scholarly journals Type I Phosphatidylinositol Phosphate Kinase Beta Regulates Focal Adhesion Disassembly by Promoting β1 Integrin Endocytosis

2010 ◽  
Vol 30 (18) ◽  
pp. 4463-4479 ◽  
Author(s):  
Wei-Ting Chao ◽  
Felicity Ashcroft ◽  
Alexes C. Daquinag ◽  
Tegy Vadakkan ◽  
Zhubo Wei ◽  
...  
Keyword(s):  
Cell Migration ◽  
Focal Adhesion ◽  
Focal Adhesions ◽  
Type I ◽  
Adhesion Sites ◽  
Phosphatidylinositol Phosphate ◽  
Β1 Integrins ◽  
Focal Adhesion Turnover ◽  
Dynamin 2 ◽  
Phosphatidylinositol Phosphate Kinase

ABSTRACT Cell migration requires the regulated disassembly of focal adhesions, but the underlying mechanisms remain poorly defined. We have previously shown that focal adhesion disassembly requires the dynamin 2- and clathrin-dependent endocytosis of ligand-activated β1 integrins. Here, we identify type I phosphatidylinositol phosphate kinase beta (PIPKIβ), an enzyme that generates phosphatidylinositol-4,5-bisphosphate (PI4,5P2), as a key regulator of this process. We found that knockdown of PIPKIβ by RNA interference blocks the internalization of active β1 integrins and impairs focal adhesion turnover and cell migration. These defects are caused by the failure to target the endocytic machinery, including clathrin adaptors and dynamin 2, to focal adhesion sites. As a consequence, depletion of PIPKIβ blocks clathrin assembly at adhesion plaques and prevents complex formation between dynamin 2 and focal adhesion kinase (FAK), a critical step in focal adhesion turnover. Together, our findings identify PIPKIβ as a novel regulator of focal adhesion disassembly and suggest that PIPKIβ spatially regulates integrin endocytosis at adhesion sites to control cell migration.

scholarly journals Interaction of Paxillin with Poly(A)-Binding Protein 1 and Its Role in Focal Adhesion Turnover and Cell Migration

2005 ◽  
Vol 25 (9) ◽  
pp. 3763-3773 ◽  
Author(s):  
Alison J. Woods ◽  
Theodoros Kantidakis ◽  
Hisataka Sabe ◽  
David R. Critchley ◽  
Jim C. Norman
Keyword(s):  
Cell Migration ◽  
Rna Interference ◽  
Focal Adhesion ◽  
Nuclear Export ◽  
Binding Protein ◽  
Focal Adhesions ◽  
Nuclear Accumulation ◽  
Two Dimensional ◽  
Nucleocytoplasmic Shuttling ◽  
Focal Adhesion Turnover

ABSTRACT We have previously identified poly(A)-binding protein 1 (PABP1) as a ligand for paxillin and shown that the paxillin-PABP1 complex undergoes nucleocytoplasmic shuttling. By targeting the paxillin-binding subdomain sequences in PABP1, we have generated mutants of PABP1 that do not bind to cellular paxillin. Here we report that paxillin association is necessary for efficient nuclear export of PABP1 and that RNA interference of paxillin drives the nuclear accumulation of PABP1. Furthermore, ablation of paxillin-PABP1 association impeded a number of indices of cell motility including spreading on fibronectin, cell migration on two-dimensional matrices, and transmigration in Boyden chambers. These data indicate that PABP1 must associate with paxillin in order to be efficiently transported from the nucleus to the cytoplasm and that this event is necessary for cells to remodel their focal adhesions during cell migration.

scholarly journals Microtubule acetylation but not detyrosination promotes focal adhesion dynamics and cell migration

2018 ◽  
Author(s):  
Bertille Bance ◽  
Shailaja Seetharaman ◽  
Cécile Leduc ◽  
Batiste Boëda ◽  
Sandrine Etienne-Manneville
Keyword(s):  
Cell Migration ◽  
Focal Adhesion ◽  
Focal Adhesions ◽  
Cell Polarization ◽  
Post Translational Modifications ◽  
Tubulin Acetylation ◽  
Focal Adhesion Turnover ◽  
Regulatory Functions ◽  
Insight Into

