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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)
The product of the herpes simplex virus 1 (HSV-1) US3 gene is a multifunctional serine-threonine protein kinase that can block apoptosis induced by proapoptotic cellular proteins, exogenous agents, or replication-defective viruses. Earlier studies showed that the U(S)3 kinase activates and functionally overlaps cellular protein kinase A (PKA). In this study we examined the status of phosphatidylinositol 3-kinase [PI3K] and of its effector, protein kinase B/Akt (
PKB
/Akt), a component of a major pathway of mammalian antiapoptotic signaling systems. We report the following. (i)
Infection
of target cells with HSV-1 induces transient phosphorylation of serine 473 of
PKB
/Akt early in infection, with a mechanism that is dependent on PI3K. Inhibition of PI3K induced apoptosis in mock-infected or deltaU(S)3 mutant-virus-infected but not in wild-type-virus-infected cells and reduced the accumulation of specific viral gene products, including the U(S)3 protein kinase, but had a marginal effect on virus yields. (ii) At later times after infection, the total amounts of
PKB
/Akt decreased and phosphorylated
PKB
/Akt forms disappeared in a U(S)3-dependent and protein phosphatase 2A-independent manner. (iii) Activation of PKA by forskolin did not mediate significant dephosphorylation of
PKB
/Akt. Our results are consistent with the model that
PKB
/Akt is activated early in infection and acts to block apoptosis in infected cells prior to the accumulation of U(S)3 protein kinase and that it persists and continues to function as an antiapoptotic protein in the absence of U(S)3 but becomes redundant or even inimical once U(S)3 protein kinase accumulates in effective amounts.
...
PMID:Protein kinase B/Akt is present in activated form throughout the entire replicative cycle of deltaU(S)3 mutant virus but only at early times after infection with wild-type herpes simplex virus 1. 1653 1
Interleukin-15 (IL-15) is a pleiotropic cytokine of the 4 alpha-helix bundle family, which binds to a receptor complex that displays common elements with the IL-2 receptor and a unique high-affinity alpha chain. This review focuses on juxtacrine and reverse signaling levels in the IL-15/IL-15R system. Specifically, we discuss how agonistic stimulation of membrane-bound IL-15 induces phosphorylation of members of the MAP kinase family and of
focal adhesion kinase
(
FAK
), thereby upregulating processes including cytokine secretion, cell adhesion and migration. In addition, we explore IL-15 trans-presentation and intracellular signaling, and define promising molecular targets for future pharmacological intervention in
infectious diseases
and immunological disorders. These frontiers in IL-15/IL-15Ralpha research serve as highly instructive examples for key concepts, unsolved problems and therapeutic opportunities in juxtacrine and reverse signaling in general.
...
PMID:The interleukin-15/interleukin-15 receptor system as a model for juxtacrine and reverse signaling. 2188 65
To define better the subcellular mechanism of heat shock (HS)-induced cardioprotection, we examined the effect of HS, as well as selective expression of individual HS proteins (HSPs), on cell injury in neonatal rat ventricular myocytes (NRVM). HS was induced in NRVM by a rapid elevation of temperature to 42 degrees C for 20 min followed by 20-24 h of recovery at 37 degrees C. Other NRVM were infected with a replication-deficient adenovirus encoding HSP27 or HSP70. On the same day, all groups were subjected to metabolic inhibition (MI). Cell injury was assayed by measurement of the percentage of total lactate dehydrogenase released, the percentage of cells staining with trypan blue, or TdT-mediated dUTP nick-end labeling, whereas cell signaling was assayed by immunoblot analysis and coimmunoprecipitation. Before MI, the viability of all treated groups did not differ significantly from control NRVM. HS resulted in a significant increase in HSP70 and HSP27 expression.
Infection
with either virus caused a significant increase in selective HSP content compared with control NRVM. HS protected NRVM from injury. Selective expression of HSP27 or HSP70 alone was not protective in NRVM, but dual infection with both viral vectors (HSP27 + HSP70) was protective. HS and HSP27 + HSP70 expression caused increased paxillin localization in the membrane fraction, which persisted in response to MI, compared with control NRVM. HS increased the integrin-paxillin-
focal adhesion kinase
interaction, whereas targeted inhibition of
focal adhesion kinase
activity abolished the integrin-paxillin association and resulted in an increase in cell death. HS and HSP27 + HSP70 expression increased the association of members of the focal adhesion complex and protected NRVM against irreversible injury. Cytoskeletal-based signaling pathways at focal adhesion junctions may represent a unique pathway of cardioprotection.
