Faculty Opinions recommendation of Mechanosensing during directed cell migration requires dynamic actin polymerization at focal adhesions.

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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Faculty Opinions recommendation of Vinculin Force-Sensitive Dynamics at Focal Adhesions Enable Effective Directed Cell Migration.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.733028693.793546143 ◽

2018 ◽

Author(s):

Sanjay Kumar

Keyword(s):

Cell Migration ◽

Focal Adhesions ◽

Directed Cell Migration

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The Abl-related Gene Tyrosine Kinase Acts through p190RhoGAP to Inhibit Actomyosin Contractility and Regulate Focal Adhesion Dynamics upon Adhesion to Fibronectin

Molecular Biology of the Cell ◽

10.1091/mbc.e07-01-0075 ◽

2007 ◽

Vol 18 (10) ◽

pp. 3860-3872 ◽

Cited By ~ 55

Author(s):

Justin G. Peacock ◽

Ann L. Miller ◽

William D. Bradley ◽

Olga C. Rodriguez ◽

Donna J. Webb ◽

...

Keyword(s):

Cell Migration ◽

Focal Adhesion ◽

Actin Polymerization ◽

Focal Adhesions ◽

Fiber Formation ◽

Cell Periphery ◽

Related Gene ◽

Cell Contractility ◽

Fibroblast Migration ◽

Actomyosin Contractility

In migrating cells, actin polymerization promotes protrusion of the leading edge, whereas actomyosin contractility powers net cell body translocation. Although they promote F-actin–dependent protrusions of the cell periphery upon adhesion to fibronectin (FN), Abl family kinases inhibit cell migration on FN. We provide evidence here that the Abl-related gene (Arg/Abl2) kinase inhibits fibroblast migration by attenuating actomyosin contractility and regulating focal adhesion dynamics. arg−/− fibroblasts migrate at faster average speeds than wild-type (wt) cells, whereas Arg re-expression in these cells slows migration. Surprisingly, the faster migrating arg−/− fibroblasts have more prominent F-actin stress fibers and focal adhesions and exhibit increased actomyosin contractility relative to wt cells. Interestingly, Arg requires distinct functional domains to inhibit focal adhesions and actomyosin contractility. The kinase domain–containing Arg N-terminal half can act through the RhoA inhibitor p190RhoGAP to attenuate stress fiber formation and cell contractility. However, Arg requires both its kinase activity and its cytoskeleton-binding C-terminal half to fully inhibit focal adhesions. Although focal adhesions do not turn over efficiently in the trailing edge of arg−/− cells, the increased contractility of arg−/− cells tears the adhesions from the substrate, allowing for the faster migration observed in these cells. Together, our data strongly suggest that Arg inhibits cell migration by restricting actomyosin contractility and regulating its coupling to the substrate through focal adhesions.

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The PCH Family Member Proline-Serine-Threonine Phosphatase–interacting Protein 1 Targets to the Leukocyte Uropod and Regulates Directed Cell Migration

Molecular Biology of the Cell ◽

10.1091/mbc.e08-02-0225 ◽

2008 ◽

Vol 19 (8) ◽

pp. 3180-3191 ◽

Cited By ~ 20

Author(s):

Kate M. Cooper ◽

David A. Bennin ◽

Anna Huttenlocher

Keyword(s):

Cell Migration ◽

Family Member ◽

Actin Polymerization ◽

Stable Population ◽

Type I ◽

Microtubule Network ◽

Interacting Protein ◽

Directed Cell Migration ◽

Transferrin Uptake ◽

Dynamin 2

Pombe Cdc15 homology (PCH) family members have emerged as important regulators of membrane–cytoskeletal interactions. Here we show that PSTPIP1, a PCH family member expressed in hematopoietic cells, regulates the motility of neutrophil-like cells and is a novel component of the leukocyte uropod where it colocalizes with other uropod components, such as type I PIPKIγ. Furthermore, we show that PSTPIP1 association with the regulator of endocytosis, dynamin 2, and PSTPIP1 expression impairs transferrin uptake and endocytosis. We also show that PSTPIP1 localizes at the rear of neutrophils with a subpopulation of F-actin that is specifically detected by the binding of an F-actin probe that detects a more stable population of actin. Finally, we show that actin polymerization, but not the microtubule network, is necessary for the polarized distribution of PSTPIP1 toward the rear of the cell. Together, our findings demonstrate that PSTPIP1 is a novel component of the leukocyte uropod that regulates endocytosis and cell migration.

