scholarly journals Phosphorylation of actopaxin regulates cell spreading and migration

2004 ◽  
Vol 166 (6) ◽  
pp. 901-912 ◽  
Author(s):  
Dominic M. Clarke ◽  
Michael C. Brown ◽  
David P. LaLonde ◽  
Christopher E. Turner

Actopaxin is an actin and paxillin binding protein that localizes to focal adhesions. It regulates cell spreading and is phosphorylated during mitosis. Herein, we identify a role for actopaxin phosphorylation in cell spreading and migration. Stable clones of U2OS cells expressing actopaxin wild-type (WT), nonphosphorylatable, and phosphomimetic mutants were developed to evaluate actopaxin function. All proteins targeted to focal adhesions, however the nonphosphorylatable mutant inhibited spreading whereas the phosphomimetic mutant cells spread more efficiently than WT cells. Endogenous and WT actopaxin, but not the nonphosphorylatable mutant, were phosphorylated in vivo during cell adhesion/spreading. Expression of the nonphosphorylatable actopaxin mutant significantly reduced cell migration, whereas expression of the phosphomimetic increased cell migration in scrape wound and Boyden chamber migration assays. In vitro kinase assays demonstrate that extracellular signal-regulated protein kinase phosphorylates actopaxin, and treatment of U2OS cells with the MEK1 inhibitor UO126 inhibited adhesion-induced phosphorylation of actopaxin and also inhibited cell migration.

2010 ◽  
Vol 21 (2) ◽  
pp. 369-376 ◽  
Author(s):  
Vicente A. Torres ◽  
Ainhoa Mielgo ◽  
Simone Barbero ◽  
Ruth Hsiao ◽  
John A. Wilkins ◽  
...  

Caspase-8 is a key apical sensory protein that governs cell responses to environmental cues, alternatively promoting apoptosis, proliferation, and cell migration. The proteins responsible for integration of these pathways, however, have remained elusive. Here, we reveal that Rab5 regulates caspase-8–dependent signaling from integrins. Integrin ligation leads to Rab5 activation, association with integrins, and activation of Rac, in a caspase-8–dependent manner. Rab5 activation promotes colocalization and coprecipitation of integrins with caspase-8, concomitant with Rab5 recruitment to integrin-rich regions such as focal adhesions and membrane ruffles. Moreover, caspase-8 expression promotes Rab5-mediated internalization and the recycling of β1 integrins, increasing cell migration independently of caspase catalytic activity. Conversely, Rab5 knockdown prevented caspase-8–mediated integrin signaling for Rac activation, cell migration, and apoptotic signaling, respectively. Similarly, Rab5 was critical for caspase-8–driven cell migration in vivo, because knockdown of Rab5 compromised the ability of caspase-8 to promote metastasis under nonapoptotic conditions. These studies identify Rab5 as a key integrator of caspase-8–mediated signal transduction downstream of integrins, regulating cell survival and migration in vivo and in vitro.


2018 ◽  
Vol 115 (34) ◽  
pp. 8581-8586 ◽  
Author(s):  
Pengbo Wang ◽  
Marcel Dreger ◽  
Elena Madrazo ◽  
Craig J. Williams ◽  
Rafael Samaniego ◽  
...  

Cell migration through extracellular matrices requires nuclear deformation, which depends on nuclear stiffness. In turn, chromatin structure contributes to nuclear stiffness, but the mechanosensing pathways regulating chromatin during cell migration remain unclear. Here, we demonstrate that WD repeat domain 5 (WDR5), an essential component of H3K4 methyltransferase complexes, regulates cell polarity, nuclear deformability, and migration of lymphocytes in vitro and in vivo, independent of transcriptional activity, suggesting nongenomic functions for WDR5. Similarly, depletion of RbBP5 (another H3K4 methyltransferase subunit) promotes similar defects. We reveal that a 3D environment increases the H3K4 methylation dependent on WDR5 and results in a globally less compacted chromatin conformation. Further, using atomic force microscopy, nuclear particle tracking, and nuclear swelling experiments, we detect changes in nuclear mechanics that accompany the epigenetic changes induced in 3D conditions. Indeed, nuclei from cells in 3D environments were softer, and thereby more deformable, compared with cells in suspension or cultured in 2D conditions, again dependent on WDR5. Dissecting the underlying mechanism, we determined that actomyosin contractility, through the phosphorylation of myosin by MLCK (myosin light chain kinase), controls the interaction of WDR5 with other components of the methyltransferase complex, which in turn up-regulates H3K4 methylation activation in 3D conditions. Taken together, our findings reveal a nongenomic function for WDR5 in regulating H3K4 methylation induced by 3D environments, physical properties of the nucleus, cell polarity, and cell migratory capacity.


