Sphingosine 1-Phosphate Stimulates Tyrosine Phosphorylation of Focal Adhesion Kinase and Chemotactic Motility of Endothelial Cells via the Gi Protein-Linked Phospholipase C Pathway

2000 ◽  
Vol 268 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Ok-Hee Lee ◽  
Doo-Jae Lee ◽  
Young-Mi Kim ◽  
Yong Sun Kim ◽  
Ho Jeong Kwon ◽  
...  
2002 ◽  
Vol 70 (7) ◽  
pp. 3804-3815 ◽  
Author(s):  
Giorgio Santoni ◽  
Roberta Lucciarini ◽  
Consuelo Amantini ◽  
Jordan Jacobelli ◽  
Elisabetta Spreghini ◽  
...  

ABSTRACT The signaling pathways triggered by adherence of Candida albicans to the host cells or extracellular matrix are poorly understood. We provide here evidence in C. albicans yeasts of a p105 focal adhesion kinase (Fak)-like protein (that we termed CaFak), antigenically related to the vertebrate p125Fak, and its involvement in integrin-like-mediated fungus adhesion to vitronectin (VN) and EA.hy 926 human endothelial cell line. Biochemical analysis with different anti-chicken Fak antibodies identified CaFak as a 105-kDa protein and immunofluorescence and cytofluorimetric analysis on permeabilized cells specifically stain C. albicans yeasts; moreover, confocal microscopy evidences CaFak as a cytosolic protein that colocalizes on the membrane with the integrin-like VN receptors upon yeast adhesion to VN. The protein tyrosine kinase (PTK) inhibitors genistein and herbimycin A strongly inhibited C. albicans yeast adhesion to VN and EA.hy 926 endothelial cells. Moreover, engagement of αvβ3 and αvβ5 integrin-like on C. albicans either by specific monoclonal antibodies or upon adhesion to VN or EA.hy 926 endothelial cells stimulates CaFak tyrosine phosphorylation that is blocked by PTK inhibitor. A role for CaFak in C. albicans yeast adhesion was also supported by the failure of VN to stimulate its tyrosine phosphorylation in a C. albicans mutant showing normal levels of CaFak and VNR-like integrins but displaying reduced adhesiveness to VN and EA.hy 926 endothelial cells. Our results suggest that C. albicans Fak-like protein is involved in the control of yeast cell adhesion to VN and endothelial cells.


2000 ◽  
Vol 68 (11) ◽  
pp. 6423-6430 ◽  
Author(s):  
Marpadga A. Reddy ◽  
Carol A. Wass ◽  
Kwang Sik Kim ◽  
David D. Schlaepfer ◽  
Nemani V. Prasadarao

ABSTRACT Escherichia coli K1 traversal across the blood-brain barrier is an essential step in the pathogenesis of neonatal meningitis. We have previously shown that invasive E. colipromotes the actin rearrangement of brain microvascular endothelial cells (BMEC), which constitute a lining of the blood-brain barrier, for invasion. However, signal transduction mechanisms involved in E. coli invasion are not defined. In this report we show that tyrosine kinases play a major role in E. coli invasion of human BMEC (HBMEC). E. coli induced tyrosine phosphorylation of HBMEC cytoskeletal proteins, focal adhesion kinase (FAK), and paxillin, with a concomitant increase in the association of paxillin with FAK. Overexpression of a dominant interfering form of the FAK C-terminal domain, FRNK (FAK-related nonkinase), significantly inhibited E. coli invasion of HBMEC. Furthermore, we found that FAK kinase activity and the autophosphorylation site (Tyr397) are important in E. coli invasion of HBMEC, whereas the Grb2 binding site (Tyr925) is not required. Immunocytochemical studies demonstrated that FAK is recruited to focal plaques at the site of bacterial entry. Consistent with the invasion results, overexpression of FRNK, a kinase-negative mutant (Arg454 FAK), and a Src binding mutant (Phe397 FAK) inhibited the accumulation of FAK at the bacterial entry site. The overexpression of FAK mutants in HBMEC also blocked theE. coli-induced tyrosine phosphorylation of FAK and its association with paxillin. These observations provide evidence that FAK tyrosine phosphorylation and its recruitment to the cytoskeleton play a key role in E. coli invasion of HBMEC.


