α-Tubulin K40 acetylation is required for contact inhibition of proliferation and cell–substrate adhesion

Acetylation of α-tubulin on lysine 40 marks long-lived microtubules in structures such as axons and cilia, and yet the physiological role of α-tubulin K40 acetylation is elusive. Although genetic ablation of the α-tubulin K40 acetyltransferase αTat1 in mice did not lead to detectable phenotypes in the developing animals, contact inhibition of proliferation and cell–substrate adhesion were significantly compromised in cultured αTat1−/− fibroblasts. First, αTat1−/− fibroblasts kept proliferating beyond the confluent monolayer stage. Congruently, αTat1−/− cells failed to activate Hippo signaling in response to increased cell density, and the microtubule association of the Hippo regulator Merlin was disrupted. Second, αTat1−/− cells contained very few focal adhesions, and their ability to adhere to growth surfaces was greatly impaired. Whereas the catalytic activity of αTAT1 was dispensable for monolayer formation, it was necessary for cell adhesion and restrained cell proliferation and activation of the Hippo pathway at elevated cell density. Because α-tubulin K40 acetylation is largely eliminated by deletion of αTAT1, we propose that acetylated microtubules regulate contact inhibition of proliferation through the Hippo pathway.

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Supervillin modulation of focal adhesions involving TRIP6/ZRP-1

The Journal of Cell Biology ◽

10.1083/jcb.200512051 ◽

2006 ◽

Vol 174 (3) ◽

pp. 447-458 ◽

Cited By ~ 36

Author(s):

Norio Takizawa ◽

Tara C. Smith ◽

Thomas Nebl ◽

Jessica L. Crowley ◽

Stephen J. Palmieri ◽

...

Keyword(s):

Focal Adhesions ◽

Stress Fibers ◽

Regulatory Sequence ◽

Interacting Protein ◽

Substrate Adhesion ◽

Lim Domains ◽

Cell Substrate ◽

Thyroid Receptor ◽

And Function ◽

Cell Substrate Adhesion

Cell–substrate contacts, called focal adhesions (FAs), are dynamic in rapidly moving cells. We show that supervillin (SV)—a peripheral membrane protein that binds myosin II and F-actin in such cells—negatively regulates stress fibers, FAs, and cell–substrate adhesion. The major FA regulatory sequence within SV (SV342-571) binds to the LIM domains of two proteins in the zyxin family, thyroid receptor–interacting protein 6 (TRIP6) and lipoma-preferred partner (LPP), but not to zyxin itself. SV and TRIP6 colocalize within large FAs, where TRIP6 may help recruit SV. RNAi-mediated decreases in either protein increase cell adhesion to fibronectin. TRIP6 partially rescues SV effects on stress fibers and FAs, apparently by mislocating SV away from FAs. Thus, SV interactions with TRIP6 at FAs promote loss of FA structure and function. SV and TRIP6 binding partners suggest several specific mechanisms through which the SV–TRIP6 interaction may regulate FA maturation and/or disassembly.

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Contact inhibition of locomotion and mechanical cross-talk between cell–cell and cell–substrate adhesion determine the pattern of junctional tension in epithelial cell aggregates

Molecular Biology of the Cell ◽

10.1091/mbc.e16-04-0226 ◽

2016 ◽

Vol 27 (22) ◽

pp. 3436-3448 ◽

Cited By ~ 17

Author(s):

Luke Coburn ◽

Hender Lopez ◽

Benjamin J. Caldwell ◽

Elliott Moussa ◽

Chloe Yap ◽

...

Keyword(s):

Epithelial Cell ◽

Cross Talk ◽

Contact Inhibition ◽

Cell Junctions ◽

Asymmetric Distribution ◽

Cell Aggregates ◽

Substrate Adhesion ◽

Cell Substrate ◽

Cell Substrate Adhesion ◽

Cell Cell

We used a computational approach to analyze the biomechanics of epithelial cell aggregates—islands, stripes, or entire monolayers—that combines both vertex and contact-inhibition-of-locomotion models to include cell–cell and cell–substrate adhesion. Examination of the distribution of cell protrusions (adhesion to the substrate) in the model predicted high-order profiles of cell organization that agree with those previously seen experimentally. Cells acquired an asymmetric distribution of basal protrusions, traction forces, and apical aspect ratios that decreased when moving from the edge to the island center. Our in silico analysis also showed that tension on cell–cell junctions and apical stress is not homogeneous across the island. Instead, these parameters are higher at the island center and scale up with island size, which we confirmed experimentally using laser ablation assays and immunofluorescence. Without formally being a three-dimensional model, our approach has the minimal elements necessary to reproduce the distribution of cellular forces and mechanical cross-talk, as well as the distribution of principal stress in cells within epithelial cell aggregates. By making experimentally testable predictions, our approach can aid in mechanical analysis of epithelial tissues, especially when local changes in cell–cell and/or cell–substrate adhesion drive collective cell behavior.

