2'-azo-bis(2,4-dimethylvaleronitrile) (AMVN; ii) ascorbate can recycle endogenous vitamin E and exogenously added chromanols by direct reduction of chromanoxyl radicals in LDL; iii) dihydrolipoic acid is not efficient in direct reduction of chromanoxyl radicals but recycles vitamin E by synergistically interacting with ascorbate (reduces dehydroascorbate thus maintaining the steady-state concentration of ascorbate); and iv) beta-carotene is not active in vitamin E recycling but may itself be protected against oxidative destruction by the reductants of chromanoxyl radicals. We suggest that the recycling of vitamin E and other phenolic antioxidants by plasma reductants may be an important mechanism for the enhanced antioxidant protection of LDL.
- Published
- 1992
187. Uptake and cleavage of β-carotene by cultures of rat small intestinal cells and human lung fibroblasts
- Author
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Giorgio Scita, George Wolf, and Gregory W. Aponte
- Subjects
Vitamin ,medicine.medical_specialty ,Nutrition and Dietetics ,Endocrinology, Diabetes and Metabolism ,medicine.medical_treatment ,Clinical Biochemistry ,Carotene ,Retinol ,Retinoic acid ,Retinal ,Biochemistry ,chemistry.chemical_compound ,Endocrinology ,chemistry ,beta-Carotene ,Internal medicine ,medicine ,Canthaxanthin ,Molecular Biology ,Anticarcinogen - Abstract
Publisher Summary β -Carotene (BC) has assumed importance as an anticarcinogen, both in epidemiologic studies in human beings and in animal models. Recent publications show that the fibroblastic cell line C3H/10T1/2, BC, and canthaxanthin inhibit chemically and physically induced transformation without being converted to retinol, retinal, or retinoic acid (RA). Another important property of BC that has been known for a long time is its lack of toxicity in contrast to retinol. When increasing concentrations of BC are given to rats, the conversion of BC to retinol levels off before the retinol produced becomes toxic. In a study of liver storage of vitamin A in rats and chicks fed with BC, it is reported that for the rat in the range of about one to a maximum of 10 times the daily vitamin A requirement, BC is completely absorbed and transformed to vitamin A, with a relationship of one molecule BC corresponding to one molecule of retinol. With a higher intake, the log of the absorption or transformation rate decreases linearly, inverse to the log of intake.
- Published
- 1992
188. The stability of β-carotene under different laboratory conditions
- Author
-
Giorgio Scita
- Subjects
Nutrition and Dietetics ,Chemistry ,Endocrinology, Diabetes and Metabolism ,medicine.medical_treatment ,Clinical Biochemistry ,Carotene ,Food storage ,Biochemistry ,Fluorescence ,Solvent ,Pigment ,chemistry.chemical_compound ,beta-Carotene ,visual_art ,visual_art.visual_art_medium ,medicine ,Butylated hydroxytoluene ,Molecular Biology ,Incubation ,Nuclear chemistry - Abstract
The stability of β-carotene, the carotenoid with the highest vitamin A activity, has been investigated under laboratory conditions, other than food processing or food storage, β-Carotene appears to be fairly stable over 24 h (loss< 4%) and 48 h (loss < 15%) when micellar solutions in aqueous medium of this pigment were incubated at 37° C, in the dark, in a 5% CO2 in air atmosphere to simulate incubation conditions (used for cell culture systems). The effect of both UV light and fluorescent light on solutions of β-carotene in toluene was highly damaging (50% loss occurred after 8 h under UV light and after 24 h under daylight). Butylated hydroxytoluene (BHT) and alpha-tocopherol, two common antioxidants, were able to reduce significantly the degradation of β-carotene under light exposure. At the same concentration of BHT (1 mM), alpha-tocopherol had a much stronger relative potency to prevent the loss of the pigment (50% loss occurred after 48 h in fluorescent and 40 h in UV light in presence of alpha-tocopherol and after 23 h and 17 h, respectively, in fluorescent and UV light in presence of BHT). Increasing the rate of air-solution exchange by increasing the surface of β-carotene solution exposed to air caused an increase of the loss of the pigment of more than 3 times. Under storage conditions (−20° C, in the dark, under N2), the rate of loss of β-carotene was 1.5%/month and 1.1%/month, respectively, in absence or in presence of 0.025% BHT.
