scholarly journals Coordination of mitochondrial and cellular dynamics by the actin-based motor Myo19

2021 ◽  
Vol 134 (10) ◽  
Author(s):  
Katarzyna Majstrowicz ◽  
Ulrike Honnert ◽  
Petra Nikolaus ◽  
Vera Schwarz ◽  
Stefanie J. Oeding ◽  
...  
Keyword(s):  
Molecular Level ◽  
Focal Adhesions ◽  
Adaptor Proteins ◽  
Cellular Level ◽  
Ros Generation ◽  
Cellular Processes ◽  
Daughter Cells ◽  
Cell Matrix ◽  
Motor Activities ◽  
Cell Matrix Adhesion

ABSTRACT Myosin XIX (Myo19) is an actin-based motor that competes with adaptors of microtubule-based motors for binding to the outer mitochondrial transmembrane proteins Miro1 and Miro2 (collectively Miro, also known as RhoT1 and RhoT2, respectively). Here, we investigate which mitochondrial and cellular processes depend on the coordination of Myo19 and microtubule-based motor activities. To this end, we created Myo19-deficient HEK293T cells. Mitochondria in these cells were not properly fragmented at mitosis and were partitioned asymmetrically to daughter cells. Respiratory functions of mitochondria were impaired and ROS generation was enhanced. On a cellular level, cell proliferation, cytokinesis and cell–matrix adhesion were negatively affected. On a molecular level, Myo19 regulates focal adhesions in interphase, and mitochondrial fusion and mitochondrially associated levels of fission protein Drp1 and adaptor proteins dynactin and TRAK1 at prometaphase. These alterations were due to a disturbed coordination of Myo19 and microtubule-based motor activities by Miro.

Ezrin regulates cell-cell and cell-matrix adhesion, a possible role with E-cadherin/beta-catenin

1999 ◽  
Vol 112 (18) ◽  
pp. 3081-3090 ◽  
Author(s):  
S. Hiscox ◽  
W.G. Jiang
Keyword(s):  
Cancer Cells ◽  
Focal Adhesions ◽  
Beta Catenin ◽  
Matrix Adhesion ◽  
Cell Matrix ◽  
Ezrin Expression ◽  
Coated Surfaces ◽  
Cell Matrix Adhesion ◽  
E Cadherin ◽  
Cell Cell

Ezrin, radixin, moesin and merlin form a subfamily of conserved proteins in the band 4.1 superfamily. The function of these proteins is to link the plasma membrane to the actin cytoskeleton. Merlin is defective or absent in schwannomas and meningiomas and has been suggested to function as a tumour suppressor. In this study, we have examined the role of ezrin as a potential regulator of the adhesive and invasive behaviour of tumour cells. We have shown that following inhibition of ezrin expression in colo-rectal cancer cells using antisense oligonucleotides, these cells displayed a reduced cell-cell adhesiveness together with a gain in their motile and invasive behaviour. These cells also displayed increased spreading over matrix-coated surfaces. Immunofluorescence studies revealed that antisense-treated cells also displayed an increased staining of paxillin in areas representing focal adhesions. Furthermore, coprecipitation studies revealed an association of ezrin with E-cadherin and beta-catenin. Induction of the phosphorylation of ezrin by orthovanadate and hepatocyte growth factor/scatter factor resulted in changes similar to those seen with antisense treatment, together with a marked decrease in the association of ezrin with both beta-catenin and E-cadherin. It is concluded that ezrin regulates cell-cell and cell-matrix adhesion, by interacting with cell adhesion molecules E-cadherin and beta-catenin, and may thus play an important role in the control of adhesion and invasiveness of cancer cells.

