α–E-catenin binds to dynamitin and regulates dynactin-mediated intracellular traffic

α–Epithelial catenin (E-catenin) is an important cell–cell adhesion protein. In this study, we show that α–E-catenin also regulates intracellular traffic by binding to the dynactin complex component dynamitin. Dynactin-mediated organelle trafficking is increased in α–E-catenin−/− keratinocytes, an effect that is reversed by expression of exogenous α–E-catenin. Disruption of adherens junctions in low-calcium media does not affect dynactin-mediated traffic, indicating that α–E-catenin regulates traffic independently from its function in cell–cell adhesion. Although neither the integrity of dynactin–dynein complexes nor their association with vesicles is affected by α–E-catenin, α–E-catenin is necessary for the attenuation of microtubule-dependent trafficking by the actin cytoskeleton. Because the actin-binding domain of α–E-catenin is necessary for this regulation, we hypothesize that α–E-catenin functions as a dynamic link between the dynactin complex and actin and, thus, integrates the microtubule and actin cytoskeleton during intracellular trafficking.

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α-Catenin-independent Recruitment of ZO-1 to Nectin-based Cell-Cell Adhesion Sites through Afadin

Molecular Biology of the Cell ◽

10.1091/mbc.12.6.1595 ◽

2001 ◽

Vol 12 (6) ◽

pp. 1595-1609 ◽

Cited By ~ 67

Author(s):

Shigekazu Yokoyama ◽

Kouichi Tachibana ◽

Hiroyuki Nakanishi ◽

Yasunori Yamamoto ◽

Kenji Irie ◽

...

Keyword(s):

Cell Adhesion ◽

Actin Cytoskeleton ◽

Tight Junctions ◽

Cell Lines ◽

Adhesion Molecule ◽

Binding Protein ◽

Actin Binding ◽

Actin Binding Protein ◽

Adhesion Sites ◽

Cell Cell

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.

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The Cryogenic Electron Microscopy Structure of the Cell Adhesion Regulator Metavinculin Reveals an Isoform-Specific Kinked Helix in Its Cytoskeleton Binding Domain

International Journal of Molecular Sciences ◽

10.3390/ijms22020645 ◽

2021 ◽

Vol 22 (2) ◽

pp. 645

Author(s):

Erumbi S. Rangarajan ◽

Tina Izard

Keyword(s):

Electron Microscopy ◽

Cell Adhesion ◽

Binding Domain ◽

Cytoskeletal Proteins ◽

Cell Junctions ◽

Actin Binding ◽

Cell Matrix ◽

Actin Binding Domain ◽

Α Helix ◽

Cell Cell

Vinculin and its heart-specific splice variant metavinculin are key regulators of cell adhesion processes. These membrane-bound cytoskeletal proteins regulate the cell shape by binding to several other proteins at cell–cell and cell–matrix junctions. Vinculin and metavinculin link integrin adhesion molecules to the filamentous actin network. Loss of both proteins prevents cell adhesion and cell spreading and reduces the formation of stress fibers, focal adhesions, or lamellipodia extensions. The binding of talin at cell–matrix junctions or of α-catenin at cell–cell junctions activates vinculin and metavinculin by releasing their autoinhibitory head–tail interaction. Once activated, vinculin and metavinculin bind F-actin via their five-helix bundle tail domains. Unlike vinculin, metavinculin has a 68-amino-acid insertion before the second α-helix of this five-helix F-actin–binding domain. Here, we present the full-length cryogenic electron microscopy structure of metavinculin that captures the dynamics of its individual domains and unveiled a hallmark structural feature, namely a kinked isoform-specific α-helix in its F-actin-binding domain. Our identified conformational landscape of metavinculin suggests a structural priming mechanism that is consistent with the cell adhesion functions of metavinculin in response to mechanical and cellular cues. Our findings expand our understanding of metavinculin function in the heart with implications for the etiologies of cardiomyopathies.

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αE-catenin actin-binding domain alters actin filament conformation and regulates binding of nucleation and disassembly factors

Molecular Biology of the Cell ◽

10.1091/mbc.e13-07-0388 ◽

2013 ◽

Vol 24 (23) ◽

pp. 3710-3720 ◽

Cited By ~ 62

Author(s):

Scott D. Hansen ◽

Adam V. Kwiatkowski ◽

Chung-Yueh Ouyang ◽

HongJun Liu ◽

Sabine Pokutta ◽

...