- Published
- 1992
189. Ultraviolet Light-Induced Generation of Vitamin E Radicals and Their Recycling. a Possible Photosensitizing Effect of Vitamin E IN Skin
- Author
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Lester Packer, Radoslav Goldman, Eric Witt, Valerian E. Kagan, and Giorgio Scita
- Subjects
Neoplasms, Radiation-Induced ,Skin Neoplasms ,Antioxidant ,Free Radicals ,Ultraviolet Rays ,medicine.medical_treatment ,Radical ,Ascorbic Acid ,Photochemistry ,Models, Biological ,Radiation Tolerance ,Biochemistry ,Antioxidants ,Mice ,chemistry.chemical_compound ,Suspensions ,Dihydrolipoic acid ,beta-Carotene ,medicine ,Ultraviolet light ,Animals ,Vitamin E ,Photosensitizer ,Skin ,Mice, Hairless ,Liposome ,Thioctic Acid ,Methanol ,Electron Spin Resonance Spectroscopy ,Water ,beta Carotene ,Carotenoids ,Oxygen ,chemistry ,Liposomes ,Phosphatidylcholines - Abstract
Vitamin E (alpha-tocopherol) is the major lipid-soluble chain-breaking antioxidant of membranes. Its UV-absorbance spectrum (lambda max 295 nm) extends well into the solar spectrum. We hypothesize that in skin alpha-tocopherol may absorb solar UV light and generate tocopheroxyl radicals. Reduction of tocopheroxyl radicals by other antioxidants (e.g. ascorbate, thiols) will regenerate (recycle) vitamin E at the expense of their own depletion. Hence, vitamin E in skin may act in two conflicting manners upon solar illumination: in addition to its antioxidant function as a peroxyl radical scavenger, it may act as an endogenous photosensitizer, enhancing light-induced oxidative damage. To test this hypothesis, we have illuminated various systems (methanol-buffer dispersions, liposomes and skin homogenates) containing alpha-tocopherol or its homologue with a shorter 6-carbon side chain, chromanol-alpha-C6 with UV light closely matching solar UV light, in the presence or absence of endogenous or exogenous reductants. We found that: (i) alpha-tocopheroxyl (chromanoxyl) radicals are directly generated by solar UV light in model systems (methanol-water dispersions, liposomes) and in skin homogenates; (ii) reducing antioxidants (ascorbate, ascorbate+dihydrolipoic acid) can donate electrons to alpha-tocopheroxyl (chromanoxyl) radicals providing for vitamin E (chromanol-alpha-C6) recycling; (iii) recycling of UV-induced alpha-tocopheroxyl radicals depletes endogenous antioxidant pools (accelerates ascorbate oxidation); (iv) beta-carotene, a non-reducing antioxidant, is not active in alpha-tocopherol recycling, and its UV-dependent depletion is unaffected by vitamin E.