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Cell contact and Nf2/Merlin-dependent regulation of TEAD palmitoylation and activity

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1819400116 ◽

2019 ◽

Vol 116 (20) ◽

pp. 9877-9882 ◽

Cited By ~ 18

Author(s):

Nam-Gyun Kim ◽

Barry M. Gumbiner

Keyword(s):

Cell Density ◽

Ubiquitin Ligase ◽

Fatty Acid Synthase ◽

De Novo ◽

Hippo Pathway ◽

E3 Ubiquitin Ligase ◽

Cell Contact ◽

Dependent Manner ◽

Inhibition Of Proliferation ◽

The Hippo Pathway

The Hippo pathway is involved in regulating contact inhibition of proliferation and organ size control and responds to various physical and biochemical stimuli. It is a kinase cascade that negatively regulates the activity of cotranscription factors YAP and TAZ, which interact with DNA binding transcription factors including TEAD and activate the expression of target genes. In this study, we show that the palmitoylation of TEAD, which controls the activity and stability of TEAD proteins, is actively regulated by cell density independent of Lats, the key kinase of the Hippo pathway. The expression of fatty acid synthase and acetyl-CoA carboxylase involved in de novo biosynthesis of palmitate is reduced by cell density in an Nf2/Merlin-dependent manner. Depalmitoylation of TEAD is mediated by depalmitoylases including APT2 and ABHD17A. Palmitoylation-deficient TEAD4 mutant is unstable and degraded by proteasome through the activity of the E3 ubiquitin ligase CHIP. These findings show that TEAD activity is tightly controlled through the regulation of palmitoylation and stability via the orchestration of FASN, depalmitoylases, and E3 ubiquitin ligase in response to cell contact.

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Myoferlin depletion elevates focal adhesion kinase and paxillin phosphorylation and enhances cell-matrix adhesion in breast cancer cells

AJP Cell Physiology ◽

10.1152/ajpcell.00276.2014 ◽

2015 ◽

Vol 308 (8) ◽

pp. C642-C649 ◽

Cited By ~ 11

Author(s):

B. N. Blackstone ◽

R. Li ◽

W. E. Ackerman ◽

S. N. Ghadiali ◽

H. M. Powell ◽

...

Keyword(s):

Breast Cancer ◽

Focal Adhesion Kinase ◽

Cancer Cells ◽

Breast Cancer Cell ◽

Focal Adhesion ◽

Breast Cancer Cells ◽

Focal Adhesions ◽

Substrate Adhesion ◽

Cell Substrate ◽

Cell Substrate Adhesion

Breast cancer is the second leading cause of malignant death among women. A crucial feature of metastatic cancers is their propensity to lose adhesion to the underlying basement membrane as they transition to a motile phenotype and invade surrounding tissue. Attachment to the extracellular matrix is mediated by a complex of adhesion proteins, including integrins, signaling molecules, actin and actin-binding proteins, and scaffolding proteins. Focal adhesion kinase (FAK) is pivotal for the organization of focal contacts and maturation into focal adhesions, and disruption of this process is a hallmark of early cancer invasive potential. Our recent work has revealed that myoferlin (MYOF) mediates breast tumor cell motility and invasive phenotype. In this study we demonstrate that noninvasive breast cancer cell lines exhibit increased cell-substrate adhesion and that silencing of MYOF using RNAi in the highly invasive human breast cancer cell line MDA-MB-231 also enhances cell-substrate adhesion. In addition, we detected elevated tyrosine phosphorylation of FAK (FAKY397) and paxillin (PAXY118), markers of focal adhesion protein activation. Morphometric analysis of PAX expression revealed that RNAi-mediated depletion of MYOF resulted in larger, more elongated focal adhesions, in contrast to cells transduced with a control virus (MDA-231LVC cells), which exhibited smaller focal contacts. Finally, MYOF silencing in MDA-MB-231 cells exhibited a more elaborate ventral cytoskeletal structure near focal adhesions, typified by pronounced actin stress fibers. These data support the hypothesis that MYOF regulates cell adhesions and cell-substrate adhesion strength and may account for the high degree of motility in invasive breast cancer cells.

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A New Member of the Rho Family, Rnd1, Promotes Disassembly of Actin Filament Structures and Loss of Cell Adhesion

The Journal of Cell Biology ◽

10.1083/jcb.141.1.187 ◽

1998 ◽

Vol 141 (1) ◽

pp. 187-197 ◽

Cited By ~ 246

Author(s):

Catherine D. Nobes ◽

Inger Lauritzen ◽

Marie-Geneviève Mattei ◽

Sonia Paris ◽

Alan Hall ◽

...