...
PMID:Heat shock-induced cardioprotection activates cytoskeletal-based cell survival pathways. 1656 16
The study was designed to assess the association between drug use and gonorrhoea in a UK setting and determine whether any differences identified could be explained by variations in sexual behaviour. A case control analysis was undertaken in a population of men and women presenting to an inner city sexually transmitted diseases clinic. The results were analysed using a multivariate model incorporating demographic and behavioural factors potentially associated with acquiring gonorrhoea.
Infection
with gonorrhoea was found to be associated with illicit drug use (odds ratio 1.8, 1.2-2.8) and the association became non-significant after controlling for sexual behaviour factors. Moderate alcohol use (<5 units/week) was associated with acquiring gonorrhoea but heavier use was not. Patients who used illicit drugs had more casual partners and more foreign partners than those with no history of drug use, but an increased numbers of foreign partners were not associated with a higher prevalence of gonorrhoea. It was concluded that drug use is associated with gonorrhoea in a UK setting. Specific sexual behaviours reported by drug users may increase their risk of gonorrhoea and provide potential targets for behavioural interventions.
Int J
STD
AIDS 2006 Apr
PMID:Why do those using illicit drugs have higher rates of sexually transmitted infection? 1705 45
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
Infection
with group B streptococcus (GBS) is the most common cause of early onset neonatal sepsis in many countries, leading to neonatal morbidity and mortality. There is much evidence for a direct involvement of platelets in the pathogenesis of inflammation and sepsis. Several bacteria are known to directly interact with platelets leading to activation and aggregation, a phenomenon also observed with GBS. Here, we demonstrate that GBS rapidly bound to platelets; however, only strains isolated from septic patients bound fibrinogen on their surface and induced platelet thromboxane synthesis, platelet aggregation, and P-selectin (CD62P) expression. In contrast, GBS strains isolated from healthy newborns or healthy pregnant women induced only shape change, but not platelet thromboxane synthesis, platelet aggregation, or CD62P expression. All GBS strains investigated were able to activate FcgammaRIIA receptor signaling pathways including phospholipase C gamma2 (PLCgamma2), as well as calcium/calmodulin-dependent myosin kinase II (CaMKII) and phosphorylation of myosin light chain (MLC). In contrast, protein kinase C (PKC) was exclusively activated by GBS strains isolated from septic patients, and p38 mitogen activated protein kinase (p38 MAP kinase) was preferentially activated by septic GBS strains. Furthermore, stress signaling kinase SEK1/MKK4 and
focal adhesion kinase
(
FAK
) were activated by all tested GBS strains in a FcgammaRIIA-independent way. This study demonstrates that septic, but not colonizing, GBS strains bind fibrinogen on their surface, and that septic GBS strains influence platelet function not only via the FcgammaRIIA receptor, but also via pathways distinct from IgG-mediated signalling. These mechanisms lead to platelet aggregation and secretion, thereby possibly modulating the pathophysiologic course of GBS infections.
...
PMID:Group B streptococcus isolates from septic patients and healthy carriers differentially activate platelet signaling cascades. 1667 76
Loss of function of the tumor suppressor gene PTEN is more frequently encountered in high-grade malignant gliomas than in low-grade gliomas. High-grade gliomas are characterized by their extremely invasive behavior, suggesting that PTEN is one of the important regulators of cell motility and that alterations of its coding gene contribute to a much more invasive tumor cell phenotype. In order to clarify a role of PTEN in glioma invasion, we introduced the wild-type PTEN gene into human malignant glioma cell lines and investigated their motile and invasive activity in a brain slice model that presents circumstances analogous to normal brain conditions in vivo. In addition, we analyzed biochemical and molecular changes resulting from the transfer of PTEN in the glioma cells.
Infection
of recombinant replication-defective adenovirus vector containing the wild-type PTEN cDNA (Ad5CMV-PTEN) significantly inhibited the cell migration and invasion activities of PTEN-mutated glioma cell lines in in vitro migration and chemoinvasion assays. In an organotypic brain slice model, co-culture of glioma spheroids and rat brain slices demonstrated that Ad5CMV-PTEN transfected cells failed to invade surrounding normal brain tissues. Ad5CMV-PTEN transfer into the glioma cell lines lacking the wild-type gene product decreased the levels of matrix metalloproteinase (MMP)-2 mRNA and inhibited the enzymatic activities of MMP-2 and MMP-9. In contrast, mRNA expression of tissue inhibitor of metalloproteinase (TIMP)-2 was upregulated by the PTEN gene transfer. Introduction of PTEN gene in glioma cell lines markedly reduced the levels of Rac-GTP and Cdc42-GTP, activated forms of these small GTP-binding proteins, and decreased the phosphorylation levels of
focal adhesion kinase
. These results suggest that PTEN inhibits glioma cell invasion in two ways: suppressing proteolysis of the extracellular matrix by MMPs and modulating the migratory activity of glioma cells to a less motile nature by inactivating two Rho-family GTP-binding proteins, Rac and Cdc42.