Hierarchical assembly of cell–matrix adhesion complexes

2004 ◽  
Vol 32 (3) ◽  
pp. 416-420 ◽  
Author(s):  
R. Zaidel-Bar ◽  
M. Cohen ◽  
L. Addadi ◽  
B. Geiger
Keyword(s):  
Extracellular Matrix ◽  
Cell Surface ◽  
Focal Adhesions ◽  
Leading Edge ◽  
Cellular Migration ◽  
Hierarchical Assembly ◽  
Surface Recognition ◽  
Cell Matrix ◽  
Molecular Events ◽  
Cell Matrix Adhesion

The adhesion of cells to the extracellular matrix is a dynamic process, mediated by a series of cell-surface and matrix-associated molecules that interact with each other in a spatially and temporally regulated manner. These interactions play a major role in tissue formation, cellular migration and the induction of adhesion-mediated transmembrane signals. In this paper, we show that the formation of matrix adhesions is a hierarchical process, consisting of several sequential molecular events. One of the earliest steps in surface recognition is mediated, in some cells, by a 1 μm-thick cell-surface hyaluronan coat, which precedes the establishment of stable, cytoskeleton-associated adhesions. The earliest forms of these integrin-mediated contacts are dot-shaped FXs (focal complexes), which are formed under the protrusive lamellipodium of migrating cells. These adhesions recruit, sequentially, different anchor proteins that are involved in binding the actin cytoskeleton to the membrane. Conspicuous in its absence from FXs is zyxin, which is recruited to these sites only on retraction of the leading edge and the transformation of the FXs into a focal adhesion. Continuing application of force to focal adhesions results in the formation of fibrillar adhesions and reorganization of the extracellular matrix. The formation of these adhesions depends on actomyosin contractility and matrix pliability.

scholarly journals Zasp is required for the assembly of functional integrin adhesion sites

2007 ◽  
Vol 179 (7) ◽  
pp. 1583-1597 ◽  
Author(s):  
Klodiana Jani ◽  
Frieder Schöck
Keyword(s):  
Focal Adhesions ◽  
Myotendinous Junction ◽  
Lim Domain ◽  
Transmembrane Receptors ◽  
Cell Matrix ◽  
Adhesion Sites ◽  
Alternatively Spliced ◽  
Dependent Cell ◽  
Cell Matrix Adhesion ◽  
Myotendinous Junctions

The integrin family of heterodimeric transmembrane receptors mediates cell–matrix adhesion. Integrins often localize in highly organized structures, such as focal adhesions in tissue culture and myotendinous junctions in muscles. Our RNA interference screen for genes that prevent integrin-dependent cell spreading identifies Z band alternatively spliced PDZ-motif protein (zasp), encoding the only known Drosophila melanogaster Alp/Enigma PDZ-LIM domain protein. Zasp localizes to integrin adhesion sites and its depletion disrupts integrin adhesion sites. In tissues, Zasp colocalizes with βPS integrin in myotendinous junctions and with α-actinin in muscle Z lines. Zasp also physically interacts with α-actinin. Fly larvae lacking Zasp do not form Z lines and fail to recruit α-actinin to the Z line. At the myotendinous junction, muscles detach in zasp mutants with the onset of contractility. Finally, Zasp interacts genetically with integrins, showing that it regulates integrin function. Our observations point to an important function for Zasp in the assembly of integrin adhesion sites both in cell culture and in tissues.

scholarly journals Ligand Geometry Controls Adhesion formation via Integrin Clustering

2018 ◽  
Author(s):  
Rishita Changede ◽  
Haogang Cai ◽  
Shalom Wind ◽  
Michael P. Sheetz
Keyword(s):  
Adhesion Formation ◽  
Focal Adhesions ◽  
Super Resolution ◽  
Total Width ◽  
Cellular Processes ◽  
Cell Matrix ◽  
Integrin Clustering ◽  
Super Resolution Microscopy ◽  
Fiber Mesh