Author(s):  
Willow Hight-Warburton ◽  
Robert Felix ◽  
Andrew Burton ◽  
Hannah Maple ◽  
Magda S. Chegkazi ◽  
...  

Adhesion of basal keratinocytes to the underlying extracellular matrix (ECM) plays a key role in the control of skin homeostasis and response to injury. Integrin receptors indirectly link the ECM to the cell cytoskeleton through large protein complexes called focal adhesions (FA). FA also function as intracellular biochemical signaling platforms to enable cells to respond to changing extracellular cues. The α4β1 and α9β1 integrins are both expressed in basal keratinocytes, share some common ECM ligands, and have been shown to promote wound healing in vitro and in vivo. However, their roles in maintaining epidermal homeostasis and relative contributions to pathological processes in the skin remain unclear. We found that α4β1 and α9β1 occupied distinct regions in monolayers of a basal keratinocyte cell line (NEB-1). During collective cell migration (CCM), α4 and α9 integrins co-localized along the leading edge. Pharmacological inhibition of α4β1 and α9β1 integrins increased keratinocyte proliferation and induced a dramatic change in cytoskeletal remodeling and FA rearrangement, detrimentally affecting CCM. Further analysis revealed that α4β1/α9β1 integrins suppress extracellular signal-regulated kinase (ERK1/2) activity to control migration through the regulation of downstream kinases including Mitogen and Stress Activated Kinase 1 (MSK1). This work demonstrates the roles of α4β1 and α9β1 in regulating migration in response to damage cues.


Biomolecules ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1471
Author(s):  
Thamir M. Ismail ◽  
Stephane R. Gross ◽  
Tara Lancaster ◽  
Philip S. Rudland ◽  
Roger Barraclough

S100P protein is a potent inducer of metastasis in a model system, and its presence in cancer cells of patients is strongly associated with their reduced survival times. A well-established Furth Wistar rat metastasis model system, methods for measuring cell migration, and specific inhibitors were used to study pathways of motility-driven metastasis. Cells expressing C-terminal mutant S100P proteins display markedly-reduced S100P-driven metastasis in vivo and cell migration in vitro. These cells fail to display the low focal adhesion numbers observed in cells expressing wild-type S100P, and the mutant S100P proteins exhibit reduced biochemical interaction with non-muscle myosin heavy chain isoform IIA in vitro. Extracellular inhibitors of the S100P-dependent plasminogen activation pathway reduce, but only in part, wild-type S100P-dependent cell migration; they are without effect on S100P-negative cells or cells expressing C-terminal mutant S100P proteins and have no effect on the numbers of focal adhesions. Recombinant wild-type S100P protein, added extracellularly to S100P-negative cells, stimulates cell migration, which is abolished by these inhibitors. The results identify at least two S100P-dependent pathways of migration, one cell surface and the other intracellularly-linked, and identify its C-terminal lysine as a target for inhibiting multiple migration-promoting activities of S100P protein and S100P-driven metastasis.


Author(s):  
Debra T Linfield ◽  
Nannan Gao ◽  
Andjela Raduka ◽  
Terri J Harford ◽  
Giovanni Piedimonte ◽  
...  

The airway epithelium's ability to repair itself after injury, known as epithelial restitution, is an essential mechanism enabling the respiratory tract's normal functions. Respiratory Syncytial Virus (RSV) is the leading cause of lower respiratory tract infections worldwide. We sought to determine whether RSV delays the airway epithelium wound repair process both in vitro and in vivo. We found that RSV infection attenuated epithelial cell migration, a step in wound repair, promoted stress fiber formation, and mediated assembly of large focal adhesions (FA). Inhibition of Rho kinase (ROCK), a master regulator of actin function, reversed these effects. There was increased RhoA and phospho-myosin light chain (pMLC2) following RSV infection. In vivo, mice were intraperitoneally inoculated with naphthalene to induce lung injury, followed by RSV infection. RSV infection delayed re-epithelialization. There were increased concentrations of pMLC2 in day 7 naphthalene plus RSV animals which normalized by day 14. This study suggests a key mechanism by which RSV infection delays wound healing.


2020 ◽  
Author(s):  
Zi-Qing Shi ◽  
Zi-Yan Chen ◽  
Yao Han ◽  
Heng-Yan Zhu ◽  
Meng-Dan Lyu ◽  
...  