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Actin-dependent Lamellipodia Formation and Microtubule-dependent Tail Retraction Control-directed Cell Migration

Molecular Biology of the Cell ◽

10.1091/mbc.11.9.2999 ◽

2000 ◽

Vol 11 (9) ◽

pp. 2999-3012 ◽

Cited By ~ 141

Author(s):

Christoph Ballestrem ◽

Bernhard Wehrle-Haller ◽

Boris Hinz ◽

Beat A. Imhof

Keyword(s):

Cell Migration ◽

Cell Body ◽

Actin Polymerization ◽

Green Fluorescence Protein ◽

Time Lapse ◽

Dependent Manner ◽

Directed Cell Migration ◽

Cell Front ◽

Fluorescence Protein

Migrating cells are polarized with a protrusive lamella at the cell front followed by the main cell body and a retractable tail at the rear of the cell. The lamella terminates in ruffling lamellipodia that face the direction of migration. Although the role of actin in the formation of lamellipodia is well established, it remains unclear to what degree microtubules contribute to this process. Herein, we have studied the contribution of microtubules to cell motility by time-lapse video microscopy on green flourescence protein-actin- and tubulin-green fluorescence protein–transfected melanoma cells. Treatment of cells with either the microtubule-disrupting agent nocodazole or with the stabilizing agent taxol showed decreased ruffling and lamellipodium formation. However, this was not due to an intrinsic inability to form ruffles and lamellipodia because both were restored by stimulation of cells with phorbol 12-myristate 13-acetate in a Rac-dependent manner, and by stem cell factor in melanoblasts expressing the receptor tyrosine kinase c-kit. Although ruffling and lamellipodia were formed without microtubules, the microtubular network was needed for advancement of the cell body and the subsequent retraction of the tail. In conclusion, we demonstrate that the formation of lamellipodia can occur via actin polymerization independently of microtubules, but that microtubules are required for cell migration, tail retraction, and modulation of cell adhesion.

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The Activity of Kv 11.1 Potassium Channel Modulates F-Actin Organization During Cell Migration of Pancreatic Ductal Adenocarcinoma Cells

Cancers ◽

10.3390/cancers11020135 ◽

2019 ◽

Vol 11 (2) ◽

pp. 135 ◽

Cited By ~ 6

Author(s):

Sagar Manoli ◽

Stefano Coppola ◽

Claudia Duranti ◽

Matteo Lulli ◽

Lara Magni ◽

...

Keyword(s):

Cell Migration ◽

Potassium Channel ◽

Pancreatic Ductal Adenocarcinoma ◽

Actin Polymerization ◽

Focal Adhesions ◽

Stress Fibers ◽

Pancreatic Stellate Cells ◽

Ductal Adenocarcinoma ◽

Actin Organization ◽

Cells Cultured

Cell migration exerts a pivotal role in tumor progression, underlying cell invasion and metastatic spread. The cell migratory program requires f-actin re-organization, generally coordinated with the assembly of focal adhesions. Ion channels are emerging actors in regulating cell migration, through different mechanisms. We studied the role of the voltage dependent potassium channel KV 11.1 on cell migration of pancreatic ductal adenocarcinoma (PDAC) cells, focusing on its effects on f-actin organization and dynamics. Cells were cultured either on fibronectin (FN) or on a desmoplastic matrix (DM) with the addition of a conditioned medium produced by pancreatic stellate cells (PSC) maintained in hypoxia (Hypo-PSC-CM), to better mimic the PDAC microenvironment. KV11.1 was essential to maintain stress fibers in a less organized arrangement in cells cultured on FN. When PDAC cells were cultured on DM plus Hypo-PSC-CM, KV11.1 activity determined the organization of cortical f-actin into sparse and long filopodia, and allowed f-actin polymerization at a high speed. In both conditions, blocking KV11.1 impaired PDAC cell migration, and, on cells cultured onto FN, the effect was accompanied by a decrease of basal intracellular Ca2+ concentration. We conclude that KV11.1 is implicated in sustaining pro-metastatic signals in pancreatic cancer, through a reorganization of f-actin in stress fibers and a modulation of filopodia formation and dynamics.

