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Title: Lamellipodia nucleation by filopodia depends on integrin occupancy and downstream Rac1 signaling

Abstract

Time-lapse video-microscopy unambiguously shows that fibroblast filopodia are the scaffold of lamellipodia nucleation that allows anisotropic cell spreading. This process was dissected into elementary stages by monitoring cell adhesion on micropatterned extracellular matrix arrays of various pitches. Adhesion structures are stabilized by contact with the adhesive plots and subsequently converted into lamellipodia-like extensions starting at the filopodia tips. This mechanism progressively leads to full cell spreading. Stable expression of the dominant-negative Rac1 N17 impairs this change in membrane extension mode and stops cell spreading on matrix arrays. Similar expression of the dominant-negative Cdc42 N17 impairs cell spreading on homogenous and structured substrate, suggesting that filopodia extension is a prerequisite for cell spreading in this model. The differential polarity of the nucleation of lamellipodial structures by filopodia on homogenous and structured surfaces starting from the cell body and of filopodia tip, respectively, suggested that this process is triggered by areas that are in contact with extracellular matrix proteins for longer times. Consistent with this view, wild-type cells cannot spread on microarrays made of function blocking or neutral anti-{beta}{sub 1} integrin antibodies. However, stable expression of a constitutively active Rac1 mutant rescues the cell ability to spread on these integrin microarrays. Thereby,more » lamellipodia nucleation by filopodia requires integrin occupancy by matrix substrate and downstream Rac1 signaling.« less

Authors:
 [1]; ;  [1];  [1];  [2];  [1];  [1];  [1]
  1. Universite Joseph Fourier, Grenoble (France)
  2. CNRS UPR 2940, Institut Neel, BP 166X, 38042 Grenoble Cedex 09 (France)
Publication Date:
OSTI Identifier:
21045932
Resource Type:
Journal Article
Journal Name:
Experimental Cell Research
Additional Journal Information:
Journal Volume: 314; Journal Issue: 3; Other Information: DOI: 10.1016/j.yexcr.2007.10.026; PII: S0014-4827(07)00514-9; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0014-4827
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; ACETIC ACID; ACTIN; EDTA; ELECTROMECHANICS; ETHYLENE; FIBROBLASTS; FLUORESCEIN; ISOTHIOCYANATES; MATRICES; NUCLEATION; PHOSPHATES

