Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.7.10.2 (focal adhesion kinase)
44,029 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In vascular smooth muscle cells (VSMCs), the focal adhesion kinase-related tyrosine kinase PYK2/CAKbeta is activated by vascular mitogens. Because reactive oxygen species (ROS) are assumed to mediate mitogenic signals by these agonists, we examined the possible link between ROS and PYK2 in cultured rat VSMCs. Here we present several lines of evidence showing that PYK2 is activated by ROS in VSMCs. The inhibitory effect of an antioxidant, N-acetyl-cysteine, on PYK2 activation by its specific agonists further suggests the pivotal role of PYK2 in vascular remodeling associated with enhanced ROS production.
...
PMID:PYK2/CAKbeta represents a redox-sensitive tyrosine kinase in vascular smooth muscle cells. 1077 98

Since sphingosine 1-phosphate (Sph-1-P) is stored in abundant amounts in blood platelets and released extracellularly upon stimulation, it is important to clarify the effects of this bioactive lysophospholipid on vascular endothelial cells from the viewpoint of platelet-endothelial cell interactions. In this study, we investigated the effects of Sph-1-P on the cytoskeletal remodeling of human umbilical vein endothelial cells (HUVECs). Of a focal adhesion kinase (FAK) family of non-receptor protein-tyrosine kinases, HUVECs were found to express FAK, but scarcely proline-rich tyrosine kinase 2. Sph-1-P induced FAK tyrosine phosphorylation, myosin light chain phosphorylation, and the formation of stress fibers in HUVECs. The specific Rho inactivator C3 transferase from Clostridium botulinum abolished all of these cytoskeletal responses induced by Sph-1-P, while pertussis toxin only partly inhibited FAK tyrosine phosphorylation, and hardly affected myosin light chain phosphorylation and stress fiber formation. In contrast, Sph-1-P-induced intracellular Ca(2)(+) mobilization was suppressed by pertussis toxin, but not at all by C3 exoenzyme. Our results suggest that Sph-1-P, a bioactive lipid released from activated platelets, induces endothelial cell cytoskeletal reorganization, mainly through Rho-mediated signaling pathways.
...
PMID:Rho-mediated phosphorylation of focal adhesion kinase and myosin light chain in human endothelial cells stimulated with sphingosine 1-phosphate, a bioactive lysophospholipid released from activated platelets. 1078 2

Hic-5 is a CAKbeta-binding protein localized at focal adhesions. Here we show that overexpression of CAKbeta or Fyn, but not FAK, enhanced the tyrosine phosphorylation of coexpressed Hic-5 in COS-7 cells. These phosphorylations were further augmented by stimulating cells with osmotic stress. The Y60F mutant of Hic-5 was not phosphorylated, and Hic-5 phosphorylated on tyrosine 60 was bound specifically to the SH2 domain of Csk. Coexpression experiments revealed that the phosphorylation of Hic-5 by CAKbeta required the kinase activation of CAKbeta and binding of Hic-5 by CAKbeta. Specific phosphorylation of Hic-5 by CAKbeta and Fyn may activate a signaling pathway mediated by Hic-5.
...
PMID:Phosphorylation of Hic-5 at tyrosine 60 by CAKbeta and Fyn. 1083 81

The NMDA subtype of the glutamate-gated channel exhibits a high permeability to Ca(2+). The influx of Ca(2+) through NMDA channels is limited by a rapid and Ca(2+)/calmodulin (CaM)-dependent inactivation that results from a competitive displacement of cytoskeleton-binding proteins from the NR1 subunit of the receptor by Ca(2+)/CaM (Zhang et al., 1998; Krupp et al., 1999). The C terminal of this subunit can be phosphorylated by protein kinase C (PKC) (Tingley et al., 1993). The present study sought to investigate whether PKC regulates Ca(2+)-dependent inactivation of the NMDA channel in hippocampal neurons. Activation of endogenous PKC by 4beta-phorbol 12-myristate 13-acetate enhanced peak (I(p)) and depressed steady-state (I(ss)) NMDA-evoked currents, resulting in a reduction in the ratio of these currents (I(ss)/I(p)). We demonstrated previously that PKC activity enhances I(P) via a sequential activation of the focal adhesion kinase cell adhesion kinase beta/proline-rich tyrosine kinase 2 (CAKbeta/Pyk2) and the nonreceptor tyrosine kinase Src (Huang et al., 1999; Lu et al., 1999). Here, we report that the PKC-induced depression of I(ss) is unrelated to the PKC/CAKbeta/Src-signaling pathway but depends on the concentration of extracellular Ca(2+). Intracellular applications of CaM reduced I(ss)/I(p) and occluded the Ca(2+)-dependent effect of phorbol esters on I(ss.) Moreover, increasing the concentration of intracellular Ca(2+) buffer or intracellular application of the inhibitory CaM-binding peptide (KY9) greatly reduced the phorbol ester-induced depression of I(ss). Taken together, these results suggest that PKC enhances Ca(2+)/CaM-dependent inactivation of the NMDA channel, most likely because of a phosphorylation-dependent regulation of interactions between receptor subunits, CaM, and other postsynaptic density proteins.
...
PMID:In CA1 pyramidal neurons of the hippocampus protein kinase C regulates calcium-dependent inactivation of NMDA receptors. 1084 14