...
PMID:PTEN gene transfer suppresses the invasive potential of human malignant gliomas by regulating cell invasion-related molecules. 1677 87
Salmonella typhimurium colonizes the intestinal epithelium by injecting an array of effector proteins into host cells that induces phagocytic uptake of attached bacteria. However, the host molecules targeted by these effectors remain poorly defined. Here, we demonstrate that S. typhimurium induces formation of focal adhesion-like complexes at sites of bacterial attachment and that both
focal adhesion kinase
(
FAK
) and the scaffolding protein p130Cas are required for Salmonella uptake. Entry of Salmonella into
FAK
(-/-) cells is dramatically impaired and can be restored to control levels by expression of wild-type
FAK
. Surprisingly, reconstitution of bacterial internalization requires neither the kinase domain of
FAK
nor activation of c-Src, but does require a C-terminal PXXP motif through which
FAK
interacts with Cas.
Infection
of Cas(-/-) cells is also impaired, and reconstitution of invasiveness requires the central Cas YXXP repeat domain. The invasion defect in Cas(-/-) cells can be suppressed by overexpression of
FAK
, suggesting a functional link between
FAK
and Cas in the regulation of Salmonella invasion. Together, these findings reveal a novel role for focal adhesion proteins in the invasion of host cells by Salmonella.
...
PMID:Invasion of host cells by Salmonella typhimurium requires focal adhesion kinase and p130Cas. 1691 15
Viral entry may preferentially occur at the apical or the basolateral surfaces of polarized cells, and differences may impact pathogenesis, preventative strategies, and successful implementation of viral vectors for gene therapy. The objective of these studies was to examine the polarity of herpes simplex virus (HSV) entry using several different human epithelial cell lines. Human uterine (ECC-1), colonic (CaCo-2), and retinal pigment (ARPE-19) epithelial cells were grown on collagen-coated inserts, and the polarity was monitored by measuring the transepithelial cell resistance. Controls were CaSki cells, a human cervical cell line that does not polarize in vitro. The polarized cells, but not CaSki cells, were 16- to 50-fold more susceptible to HSV infection at the apical surface than at the basolateral surface. Disruption of the tight junctions by treatment with EGTA overcame the restriction on basolateral infection but had no impact on apical infection. No differences in binding at the two surfaces were observed. Confocal microscopy demonstrated that nectin-1, the major coreceptor for HSV entry, sorted preferentially to the apical surface, overlapping with adherens and tight junction proteins. Transfection with small interfering RNA specific for nectin-1 resulted in a significant reduction in susceptibility to HSV at the apical surface but had little impact on basolateral infection.
Infection
from the apical but not the basolateral surface triggered
focal adhesion kinase
phosphorylation and led to nuclear transport of viral capsids and viral gene expression. These studies indicate that access to nectin-1 contributes to preferential apical infection of these human epithelial cells by HSV.
...
PMID:Access to nectin favors herpes simplex virus infection at the apical surface of polarized human epithelial cells. 1700 57
Bruton's disease is the most frequently primary X-linked immunodeficiency.
Bruton's tyrosine kinase
(
Btk
) is encoded by the XLA gene that when mutated causes bruton's disease. This protein acts in multiple intracellular signaling pathways where the BCR (B-cell receptor) pathway is the most elucidated. Moreover 400 mutations were found and identified as responsible for B-cells differentiation block; consequences are a lack of B-cells in peripheral blood and hypo/agammaglobulinemia. Thus, patients are more susceptible to early and recurring infections occurring before the age of one year. Laboratory testing allow differential diagnosis among primary immunodeficiencies in which others hypogammaglobulinemia. Genetic analyses help physicians for clinical and biological diagnosis, and allow prenatal diagnosis for patient's family. Patient's management is based upon polyclonal immunoglobulin supplementation,
infectious diseases
prevention and genetic advice.
...
PMID:[Primary immunodeficiencies and Bruton's disease genetic analysis: which prospects offers this genetic diagnosis?]. 1704 Aug 72
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