- Published
- 1992
190. Cdc42- and IRSp53-dependent contractile filopodia tether presumptive lens and retina to coordinate epithelial invagination
- Author
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Giorgio Scita, Sue-Yeon Choi, Andrea Disanza, Yi Zheng, Richard A. Lang, Bharesh K. Chauhan, Ming Lou, Hilary E. Beggs, and Sonya C. Faber
- Subjects
animal structures ,Ectoderm ,CDC42 ,macromolecular substances ,Biology ,Myosins ,Retina ,Mice ,Lens, Crystalline ,medicine ,Animals ,Lens placode ,Pseudopodia ,Molecular Biology ,Research Articles ,Invagination ,Dorsal closure ,Actins ,Cell biology ,Specific Pathogen-Free Organisms ,medicine.anatomical_structure ,Focal Adhesion Kinase 1 ,embryonic structures ,Archenteron ,Filopodia ,Developmental Biology - Abstract
The vertebrate lens provides an excellent model with which to study the mechanisms required for epithelial invagination. In the mouse, the lens forms from the head surface ectoderm. A domain of ectoderm first thickens to form the lens placode and then invaginates to form the lens pit. The epithelium of the lens placode remains in close apposition to the epithelium of the presumptive retina as these structures undergo a coordinated invagination. Here, we show that F-actin-rich basal filopodia that link adjacent presumptive lens and retinal epithelia function as physical tethers that coordinate invagination. The filopodia, most of which originate in the presumptive lens, form at E9.5 when presumptive lens and retinal epithelia first come into close contact, and have retracted by E11.5 when invagination is complete. At E10.5 - the lens pit stage - there is approximately one filopodium per epithelial cell. Formation of filopodia is dependent on the Rho family GTPase Cdc42 and the Cdc42 effector IRSp53 (Baiap2). Loss of filopodia results in reduced lens pit invagination. Pharmacological manipulation of the actin-myosin contraction pathway showed that the filopodia can respond rapidly in length to change inter-epithelial distance. These data suggest that the lens-retina inter-epithelial filopodia are a fine-tuning mechanism to assist in lens pit invagination by transmitting the forces between presumptive lens and retina. Although invagination of the archenteron in sea urchins and dorsal closure in Drosophila are known to be partly dependent on filopodia, this mechanism of morphogenesis has not previously been identified in vertebrates.
- Published
- 2009
191. Requirements for F-BAR proteins TOCA-1 and TOCA-2 in actin dynamics and membrane trafficking during Caenorhabditis elegans oocyte growth and embryonic epidermal morphogenesis
- Author
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Martha C. Soto, Falshruti B. Patel, Giuseppe Cassata, Maria Grazia Malabarba, Andrea Disanza, Stefano Confalonieri, Flavia Troglio, Theresia B. Stradal, Chiara Giuliani, Zhiyong Bai, Giorgio Scita, Barth D. Grant, Adriana Zucconi, and Jeff Hardin
- Subjects
Male ,Cancer Research ,lcsh:QH426-470 ,Developmental Biology/Germ Cells ,Morphogenesis ,Plasma protein binding ,macromolecular substances ,Cell Biology/Cell Signaling ,Cell membrane ,03 medical and health sciences ,0302 clinical medicine ,Cell Biology/Membranes and Sorting ,Cell Biology/Cytoskeleton ,Embryonic morphogenesis ,Genetics ,medicine ,Biochemistry/Cell Signaling and Trafficking Structures ,Animals ,Caenorhabditis elegans ,Caenorhabditis elegans Proteins ,Molecular Biology ,Genetics (clinical) ,Ecology, Evolution, Behavior and Systematics ,Actin ,030304 developmental biology ,Developmental Biology/Embryology ,0303 health sciences ,biology ,Cell Membrane ,Membrane Proteins ,biology.organism_classification ,Actins ,Cell biology ,Transport protein ,lcsh:Genetics ,Protein Transport ,medicine.anatomical_structure ,Membrane protein ,Oocytes ,Female ,Epidermis ,030217 neurology & neurosurgery ,Protein Binding ,Research Article ,Developmental Biology - Abstract
