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Query: EC:2.7.10.2 (
focal adhesion kinase
)
44,029
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Src family tyrosine kinases are signaling intermediates in a diverse array of cellular events including cell differentiation, motility, proliferation, and survival. In nonairway smooth muscle cells, muscarinic receptors directly interact with Src family tyrosine kinases. As little is known about the expression and signaling of these Src family tyrosine kinases in human airway smooth muscle cells, we determined the expression of Src family members and characterized the muscarinic receptor-mediated activation of Lyn kinase in these cells. RT-PCR revealed mRNA transcripts for
FYN
, c-SRC, YES,
FRK
, and
LYN
. Fyn, c-Src, Yes, and Lyn were identified in cultured airway smooth muscle cells by immunoblot analysis. In both nontransformed human cultured airway smooth muscle cells and cells transduced with wild-type human Lyn kinase, carbachol increased Lyn kinase activity.
Pertussis
toxin pretreatment failed to block carbachol activation of Lyn kinase but did attenuate the carbachol-induced increase in ERK/MAPK phosphorylation. Moreover, carbachol inhibited adenylyl cyclase but failed to increase total inositol phosphate synthesis in these cells. The present study shows that Lyn kinase is expressed in human cultured airway smooth muscle cells at both the mRNA and protein levels and that carbachol, an M2 muscarinic receptor agonist in these cells, activates Lyn kinase by a
pertussis
toxin-insensitive signaling pathway.
...
PMID:Expression and muscarinic receptor coupling of Lyn kinase in cultured human airway smooth muscle cells. 1622 19
The membrane redistribution and phosphorylation of
focal adhesion kinase
(
FAK
) have been reported to be important for cell migration. We previously showed that Lysophosphatidic acid (LPA) induced
FAK
membrane redistribution and autophosphorylation in ovarian cancer SK-OV3 cells and the signaling pathway consisting of Gi-Ras-MEKK1 mediated LPA-induced
FAK
membrane redistribution but not
FAK
autophosphorylation. We also showed that the disruption of the Gi-Ras-MEKK1 pathway led to a significant reduction in LPA-stimulated cell migration. These findings raised the question of whether LPA-induced
FAK
autophosphorylation was required for LPA-stimulated cell migration and what signaling mechanism was involved in LPA-induced
FAK
autophosphorylation. In this study, we expressed the membrane anchored wild-type
FAK
(CD2-
FAK
) in SK-OV3 cells and found that the expression of CD2-
FAK
greatly rescued LPA-stimulated cell migration in Gi or Ras-inhibited cells. However, Gi inhibitor
pertussis
toxin or dominant-negative H-Ras still significantly inhibited LPA-stimulated cell migration in cells expressing the membrane anchored
FAK
containing a mutation in the autophosphorylation site [CD2-
FAK
(Y397A)]. These results suggest that
FAK
autophosphorylation plays a role in LPA-stimulated cell migration. With the aid of p115RhoGEF-RGS, G12 and G13 minigenes to inhibit G12/13, we found that the G12/13 pathway was required for LPA-induced
FAK
autophosphorylation and efficient cell migration. Moreover, LPA activated RhoA and Rho kinase (ROCK) in a G12/13-dependent manner and their activities were required for LPA-induced
FAK
autophosphorylation. However, Rho or ROCK inhibitors displayed no effect on LPA-induced
FAK
membrane redistribution although they abolished LPA-induced cytoskeleton reorganization. Our studies show that the G12/13-RhoA-ROCK signaling pathway mediates LPA-induced
FAK
autophosphorylation and contributes to LPA-stimulated cell migration.
...
PMID:The G12/13-RhoA signaling pathway contributes to efficient lysophosphatidic acid-stimulated cell migration. 1630 93
Infection with the intracellular parasite Toxoplasma gondii renders cells resistant to multiple pro-apoptotic signals, but underlying mechanisms have not been delineated. The phosphoinositide 3-kinase (PI 3-kinase) pathway and the immediate downstream effector protein kinase B (
PKB
/Akt) play important roles in cell survival and apoptosis inhibition. Here, we show that Toxoplasma infection of mouse macrophages activates
PKB
/Akt in vivo and in vitro. In a mixed population of infected and non-infected macrophages, activation is only observed in parasite-infected cells. The PI 3-kinase inhibitors wortmannin and LY294002 block parasite-induced
PKB
phosphorylation.
