scholarly journals Mechanical stability of αT-catenin and its activation by force for vinculin binding

2019 ◽  
Vol 30 (16) ◽  
pp. 1930-1937 ◽  
Author(s):  
Si Ming Pang ◽  
Shimin Le ◽  
Adam V. Kwiatkowski ◽  
Jie Yan
Keyword(s):  
Cell Adhesion ◽  
Binding Site ◽  
Connexin 43 ◽  
Mechanical Stability ◽  
Critical Factor ◽  
Mechanical Stretch ◽  
Cell Junction ◽  
Unique Cell ◽  
Actomyosin Contraction ◽  
Cell Cell

αT (Testes)-catenin, a critical factor regulating cell–cell adhesion in the heart, directly couples the cadherin-catenin complex to the actin cytoskeleton at the intercalated disk (ICD), a unique cell–cell junction that couples cardiomyocytes. Loss of αT-catenin in mice reduces plakophilin2 and connexin 43 recruitment to the ICD. Since αT-catenin is subjected to mechanical stretch during actomyosin contraction in cardiomyocytes, its activity could be regulated by mechanical force. To provide insight in how force regulates αT-catenin function, we investigated the mechanical stability of the putative, force-sensing middle (M) domain of αT-catenin and determined how force impacts vinculin binding to αT-catenin. We show that 1) physiological levels of force, <15 pN, are sufficient to unfold the three M domains; 2) the M1 domain that harbors the vinculin-binding site is unfolded at ∼6 pN; and 3) unfolding of the M1 domain is necessary for high-affinity vinculin binding. In addition, we quantified the binding kinetics and affinity of vinculin to the mechanically exposed binding site in M1 and observed that αT-catenin binds vinculin with low nanomolar affinity. These results provide important new insights into the mechanosensing properties of αT-catenin and how αT-catenin regulates cell–cell adhesion at the cardiomyocyte ICD.

How cells tell up from down and stick together to construct multicellular tissues – interplay between apicobasal polarity and cell–cell adhesion

2021 ◽  
Vol 134 (21) ◽  
Author(s):  
Claudia G. Vasquez ◽  
Eva L. de la Serna ◽  
Alexander R. Dunn
Keyword(s):  
Cell Adhesion ◽  
Protein Complexes ◽  
Basic Function ◽  
Cell Junction ◽  
Evolutionary Innovation ◽  
Apicobasal Polarity ◽  
Complex Architectures ◽  
Main Components ◽  
Definition Of ◽  
Cell Cell

ABSTRACT Polarized epithelia define a topological inside and outside, and hence constitute a key evolutionary innovation that enabled the construction of complex multicellular animal life. Over time, this basic function has been elaborated upon to yield the complex architectures of many of the organs that make up the human body. The two processes necessary to yield a polarized epithelium, namely regulated adhesion between cells and the definition of the apicobasal (top–bottom) axis, have likewise undergone extensive evolutionary elaboration, resulting in multiple sophisticated protein complexes that contribute to both functions. Understanding how these components function in combination to yield the basic architecture of a polarized cell–cell junction remains a major challenge. In this Review, we introduce the main components of apicobasal polarity and cell–cell adhesion complexes, and outline what is known about their regulation and assembly in epithelia. In addition, we highlight studies that investigate the interdependence between these two networks. We conclude with an overview of strategies to address the largest and arguably most fundamental unresolved question in the field, namely how a polarized junction arises as the sum of its molecular parts.

scholarly journals Effect of lengthening lymphocyte function-associated antigen 3 on adhesion to CD2.

1992 ◽  
Vol 3 (2) ◽  
pp. 157-166 ◽  
Author(s):  
P Y Chan ◽  
T A Springer
Keyword(s):  
Cell Adhesion ◽  
Binding Site ◽  
Chinese Hamster ◽  
Lymphocyte Function ◽  
Wild Type ◽  
Membrane Anchor ◽  
Receptor Binding Site ◽  
Type Molecule ◽  
Repulsive Forces ◽  
Cell Cell