Keyword(s):

Cell Adhesion ◽

Actin Cytoskeleton ◽

Rho Gtpase ◽

Focal Adhesions ◽

Substrate Adhesion ◽

Cell Substrate ◽

Rho Family ◽

Cell Substrate Adhesion ◽

Distinct Branch

Members of the Rho GTPase family regulate the organization of the actin cytoskeleton in response to extracellular growth factors. We have identified three proteins that form a distinct branch of the Rho family: Rnd1, expressed mostly in brain and liver; Rnd2, highly expressed in testis; and Rnd3/RhoE, showing a ubiquitous low expression. At the subcellular level, Rnd1 is concentrated at adherens junctions both in confluent fibroblasts and in epithelial cells. Rnd1 has a low affinity for GDP and spontaneously exchanges nucleotide rapidly in a physiological buffer. Furthermore, Rnd1 lacks intrinsic GTPase activity suggesting that in vivo, it might be constitutively in a GTP-bound form. Expression of Rnd1 or Rnd3/RhoE in fibroblasts inhibits the formation of actin stress fibers, membrane ruffles, and integrin-based focal adhesions and induces loss of cell–substrate adhesion leading to cell rounding (hence Rnd for “round”). We suggest that these proteins control rearrangements of the actin cytoskeleton and changes in cell adhesion.

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A Stochastic Modelling Framework for Single Cell Migration: Coupling Contractility and Focal Adhesions

Symmetry ◽

10.3390/sym12081348 ◽

2020 ◽

Vol 12 (8) ◽

pp. 1348

Author(s):

Aydar Uatay

Keyword(s):

Cell Migration ◽

Cell Motility ◽

Focal Adhesions ◽

Stochastic Modelling ◽

Modelling Framework ◽

Substrate Adhesion ◽

Actomyosin Contractility ◽

Motile Cells ◽

Cell Substrate ◽

Cell Substrate Adhesion

The interaction of the actin cytoskeleton with cell–substrate adhesions is necessary for cell migration. While the trajectories of motile cells have a stochastic character, investigations of cell motility mechanisms rarely elaborate on the origins of the observed randomness. Here, guided by a few fundamental attributes of cell motility, I construct a minimal stochastic cell migration model from ground-up. The resulting model couples a deterministic actomyosin contractility mechanism with stochastic cell–substrate adhesion kinetics, and yields a well-defined piecewise deterministic process. Numerical simulations reproduce several experimentally observed results, including anomalous diffusion, tactic migration and contact guidance. This work provides a basis for the development of cell–cell collision and population migration models.

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Cadherin-11 localizes to focal adhesions and promotes cell–substrate adhesion

Nature Communications ◽

10.1038/ncomms10909 ◽

2016 ◽

Vol 7 (1) ◽

Cited By ~ 45

Author(s):

Rahul P. Langhe ◽

Tetyana Gudzenko ◽

Michael Bachmann ◽

Sarah F. Becker ◽

Carina Gonnermann ◽

...

Keyword(s):

Focal Adhesions ◽

Substrate Adhesion ◽

Cell Substrate ◽

Cell Substrate Adhesion

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Evidence of signaling and adhesion roles for β-catenin in the sponge Ephydatia muelleri

10.1101/164012 ◽

2017 ◽

Cited By ~ 2

Author(s):

Klaske J. Schippers ◽

Scott A. Nichols

Keyword(s):

Cell Adhesion ◽

Wnt Pathway ◽

Focal Adhesions ◽

Fundamental Difference ◽

Limited Data ◽

Adhesion Properties ◽

Substrate Adhesion ◽

Cell Substrate ◽

Cell Substrate Adhesion ◽

Ephydatia Muelleri

ABSTRACTβ-catenin acts as a transcriptional co-activator in the Wnt/β-catenin signaling pathway and a cytoplasmic effector in cadherin-based cell adhesion. These functions are ancient within animals, but the earliest steps in β-catenin evolution remain unresolved due to limited data from key lineages – sponges, ctenophores and placozoans. Previous studies in sponges have characterized β-catenin expression dynamics and used GSK3B antagonists to ectopically activate the Wnt/β-catenin pathway; both approaches rely upon untested assumptions about the conservation of β-catenin function and regulation in sponges. Here, we test these assumptions using an antibody raised against β-catenin from the sponge Ephydatia muelleri. We find that cadherin-complex genes co-precipitate with endogenous Em β-catenin from cell lysates, but that Wnt pathway components do not. However, through immunostaining we detect both cell boundary and nuclear populations, and we find evidence that Em β-catenin is a conserved substrate of GSK3B. Collectively, these data support conserved roles for Em β-catenin in both cell adhesion and Wnt signaling. Additionally, we find evidence for an Em β-catenin population associated with the distal ends of F-actin stress fibers in apparent cell-substrate adhesion structures that resemble focal adhesions. This finding suggests a fundamental difference in the adhesion properties of sponge tissues relative to other animals, in which the adhesion functions of β-catenin are typically restricted to cell-cell adhesions.

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