AbstractIntegrin-mediated cell matrix adhesions are key to sensing the geometry and rigidity of the extracellular environment to regulate vital cellular processes. In vivo, the extracellular matrix (ECM) is composed of a fibrous mesh. To understand the geometry that supports adhesion formation on fibrous substrates, we patterned 10 nm gold-palladium single lines or pairs of lines (total width within 100 nm), mimicking thin single ECM fibers or a minimal mesh geometry, respectively and functionalized it with integrin binding ligand Arg-Gly-Asp (RGD). Single lines showed reduced focal adhesion kinase (FAK) recruitment and did not support cell spreading or formation of focal adhesions, despite the presence of a high density of integrin-binding ligands. Using super resolution microscopy, we observed transient integrin clusters on single lines, whereas stable 110 nm integrin clusters formed on pairs of lines similar to those on continuous substrates. This indicated that two-dimensional ligand geometry is required for adhesion formation on rigid substrates. A mechanism to form modular 100nm integrin clusters bridging the minimal fiber mesh would require unliganded integrins. We observed that integrin mutants unable to bind ligand co-clustered with ligand-bound integrins when present in an active extended conformation. Thus, these results indicate that functional integrin clusters are required to form focal adhesions and unliganded integrins can co-cluster to bridge between thin matrix fibers and can form stable integrin adhesions on dense fibrous networks.

scholarly journals Direct single-molecule quantification reveals unexpectedly high mechanical stability of vinculin—talin/α-catenin linkages

2019 ◽  
Vol 5 (12) ◽  
pp. eaav2720 ◽  
Author(s):  
Shimin Le ◽  
Miao Yu ◽  
Jie Yan
Keyword(s):  
Single Molecule ◽  
Binding Sites ◽  
Mechanical Stability ◽  
Adherens Junctions ◽  
Focal Adhesions ◽  
Adaptor Proteins ◽  
Cell Matrix ◽  
High Mechanical Stability ◽  
Direct Quantification ◽  
Cell Cell

The vinculin-mediated mechanosensing requires establishment of stable mechanical linkages between vinculin to integrin at focal adhesions and to cadherins at adherens junctions through associations with the respective adaptor proteins talin and α-catenin. However, the mechanical stability of these critical vinculin linkages has yet to be determined. Here, we developed a single-molecule detector assay to provide direct quantification of the mechanical lifetime of vinculin association with the vinculin binding sites in both talin and α-catenin, which reveals a surprisingly high mechanical stability of the vinculin—talin and vinculin—α-catenin interfaces that have a lifetime of >1000 s at forces up to 10 pN and can last for seconds to tens of seconds at 15 to 25 pN. Our results suggest that these force-bearing intermolecular interfaces provide sufficient mechanical stability to support the vinculin-mediated mechanotransduction at cell-matrix and cell-cell adhesions.

scholarly journals Probing mechanical principles of focal contacts in cell–matrix adhesion with a coupled stochastic–elastic modelling framework

2011 ◽  
Vol 8 (62) ◽  
pp. 1217-1232 ◽  
Author(s):  
Huajian Gao ◽  
Jin Qian ◽  
Bin Chen
Keyword(s):  
Numerical Models ◽  
Focal Adhesions ◽  
Point Of View ◽  
Matrix Adhesion ◽  
Modelling Framework ◽  
Cell Matrix ◽  
Focal Contacts ◽  
Wide Range ◽  
Sense And Respond ◽  
Cell Matrix Adhesion

Cell–matrix adhesion depends on the collective behaviours of clusters of receptor–ligand bonds called focal contacts between cell and extracellular matrix. While the behaviour of a single molecular bond is governed by statistical mechanics at the molecular scale, continuum mechanics should be valid at a larger scale. This paper presents an overview of a series of recent theoretical studies aimed at probing the basic mechanical principles of focal contacts in cell–matrix adhesion via stochastic–elastic models in which stochastic descriptions of molecular bonds and elastic descriptions of interfacial traction–separation are unified in a single modelling framework. The intention here is to illustrate these principles using simple analytical and numerical models. The aim of the discussions is to provide possible clues to the following questions: why does the size of focal adhesions (FAs) fall into a narrow range around the micrometre scale? How can cells sense and respond to substrates of varied stiffness via FAs? How do the magnitude and orientation of mechanical forces affect the binding dynamics of FAs? The effects of cluster size, cell–matrix elastic modulus, loading direction and cytoskeletal pretension on the lifetime of FA clusters have been investigated by theoretical arguments as well as Monte Carlo numerical simulations, with results showing that intermediate adhesion size, stiff substrate, cytoskeleton stiffening, low-angle pulling and moderate cytoskeletal pretension are factors that contribute to stable FAs. From a mechanistic point of view, these results provide possible explanations for a wide range of experimental observations and suggest multiple mechanisms by which cells can actively control adhesion and de-adhesion via cytoskeletal contractile machinery in response to mechanical properties of their surroundings.