The effect of lengthening the distance in an adhesion molecule between the receptor binding site and the membrane anchor was studied by inserting four Ig-like domains into the two Ig domain lymphocyte function-associated antigen 3 (LFA-3) molecule. The extended molecule expressed in Chinese hamster ovary (CHO) cells bound to CD2 on T lymphocytes 4- to 20-fold more efficiently than the wild-type molecule at 4 degrees C. Treatment of the CHO clones with neuraminidase to remove sialic acid, or with deoxymannojirimycin to reduce the bulk of N-linked glycosylation, showed that adhesion to both the wild-type and the chimeric LFA-3 molecules was under the influence of cell-cell repulsive forces to a similar extent and that these treatments had less effect than lengthening LFA-3. At higher temperatures, such as 22 and 37 degrees C, the efficiency of binding to the wild-type LFA-3 increased to levels comparable with binding to extended LFA-3. Our results suggest that more distal locations of the adhesive binding site from the cell membrane anchor increase the efficiency of cell-cell adhesion by enhancing the frequency of receptor encounter with ligand and that more proximal locations of the adhesive binding site can provide efficient cell-cell adhesion at physiological temperatures.

scholarly journals BRAF Modulates Stretch-Induced Intercellular Gap Formation through Localized Actin Reorganization

2021 ◽  
Vol 22 (16) ◽  
pp. 8989
Author(s):  
Anna Hollósi ◽  
Katalin Pászty ◽  
Miklós Kellermayer ◽  
Guillaume Charras ◽  
Andrea Varga
Keyword(s):  
Cell Adhesion ◽  
Barrier Function ◽  
Mechanical Stretch ◽  
Fiber Formation ◽  
Cell Junctions ◽  
Induced Response ◽  
Gap Formation ◽  
External Forces ◽  
Actin Cables ◽  
Cell Cell

Mechanical forces acting on cell–cell adhesion modulate the barrier function of endothelial cells. The actively remodeled actin cytoskeleton impinges on cell–cell adhesion to counteract external forces. We applied stress on endothelial monolayers by mechanical stretch to uncover the role of BRAF in the stress-induced response. Control cells responded to external forces by organizing and stabilizing actin cables in the stretched cell junctions. This was accompanied by an increase in intercellular gap formation, which was prevented in BRAF knockdown monolayers. In the absence of BRAF, there was excess stress fiber formation due to the enhanced reorganization of actin fibers. Our findings suggest that stretch-induced intercellular gap formation, leading to a decrease in barrier function of blood vessels, can be reverted by BRAF RNAi. This is important when the endothelium experiences changes in external stresses caused by high blood pressure, leading to edema, or by immune or cancer cells in inflammation or metastasis.

Abstract 300: The Actin Cytoskeleton Confers Specificity of Cx43 Delivery to Intercalated Discs

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Shan-Shan Zhang ◽  
SoonGweon Hong ◽  
Luke P Lee ◽  
Robin M Shaw
Keyword(s):  
Connexin 43 ◽  
Single Particle Tracking ◽  
Cell Junction ◽  
Cell Border ◽  
Intercalated Discs ◽  
Biochemical Interaction ◽  
Junction Protein ◽  
Latrunculin A ◽  
Long Fibers ◽  
Cell Cell

Connexin 43 (Cx43) gap junctions (GJs) electrically couple ventricular cardiomyocytes at the intercalated disc (ID), orchestrating organized organ level contraction with each heartbeat. Disease-related disruption of the Cx43 cytoskeletal trafficking machinery is associated with mislocalization of the Cx43 gap junction protein away from the ID and lethal arrhythmias. We recently found that the majority of intracellular Cx43 cargo is associated with actin, not microtubules, and is either paused or moving slowly. It is not understood why actin is involved in Cx43 trafficking. Using micropatterned HeLa cell pairs and whole-cell automated single particle tracking algorithms, we detected that distinct actin polarity exists in the cell, including highly oriented long fibers associated with fast-moving Cx43 cargo aligned toward actively forming GJ plaques. F-actin disruption with latrunculin A (LatA) leads to a loss of Cx43 cargo directionality toward the cell-cell border, as well as a marked decrease in overall microtubule length. We also found a LatA-dependent biochemical interaction between β-actin and the microtubule plus-end-binding protein EB1, which leads growing microtubules and is a necessary component of the Cx43 forward trafficking machinery. In live cell pairs, F-actin disruption resulted in a decrease in overall EB1 activity and in the number of fully extended microtubules that reach the cell-cell border. Together, these results indicate that actin contributes to the specificity of Cx43 delivery by directing EB1-based microtubule growth toward the cell-cell junction (Please refer to attached diagram).

