Cdc42Hs and Rac1 GTPases Induce the Collapse of the Vimentin Intermediate Filament Network

Mériane, Mayya; Mary, Sophie; Comunale, Franck; Vignal, Emmanuel; Fort, Philippe; Gauthier-Rouvière, Cécile

doi:10.1074/jbc.m001566200

Cited by 58 publications

(66 citation statements)

References 49 publications

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“…This is in agreement with the finding that different GPCR agonists, including bradykinin and serotonin, induce remodeling of the vimentin intermediate filament network through phosphorylation events [27,32,37]. While tyrosine phosphorylation of vimentin has been detected in cancer cells and putatively linked to migration and invasion [38], little is known about the specific function of vimentin phosphotyrosines.…”

Section: Discussionsupporting

confidence: 89%

“…PI3K inhibition did not affect the response to CSF-1 (Fig. 3B), in agreement with the report that tyrosine kinase receptors induce vimentin phosphorylation in a PI3K-independent way [32]. Conversely, LY294002 treatment reduced vimentin tyrosine phosphorylation at 5 min after chemokine stimulation (Fig.…”

Section: Chemokine-driven Pi3kc-dependent Tyrosine Phosphorylation Ofsupporting

confidence: 92%

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Leukocyte transmigration is modulated by chemokine‐mediated PI3Kγ‐dependent phosphorylation of vimentin

et al. 2009

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Phosphoinositide 3-kinase c (PI3Kc) plays a fundamental role in mediating leukocyte migration to inflammation sites. However, the downstream cytoplasmic events triggered by its signaling activity are still largely obscure. To address this issue, tyrosine and serine/threonine phosphorylated proteins of chemokine-stimulated WT or PI3Kc-null macrophages were investigated. Among the proteins analyzed, the intermediate filament vimentin was found as a downstream effector of the PI3Kc signaling pathway. Specific analysis of the phosphorylation state of vimentin in macrophages showed that this protein becomes rapidly phosphorylated in both tyrosine and serine residues upon chemokine stimulation. In the absence of PI3Kc or the kinase activity of PI3Kc (PI3Kc KD/KD ), phosphorylation of vimentin was reduced. PI3Kc-null macrophages displayed impaired chemokine-driven vimentin fiber disassembly as well as reduced ability to transmigrate across endothelial cells. While WT macrophages infected with a vimentin mutant resistant to N-terminal serine phosphorylation showed a reduction in transendothelial migration, infection of PI3Kc-null macrophages with a vimentin mutant mimicking serine phosphorylation of N-terminal residues rescued the transendothelial migration defect. These results define vimentin N-terminal phosphorylation and fiber reorganization as a target of chemokine-dependent PI3Kc signaling in leukocytes.Key words: Cell migration . Intermediate filaments . Phosphoinositide 3-kinases .Signal transduction IntroductionPhosphoinositide 3-kinases (PI3K) are a family of ubiquitously expressed lipid and protein kinases. They are activated downstream transmembrane receptors [1] and are involved in several cellular responses such as metabolic regulation, survival, proliferation, cell migration and adhesion. PI3K convert PtdIns(4,5)P 2 into PtdIns(3,4,5)P 3 , a second lipid messenger product forming a docking site for various proteins harboring lipid binding modules such as the pleckstrin homology domain [2].Ã These authors contributed equally to this work. 1136Class I PI3K are heterodimeric proteins composed of a p110 catalytic subunit (a, b, g and d) and a regulatory adaptor subunit. According to their mechanism of activation, these enzymes can be further classified into two subclasses: while class IA PI3K (PI3Ka, b and d) include an adaptor protein of the p85 family and are activated by tyrosine kinase receptors, the sole known element of class IB, PI3Kg, is specifically activated by G protein-coupled receptors (GPCR) [3]. This effect is regulated by the interaction of PI3Kg with Gbg subunits of active G proteins through the involvement of either the p101 adaptor or its homologue p84/p87 [4]. Among mammalian tissues, the highest level of PI3Kg expression is found in leukocytes where this enzyme directs the chemotactic response to GPCR agonists [3]. Indeed, PI3Kg-null granulocytes show a significant reduction in chemotaxis toward chemokines and severely impaired bacteria-elicited peritoneal recruitment [5,6]. This migrati...

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Section: Discussionsupporting

confidence: 89%

Section: Chemokine-driven Pi3kc-dependent Tyrosine Phosphorylation Ofsupporting

confidence: 92%

Leukocyte transmigration is modulated by chemokine‐mediated PI3Kγ‐dependent phosphorylation of vimentin

et al. 2009

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“…Future studies evaluating the extent and duration of WFA retention in tumor tissue will fully characterize the disposition and pharmacodynamic properties of WFA in preventing metastatic growth. Vimentin phosphorylation regulates vimentin dynamics [42][43][44][45] and ser56 phosphorylation is associated with cell motility signaling pathways. 40,46 Specifically, vimentin ser56 phosphorylation inversely regulates PAK activation and is critical for vimentin filament spatial rearrangement elicited by agonists.…”

Section: Cancer Therapymentioning

confidence: 99%

Withaferin A inhibits breast cancer invasion and metastasis at sub‐cytotoxic doses by inducing vimentin disassembly and serine 56 phosphorylation