AbstractMicrotubules play a crucial role in mesenchymal migration by controlling cell polarity and the turnover of cell adhesive structures on the extracellular matrix. The polarized functions of microtubules imply that microtubules are locally regulated. Here, we investigated the regulation and role of two major tubulin post-translational modifications, acetylation and detyrosination, which have been associated with stable microtubules. Using primary astrocytes in a wound healing assay, we show that these tubulin modifications are independently regulated during cell polarization and differently affect cell migration. In contrast to microtubule detyrosination, αTAT1-mediated microtubule acetylation increases in the vicinity of focal adhesions and promotes cell migration. We further demonstrate that αTAT1 increases focal adhesion turnover by promoting Rab6-positive vesicle fusion at focal adhesions. Our results highlight the specificity of microtubule post-translational modifications and bring new insight into the regulatory functions of tubulin acetylation.

scholarly journals Extracellular matrix-specific focal adhesions in vascular smooth muscle produce mechanically active adhesion sites

2008 ◽  
Vol 295 (1) ◽  
pp. C268-C278 ◽  
Author(s):  
Zhe Sun ◽  
Luis A. Martinez-Lemus ◽  
Michael A. Hill ◽  
Gerald A. Meininger
Keyword(s):  
Extracellular Matrix ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Focal Adhesion ◽  
Focal Adhesions ◽  
Mechanical Activity ◽  
Tissue Blood Flow ◽  
Cell Contact ◽  
Type I ◽  
Adhesion Sites

Integrin-mediated mechanotransduction in vascular smooth muscle cells (VSMCs) plays an important role in the physiological control of tissue blood flow and vascular resistance. To test whether force applied to specific extracellular matrix (ECM)-integrin interactions could induce myogenic-like mechanical activity at focal adhesion sites, we used atomic force microscopy (AFM) to apply controlled forces to specific ECM adhesion sites on arteriolar VSMCs. The tip of AFM probes were fused with a borosilicate bead (2∼5 μm) coated with fibronectin (FN), collagen type I (CNI), laminin (LN), or vitronectin (VN). ECM-coated beads induced clustering of α5- and β3-integrins and actin filaments at sites of bead-cell contact indicative of focal adhesion formation. Step increases of an upward ( z-axis) pulling force (800∼1,600 pN) applied to the bead-cell contact site for FN-specific focal adhesions induced a myogenic-like, force-generating response from the VSMC, resulting in a counteracting downward pull by the cell. This micromechanical event was blocked by cytochalasin D but was enhanced by jasplakinolide. Function-blocking antibodies to α5β1- and αvβ3-integrins also blocked the micromechanical cell event in a concentration-dependent manner. Similar pulling experiments with CNI, VN, or LN failed to induce myogenic-like micromechanical events. Collectively, these results demonstrate that mechanical force applied to integrin-FN adhesion sites induces an actin-dependent, myogenic-like, micromechanical event. Focal adhesions formed by different ECM proteins exhibit different mechanical characteristics, and FN appears of particular relevance in its ability to strongly attach to VSMCs and to induce myogenic-like, force-generating reactions from sites of focal adhesion in response to externally applied forces.

scholarly journals FAK phosphorylation at Tyr-925 regulates cross-talk between focal adhesion turnover and cell protrusion

2011 ◽  
Vol 22 (7) ◽  
pp. 964-975 ◽  
Author(s):  
Therese B. Deramaudt ◽  
Denis Dujardin ◽  
Abdelkader Hamadi ◽  
Fanny Noulet ◽  
Kaouther Kolli ◽  
...  
Keyword(s):  
Cell Migration ◽  
Focal Adhesion ◽  
Focal Adhesions ◽  
Embryonic Fibroblasts ◽  
Tyrosine Residues ◽  
Cell Protrusion ◽  
Complex Process ◽  
Cell Front ◽  
Focal Adhesion Turnover