The signals involved in restitution during mucosal healing are poorly understood. We compared focal adhesion kinase (FAK) and paxillin protein and phosphorylation, extracellular signal-regulated kinase (ERK) 1, ERK2, and p38 activation, as well as FAK and paxillin organization in static and migrating human intestinal Caco-2 cells on matrix proteins and anionically derivatized polystyrene dishes (tissue culture plastic). We also studied effects of FAK, ERK, and p38 blockade in a monolayer-wounding model. Compared with static cells, cells migrating across matrix proteins matrix-dependently decreased membrane/cytoskeletal FAK and paxillin and cytosolic FAK. Tyrosine phosphorylated FAK and paxillin changed proportionately to FAK and paxillin protein. Conversely, cells migrating on plastic increased FAK and paxillin protein and phosphorylation. Migration matrix-dependently activated p38 and inactivated ERK1 and ERK2. Total p38, ERK1, and ERK2 did not change. Caco-2 motility was inhibited by transfection of FRNK (the COOH-terminal region of FAK) and PD-98059, a mitogen-activated protein kinase-ERK kinase inhibitor, but not by SB-203580, a p38 inhibitor, suggesting that FAK and ERK modulate Caco-2 migration. In contrast to adhesion-induced phosphorylation, matrix may regulate motile intestinal epithelial cells by altering amounts and distribution of focal adhesion plaque proteins available for phosphorylation as well as by p38 activation and ERK inactivation. Motility across plastic differs from migration across matrix.
...
PMID:Human caco-2 motility redistributes FAK and paxillin and activates p38 MAPK in a matrix-dependent manner. 1085 26

Disruption of integrin-extracellular matrix interactions in normal epithelial cells induces apoptosis, a process termed anoikis. Reduced sensitivity to anoikis appears to be an important hallmark of oncogenic transformation, particularly in the process of metastasis. Several pathways have been implicated in the suppression of anoikis, however, the events which take place proximal to the integrin receptors remain unclear. Integrin-linked kinase (ILK) is an integrin-interacting protein kinase which has been identified as a potential PDK-2, as it is capable of phosphorylating PKB/Akt on Ser-473, and stimulating its activity. Here, we show that ILK activity is stimulated upon adhesion of SCP2 mouse mammary epithelial cells to fibronectin, and inhibited in suspended cells. Overexpression of ILK in the anoikis-sensitive SCP2 cells results in a profound inhibition of anoikis, as determined by annexin V binding and activation of caspases 8 and 3. This effect is reversible by the transfection and expression of a dominant-negative, kinase deficient ILK (ILK KD), as well as by a dominant negative PKB/Akt (PKB AAA). On the other hand, transfection of a dominant negative form of FAK (FRNK) failed to reverse the suppression of anoikis by ILK. Furthermore, inhibition of ILK activity induced anoikis in two anoikis-resistant human breast cancer cell lines. These findings suggest that ILK plays a major role in the suppression of anoikis.
...
PMID:The integrin-linked kinase (ILK) suppresses anoikis. 1094 37