Abstract Background Wnt inducible signaling protein 2 (WISP2) is a wnt1-induced signaling pathway protein 2. Although studies indicate that WISP2 may promote the development of various tumors, its role in ovarian cancer remains unclear. The objective of the current study was to analyze the effects of WISP2 on proliferation and migration of ovarian cancer cells in vitro and in vivo . Results Immunohistochemistry and western blot results indicated that WISP2 was highly expressed in various ovarian tissues and cell lines. WISP2 deletion inhibited cell growth, clone formation, and migration of ovarian cancer cells. WISP2 deletion promoted cell apoptosis and affected the cell cycle. This growth inhibitory effect caused by WISP2 loss is due to the inhibition of extracellular signal-related kinase (p-ERK)1/2, as well as CEBPα and CEBPβ. In addition, WISP2 deletion also activated the Yes-associated protein (YAP). Conclusion WISP2 deletion inhibits ovarian cancer cell proliferation by affecting ERK signaling pathways.


2008 ◽  
Vol 295 (5) ◽  
pp. C1113-C1122 ◽  
Author(s):  
Anne E. Kruchten ◽  
Eugene W. Krueger ◽  
Yu Wang ◽  
Mark A. McNiven

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.


2004 ◽  
Vol 24 (24) ◽  
pp. 10905-10922 ◽  
Author(s):  
Matthew Grove ◽  
Galina Demyanenko ◽  
Asier Echarri ◽  
Patricia A. Zipfel ◽  
Marisol E. Quiroz ◽  
...  

ABSTRACT The Abl-interactor (Abi) family of adaptor proteins has been linked to signaling pathways involving the Abl tyrosine kinases and the Rac GTPase. Abi proteins localize to sites of actin polymerization in protrusive membrane structures and regulate actin dynamics in vitro. Here we demonstrate that Abi2 modulates cell morphogenesis and migration in vivo. Homozygous deletion of murine abi2 produced abnormal phenotypes in the eye and brain, the tissues with the highest Abi2 expression. In the absence of Abi2, secondary lens fiber orientation and migration were defective in the eye, without detectable defects in proliferation, differentiation, or apoptosis. These phenotypes were consistent with the localization of Abi2 at adherens junctions in the developing lens and at nascent epithelial cell adherens junctions in vitro. Downregulation of Abi expression by RNA interference impaired adherens junction formation and correlated with downregulation of the Wave actin-nucleation promoting factor. Loss of Abi2 also resulted in cell migration defects in the neocortex and hippocampus, abnormal dendritic spine morphology and density, and severe deficits in short- and long-term memory. These findings support a role for Abi2 in the regulation of cytoskeletal dynamics at adherens junctions and dendritic spines, which is critical for intercellular connectivity, cell morphogenesis, and cognitive functions.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
D. Cruz-Zárate ◽  
O. López-Ortega ◽  
D. A. Girón-Pérez ◽  
A. M. Gonzalez-Suarez ◽  
J. L. García-Cordero ◽  
...  

AbstractCell migration is a dynamic process that involves adhesion molecules and the deformation of the moving cell that depends on cytoskeletal remodeling and actin-modulating proteins such as myosins. In this work, we analyzed the role of the class I Myosin-1 g (Myo1g) in migratory processes of LPS + IL-4 activated B lymphocytes in vivo and in vitro. In vivo, the absence of Myo1g reduced homing of activated B lymphocytes into the inguinal lymph node. Using microchannel chambers and morphology analysis, we found that the lack of Myo1g caused adhesion and chemotaxis defects. Additionally, deficiency in Myo1g causes flaws in adopting a migratory morphology. Our results highlight the importance of Myo1g during B cell migration.


2020 ◽  
Author(s):  
Zi-Qing Shi ◽  
Zi-Yan Chen ◽  
Yao Han ◽  
Heng-Yan Zhu ◽  
Meng-Dan Lyu ◽  
...  

Abstract Background: Wnt-inducible signaling pathway protein 2 (WISP2) is a wnt1-induced signaling pathway protein 2. Although studies indicate that WISP2 may promote the development of various tumors, its role in ovarian cancer remains unclear. The objective of the current study was to analyze the effects of WISP2 on the proliferation and migration of ovarian cancer cells in vitro and in vivo.Results: Immunohistochemistry and western blotting indicated that WISP2 was highly expressed in various ovarian cancer tissues and cell lines,but weakly expressed in normal ovary tissue. WISP2 deletion inhibited cell growth, clone formation, and migration of ovarian cancer cells while promoting cell apoptosis and affecting the cell cycle. This growth inhibitory effect caused by WISP2 loss is due to the inhibition of phosphorylated extracellular signal-related kinase (p-ERK)1/2, as well as CCAAT/enhancer-binding protein α (CEBPα) and CEPBβ. In addition, WISP2 deletion also activated the Yes-associated protein (YAP).Conclusion: WISP2 deletion inhibits ovarian cancer cell proliferation by affecting ERK signaling pathways.


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