Keyword(s):

Actin Filament ◽

Actin Filaments ◽

Binding Domain ◽

Actin Binding ◽

Filamentous Actin ◽

Filament Structure ◽

Actin Binding Domain ◽

Filament Bundles ◽

Underlying Mechanisms ◽

Cell Cell

The actin-binding protein αE-catenin may contribute to transitions between cell migration and cell–cell adhesion that depend on remodeling the actin cytoskeleton, but the underlying mechanisms are unknown. We show that the αE-catenin actin-binding domain (ABD) binds cooperatively to individual actin filaments and that binding is accompanied by a conformational change in the actin protomer that affects filament structure. αE-catenin ABD binding limits barbed-end growth, especially in actin filament bundles. αE-catenin ABD inhibits actin filament branching by the Arp2/3 complex and severing by cofilin, both of which contact regions of the actin protomer that are structurally altered by αE-catenin ABD binding. In epithelial cells, there is little correlation between the distribution of αE-catenin and the Arp2/3 complex at developing cell–cell contacts. Our results indicate that αE-catenin binding to filamentous actin favors assembly of unbranched filament bundles that are protected from severing over more dynamic, branched filament arrays.

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Vascular-endothelial-cadherin modulates endothelial monolayer permeability

Journal of Cell Science ◽

10.1242/jcs.112.12.1915 ◽

1999 ◽

Vol 112 (12) ◽

pp. 1915-1923 ◽

Cited By ~ 3

Author(s):

P.L. Hordijk ◽

E. Anthony ◽

F.P. Mul ◽

R. Rientsma ◽

L.C. Oomen ◽

...

Keyword(s):

Cell Adhesion ◽

Actin Cytoskeleton ◽

Adhesion Molecule ◽

Cell Adhesion Molecule ◽

Transendothelial Migration ◽

Stress Fibers ◽

Vascular Endothelial ◽

Monolayer Permeability ◽

Actin Stress Fibers ◽

Cell Cell

Vascular endothelial (VE)-cadherin is the endothelium-specific member of the cadherin family of homotypic cell adhesion molecules. VE-cadherin, but not the cell adhesion molecule platelet/endothelial cell adhesion molecule (PECAM-1), markedly colocalizes with actin stress fibers at cell-cell junctions between human umbilical vein endothelial cells. Inhibition of VE-cadherin-mediated, but not PECAM-1-mediated, adhesion induced reorganization of the actin cytoskeleton, loss of junctional VE-cadherin staining and loss of cell-cell adhesion. In functional assays, inhibition of VE-cadherin caused increased monolayer permeability and enhanced neutrophil transendothelial migration. In a complementary set of experiments, modulation of the actin cytoskeleton was found to strongly affect VE-cadherin distribution. Brief stimulation of the beta2-adrenergic receptor with isoproterenol induced a loss of actin stress fibers resulting in a linear, rather than ‘jagged’, VE-cadherin distribution. The concomitant, isoproterenol-induced, reduction in monolayer permeability was alleviated by a VE-cadherin-blocking antibody. Finally, cytoskeletal reorganization resulting from the inactivation of p21Rho caused a diffuse localization of VE-cadherin, which was accompanied by reduced cell-cell adhesion. Together, these data show that monolayer permeability and neutrophil transendothelial migration are modulated by VE-cadherin-mediated cell-cell adhesion, which is in turn controlled by the dynamics of the actin cytoskeleton.

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NUANCE, a giant protein connecting the nucleus and actin cytoskeleton

Journal of Cell Science ◽

10.1242/jcs.115.15.3207 ◽

2002 ◽

Vol 115 (15) ◽

pp. 3207-3222 ◽

Cited By ~ 25

Author(s):

Yen-Yi Zhen ◽

Thorsten Libotte ◽

Martina Munck ◽

Angelika A. Noegel ◽

Elena Korenbaum

Keyword(s):

Actin Cytoskeleton ◽

Transmembrane Domain ◽

Coiled Coil ◽

Peripheral Blood Lymphocytes ◽

Binding Domain ◽

Actin Binding ◽

Actin Binding Domain ◽

Microfilament System

NUANCE (NUcleus and ActiN Connecting Element) was identified as a novel protein with an α-actinin-like actin-binding domain. A human 21.8 kb cDNA of NUANCE spreads over 373 kb on chromosome 14q22.1-q22.3. The cDNA sequence predicts a 796 kDa protein with an N-terminal actin-binding domain, a central coiled-coil rod domain and a predicted C-terminal transmembrane domain. High levels of NUANCE mRNA were detected in the kidney, liver,stomach, placenta, spleen, lymphatic nodes and peripheral blood lymphocytes. At the subcellular level NUANCE is present predominantly at the outer nuclear membrane and in the nucleoplasm. Domain analysis shows that the actin-binding domain binds to Factin in vitro and colocalizes with the actin cytoskeleton in vivo as a GFP-fusion protein. The C-terminal transmembrane domain is responsible for the targeting the nuclear envelope. Thus, NUANCE is the firstα-actinin-related protein that has the potential to link the microfilament system with the nucleus.

