scholarly journals Focal adhesion-associated proteins p125FAK and paxillin are substrates for bradykinin-stimulated tyrosine phosphorylation in Swiss 3T3 cells.

1994 ◽  
Vol 269 (39) ◽  
pp. 24328-24334
Author(s):  
L.M. Leeb-Lundberg ◽  
X.H. Song ◽  
S.A. Mathis
Keyword(s):  
Tyrosine Phosphorylation ◽  
Focal Adhesion ◽  
3T3 Cells ◽  
Associated Proteins ◽  
Swiss 3T3

scholarly journals Dissociation of mitogen-activated protein kinase activation from p125 focal adhesion kinase tyrosine phosphorylation in Swiss 3T3 cells stimulated by bombesin, lysophosphatidic acid, and platelet-derived growth factor.

1996 ◽  
Vol 7 (12) ◽  
pp. 1865-1875 ◽  
Author(s):  
T Seufferlein ◽  
D J Withers ◽  
D Mann ◽  
E Rozengurt
Keyword(s):  
Protein Kinase ◽  
Tyrosine Phosphorylation ◽  
Focal Adhesion ◽  
Lysophosphatidic Acid ◽  
Mitogen Activated Protein Kinase ◽  
Platelet Derived Growth Factor ◽  
3T3 Cells ◽  
Kinase C ◽  
Mitogen Activated Protein ◽  
Swiss 3T3

The experiments presented here were designed to examine the contribution of p125 focal adhesion kinase (p125FAK) tyrosine phosphorylation to the activation of the mitogen-activated protein kinase cascade induced by bombesin, lysophosphatidic acid (LPA), and platelet-derived growth factor (PDGF) in Swiss 3T3 cells. We found that tyrosine phosphorylation of p125FAK in response to these growth factors is completely abolished in cells treated with cytochalasin D or in cells that were suspended in serum-free medium for 30 min. In marked contrast, the activation of p42mapk by these factors was independent of the integrity of the actin cytoskeleton and of the interaction of the cells with the extracellular matrix. The protein kinase C inhibitor GF 109203X and down-regulation of protein kinase C by prolonged pretreatment of cells with phorbol esters blocked bombesin-stimulated activation of p42mapk, p90rsk, and MAPK kinase-1 but did not prevent bombesin-induced tyrosine phosphorylation of p125FAK. Furthermore, LPA-induced p42mapk activation involved a pertussis toxin-sensitive guanylate nucleotide-binding protein, whereas tyrosine phosphorylation of p125FAK in response to LPA was not prevented by pretreatment with pertussis toxin. Finally, PDGF induced maximum p42mapk activation at concentrations (30 ng/ml) that failed to induce tyrosine phosphorylation of p125FAK. Thus, our results demonstrate that p42mapk activation in response to bombesin, LPA, and PDGF can be dissociated from p125FAK tyrosine phosphorylation in Swiss 3T3 cells.

scholarly journals Lysophosphatidic acid induces tyrosine phosphorylation and activation of MAP-kinase and focal adhesion kinase in cultured Swiss 3T3 cells

FEBS Letters ◽  
1993 ◽  
Vol 329 (3) ◽  
pp. 273-276 ◽  
Author(s):  
Naokazu Kumagai ◽  
Narito Morii ◽  
Kazuko Fujisawa ◽  
Takaaki Yoshimasa ◽  
Kazuwa Nakao ◽  
...  
Keyword(s):  
Map Kinase ◽  
Focal Adhesion Kinase ◽  
Tyrosine Phosphorylation ◽  
Focal Adhesion ◽  
Lysophosphatidic Acid ◽  
3T3 Cells ◽  
Swiss 3T3

Cytoskeletal changes induced by GRAF, the GTPase regulator associated with focal adhesion kinase, are mediated by Rho

1999 ◽  
Vol 112 (2) ◽  
pp. 231-242 ◽  
Author(s):  
J.M. Taylor ◽  
M.M. Macklem ◽  
J.T. Parsons
Keyword(s):  
Focal Adhesion Kinase ◽  
Pc12 Cells ◽  
Focal Adhesion ◽  
Fiber Formation ◽  
Serum Starvation ◽  
3T3 Cells ◽  
Neurite Retraction ◽  
Swiss 3T3