The effects of mechanical stretch on keratinocyte cell-cell adhesion

2017 ◽  
Vol 2017.29 (0) ◽  
pp. 1A15
Author(s):  
Katie R. Ryan ◽  
Akihisa Koyama ◽  
Katsuko S. Furukawa ◽  
Takashi Ushida
Keyword(s):  
Cell Adhesion ◽  
Mechanical Stretch ◽  
Keratinocyte Cell ◽  
Cell Cell

Role of Ponticulin in Pseudopod Dynamics, Cell-Cell Adhesion, and Mechanical Stability of an Amoeboid Membrane Skeleton

1998 ◽  
Vol 194 (3) ◽  
pp. 345-347
Author(s):  
E. J. Luna ◽  
A. L. Hitt ◽  
D. Shutt ◽  
D. Wessels ◽  
D. Soll ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Mechanical Stability ◽  
Membrane Skeleton ◽  
Cell Cell

scholarly journals p120-catenin prevents multinucleation through control of MKLP1-dependent RhoA activity during cytokinesis

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Robert A.H. van de Ven ◽  
Jolien S. de Groot ◽  
Danielle Park ◽  
Robert van Domselaar ◽  
Danielle de Jong ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Chromosomal Instability ◽  
Tumour Progression ◽  
Coiled Coil ◽  
Cellular Adhesion ◽  
P120 Catenin ◽  
Rhoa Activity ◽  
Rhoa Gtpase ◽  
Actomyosin Contraction ◽  
Cell Cell

Abstract Spatiotemporal activation of RhoA and actomyosin contraction underpins cellular adhesion and division. Loss of cell–cell adhesion and chromosomal instability are cardinal events that drive tumour progression. Here, we show that p120-catenin (p120) not only controls cell–cell adhesion, but also acts as a critical regulator of cytokinesis. We find that p120 regulates actomyosin contractility through concomitant binding to RhoA and the centralspindlin component MKLP1, independent of cadherin association. In anaphase, p120 is enriched at the cleavage furrow where it binds MKLP1 to spatially control RhoA GTPase cycling. Binding of p120 to MKLP1 during cytokinesis depends on the N-terminal coiled-coil domain of p120 isoform 1A. Importantly, clinical data show that loss of p120 expression is a common event in breast cancer that strongly correlates with multinucleation and adverse patient survival. In summary, our study identifies p120 loss as a driver event of chromosomal instability in cancer.

scholarly journals The F-BAR domain of SRGP-1 facilitates cell–cell adhesion during C. elegans morphogenesis

2010 ◽  
Vol 191 (4) ◽  
pp. 761-769 ◽  
Author(s):  
Ronen Zaidel-Bar ◽  
Michael J. Joyce ◽  
Allison M. Lynch ◽  
Kristen Witte ◽  
Anjon Audhya ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Molecular Mechanisms ◽  
Function Analysis ◽  
Membrane Dynamics ◽  
Protein Domain ◽  
Cell Junctions ◽  
Cell Junction ◽  
Loss Of Function ◽  
Bar Domain ◽  
Cell Cell

Robust cell–cell adhesion is critical for tissue integrity and morphogenesis, yet little is known about the molecular mechanisms controlling cell–cell junction architecture and strength. We discovered that SRGP-1 is a novel component of cell–cell junctions in Caenorhabditis elegans, localizing via its F-BAR (Bin1, Amphiphysin, and RVS167) domain and a flanking 200–amino acid sequence. SRGP-1 activity promotes an increase in membrane dynamics at nascent cell–cell contacts and the rapid formation of new junctions; in addition, srgp-1 loss of function is lethal in embryos with compromised cadherin–catenin complexes. Conversely, excess SRGP-1 activity leads to outward bending and projections of junctions. The C-terminal half of SRGP-1 interacts with the N-terminal F-BAR domain and negatively regulates its activity. Significantly, in vivo structure–function analysis establishes a role for the F-BAR domain in promoting rapid and robust cell adhesion during embryonic closure events, independent of the Rho guanosine triphosphatase–activating protein domain. These studies establish a new role for this conserved protein family in modulating cell–cell adhesion.