scholarly journals Vascular Endothelial-Cadherin Regulates Cytoskeletal Tension, Cell Spreading, and Focal Adhesions by Stimulating RhoA

2004 ◽  
Vol 15 (6) ◽  
pp. 2943-2953 ◽  
Author(s):  
Celeste M. Nelson ◽  
Dana M. Pirone ◽  
John L. Tan ◽  
Christopher S. Chen
Keyword(s):  
Adhesion Formation ◽  
Focal Adhesions ◽  
Cell Spreading ◽  
Cell Contact ◽  
Matrix Adhesion ◽  
Cell Matrix ◽  
Focal Adhesion Formation ◽  
Cytoskeletal Tension ◽  
Cell Matrix Adhesion ◽  
Cell Cell

Changes in vascular endothelial (VE)-cadherin–mediated cell-cell adhesion and integrin-mediated cell-matrix adhesion coordinate to affect the physical and mechanical rearrangements of the endothelium, although the mechanisms for such cross talk remain undefined. Herein, we describe the regulation of focal adhesion formation and cytoskeletal tension by intercellular VE-cadherin engagement, and the molecular mechanism by which this occurs. Increasing the density of endothelial cells to increase cell-cell contact decreased focal adhesions by decreasing cell spreading. This contact inhibition of cell spreading was blocked by disrupting VE-cadherin engagement with an adenovirus encoding dominant negative VE-cadherin. When changes in cell spreading were prevented by culturing cells on a micropatterned substrate, VE-cadherin–mediated cell-cell contact paradoxically increased focal adhesion formation. We show that VE-cadherin engagement mediates each of these effects by inducing both a transient and sustained activation of RhoA. Both the increase and decrease in cell-matrix adhesion were blocked by disrupting intracellular tension and signaling through the Rho-ROCK pathway. In all, these findings demonstrate that VE-cadherin signals through RhoA and the actin cytoskeleton to cross talk with cell-matrix adhesion and thereby define a novel pathway by which cell-cell contact alters the global mechanical and functional state of cells.

scholarly journals Regulation and dynamics of force transmission at individual cell-matrix adhesion bonds

2019 ◽  
Author(s):  
Steven J. Tan ◽  
Alice C. Chang ◽  
Cayla M. Miller ◽  
Sarah M. Anderson ◽  
Louis S. Prahl ◽  
...  
Keyword(s):  
Biological Function ◽  
Molecular Level ◽  
Individual Cell ◽  
Ligand Specificity ◽  
Force Transmission ◽  
Animal Tissues ◽  
Cell Matrix ◽  
Mechanical Homeostasis ◽  
Cell Matrix Adhesion ◽  
Adhesion Complex

AbstractIntegrin-based adhesion complexes link the cytoskeleton to the extracellular matrix (ECM) and are central to the construction of multicellular animal tissues. How biological function emerges from the 10s-1000s of proteins present within a single adhesion complex has remained unclear. We used fluorescent molecular tension sensors to visualize force transmission by individual integrins in living cells. These measurements revealed an underlying functional modularity in which integrin class controlled adhesion size and ECM ligand specificity, while the number and type of connections between integrins and F-actin determined the force per individual integrin. In addition, we found that most integrins existed in a state of near-mechanical equilibrium, a result not predicted by existing models of cytoskeletal force transduction. A revised model that includes reversible crosslinks within the F-actin network accounts for this result, and suggests how cellular mechanical homeostasis can arise at the molecular level.