The TOCA family of F-BAR–containing proteins bind to and remodel lipid bilayers via their conserved F-BAR domains, and regulate actin dynamics via their N-Wasp binding SH3 domains. Thus, these proteins are predicted to play a pivotal role in coordinating membrane traffic with actin dynamics during cell migration and tissue morphogenesis. By combining genetic analysis in Caenorhabditis elegans with cellular biochemical experiments in mammalian cells, we showed that: i) loss of CeTOCA proteins reduced the efficiency of Clathrin-mediated endocytosis (CME) in oocytes. Genetic interference with CeTOCAs interacting proteins WSP-1 and WVE-1, and other components of the WVE-1 complex, produced a similar effect. Oocyte endocytosis defects correlated well with reduced egg production in these mutants. ii) CeTOCA proteins localize to cell–cell junctions and are required for proper embryonic morphogenesis, to position hypodermal cells and to organize junctional actin and the junction-associated protein AJM-1. iii) Double mutant analysis indicated that the toca genes act in the same pathway as the nematode homologue of N-WASP/WASP, wsp-1. Furthermore, mammalian TOCA-1 and C. elegans CeTOCAs physically associated with N-WASP and WSP-1 directly, or WAVE2 indirectly via ABI-1. Thus, we propose that TOCA proteins control tissues morphogenesis by coordinating Clathrin-dependent membrane trafficking with WAVE and N-WASP–dependent actin-dynamics., Author Summary Cells continuously remodel their shape especially during cell migration, differentiation, and tissues morphogenesis. This occurs through the dynamic reorganization of their plasma membrane and actin cytoskeleton: two processes that must therefore be intimately linked and coordinated. Molecules that sit at the crossroads of membrane remodeling and actin dynamics are predicted to play a pivotal role in coordinating these processes. The TOCA family of proteins represents a case in point. These proteins bind to and deform membranes during processes such as membrane trafficking. They also control actin dynamics through their interactions with actin remodeling factors, such as WASP and WAVEs. Here, we characterize the functional role of TOCA proteins in a model organism, the nematode Caenorhabditis elegans. We established that toca genes regulate Clathrin-mediated membrane trafficking during oocyte growth. We further discovered that these proteins play an important role in epithelial morphogenesis in developing embryos, and in egg production in adult nematodes. Moreover, the TOCA interacting proteins WASP/WSP-1 and WAVE/WVE-1, as well as other components of the WVE-1 complex, appear to be involved in TOCA-dependent processes. Thus, we propose that TOCA proteins control tissue morphogenesis by coordinating Clathrin-dependent membrane trafficking with WAVE and N-WASP–dependent actin-dynamics.
- Published
- 2009
192. Endocytosis and spatial restriction of cell signaling
- Author
-
Giorgio Scita, Andrea Disanza, Emanuela Frittoli, and Andrea Palamidessi
- Subjects
Cancer Research ,Cell signaling ,media_common.quotation_subject ,Reviews ,General Medicine ,Compartmentalization (psychology) ,Biology ,Endocytosis ,Models, Biological ,Cell biology ,Oncology ,Cell Movement ,Actin dynamics ,Genetics ,Molecular Medicine ,Animals ,Humans ,Endomembrane system ,Internalization ,Cell Division ,media_common ,Signal Transduction - Abstract
Endocytosis and recycling are essential components of the wiring enabling cells to perceive extracellular signals and transduce them in a temporally and spatially controlled fashion, directly influencing not only the duration and intensity of the signaling output, but also their correct location. Here, we will discuss key experimental evidence that support how different internalization routes, the generation of diverse endomembrane platforms, and cycles of internalization and recycling ensure polarized compartmentalization of signals, regulating a number of physiological and pathologically-relevant processes in which the resolution of spatial information is vital for their execution.
- Published
- 2009
193. Insulin receptor substrate of 53 kDa (IRSp53) controls synaptic plasticity
- Author
-
Giorgio Scita, Tobias Böckers, Martin Korte, Michael Kintscher, Fabio Morellini, Hans-Jürgen Kreienkamp, Andrea Disanza, Corinna Sawallisch, Alexander Dityatev, and Kerstin Berhörster
- Subjects
Insulin receptor ,biology ,Chemistry ,Insulin receptor substrate ,Synaptic plasticity ,biology.protein ,Cell biology - Published
- 2009
194. The insulin receptor substrate of 53 kDa (IRSp53) limits hippocampal synaptic plasticity
- Author
-
Corinna Sawallisch, Kerstin Berhörster, Tobias M. Boeckers, Michaela Schweizer, Alexander Dityatev, Giorgio Scita, Stefan Kindler, Andrea Disanza, Michael Kintscher, Sabrina Sieber, Fabio Morellini, Sara Mantoani, Hans-Jürgen Kreienkamp, Martin Korte, and Luminita Stoenica
- Subjects
HOMER1 ,Nonsynaptic plasticity ,Nerve Tissue Proteins ,Biology ,Biochemistry ,Hippocampus ,Cell Line ,Tissue Culture Techniques ,Mice ,Cellular neuroscience ,Postsynaptic potential ,Animals ,Molecular Biology ,Cell Shape ,Mice, Knockout ,Synaptic scaling ,Neuronal Plasticity ,Mechanisms of Signal Transduction ,Long-term potentiation ,Cell Biology ,Embryo, Mammalian ,Cell biology ,Microscopy, Electron ,Synaptic plasticity ,Synapses ,Postsynaptic density - Abstract