Integrity of the homophilic binding site is required for the preferential localization of NCAM in intercellular contacts

1996 ◽  
Vol 74 (3) ◽  
pp. 373-381 ◽  
Author(s):  
Martin Sandig ◽  
Yong Rao ◽  
Chi-Hung Siu ◽  
Vitauts I. Kalnins
Keyword(s):  
Cell Adhesion ◽  
Binding Site ◽  
Adhesion Molecule ◽  
Laser Scanning ◽  
Wild Type ◽  
Surface Distribution ◽  
Homophilic Binding ◽  
L Cell ◽  
Intercellular Contacts ◽  
Cell Cell

The neural cell adhesion molecule NCAM is a member of the immunoglobulin (Ig) superfamily. NCAM can undergo homophilic binding and heterophilic interactions with cell surface components and is often concentrated at sites of intercellular contact. To investigate the molecular basis of this biased surface distribution, we examined L cell transfectants expressing wild-type or mutant forms of chick NCAM-140 by laser scanning confocal microscopy. Mutant NCAMs that lacked Ig-like domains 1, 2, 4, or 5 were preferentially localized in contact regions. However, the relative concentration of these mutant NCAMs in contact sites was substantially reduced compared with wild-type NCAM. In contrast, NCAM redistribution to intercellular contacts was abolished in cells expressing mutant NCAMs that either lacked Ig-like domain 3 or contained mutations in the homophilic binding site in this domain. In heterotypic contacts between PC12 cells and L cell transfectants, colocalization of rat NCAM and chick NCAM was again dependent on the integrity of the homophilic binding site of the NCAM expressed on L cells. These results provide evidence that homophilic binding is the main mechanism by which NCAM becomes redistributed to intercellular contacts. They also implicate a role for other Ig-like domains in the accumulation of NCAM at cell–cell contacts.Key words: cell–cell adhesion, adhesion molecule, NCAM, homophilic binding, surface distribution.

scholarly journals Characterization of the strain-rate–dependent mechanical response of single cell–cell junctions

2021 ◽  
Vol 118 (7) ◽  
pp. e2019347118
Author(s):  
Amir Monemian Esfahani ◽  
Jordan Rosenbohm ◽  
Bahareh Tajvidi Safa ◽  
Nickolay V. Lavrik ◽  
Grayson Minnick ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Stress Relaxation ◽  
Strain Rate ◽  
Single Cell ◽  
High Strain ◽  
Cell Junction ◽  
Strain Rates ◽  
High Strain Rates ◽  
Rate Dependent ◽  
Cell Cell

Cell–cell adhesions are often subjected to mechanical strains of different rates and magnitudes in normal tissue function. However, the rate-dependent mechanical behavior of individual cell–cell adhesions has not been fully characterized due to the lack of proper experimental techniques and therefore remains elusive. This is particularly true under large strain conditions, which may potentially lead to cell–cell adhesion dissociation and ultimately tissue fracture. In this study, we designed and fabricated a single-cell adhesion micro tensile tester (SCAµTT) using two-photon polymerization and performed displacement-controlled tensile tests of individual pairs of adherent epithelial cells with a mature cell–cell adhesion. Straining the cytoskeleton–cell adhesion complex system reveals a passive shear-thinning viscoelastic behavior and a rate-dependent active stress-relaxation mechanism mediated by cytoskeleton growth. Under low strain rates, stress relaxation mediated by the cytoskeleton can effectively relax junctional stress buildup and prevent adhesion bond rupture. Cadherin bond dissociation also exhibits rate-dependent strengthening, in which increased strain rate results in elevated stress levels at which cadherin bonds fail. This bond dissociation becomes a synchronized catastrophic event that leads to junction fracture at high strain rates. Even at high strain rates, a single cell–cell junction displays a remarkable tensile strength to sustain a strain as much as 200% before complete junction rupture. Collectively, the platform and the biophysical understandings in this study are expected to build a foundation for the mechanistic investigation of the adaptive viscoelasticity of the cell–cell junction.

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