PKB
activation occurs independently of Toll-like receptor adaptor protein MyD88 but uncoupling of Gi-protein-mediated signaling with
pertussis
toxin prevents
PKB
phosphorylation. Moreover, in the presence of PI 3-kinase inhibitors or
pertussis
toxin, not only
PKB
activation but also ERK1/2 activation during T. gondii infection is defective. Most importantly, the parasite's ability to induce macrophage resistance to pro-apoptotic signaling is prevented by incubation with PI 3-kinase inhibitors. This study demonstrates that T. gondii exploits host Gi-protein-dependent PI 3-kinase signaling to prevent induction of apoptosis in infected macrophages.
...
PMID:Toxoplasma gondii triggers Gi-dependent PI 3-kinase signaling required for inhibition of host cell apoptosis. 1663 8
We have recently demonstrated that endothelial beta(2) adrenergic receptors (beta(2)AR) regulate eNOS activity and consequently vascular tone, through means of
PKB
/AKT. In this work we explored the signal transduction pathway leading to AKT/eNOS activation in endothelial cells (EC). Using pharmacological and molecular inhibitors both in cultured EC cells and in ex vivo rat carotid preparations, we found that G(i) coupling of the beta(2)AR is needed for AKT activation and vasorelaxation. Since endothelial activation is sensitive to
pertussis
toxin but not to G(ibetagamma) inhibition by betaARKct, we conclude that G(alphai) mediates betaAR induced AKT activation. Downstream, betaAR signalling requires the soluble tyrosine kinase
SRC
, as both in cultured EC and rat carotid, the mutant dominant negative of
SRC
prevent beta(2)AR induced endothelial activation and vasodilation. In EC, G(alphai) directly interacts with
SRC
and this interaction leads to
SRC
activation and phosphorylation in a manner that is regulated by beta(2)AR stimulation. We propose a novel signal transduction pathway for beta(2)AR stimulation trough G(alphai) and
SRC
, leading to activation of AKT.
...
PMID:Endothelial beta2 adrenergic signaling to AKT: role of Gi and SRC. 1762 54
We have previously shown that endothelin-B receptor stimulation increases neural progenitor proliferation, partly in G(i) and extracellular matrix molecule-dependent manner. In the present study, we investigated whether G(q/11) is also involved in this response and how G(i) and G(q/11) might regulate the extracellular signal-regulated kinase (ERK) pathway and integrin signaling. Endothelin-induced ERK phosphorylation was independent of integrin ligands, and an inhibitor of G(q/11), YM-254890, as well as
pertussis
toxin, partially inhibited endothelin-stimulated phosphorylation of Raf-1 and ERK. Endothelin-stimulated protein kinase C (PKC) was partially inhibited by both YM-254890 and
pertussis
toxin, while only
pertussis
toxin attenuated endothelin-induced Ras activation. In contrast, endothelin increased tyrosine phosphorylation of
focal adhesion kinase
(
FAK
) and paxillin in an integrin ligand-dependent manner. Both YM-254890 and
pertussis
toxin partially inhibited endothelin-stimulated phosphorylation of these proteins. A PKC inhibitor and down-regulation of PKC prevented endothelin-induced phosphorylation of paxillin and ERK. In addition, endothelin-induced proliferation and DNA synthesis were partially inhibited by YM-254890 and
pertussis
toxin. Taken together, the results indicate that endothelin activates PKC via G(q/11) and G(i), and consequently stimulates the ERK cascade in cooperation with Ras signaling stimulated by G(i). PKC appears to increase tyrosine phosphorylation of paxillin to enhance integrin signaling, which further increases DNA synthesis and proliferation.
...