Thaiparambil

Bender

Ganesh

et al. 2011

Intl Journal of Cancer

229

208

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Withaferin A (WFA) is purified from the plant Withania somnifera and inhibits the vimentin cytoskeleton. Vimentin overexpression in cancer correlates with metastatic disease, induction of epithelial to mesenchymal transition and reduced patient survival. As vimentin functions in cell motility, we wanted to test the hypothesis that WFA inhibits cancer metastasis by disrupting vimentin function. These data showed that WFA had weak cytotoxic and apoptotic activity at concentrations less than or equal to 500 nM, but retained potent anti-invasive activity at these low doses. Imaging of breast cancer cell lines revealed that WFA induces perinuclear vimentin accumulation followed by rapid vimentin depolymerization. A concomitant induction of vimentin ser56 phosphorylation was observed, which is consistent with vimentin disassembly. Structure activity relationships were established using a set of chemically modified WFA analogs and showed that the predicted vimentin-binding region of WFA is necessary to induce vimentin ser56 phosphorylation and for its anti-invasive activity. Pharmacokinetic studies in mice revealed that WFA reaches peak concentrations up to 2 lM in plasma with a half-life of 1.36 hr following a single 4 mg/kg dose. In a breast cancer metastasis mouse model, WFA showed dose-dependent inhibition of metastatic lung nodules and induced vimentin ser56 phosphorylation, with minimal toxicity to lung tissue. Based upon these studies, we conclude that WFA is a potent breast cancer anti-metastatic agent and the anti-metastatic activity of WFA is, at least in part, mediated through its effects on vimentin and vimentin ser56 phosphorylation.Metastatic disease is the major cause of death in almost all cancer types; however, most treatments are developed to target the primary tumor and not the metastases. This is due to metastatic cells being difficult to detect, highly aggressive, chemoresistant and experimentally challenging to model. 1 At present, there is no agent in clinical use that effectively prevents metastasis and most patients ultimately succumb to metastatic disease.The metastatic process can be broadly categorized into three stages-tumor cell invasion into surrounding tissue, intravasation into blood or lymphatic vessels and extravasation into a new host environment. These events are triggered by genetic and epigenetic alterations that transform stationary epithelial cells into migratory cells, a process termed epithelialmesenchymal transition (EMT). 2,3 Recent data suggests that cancer cells can re-trigger EMT to migrate into surrounding tissue. 3,4 A classical EMT protein is vimentin; numerous reports show that vimentin is overexpressed in invasive human tumors but is nearly undetectable in non-invasive, stationary tumors. 3,[5][6][7] Vimentin is a Type III intermediate filament 8 and its overexpression correlates with metastatic disease, EMT induction, poor prognosis and reduced patient survival. 7,[9][10][11] Similar correlations between vimentin overexpression and invasion are observed in cancer ce...

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“…In the present study, Cdc42GAP, but not its inactive mutant, is able to modulate phosphorylation and partial disassembly of vimentin and the spatial reorientation of vimentin filaments during agonist stimulation. Vimentin consists of an NH 2 -terminal head domain containing several phosphorylation sites, a central ␣-helical rod domain (forming the backbone of filaments) and a COOHterminal tail domain (16,26 (4,24,40,46). In smooth muscle cells/tissues, disassembly of the vimentin system may regulate the translocation of Crk-associated substrate (CAS) and Ca 2ϩ /calmodulin-dependent protein kinase II (CamKII), which may participate in the cellular processes that control force development (1,21,23,27,29,35,37,45).…”

Section: Discussionmentioning

confidence: 99%

Cdc42GAP, reactive oxygen species, and the vimentin network

Spinelli²,

Tang³

2009

American Journal of Physiology-Cell Physiology

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Cdc42GAP (GTPase-activating protein) has been implicated in the regulation of cell motility, adhesion, proliferation, and apoptosis. In this study, Cdc42GAP was cloned from smooth muscle tissues. Cdc42GAP, but not inactive R282A Cdc42GAP (alanine substitution at arginine-282), enhanced the GTP hydrolysis of Cdc42 in an in vitro assay. Furthermore, we developed an assay to evaluate the activity of Cdc42GAP in vivo. Stimulation of smooth muscle cells with 5-hydroxytryptamine (5-HT) resulted in the decrease in Cdc42GAP activity. The agonist-induced GAP suppression was reversed by reactive oxygen species inhibitors. Treatment with hydrogen peroxide also inhibited GAP activity in smooth muscle cells. Because the vimentin cytoskeleton undergoes dynamic changes in response to contractile activation, we evaluated the role of Cdc42GAP in regulating vimentin filaments. Smooth muscle cells were infected with retroviruses encoding wild-type Cdc42GAP or its R282A mutant. Expression of wild-type Cdc42GAP, but not mutant R282A GAP, inhibited the increase in the activation of Cdc42 upon agonist stimulation. Phosphorylation of p21-activated kinase (PAK) at Thr-423 (an indication of PAK activation), vimentin phosphorylation (Ser-56), partial disassembly and spatial remodeling, and contraction were also attenuated in smooth muscle cells expressing Cdc42GAP. Our results suggest that the activity of Cdc42GAP is regulated upon contractile activation, which is mediated by intracellular ROS. Cdc42GAP regulates the vimentin network through the Cdc42-PAK pathway in smooth muscle cells during 5-HT stimulation.

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Cdc42Hs and Rac1 GTPases Induce the Collapse of the Vimentin Intermediate Filament Network

Abstract: In this study we show that expression of active Cdc42Hs and Rac1 GTPases, two Rho family members, leads to the reorganization of the vimentin intermediate filament (

Cited by 58 publications

References 49 publications

Leukocyte transmigration is modulated by chemokine‐mediated PI3Kγ‐dependent phosphorylation of vimentin

Leukocyte transmigration is modulated by chemokine‐mediated PI3Kγ‐dependent phosphorylation of vimentin

Withaferin A inhibits breast cancer invasion and metastasis at sub‐cytotoxic doses by inducing vimentin disassembly and serine 56 phosphorylation

Cdc42GAP, reactive oxygen species, and the vimentin network

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