IRSp53 is an essential intermediate between the activation of Rac and Cdc42 GTPases and the formation of cellular protrusions; it affects cell shape by coupling membrane-deforming activity with the actin cytoskeleton. IRSp53 is highly expressed in neurons where it is also an abundant component of the postsynaptic density (PSD). Here we analyze the physiological function of this protein in the mouse brain by generating IRSp53-deficient mice. Neurons in the hippocampus of young and adult knock-out (KO) mice do not exhibit morphological abnormalities in vivo. Conversely, primary cultured neurons derived from IRSp53 KO mice display retarded dendritic development in vitro. On a molecular level, Eps8 cooperates with IRSp53 to enhance actin bundling and interacts with IRSp53 in developing neurons. However, postsynaptic Shank proteins which are expressed at high levels in mature neurons compete with Eps8 to block actin bundling. In electrophysiological experiments the removal of IRSp53 increases synaptic plasticity as measured by augmented long term potentiation and paired-pulse facilitation. A primarily postsynaptic role of IRSp53 is underscored by the decreased size of the PSDs, which display increased levels of N-methyl-d-aspartate receptor subunits in IRSp53 KO animals. Our data suggest that the incorporation of IRSp53 into the PSD enables the protein to limit the number of postsynaptic glutamate receptors and thereby affect synaptic plasticity rather than dendritic morphology. Consistent with altered synaptic plasticity, IRSp53-deficient mice exhibit cognitive deficits in the contextual fear-conditioning paradigm.
- Published
- 2009
195. Eps8 Regulates Axonal Filopodia in Hippocampal Neurons in Response to Brain-Derived Neurotrophic Factor (BDNF)
- Author
-
Andrea Disanza, Cinzia Cagnoli, Corinna Sawallisch, Michela Matteoli, Pier Paolo Di Fiore, Ursula Schenk, Emanuela Frittoli, Hans Jürgen Kreienkamp, Frank B. Gertler, Giorgio Scita, Elisabetta Menna, Nina Offenhäuser, Giuliana Gelsomino, Maud Hertzog, Massachusetts Institute of Technology. Department of Biology, and Gertler, Frank
- Subjects
Brain-derived neurotrophic factor ,0303 health sciences ,General Immunology and Microbiology ,QH301-705.5 ,General Neuroscience ,Synaptogenesis ,macromolecular substances ,Biology ,SRGAP2 ,General Biochemistry, Genetics and Molecular Biology ,Cell biology ,03 medical and health sciences ,0302 clinical medicine ,nervous system ,Neurotrophic factors ,Fimbrin ,Pseudopodia ,Biology (General) ,General Agricultural and Biological Sciences ,Growth cone ,Filopodia ,030217 neurology & neurosurgery ,030304 developmental biology - Abstract
The regulation of filopodia plays a crucial role during neuronal development and synaptogenesis. Axonal filopodia, which are known to originate presynaptic specializations, are regulated in response to neurotrophic factors. The structural components of filopodia are actin filaments, whose dynamics and organization are controlled by ensembles of actin-binding proteins. How neurotrophic factors regulate these latter proteins remains, however, poorly defined. Here, using a combination of mouse genetic, biochemical, and cell biological assays, we show that genetic removal of Eps8, an actin-binding and regulatory protein enriched in the growth cones and developing processes of neurons, significantly augments the number and density of vasodilator-stimulated phosphoprotein (VASP)-dependent axonal filopodia. The reintroduction of Eps8 wild type (WT), but not an Eps8 capping-defective mutant, into primary hippocampal neurons restored axonal filopodia to WT levels. We further show that the actin barbed-end capping activity of Eps8 is inhibited by brain-derived neurotrophic factor (BDNF) treatment through MAPK-dependent phosphorylation of Eps8 residues S624 and T628. Additionally, an Eps8 mutant, impaired in the MAPK target sites (S624A/T628A), displays increased association to actin-rich structures, is resistant to BDNF-mediated release from microfilaments, and inhibits BDNF-induced filopodia. The opposite is observed for a phosphomimetic Eps8 (S624E/T628E) mutant. Thus, collectively, our data identify Eps8 as a critical capping protein in the regulation of axonal filopodia and delineate a molecular pathway by which BDNF, through MAPK-dependent phosphorylation of Eps8, stimulates axonal filopodia formation, a process with crucial impacts on neuronal development and synapse formation.