1997 ◽  
Vol 324 (2) ◽  
pp. 481-488 ◽  
Author(s):  
Fang WANG ◽  
Catherine D. NOBES ◽  
Alan HALL ◽  
Sarah SPIEGEL

Sphingosine 1-phosphate (SPP), a sphingolipid second messenger implicated in the mitogenic action of platelet-derived growth factor [Olivera, A. and Spiegel, S. (1993) Nature (London) 365, 557–560], induced rapid reorganization of the actin cytoskeleton resulting in stress-fibre formation. SPP also induced transient tyrosine phosphorylation of focal adhesion kinase (p125FAK), a cytosolic tyrosine kinase that localizes in focal adhesions, and of the cytoskeleton-associated protein paxillin. Exoenzyme C3 transferase, which ADP-ribosylates Rho (a Ras-related small GTP binding protein) on asparagine-41 and renders it biologically inactive, inhibited both stress-fibre formation and protein tyrosine phosphorylation induced by SPP. Thus Rho may be an upstream regulator of both stress-fibre formation and tyrosine phosphorylation of p125FAK and paxillin. Pretreatment with PMA, an activator of protein kinase C (PKC), inhibited the stimulation of stress-fibre formation induced by 1-oleoyl-lysophosphatidic acid (LPA) but not that by SPP. Similarly, PMA also decreased LPA-induced tyrosine phosphorylation of p125FAK and paxillin without abrogating the response to SPP. Thus PKC is involved in LPA- but not SPP-dependent signalling. The polyanionic drug suramin, a broad-specificity inhibitor of ligand–receptor interactions, did not inhibit either the mitogenic effect of SPP or its stimulation of tyrosine phosphorylation of p125FAK. However, suramin markedly inhibited these responses induced by LPA. These results suggest that in contrast with LPA, SPP may be acting intracellularly in Swiss 3T3 fibroblasts to stimulate tyrosine phosphorylation of p125FAK and paxillin and cell growth.


1998 ◽  
Vol 25 (9) ◽  
pp. 1021-1032 ◽  
Author(s):  
Alexia Gozin ◽  
Elisabeth Franzini ◽  
Valérie Andrieu ◽  
Lydie Da Costa ◽  
Emmanuelle Rollet-Labelle ◽  
...  

1999 ◽  
Vol 277 (1) ◽  
pp. L150-L158 ◽  
Author(s):  
Suryanarayana Vepa ◽  
William M. Scribner ◽  
Narasimham L. Parinandi ◽  
Denis English ◽  
Joe G. N. Garcia ◽  
...  

Reactive oxygen species (ROS) are implicated in the pathophysiology of several vascular disorders including atherosclerosis. Although the mechanism(s) of ROS-induced vascular damage remains unclear, there is increasing evidence for ROS-mediated modulation of signal transduction pathways. Exposure of bovine pulmonary artery endothelial cells to hydrogen peroxide (H2O2) enhanced tyrosine phosphorylation of 60- to 80- and 110- to 130-kDa cellular proteins, which were determined by immunoprecipitation with specific antibodies focal adhesion kinase (p125FAK) and paxillin (p68). Brief exposure of cells to a relatively high concentration of H2O2(1 mM) resulted in a time- and dose-dependent tyrosine phosphorylation of FAK, which reached maximum levels within 10 min (290% of basal levels). Cytoskeletal reorganization as evidenced by the appearance of actin stress fibers preceded H2O2-induced tyrosine phosphorylation of FAK, and the microfilament disruptor cytochalasin D also attenuated the tyrosine phosphorylation of FAK. Treatment of BPAECs with 1,2-bis(2-aminophenoxy)ethane- N, N, N′, N′-tetraacetic acid-AM attenuated H2O2-induced increases in intracellular Ca2+but did not show any consistent effect on H2O2-induced tyrosine phosphorylation of FAK. Several tyrosine kinase inhibitors, including genistein, herbimycin, and tyrphostin, had no detectable effect on tyrosine phosphorylation of FAK but attenuated the H2O2-induction of mitogen-activated protein kinase activity. We conclude that H2O2-induced increases in FAK tyrosine phosphorylation may be important in H2O2-mediated endothelial cell activation.


1998 ◽  
Vol 273 (41) ◽  
pp. 26852-26856 ◽  
Author(s):  
Francine Anfosso ◽  
Nathalie Bardin ◽  
Véronique Francès ◽  
Eric Vivier ◽  
Laurence Camoin-Jau ◽  
...  

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