scholarly journals Integrating the Actin and Vimentin Cytoskeletons

1999 ◽  
Vol 146 (4) ◽  
pp. 831-842 ◽  
Author(s):  
Ivan Correia ◽  
Donald Chu ◽  
Ying-Hao Chou ◽  
Robert D. Goldman ◽  
Paul Matsudaira

Cells adhere to the substratum through specialized structures that are linked to the actin cytoskeleton. Recent studies report that adhesion also involves the intermediate filament (IF) and microtubule cytoskeletons, although their mechanisms of interaction are unknown. Here we report evidence for a novel adhesion-dependent interaction between components of the actin and IF cytoskeletons. In biochemical fractionation experiments, fimbrin and vimentin coprecipitate from detergent extracts of macrophages using vimentin- or fimbrin-specific antisera. Fluorescence microscopy confirms the biochemical association. Both proteins colocalized to podosomes in the earliest stages of cell adhesion and spreading. The complex is also found in filopodia and retraction fibers. After detergent extraction, fimbrin and vimentin staining of podosomes, filopodia, and retraction fibers are lost, confirming that the complex is localized to these structures. A 1:4 stoichiometry of fimbrin binding to vimentin and a low percentage (1%) of the extracted vimentin suggest that fimbrin interacts with a vimentin subunit. A fimbrin-binding site was identified in the NH2-terminal domain of vimentin and the vimentin binding site at residues 143–188 in the CH1 domain of fimbrin. Based on these observations, we propose that a fimbrin–vimentin complex may be involved in directing the assembly of the vimentin cytoskeleton at cell adhesion sites.

2002 ◽  
Vol 115 (12) ◽  
pp. 2581-2590 ◽  
Author(s):  
Françoise Coussen ◽  
Daniel Choquet ◽  
Michael P. Sheetz ◽  
Harold P. Erickson

Previous studies have shown that small beads coated with FN7-10, a four-domain cell adhesion fragment of fibronectin, bind to cell surfaces and translocate rearward. Here we investigate whether soluble constructs containing two to five FN7-10 units might be sufficient for activity. We have produced a monomer, three forms of dimers, a trimer and a pentamer of FN7-10,on the end of spacer arms. These oligomers could bind small clusters of up to five integrins. Fluorescence microscopy showed that the trimer and pentamer bound strongly to the cell surface, and within 5 minutes were prominently localized to actin fiber bundles. Monomers and dimers showed only diffuse localization. Beads coated with a low concentration (probably one complex per bead) of trimer or pentamer showed prolonged binding and rearward translocation, presumably with the translocating actin cytskeleton. Beads containing monomer or dimer showed only brief binding and diffusive movements. We conclude that clusters of three integrin-binding ligands are necessary and sufficient for coupling to and translocating with the actin cytoskeleton.


2001 ◽  
Vol 12 (6) ◽  
pp. 1595-1609 ◽  
Author(s):  
Shigekazu Yokoyama ◽  
Kouichi Tachibana ◽  
Hiroyuki Nakanishi ◽  
Yasunori Yamamoto ◽  
Kenji Irie ◽  
...  

ZO-1 is an actin filament (F-actin)–binding protein that localizes to tight junctions and connects claudin to the actin cytoskeleton in epithelial cells. In nonepithelial cells that have no tight junctions, ZO-1 localizes to adherens junctions (AJs) and may connect cadherin to the actin cytoskeleton indirectly through β- and α-catenins as one of many F-actin–binding proteins. Nectin is an immunoglobulin-like adhesion molecule that localizes to AJs and is associated with the actin cytoskeleton through afadin, an F-actin–binding protein. Ponsin is an afadin- and vinculin-binding protein that also localizes to AJs. The nectin-afadin complex has a potency to recruit the E-cadherin–β-catenin complex through α-catenin in a manner independent of ponsin. By the use of cadherin-deficient L cell lines stably expressing various components of the cadherin-catenin and nectin-afadin systems, and α-catenin–deficient F9 cell lines, we examined here whether nectin recruits ZO-1 to nectin-based cell-cell adhesion sites. Nectin showed a potency to recruit not only α-catenin but also ZO-1 to nectin-based cell-cell adhesion sites. This recruitment of ZO-1 was dependent on afadin but independent of α-catenin and ponsin. These results indicate that ZO-1 localizes to cadherin-based AJs through interactions not only with α-catenin but also with the nectin-afadin system.