PMID:Involvement of Gq/11 in both integrin signal-dependent and -independent pathways regulating endothelin-induced neural progenitor proliferation. 1770 40
Integrins, a family of transmembrane heterodimeric polypeptides, mediate various biological responses including cell adhesion and migration. In this report, we show that sphingosine-1-phosphate (S1P) activates integrin alpha v beta 3 in endothelial cells (ECs) via the sphingosine-1-phosphate receptor subtype 1 (S1P1)-mediated signaling pathway. S1P treatment results in the activation of integrin alpha v beta 3 in the lamellipodia region of ECs, suggesting that integrin alpha v beta 3 plays a critical role in the S1P-stimulated chemotactic response of ECs. Indeed, S1P treatment induces the association of
focal adhesion kinase
(
FAK
) and cytoskeletal proteins with integrin alpha v beta 3, the ligation of alpha v and beta 3 subunits, as well as enhances endothelial migration on vitronectin-coated substrata. Knockdown endothelial S1P1 receptor, treatments with
pertussis
toxin or dominant-negative-Rho family GTPases abrogates the S1P-induced integrin alpha v beta 3 activation in ECs. Consequently, these treatments markedly inhibit the S1P-induced endothelial migratory response on vitronectin-coated substrata. Collectively, these data indicate that the S1P-mediated signaling via the S1P1/Gi/Rho GTPases pathway activates integrin alpha v beta 3, which is indispensable for S1P-stimulated chemotactic response of ECs.
...
PMID:Rho GTPases mediated integrin alpha v beta 3 activation in sphingosine-1-phosphate stimulated chemotaxis of endothelial cells. 1824 41
Guanosine exerts neuroprotective effects in the central nervous system. Apoptosis, a morphological form of programmed cell death, is implicated in the pathophysiology of Parkinson's disease (PD). MPP(+), a dopaminergic neurotoxin, produces in vivo and in vitro cellular changes characteristic of PD, such as cytotoxicity, resulting in apoptosis. Undifferentiated human SH-SY5Y neuroblastoma cells had been used as an in vitro model of Parkinson's disease. We investigated if extracellular guanosine affected MPP(+)-induced cytotoxicity and examined the molecular mechanisms mediating its effects. Exposure of neuroblastoma cells to MPP(+) (10 muM-5 mM for 24-72 h) induced DNA fragmentation in a time-dependent manner (p < 0.05). Administration of guanosine (100 muM) before, concomitantly with or, importantly, after the addition of MPP(+) abolished MPP(+)-induced DNA fragmentation. Addition of MPP(+) (500 muM) to cells increased caspase-3 activity over 72 h (p < 0.05), and this was abolished by pre- or co-treatment with guanosine. Exposure of cells to
pertussis
toxin prior to MPP(+) eliminated the anti-apoptotic effect of guanosine, indicating that this effect is dependent on a Gi protein-coupled receptor, most likely the putative guanosine receptor. The protection by guanosine was also abolished by the selective inhibitor of the enzyme PI-3-K/Akt/
PKB
(LY294002), confirming that this pathway plays a decisive role in this effect of guanosine. Neither MPP(+) nor guanosine had any significant effect on alpha-synuclein expression. Thus, guanosine antagonizes and reverses MPP(+)-induced cytotoxicity of neuroblastoma cells via activation of the cell survival pathway, PI-3-K/Akt/
PKB
. Our results suggest that guanosine may be an effective pharmacological intervention in PD.
...
PMID:MPP(+)-induced cytotoxicity in neuroblastoma cells: Antagonism and reversal by guanosine. 1840 53
The conditioned medium (CM) from mouse NIH3T3 fibroblast cells overexpressing phosphatidylinositol transfer protein alpha (PI-TPalpha; SPIalpha cells) demonstrates an increased anti-apoptotic activity compared with CM from wild type NIH3T3 (wtNIH3T3) cells. As previously shown, the anti-apoptotic activity acts by activating a G protein-coupled receptor, most probably a cannabinoid 1 (CB1)-like receptor as the activity was blocked by both
pertussis
toxin and rimonabant [M. Schenning, C.M. van Tiel, D. Van Manen, J.C. Stam, B.M. Gadella, K.W. Wirtz and G.T. Snoek, Phosphatidylinositol transfer protein alpha regulates growth and apoptosis of NIH3T3 cells: involvement of a cannabinoid 1-like receptor, J. Lipid Res. 45 (2004) 1555-1564]. The CB1 receptor appears to be expressed in mouse fibroblast cells, at levels in the order SPIalpha>wtNIH3T3>SPIbeta cells (i.e. wild type cells overexpressing PI-TPbeta). Upon incubation of SPIbeta cells with the PI-TPalpha-dependent anti-apoptotic factors, both the ERK/MAP kinase and the Akt/
PKB
pathway are activated in a CB1 receptor dependent manner as shown by Western blotting. In addition, activation of ERK2 was also shown by EYFP-ERK2 translocation to the nucleus, as visualized by confocal laser scanning microscopy. The subsequent activation of the anti-apoptotic transcription factor NF-kappaB is in line with the increased resistance towards UV-induced apoptosis. On the other hand, receptor activation by CM from SPIalpha cells was not linked to phospholipase C activation as the YFP-labelled C2-domain of protein kinase C was not translocated to the plasma membrane of SPIbeta cells as visualized by confocal laser scanning microscopy.