The roles of the protein tyrosine kinases Pyk2 (also called RAFTK or CAK beta) and Syk in the process of functional activation of human myeloid cells were examined. During granulocytic differentiation of HL-60 cells with dimethyl sulfoxide (DMSO), the amounts of Pyk2 and beta2 integrin increased, whereas the amount of Syk was abundant before differentiation and did not change during differentiation. When the granulocytic cells were stimulated with N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP), tyrosine phosphorylation of Pyk2 occurred promptly and subsequent association of Pyk2 with beta2 integrin was detected. In contrast, Syk was not tyrosine phosphorylated by fMLP stimulation but constitutively associated with beta2 integrin. Stimulation with fMLP also caused the alteration of beta2 integrin to an activated form, a finding that was confirmed by the observation of fMLP-induced cell attachment on fibrinogen-coated dishes and inhibition of this attachment by pretreatment with anti-beta2 integrin antibody. Cell attachment to fibrinogen caused the enhanced tyrosine phosphorylation of Pyk2 and the initial tyrosine phosphorylation of Syk, which was also inhibited by pretreatment with anti-beta2 integrin antibody. In vitro kinase assays revealed that Pyk2 and Syk represented kinase activities to induce tyrosine phosphorylation of several molecules in the anti-beta2 integrin immunoprecipitates of the attached cells. These results showed that Pyk2 is involved in the functional activation of granulocytic cells in 2 signaling pathways: an fMLP receptor-mediated "inside-out" signaling pathway that might cause beta2 integrin activation and a subsequent beta2 integrin-mediated "outside-in" signaling pathway. Syk was activated in relation to cell attachment to fibrinogen as a result of "outside-in" signaling, although it was already associated with beta2 integrin before fMLP stimulation. (Blood. 2000;96:1733-1739)
...
PMID:Pyk2 and Syk participate in functional activation of granulocytic HL-60 cells in a different manner. 1096 71

Invasion of brain microvascular endothelial cells (BMEC) is a prerequisite for successful crossing of the blood-brain barrier by Escherichia coli K1. We have previously demonstrated the requirement of cytoskeletal rearrangements and activation of focal adhesion kinase (FAK) in E. coli K1 invasion of human BMEC (HBMEC). The current study investigated the role of phosphatidylinositol 3-kinase (PI3K) activation and PI3K interaction with FAK in E. coli invasion of HBMEC. PI3K inhibitor LY294002 blocked E. coli K1 invasion of HBMEC in a dose-dependent manner, whereas an inactive analogue LY303511 had no such effect. In HBMEC, E. coli K1 increased phosphorylation of Akt, a downstream effector of PI3K, which was completely blocked by LY294002. In contrast, non-invasive E. coli failed to activate PI3K. Overexpression of PI3K mutants Deltap85 and catalytically inactive p110 in HBMEC significantly inhibited both PI3K/Akt activation and E. coli K1 invasion of HBMEC. Stimulation of HBMEC with E. coli K1 increased PI3K association with FAK. Furthermore, PI3K/Akt activation was blocked in HBMEC-overexpressing FAK dominant-negative mutants (FRNK and Phe397FAK). These results demonstrated the involvement of PI3K signaling in E. coli K1 invasion of HBMEC and identified a novel role for PI3K interaction with FAK in the pathogenesis of E. coli meningitis.
...
PMID:Phosphatidylinositol 3-kinase activation and interaction with focal adhesion kinase in Escherichia coli K1 invasion of human brain microvascular endothelial cells. 1097 83

The focal adhesion (FAK) non-receptor protein-tyrosine kinase (PTK) links both extracellular matrix/integrin and growth factor stimulation to intracellular signals promoting cell migration. Here we show that both transient and stable overexpression of the FAK C-terminal domain termed FRNK (FAK-related non-kinase) inhibits serum and platelet-derived growth factor (PDGF)-BB-induced vascular smooth muscle cell (SMC) migration in wound healing and in vitro Boyden Chamber chemotaxis assays, respectively. Expression of FRNK, but not a point mutant of FRNK (FRNK L1034S), disrupted the formation of a complex containing both FAK and the activated PDGF-beta receptor and resulted in reduced tyrosine phosphorylation of endogenous FAK at the Tyr-397 binding site for Src family PTKs. As demonstrated using FAK-deficient and FAK-reconstituted fibroblasts, FAK positively contributed to PDGF-BB-stimulated ERK2/MAP kinase activity, and in SMCs, ERK2/MAP kinase activity was required for PDGF-BB-stimulated chemotaxis. Stable expression of FRNK but not FRNK L1034S expression in SMCs lowered the extent and duration of stimulated ERK2/MAP kinase activation at low but not at high PDGF-BB concentrations. Importantly, stable expression of FRNK in SMCs did not affect SMC morphology or proliferation in culture. Because the increased migration of vascular SMCs in response to extracellular matrix proteins and growth factors contributes to neointima formation, our results show that FAK inhibition by FRNK expression may provide a novel approach to regulate abnormal vascular SMC migration in vivo.
...
PMID:Focal adhesion kinase facilitates platelet-derived growth factor-BB-stimulated ERK2 activation required for chemotaxis migration of vascular smooth muscle cells. 1099 18

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. coli promotes 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 the E. 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.
...
PMID:Involvement of focal adhesion kinase in Escherichia coli invasion of human brain microvascular endothelial cells. 1103 55


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---