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Faculty Opinions recommendation of Vinculin Force-Sensitive Dynamics at Focal Adhesions Enable Effective Directed Cell Migration.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.733028693.793550387 ◽

2018 ◽

Author(s):

Tanmay Lele ◽

Srujana Neelam

Keyword(s):

Cell Migration ◽

Focal Adhesions ◽

Directed Cell Migration

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Distinct phospho-forms of cortactin differentially regulate actin polymerization and focal adhesions

AJP Cell Physiology ◽

10.1152/ajpcell.00238.2008 ◽

2008 ◽

Vol 295 (5) ◽

pp. C1113-C1122 ◽

Cited By ~ 37

Author(s):

Anne E. Kruchten ◽

Eugene W. Krueger ◽

Yu Wang ◽

Mark A. McNiven

Keyword(s):

Cell Migration ◽

Focal Adhesion ◽

Actin Polymerization ◽

Control Cell ◽

Focal Adhesions ◽

Serine Phosphorylation ◽

Actin Binding ◽

Actin Assembly

Cortactin is an actin-binding protein that is overexpressed in many cancers and is a substrate for both tyrosine and serine/threonine kinases. Tyrosine phosphorylation of cortactin has been observed to increase cell motility and invasion in vivo, although it has been reported to have both positive and negative effects on actin polymerization in vitro. In contrast, serine phosphorylation of cortactin has been shown to stimulate actin assembly in vitro. Currently, the effects of cortactin serine phosphorylation on cell migration are unclear, and furthermore, how the distinct phospho-forms of cortactin may differentially contribute to cell migration has not been directly compared. Therefore, we tested the effects of different tyrosine and serine phospho-mutants of cortactin on lamellipodial protrusion, actin assembly within cells, and focal adhesion dynamics. Interestingly, while expression of either tyrosine or serine phospho-mimetic cortactin mutants resulted in increased lamellipodial protrusion and cell migration, these effects appeared to be via distinct processes. Cortactin mutants mimicking serine phosphorylation appeared to predominantly affect actin polymerization, whereas mutation of cortactin tyrosine residues resulted in alterations in focal adhesion turnover. Thus these findings provide novel insights into how distinct phospho-forms of cortactin may differentially contribute to actin and focal adhesion dynamics to control cell migration.

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Adenomatous polyposis coli nucleates actin assembly to drive cell migration and microtubule-induced focal adhesion turnover

The Journal of Cell Biology ◽

10.1083/jcb.201702007 ◽

2017 ◽

Vol 216 (9) ◽

pp. 2859-2875 ◽

Cited By ~ 34

Author(s):

M. Angeles Juanes ◽

Habib Bouguenina ◽

Julian A. Eskin ◽

Richa Jaiswal ◽

Ali Badache ◽

...

Keyword(s):

Cell Migration ◽

Adenomatous Polyposis Coli ◽

Focal Adhesions ◽

Adenomatous Polyposis ◽

Actin Assembly ◽

Polyposis Coli ◽

Directed Cell Migration ◽

Direct Cell ◽

Mitochondrial Distribution

Cell motility depends on tight coordination between the microtubule (MT) and actin cytoskeletons, but the mechanisms underlying this MT–actin cross talk have remained poorly understood. Here, we show that the tumor suppressor protein adenomatous polyposis coli (APC), which is a known MT-associated protein, directly nucleates actin assembly to promote directed cell migration. By changing only two residues in APC, we generated a separation-of-function mutant, APC (m4), that abolishes actin nucleation activity without affecting MT interactions. Expression of full-length APC carrying the m4 mutation (APC (m4)) rescued cellular defects in MT organization, MT dynamics, and mitochondrial distribution caused by depletion of endogenous APC but failed to restore cell migration. Wild-type APC and APC (m4) localized to focal adhesions (FAs), and APC (m4) was defective in promoting actin assembly at FAs to facilitate MT-induced FA turnover. These results provide the first direct evidence for APC-mediated actin assembly in vivo and establish a role for APC in coordinating MTs and actin at FAs to direct cell migration.

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