Citation Formats

Guillou, Herve, CNRS UPR 2940, Institut Neel, BP 166X, 38042 Grenoble Cedex 09, Depraz-Depland, Adeline, Planus, Emmanuelle, INSERM U823, Equipe DySAD, Institut Albert Bonniot, Site Sante, BP170, 38042 Grenoble, Vianay, Benoit, Cell Imaging Platform, Institut Albert Bonnot, La Tronche Cedex, Chaussy, Jacques, Grichine, Alexei, Cell Imaging Platform, Institut Albert Bonnot, La Tronche Cedex, Albiges-Rizo, Corinne, INSERM U823, Equipe DySAD, Institut Albert Bonniot, Site Sante, BP170, 38042 Grenoble, Block, Marc R, and INSERM U823, Equipe DySAD, Institut Albert Bonniot, Site Sante, BP170, 38042 Grenoble. Lamellipodia nucleation by filopodia depends on integrin occupancy and downstream Rac1 signaling. United States: N. p., 2008. Web. doi:10.1016/j.yexcr.2007.10.026.
Guillou, Herve, CNRS UPR 2940, Institut Neel, BP 166X, 38042 Grenoble Cedex 09, Depraz-Depland, Adeline, Planus, Emmanuelle, INSERM U823, Equipe DySAD, Institut Albert Bonniot, Site Sante, BP170, 38042 Grenoble, Vianay, Benoit, Cell Imaging Platform, Institut Albert Bonnot, La Tronche Cedex, Chaussy, Jacques, Grichine, Alexei, Cell Imaging Platform, Institut Albert Bonnot, La Tronche Cedex, Albiges-Rizo, Corinne, INSERM U823, Equipe DySAD, Institut Albert Bonniot, Site Sante, BP170, 38042 Grenoble, Block, Marc R, & INSERM U823, Equipe DySAD, Institut Albert Bonniot, Site Sante, BP170, 38042 Grenoble. Lamellipodia nucleation by filopodia depends on integrin occupancy and downstream Rac1 signaling. United States. https://doi.org/10.1016/j.yexcr.2007.10.026
Guillou, Herve, CNRS UPR 2940, Institut Neel, BP 166X, 38042 Grenoble Cedex 09, Depraz-Depland, Adeline, Planus, Emmanuelle, INSERM U823, Equipe DySAD, Institut Albert Bonniot, Site Sante, BP170, 38042 Grenoble, Vianay, Benoit, Cell Imaging Platform, Institut Albert Bonnot, La Tronche Cedex, Chaussy, Jacques, Grichine, Alexei, Cell Imaging Platform, Institut Albert Bonnot, La Tronche Cedex, Albiges-Rizo, Corinne, INSERM U823, Equipe DySAD, Institut Albert Bonniot, Site Sante, BP170, 38042 Grenoble, Block, Marc R, and INSERM U823, Equipe DySAD, Institut Albert Bonniot, Site Sante, BP170, 38042 Grenoble. 2008. "Lamellipodia nucleation by filopodia depends on integrin occupancy and downstream Rac1 signaling". United States. https://doi.org/10.1016/j.yexcr.2007.10.026.
@article{osti_21045932,
title = {Lamellipodia nucleation by filopodia depends on integrin occupancy and downstream Rac1 signaling},
author = {Guillou, Herve and CNRS UPR 2940, Institut Neel, BP 166X, 38042 Grenoble Cedex 09 and Depraz-Depland, Adeline and Planus, Emmanuelle and INSERM U823, Equipe DySAD, Institut Albert Bonniot, Site Sante, BP170, 38042 Grenoble and Vianay, Benoit and Cell Imaging Platform, Institut Albert Bonnot, La Tronche Cedex and Chaussy, Jacques and Grichine, Alexei and Cell Imaging Platform, Institut Albert Bonnot, La Tronche Cedex and Albiges-Rizo, Corinne and INSERM U823, Equipe DySAD, Institut Albert Bonniot, Site Sante, BP170, 38042 Grenoble and Block, Marc R and INSERM U823, Equipe DySAD, Institut Albert Bonniot, Site Sante, BP170, 38042 Grenoble},
abstractNote = {Time-lapse video-microscopy unambiguously shows that fibroblast filopodia are the scaffold of lamellipodia nucleation that allows anisotropic cell spreading. This process was dissected into elementary stages by monitoring cell adhesion on micropatterned extracellular matrix arrays of various pitches. Adhesion structures are stabilized by contact with the adhesive plots and subsequently converted into lamellipodia-like extensions starting at the filopodia tips. This mechanism progressively leads to full cell spreading. Stable expression of the dominant-negative Rac1 N17 impairs this change in membrane extension mode and stops cell spreading on matrix arrays. Similar expression of the dominant-negative Cdc42 N17 impairs cell spreading on homogenous and structured substrate, suggesting that filopodia extension is a prerequisite for cell spreading in this model. The differential polarity of the nucleation of lamellipodial structures by filopodia on homogenous and structured surfaces starting from the cell body and of filopodia tip, respectively, suggested that this process is triggered by areas that are in contact with extracellular matrix proteins for longer times. Consistent with this view, wild-type cells cannot spread on microarrays made of function blocking or neutral anti-{beta}{sub 1} integrin antibodies. However, stable expression of a constitutively active Rac1 mutant rescues the cell ability to spread on these integrin microarrays. Thereby, lamellipodia nucleation by filopodia requires integrin occupancy by matrix substrate and downstream Rac1 signaling.},
doi = {10.1016/j.yexcr.2007.10.026},
url = {https://www.osti.gov/biblio/21045932}, journal = {Experimental Cell Research},
issn = {0014-4827},
number = 3,
volume = 314,
place = {United States},
year = {Fri Feb 01 00:00:00 EST 2008},
month = {Fri Feb 01 00:00:00 EST 2008}
}