...
PMID:The anti-apoptotic activity associated with phosphatidylinositol transfer protein alpha activates the MAPK and Akt/PKB pathway. 1850 17
Differentiation of PC12 cells by nerve growth factor (NGF) requires the activation of various mitogen-activated protein kinases (MAPKs) including p38 MAPK. Accumulating evidence has suggested cross-talk regulation of NGF-induced responses by G protein-coupled receptors, thus we examined whether NGF utilizes G(i/o) proteins to regulate p38 MAPK in PC12 cells. Induction of p38 MAPK phosphorylation by NGF occurred in a time- and dose-dependent manner and was partially inhibited by
pertussis
toxin (PTX). NGF-dependent p38 MAPK phosphorylation became insensitive to PTX treatment upon transient expressions of Galpha(z) or the PTX-resistant mutants of Galpha(i2) and Galpha(oA). Moreover, Galpha(i2) was co-immunoprecipitated with the TrkA receptor from PC12 cell lysates. To discern the participation of various signaling intermediates, PC12 cells were treated with a panel of specific inhibitors prior to the NGF challenge. NGF-induced p38 MAPK phosphorylation was abolished by inhibitors of Src (PP1, PP2, and SU6656) and MEK1/2 (U0126). Inhibition of the p38 MAPK pathway also suppressed NGF-induced PC12 cell differentiation. In contrast, inhibitors of
JAK2
, phospholipase C, protein kinase C and Ca(2+)/calmodulin-dependent kinase II did not affect the ability of NGF to activate p38 MAPK. Collectively, these studies indicate that NGF-dependent p38 MAPK activity may be mediated via G(i2) protein, Src, and the MEK/ERK cascade.
...
PMID:Nerve growth factor-induced stimulation of p38 mitogen-activated protein kinase in PC12 cells is partially mediated via G(i/o) proteins. 1850 36
Hydroxyeicosatetraenoic acids (HETEs) have numerous physiological effects, including modulation of cell proliferation and differentiation. However, little is known about the selective effects of HETE enantiomers on cell proliferation and cell signalling pathways involved in the regulation of cell growth. Furthermore, information on epithelial and endothelial cells growth is controversial. Recently, we demonstrated that 5-, 12-, and 15-HETE are involved in the control of 3T6 fibroblast growth though serine/treonine Akt/
PKB
(Akt) pathway. Here we examined the participation of both enantiomers (S and R) of HETEs in the control of 3T6 fibroblast growth. Our results show that HETEs (5-, 12-, and 15-HETE) are enantioselective on protein and DNA synthesis and 3T6 fibroblast growth. Furthermore, we observed that 12(S)-HETE induces the enhancement of cAMP and intracellular calcium concentration, whereas 12(R)-HETE was uneffective. Our findings also demonstrated that 12(S)-HETE exerts these effects through enantiospecific interactions with a cellular element, probably a plasma membrane receptor coupling to a
pertussis
toxin-sensitive protein G. Moreover, these elements may be involved in the activation of mitogen-activated protein kinase pathways which induce the enhancement of cyclin D(1) levels.
...
PMID:Enantioselective effect of 12(S)-hydroxyeicosatetraenoic acid on 3T6 fibroblast growth through ERK 1/2 and p38 MAPK pathways and cyclin D1 activation. 1864 Jan 2
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