scholarly journals Dual functions of Discoidin domain receptor coordinate cell-matrix adhesion and collective polarity in migratory cardiopharyngeal progenitors

2017 ◽  
Author(s):  
Yelena Y. Bernadskaya ◽  
Saahil Brahmbhatt ◽  
Stephanie E. Gline ◽  
Wei Wang ◽  
Lionel Christiaen
Keyword(s):  
Transcriptional Networks ◽  
Cardiac Progenitors ◽  
Discoidin Domain Receptor ◽  
Cellular Processes ◽  
Matrix Adhesion ◽  
Cell Matrix ◽  
Effector Genes ◽  
Quantitative Analyses ◽  
Cell Matrix Adhesion ◽  
Dual Functions

ABSTRACTIntegrated analyses of regulated effector genes, cellular processes, and extrinsic signals are required to understand how transcriptional networks coordinate fate specification and cell behavior during embryogenesis. Migratory pairs of cardiac progenitors in the tunicate Ciona provide the simplest model of collective migration in chordate embryos. Ciona cardiopharyngeal progenitors (aka trunk ventral cells, TVCs) polarize as leader and trailer cells, and migrate between the ventral epidermis and trunk endoderm, which influences collective polarity. Using functional perturbations and quantitative analyses, we show that the TVC-specific and collagen-binding Discoidin-domain receptor (Ddr) cooperates with Integrin-β1 to promote cell-matrix adhesion to the epidermis. We found that endoderm cells secrete a collagen, Col9-a1, that is deposited in the basal epidermal matrix and activates Ddr at the ventral membrane of migrating TVCs. A functional antagonism between Ddr/Intβ1-mediated cell-matrix adhesion and Vegfr signaling appears to modulate the position of cardiopharyngeal progenitors between the endoderm and epidermis. Finally, we show that Ddr activity promotes leader-trailer-polarized BMP-Smad signaling independently of its role in cell-matrix adhesion. We propose that dual functions of Ddr act downstream of cardiopharyngeal-specific transcriptional inputs to coordinate subcellular processes underlying collective polarity and directed migration.

scholarly journals Mechanosensing during directed cell migration requires dynamic actin polymerization at focal adhesions

2019 ◽  
Vol 218 (12) ◽  
pp. 4215-4235 ◽  
Author(s):  
Julieann I. Puleo ◽  
Sara S. Parker ◽  
Mackenzie R. Roman ◽  
Adam W. Watson ◽  
Kiarash Rahmani Eliato ◽  
...  
Keyword(s):  
Cell Migration ◽  
Actin Polymerization ◽  
Focal Adhesions ◽  
Mechanical Stimuli ◽  
Matrix Stiffness ◽  
Cellular Behavior ◽  
Cytoskeletal Remodeling ◽  
Cell Matrix ◽  
Directed Cell Migration ◽  
Cell Matrix Adhesion

The mechanical properties of a cell’s microenvironment influence many aspects of cellular behavior, including cell migration. Durotaxis, the migration toward increasing matrix stiffness, has been implicated in processes ranging from development to cancer. During durotaxis, mechanical stimulation by matrix rigidity leads to directed migration. Studies suggest that cells sense mechanical stimuli, or mechanosense, through the acto-myosin cytoskeleton at focal adhesions (FAs); however, FA actin cytoskeletal remodeling and its role in mechanosensing are not fully understood. Here, we show that the Ena/VASP family member, Ena/VASP-like (EVL), polymerizes actin at FAs, which promotes cell-matrix adhesion and mechanosensing. Importantly, we show that EVL regulates mechanically directed motility, and that suppression of EVL expression impedes 3D durotactic invasion. We propose a model in which EVL-mediated actin polymerization at FAs promotes mechanosensing and durotaxis by maturing, and thus reinforcing, FAs. These findings establish dynamic FA actin polymerization as a central aspect of mechanosensing and identify EVL as a crucial regulator of this process.

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