Graf, the GTPase regulator associated with focal adhesion kinase was previously shown to have GAP activity for Ρ A and Cdc42 in vitro (Hildebrand et al 1996 Mol. Cell Biol. 16: 3169–3178). In this study we sought to determine whether Graf acted at the level of Cdc42, Rho, or both in vivo and whether Graf was a signal terminator or transducer for these proteins. Microinjection of Graf cDNA into subconfluent Swiss 3T3 cells (in the presence of serum) has marked effects on cell shape and actin localization. Graf expression causes clearing of stress fibers followed by formation of long actin based filopodial-like extensions. Similar phenotypes were observed following injection of the Rho-inhibitor, C3 into these cells. The Graf response was dependent on GAP activity, since injection of Graf cDNA containing point mutations in the GAP domain (R236Q or N351V) which block enzymatic activity, does not confer this phenotype. Injection of Graf into Swiss 3T3 cells in which Rho has been down-regulated by serum starvation has no effect on cell morphology. Using this system, we demonstrate that Graf blocks sphingosine-1-phosphate (SPP) stimulated (Rho-mediated) stress fiber formation. Conversely, Graf expression does not inhibit bradykinin stimulated (Cdc42-mediated) filopodial extensions. These data indicate that Graf is a GAP for Rho in vivo. To further substantiate these results we examined the effect of Graf over-expression on Rho-mediated neurite retraction in nerve growth factor (NGF)-differentiated PC12 cells. In PC12 cells, which express relatively high levels of endogenous Graf, overexpression of Graf (but not Graf containing the R236Q mutation) enhances SPP-induced neurite retraction. These data indicate the possibility that Graf may be an effector for Rho in certain cell types.

Differential activation of focal adhesion kinase, Rho and Rac by the ninth and tenth FIII domains of fibronectin

1999 ◽  
Vol 112 (17) ◽  
pp. 2937-2946
Author(s):  
N.A. Hotchin ◽  
A.G. Kidd ◽  
H. Altroff ◽  
H.J. Mardon
Keyword(s):  
Growth Factor ◽  
Focal Adhesion Kinase ◽  
Signaling Pathways ◽  
Focal Adhesion ◽  
Cell Attachment ◽  
Cell Types ◽  
Integrin Receptors ◽  
3T3 Cells ◽  
Swiss 3T3 ◽  
Kinase Phosphorylation

Fibronectins are widely expressed extracellular matrix ligands that are essential for many biological processes. Fibronectin-induced signaling pathways are elicited in diverse cell types when specific integrin receptors bind to the ninth and tenth FIII domains, FIII9-10. Integrin-mediated signal transduction involves activation of signaling pathways of the growth factor-dependent Ras-related small GTP-binding proteins Rho and Rac, and phosphorylation of focal adhesion kinase. We have dissected the requirement of FIII9 and FIII10 for Rho and Rac activity and phosphorylation of focal adhesion kinase in BHK fibroblasts and Swiss 3T3 cells. We demonstrate that FIII10 supports cell attachment but does not induce phosphorylation of focal adhesion kinase. In Swiss 3T3 cells, growth factor-independent phosphorylation of focal adhesion kinase and downstream adhesion events are dependent upon the presence of FIII9 in the intact FIII9-10 pair, whereas FIII10-mediated focal adhesion kinase phosphorylation requires a synergistic signal from growth factors. Furthermore, FIII10 is able to elicit cellular responses mediated by Rho, but not Rac, whereas FIII9-10 can elicit both Rho- and Rac-mediated responses. We propose that activation of specific integrin subunits by the FIII10 and FIII9-10 ligands elicits distinct signaling events. This may represent a general molecular mechanism for activation of receptor-specific signaling pathways by a multi-domain ligand.

scholarly journals Focal adhesion kinase (p125FAK) and paxillin are substrates for sphingomyelinase-induced tyrosine phosphorylation in Swiss 3T3 fibroblasts

1996 ◽  
Vol 315 (3) ◽  
pp. 1035-1040 ◽  
Author(s):  
Takehiko SASAKI ◽  
Kaoru HAZEKI ◽  
Osamu HAZEKI ◽  
Michio UI ◽  
Toshiaki KATADA
Keyword(s):  
Tyrosine Kinase ◽  
Focal Adhesion Kinase ◽  
Tyrosine Phosphorylation ◽  
Focal Adhesion ◽  
Kinase Activity ◽  
Tyrosine Kinase Activity ◽  
3T3 Fibroblasts ◽  
Kinase Cascade ◽  
Swiss 3T3 ◽  
Swiss 3T3 Fibroblasts

We examined the effect of sphingomyelinase on tyrosine phosphorylation of intracellular proteins in mouse Swiss 3T3 fibroblasts. Incubation of the cells with bacterial sphingomyelinase resulted in the elevation of tyrosine phosphorylation of multiple cellular proteins of 190, 130, 120, 97 and 70 kDa within minutes. The 120 and 70 kDa tyrosine-phosphorylated peptides were identified as p125 focal adhesion kinase (p125FAK) and paxillin respectively by the use of specific antibodies against the proteins. Tyrosine kinase activity associated with anti-p125FAK immunoprecipitate was stimulated by incubation of cells with sphingomyelinase. Cytochalasin D, which selectively disrupts the network of actin filaments, inhibited sphingomyelinase-induced tyrosine phosphorylation of p125FAK and elevation of tyrosine kinase activity in the anti-p125FAK immunoprecipitates. Sphingomyelinase-induced phosphorylation of p125FAK was not inhibited by wortmannin, an inhibitor of phosphatidylinositol 3-kinase. This was in sharp contrast with a wortmannin-sensitive phosphorylation of p125FAK observed in platelet-derived growth factor (PGDF)-stimulated cells. Thus hydrolysis of sphingomyelin is considered to regulate the tyrosine kinase cascade including p125FAK and paxillin by a mechanism distinct from PDGF.

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