1997 ◽  
Vol 136 (5) ◽  
pp. 1109-1121 ◽  
Author(s):  
Bertolt Kreft ◽  
Dietmar Berndorff ◽  
Anja Böttinger ◽  
Silvia Finnemann ◽  
Doris Wedlich ◽  
...  

The adhesive function of classical cadherins depends on the association with cytoplasmic proteins, termed catenins, which serve as a link between cadherins and the actin cytoskeleton. LI-cadherin, a structurally different member of the cadherin family, mediates Ca2+-dependent cell–cell adhesion, although its markedly short cytoplasmic domain exhibits no homology to this highly conserved region of classical cadherins. We now examined whether the adhesive function of LI-cadherin depends on the interaction with catenins, the actin cytoskeleton or other cytoplasmic components. In contrast to classical cadherins, LI-cadherin, when expressed in mouse L cells, was neither associated with catenins nor did it induce an upregulation of β-catenin. Consistent with these findings, LI-cadherin was not resistant to detergent extraction and did not induce a reorganization of the actin cytoskeleton. However, LI-cadherin was still able to mediate Ca2+dependent cell–cell adhesion. To analyze whether this function requires any interaction with proteins other than catenins, a glycosyl phosphatidylinositol–anchored form of LI-cadherin (LI-cadherinGPI) was constructed and expressed in Drosophila S2 cells. The mutant protein was able to induce Ca2+-dependent, homophilic cell–cell adhesion, and its adhesive properties were indistinguishable from those of wild type LI-cadherin. These findings indicate that the adhesive function of LI-cadherin is independent of any interaction with cytoplasmic components, and consequently should not be sensitive to regulatory mechanisms affecting the binding of classical cadherins to catenins and to the cytoskeleton. Thus, we postulate that the adhesive function of LI-cadherin is complementary to that of coexpressed classical cadherins ensuring cell–cell contacts even under conditions that downregulate the function of classical cadherins.


Oncogene ◽  
2003 ◽  
Vol 22 (14) ◽  
pp. 2097-2109 ◽  
Author(s):  
Tatsuo Katata ◽  
Kenji Irie ◽  
Atsunori Fukuhara ◽  
Tomomi Kawakatsu ◽  
Akio Yamada ◽  
...  

2016 ◽  
Author(s):  
Elena Daniela Aflorei ◽  
Benjamin Klapholz ◽  
Nina Moderau ◽  
Paulo Baptista-Ribeiro ◽  
Nic Tapon ◽  
...  

2007 ◽  
Vol 361-363 ◽  
pp. 1115-1118
Author(s):  
Un Hye Kwon ◽  
Jung Suk Han ◽  
In Young Ryu ◽  
Dae Joon Kim

The initial osteoblast like cell response to bioactive nano-sized hydroxyapatite (HAp) and bioinert zirconia was evaluated with the cell morphology by SEM and cell adhesion proteins by fluorescence microscopy. Surface roughness also measured by a confocal laser microscopy. The surface roughness and topography was almost identical among specimens. The nano-sized HAp specimens showed better initial cell adhesion and activity than bioinert zirconia ceramics.


Virology ◽  
2008 ◽  
Vol 373 (1) ◽  
pp. 211-228 ◽  
Author(s):  
Joseph M. Hyser ◽  
Carl Q.-Y. Zeng ◽  
Zanna Beharry ◽  
Timothy Palzkill ◽  
Mary K. Estes

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