 Cell migration is a highly complex process that requires the coordinated formation of membrane protrusion and focal adhesions (FAs). Focal adhesion kinase (FAK), a major signaling component of FAs, is involved in the disassembly process of FAs through phosphorylation and dephosphorylation of its tyrosine residues, but the role of such phosphorylations in nascent FA formation and turnover near the cell front and in cell protrusion is less well understood. In the present study, we demonstrate that, depending on the phosphorylation status of Tyr-925 residue, FAK modulates cell migration via two specific mechanisms. FAK−/− mouse embryonic fibroblasts (MEFs) expressing nonphosphorylatable Y925F-FAK show increased interactions between FAK and unphosphorylated paxillin, which lead to FA stabilization and thus decreased FA turnover and reduced cell migration. Conversely, MEFs expressing phosphomimetic Y925E-FAK display unchanged FA disassembly rates, show increase in phosphorylated paxillin in FAs, and exhibit increased formation of nascent FAs at the cell leading edges. Moreover, Y925E-FAK cells present enhanced cell protrusion together with activation of the p130CAS/Dock180/Rac1 signaling pathway. Together, our results demonstrate that phosphorylation of FAK at Tyr-925 is required for FAK-mediated cell migration and cell protrusion.

scholarly journals Focal adhesion kinase suppresses Rho activity to promote focal adhesion turnover

2000 ◽  
Vol 113 (20) ◽  
pp. 3673-3678 ◽  
Author(s):  
X.D. Ren ◽  
W.B. Kiosses ◽  
D.J. Sieg ◽  
C.A. Otey ◽  
D.D. Schlaepfer ◽  
...  
Keyword(s):  
Cell Migration ◽  
Cell Adhesion ◽  
Focal Adhesion Kinase ◽  
Focal Adhesion ◽  
Focal Adhesions ◽  
Small Gtpase ◽  
Embryonic Lethality ◽  
Extracellular Matrices ◽  
Constitutive Activation ◽  
Focal Adhesion Turnover

Focal adhesion kinase (FAK) is activated and localized at focal adhesions upon cell adhesion to extracellular matrices. Cells lacking FAK show increased focal adhesion number and decreased cell migration, functions that are regulated by the small GTPase Rho. We now report that fibroblasts from FAK-/- mice failed to transiently inhibit Rho activity when plated on fibronectin. Re-expression of FAK restored normal Rho regulation. Turnover of focal adhesions correlated inversely with Rho activity. The presence or absence of FAK was mimicked by inhibiting or activating Rho, respectively. These data suggest that loss of FAK resulting in constitutive activation of Rho and inhibition of focal adhesion turnover can account for deficiencies in cell migration and embryonic lethality of the FAK knockout.

scholarly journals A direct interaction between the large GTPase dynamin-2 and FAK regulates focal adhesion dynamics in response to active Src

2011 ◽  
Vol 22 (9) ◽  
pp. 1529-1538 ◽  
Author(s):  
Yu Wang ◽  
Hong Cao ◽  
Jing Chen ◽  
Mark A. McNiven
Keyword(s):  
Cell Migration ◽  
Focal Adhesion ◽  
Focal Adhesions ◽  
Direct Interaction ◽  
Dependent Manner ◽  
Tumor Cell Migration ◽  
Src Signaling ◽  
Trimeric Complex ◽  
Downstream Effector ◽  
Dynamin 2

Tumor cell migration is supported in part by the cyclic formation and disassembly of focal adhesions (FAs); however, the mechanisms that regulate this process are not fully defined. The large guanosine 5′-triphosphatase dynamin (Dyn) plays an important role in FA dynamics and is activated by tyrosine phosphorylation. Using a novel antibody specific to phospho-dynamin (pDyn–Tyr-231), we found that Dyn2 is phosphorylated at FAs by Src kinase and is recruited to FAs by a direct interaction with the 4.1/ezrin/radizin/moesin domain of focal adhesion kinase (FAK), which functions as an adaptor between Src and Dyn2 to facilitate Dyn2 phosphorylation. This Src–FAK–Dyn2 trimeric complex is essential for FA turnover, as mutants disrupting the formation of this complex inhibit FA disassembly. Importantly, phosphoactivated Dyn2 promotes FA turnover by mediating the endocytosis of integrins in a clathrin-dependent manner. This study defines a novel mechanism of how Dyn2 functions as a downstream effector of FAK–Src signaling in turning over FAs.

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