- Published
- 2009
196. The effect of diacylglycerols on fibronectin release and its reversal by retinoic acid in cell culture
- Author
-
Bernhard Gmeiner, Trissia Chandra, Helmut Scheidl, George Wolf, Giorgio Scita, and Gerold Zerlauth
- Subjects
Cancer Research ,Time Factors ,Retinoic acid ,Tretinoin ,Stimulation ,Biology ,Translocation, Genetic ,Diglycerides ,chemistry.chemical_compound ,Cytosol ,medicine ,Humans ,Cells, Cultured ,Protein Kinase C ,Protein kinase C ,Diacylglycerol kinase ,Dose-Response Relationship, Drug ,urogenital system ,Cell Membrane ,General Medicine ,Fibroblasts ,Stimulation, Chemical ,Fibronectins ,Cell biology ,Enzyme Activation ,Fibronectin ,Biochemistry ,Mechanism of action ,chemistry ,Cell culture ,biology.protein ,lipids (amino acids, peptides, and proteins) ,medicine.symptom ,medicine.drug - Abstract
Previous work from our laboratory showed that tumor promoters such as phorbol ester (TPA) stimulated the release of fibronectin (FN) from the surface of several cell types in culture, and that this stimulation was counteracted by retinoic acid. Diacylglycerols (DAGs) are the endogenous ligands of the TPA receptor and can activate and translocate protein kinase C (PKC) in a manner similar to TPA. To show that the release of FN is related to activation of PKC, we tested the action of DAGs on FN release from human lung fibroblasts and its counteraction by retinoic acid. We found that DAGs stimulated the release of FN in a concentration- and time-dependent manner. The stimulation of the release of FN correlated with the translocation-activation of PKC by DAG. Retinoic acid reversed the action of DAG with respect to stimulation of FN release and inhibited this release even in the absence of DAG. These results suggest that the release of FN is in some way related to translocation-activation of PKC.
- Published
- 1991
197. Wasp and WAVE Family Proteins
- Author
-
Giorgio Scita, Andrea Disanza, and Emanuela Frittoli
- Subjects
Protein filament ,Chemistry ,Actin dynamics ,Cellular functions ,macromolecular substances ,Signal transduction ,Elongation ,Actin ,Cell biology - Abstract
The dynamic turnover of actin filaments generates the forces driving cellular motile processes. A key factor of actin polymerization is the de novo nucleation and elongation of actin filaments, which can be catalysed by a limited number of proteins or protein complexes, the best studied of which is the Arp2/3-complex. The activity of the Arp2/3 complex is tightly regulated and controlled through signal-dependent association with nucleation promotion factors, like the WASP and WAVE family of proteins. An emerging common theme for these factors is that they act as coincident detectors of a variety of signaling pathways through the formation of large multi-molecular complexes. These complexes impose a strict spatial and temporal control on the activities of WASP and WAVE family proteins within the cells. They further contribute to fine tune Arp2/3-mediated branched actin filament elongation so as to adapt its biochemical activity to a vast array of diverse cellular functions. In this chapter we will provide an overview of the most recent finding defining the composition and mode of regulation of the WAVE-, WASP- and N/WASP-based complexes in mediating distinct actin dynamics-based cellular processes.