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Tissue Expression and Actin Binding of a Novel N-Terminal Utrophin Isoform

Journal of Biomedicine and Biotechnology ◽

10.1155/2011/904547 ◽

2011 ◽

Vol 2011 ◽

pp. 1-18

Author(s):

Richard A. Zuellig ◽

Beat C. Bornhauser ◽

Ralf Amstutz ◽

Bruno Constantin ◽

Marcus C. Schaub

Keyword(s):

Actin Cytoskeleton ◽

Tissue Expression ◽

Protein Product ◽

Binding Domain ◽

Actin Binding ◽

Rat Tissues ◽

Cortical Actin ◽

Actin Binding Domain ◽

Spectrin Repeats

Utrophin and dystrophin present two large proteins that link the intracellular actin cytoskeleton to the extracellular matrix via the C-terminal-associated protein complex. Here we describe a novel short N-terminal isoform of utrophin and its protein product in various rat tissues (N-utro, 62 kDa, amino acids 1–539, comprising the actin-binding domain plus the first two spectrin repeats). Using different N-terminal recombinant utrophin fragments, we show that actin binding exhibits pronounced negative cooperativity (affinity constantsK1=∼5×106andK2=∼1×105 M-1) and is Ca2+-insensitive. Expression of the different fragments in COS7 cells and in myotubes indicates that the actin-binding domain alone binds exlusively to actin filaments. The recombinant N-utro analogue binds in vitro to actin and in the cells associates to the membranes. The results indicate that N-utro may be responsible for the anchoring of the cortical actin cytoskeleton to the membranes in muscle and other tissues.

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Mutation Analysis of the Short Cytoplasmic Domain of the Cell-Cell Adhesion Molecule CEACAM1 Identifies Residues That Orchestrate Actin Binding and Lumen Formation

Journal of Biological Chemistry ◽

10.1074/jbc.m610903200 ◽

2006 ◽

Vol 282 (8) ◽

pp. 5749-5760 ◽

Cited By ~ 33

Author(s):

Charng-Jui Chen ◽

Julia Kirshner ◽

Mark A. Sherman ◽

Weidong Hu ◽

Tung Nguyen ◽

...

Keyword(s):

Cell Adhesion ◽

Mutation Analysis ◽

Adhesion Molecule ◽

Cell Adhesion Molecule ◽

Cytoplasmic Domain ◽

Actin Binding ◽

Lumen Formation ◽

Cell Cell

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CAR is a cell–cell adhesion protein in human cancer cells and is expressionally modulated by dexamethasone, TNFα, and TGFβ

Gene Therapy ◽

10.1038/sj.gt.3301887 ◽

2003 ◽

Vol 10 (3) ◽

pp. 198-205 ◽

Cited By ~ 46

Author(s):

A Brüning ◽

I B Runnebaum

Keyword(s):

Cell Adhesion ◽

Cancer Cells ◽

Human Cancer ◽

Adhesion Protein ◽

Human Cancer Cells ◽

Cell Adhesion Protein ◽

A Cell ◽

Cell Cell

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Antisense RNA inactivation of gene expression of a cell-cell adhesion protein (gp64) in the cellular slime mold Polysphondylium pallidum

Journal of Cell Science ◽

10.1242/jcs.109.5.1009 ◽

1996 ◽

Vol 109 (5) ◽

pp. 1009-1016

Author(s):

S. Funamoto ◽

H. Ochiai

Keyword(s):

Gene Expression ◽

Cell Adhesion ◽

Antisense Rna ◽

Resistant Cell ◽

Cell Contact ◽

Cellular Slime Mold ◽

Adhesion Protein ◽

Cell Adhesion Protein ◽

Polysphondylium Pallidum ◽

Cell Cell

The gp64 protein of Polysphondylium pallidum has been shown to mediate EDTA-stable cell-cell adhesion. To explore the functional role of gp64, we made an antisense RNA expression construct designed to prevent the gene expression of gp64; the construct was introduced into P. pallidum cells and the transformants were characterised. The antisense RNA-expressing clone L3mc2 which had just been harvested at the growth phase tended to re-form in aggregates smaller in size than did the parental cells in either the presence or absence of 10 mM EDTA. In contrast, 6.5-hour starved L3mc2 cells remained considerably dissociated from each other after 5 minutes gyrating, although aggregation gradually increased by 50% during a further 55 minutes gyrating in the presence of 10 mM EDTA. Correspondingly, L3mc2 lacked specifically the cell-cell adhesion protein, gp64. We therefore conclude that the gp64 protein is involved in forming the EDTA-resistant cell-cell contact. In spite of the absence of gp64, L3mc2 exhibited normal developmental processes, a fact which demonstrates that another cell-cell adhesion system exists in the development of Polysphondylium. This is the first report in which an antisense RNA technique was successfully applied to Polysphondylium.

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