- Published
- 2008
198. IRSp53 links the enterohemorrhagic E. coli effectors Tir and EspFU for actin pedestal formation
- Author
-
Theresia E. B. Stradal, Andrea Disanza, Lothar Jänsch, Ronald Frank, Julia Ehinger, Kai Städing, Giorgio Scita, Dorothea S Schmidt, Florian Gunzer, Silvia Lommel, Stefanie M. Weiss, Klemens Rottner, Markus Ladwein, and Ulrike Beutling
- Subjects
Cancer Research ,MICROBIO ,Nerve Tissue Proteins ,Receptors, Cell Surface ,Enterohemorrhagic e coli ,macromolecular substances ,Biology ,Escherichia coli O157 ,Microbiology ,digestive system ,Cell Line ,Immunology and Microbiology(all) ,Virology ,Actin dynamics ,parasitic diseases ,Protein Interaction Mapping ,Humans ,Receptor ,Molecular Biology ,Actin ,Intimin ,Settore MED/04 - Patologia Generale ,Effector ,Activator (genetics) ,Escherichia coli Proteins ,Intracellular Signaling Peptides and Proteins ,biochemical phenomena, metabolism, and nutrition ,Actins ,Cell biology ,SIGNALING ,Host-Pathogen Interactions ,Parasitology ,CELLBIO ,Carrier Proteins ,Tyrosine kinase ,Protein Binding - Abstract
Summary Actin pedestal formation by pathogenic E. coli requires signaling by the bacterial intimin receptor Tir, which induces host cell actin polymerization mediated by N-WASP and the Arp2/3 complex. Whereas canonical enteropathogenic E. coli (EPEC) recruit these actin regulators through tyrosine kinase signaling cascades, enterohemorrhagic E. coli (EHEC) O157:H7 employ the bacterial effector EspF U (TccP), a potent N-WASP activator. Here, we show that IRSp53 family members, key regulators of membrane and actin dynamics, directly interact with both Tir and EspF U . IRSp53 colocalizes with EspF U and N-WASP in actin pedestals. In addition, targeting of IRSp53 is independent of EspF U and N-WASP but requires Tir residues 454–463, previously shown to be essential for EspF U -dependent actin assembly. Genetic and functional loss of IRSp53 abrogates actin assembly mediated by EHEC. Collectively, these data indentify IRSp53 family proteins as the missing host cell factors linking bacterial Tir and EspF U in EHEC pedestal formation.
- Published
- 2008
199. Roles of Arp2/3 complex and mDia2 in actin‐based protrusions
- Author
-
Changsong Yang, Farida Korobova, Silke Gerboth, Giorgio Scita, and Tatyana Svitkina
- Subjects
biology ,Chemistry ,Genetics ,biology.protein ,Arp2/3 complex ,Molecular Biology ,Biochemistry ,Actin ,Biotechnology ,Cell biology - Published
- 2008
200. IRSp53: crossing the road of membrane and actin dynamics in the formation of membrane protrusions
- Author
-
Giorgio Scita, Shiro Suetsugu, Stefano Confalonieri, and Pekka Lappalainen
- Subjects
Arp2/3 complex ,Nerve Tissue Proteins ,macromolecular substances ,Membrane bending ,03 medical and health sciences ,Actin remodeling of neurons ,0302 clinical medicine ,Cell Movement ,Humans ,Cytoskeleton ,030304 developmental biology ,0303 health sciences ,biology ,Cell Membrane ,Actin remodeling ,Cell Biology ,Actin cytoskeleton ,Actins ,Cell biology ,Profilin ,Membrane curvature ,biology.protein ,MDia1 ,Cell Surface Extensions ,030217 neurology & neurosurgery ,Signal Transduction - Abstract
A tight spatiotemporal coordination of the machineries controlling membrane bending and trafficking, and actin dynamics is crucial for the generation of cellular protrusions. Proteins that are simultaneously capable of regulating actin dynamics and sensing or inducing membrane curvature are predicted to have a prominent role. A prototypical example of this type of proteins is the insulin receptor tyrosine kinase substrate of 53kDa, the founding member of a recently discovered family of proteins, including missing-in-metastasis and ABBA (actin-bundling protein with BAIAP2 homology). Structural, biochemical and cell biological experiments support the unique role of this family as transducers of signalling, linking the protruding membrane to the underlying actin cytoskeleton.
- Published
- 2007
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