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: UMLS:C0043167 (
pertussis
)
19,595
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Sodium fluoride (NaF) has previously been reported to induce a strong IL-8 response in human epithelial lung cells (A549) via mechanisms that seem to involve the activation of G proteins. In the present study the signal pathways downstream of the G proteins have been examined. NaF induced a weak, but sustained increase in PKC activity. In contrast, the PKC activator TPA induced a relatively strong, but transient effect and augmented the NaF-induced PKC activity. TPA induced a marked IL-8 response compared to NaF. PDB, another PKC activator, was less effective, but augmented the IL-8 response to NaF. Pretreatment with TPA for 20 h, or the PKC inhibitor GF109203X for 1 h, abolished the basal and NaF-induced PKC activities and partially prevented the NaF-induced IL-8 response. Inhibition of the MAP kinase p38 by SB202190 partially reduced the IL-8 response to NaF, whereas a reduction in ERK activity by PD98059 led to an increased response. The NaF-induced IL-8 response was weakly augmented by the PKA stimulator forskolin and the G(i) inhibitor
pertussis
toxin. The PKA inhibitor H89 seemed to reduce the NaF-induced IL-8 response, but the measured effect was not statistically significant. BAPTA-AM, KN93 and W7, that inhibit Ca(2+)-linked effects, did not affect the IL-8 response. Furthermore, the tyrosine kinase inhibitor genestein, the PI-3 kinase inhibitor wortmannin and
phosphatase
inhibition were without effects. In conclusion, the data suggest that NaF-induced increase of IL-8 in A549 cells involved PKC- and p38-linked pathways, whereas an ERK-dependent pathway counteracted the response. Tyrosine kinases, Ca(2+)-linked pathways, PI-3 kinase, PKA and
phosphatase
inhibition seem to play no or minor roles in the fluoride-induced IL-8 response.
...
PMID:Mechanisms in fluoride-induced interleukin-8 synthesis in human lung epithelial cells. 1156 78
Exposure of rat renal mesangial cells to angiotensin II and angiotensin III leads to a rapid phosphorylation and activation of the protein kinase B (PKB) pathway. The angiotensin II analogs angiotensin-(1-7), angiotensin-(1-6) and angiotensin-(3-8) were unable to activate PKB. The angiotensin II and III effects are mediated by the angiotensin type 1 receptor as documented by the inhibitory action of valsartan. Furthermore, angiotensin II-induced activation of PKB involves neither a
pertussis
toxin-sensitive pathway nor the small G proteins of the Rho/Rac/cdc42 family, but is completely blocked by inhibitors of the PI 3-kinase. Moreover, angiotensin II-stimulated PKB activation is inhibited by long-term pretreatment with interleukin-1 beta, an effect that is reversed by the NO synthase inhibitor, N(G)-monomethyl-L-arginine (L-NMMA). Similarly, the nitric oxide donor (Z)-1-[2-Aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate (Deta-NO) blocks the angiotensin II-induced PKB activation. The NO-mediated inhibition of PKB activation in turn is reversed by the
phosphatase
inhibitor calyculin A but not by ocadaic acid, implying the induction of a protein phosphatase 1 activity by NO.
...
PMID:Interleukin-1 inhibits angiotensin II-stimulated protein kinase B pathway in renal mesangial cells via the inducible nitric oxide synthase. 1206 72
The purified soluble forms of the histidine kinases BvgS and EvgS of Bordetella
pertussis
and Escherichia coli, respectively, are shown to be responsive to oxidized ubiquinone-0 (Q-0) in vitro. The oxidized ubiquinone is a strong inhibitor of kinase activity of both enzymes with half maximal inhibition occurring at 11 microm (BvgS) and 4 microm (EvgS). Reduced Q-0 has no effect on the histidine kinases. Kinase activity can reversibly be switched off and on by changing the oxidation status of the quinone. This inhibitory effect is due to a decrease of the kinase activity of BvgS rather than an increase of intrinsic
phosphatase
activities. Other electron carriers such as menadione (MK-3), NAD or FAD did not have a significant effect on the kinase activities of BvgS and EvgS. Nicotinic acid and sulfate ions, known to inhibit the histidine kinases in vivo, did not affect the purified truncated sensor proteins lacking their periplasmic domains in vitro. Mutations introduced by site-directed mutagenesis into the putative PAS domain of BvgS caused a weak decrease of quinone-dependent inhibition of autophosphorylation. These data suggest that BvgS and EvgS are connected with the oxidation status of the cell via the link to the ubiquinone pool.
...
PMID:The unorthodox histidine kinases BvgS and EvgS are responsive to the oxidation status of a quinone electron carrier. 1213 87
Conventional mode of activation of SH2 domain-containing
phosphatase
1 (SHP-1) by a single transmembrane (TM) inhibitory receptor such as killer cell inhibitory receptor, Fcgamma receptor type IIb1, and paired Ig-like receptors of inhibitory types requires tyrosine phosphorylation of immunoreceptor tyrosine-based inhibitory (ITIM) motifs in the cytoplasmic domains of the inhibitory receptors. Contrary to this paradigm, AT(2), a G protein-coupled 7TM receptor that does not undergo tyrosine phosphorylation in response to angiotensin II (Ang II) stimulation, also activates SHP-1. Here we show that SHP-1 constitutively and physically associates with AT(2) receptor in transfected COS-7 cells. On stimulation by Ang II, SHP-1 becomes activated and dissociated from AT(2) receptor, independent of
pertussis
toxin. Cotransfection of transducin G(betagamma) inhibits SHP-1/AT(2) association and the SHP-1 activation, whereas cotransfection of C-terminal of beta-adrenergic receptor kinase, which abrogates G(betagamma) signaling, facilitates SHP-1 activation. Surprisingly, SHP-1/AT(2) association and the SHP-1 activation requires the presence of G(alphas) as shown by differential coimmunoprecipitation, dominant negative G(alphas), constitutively active G(alphas), and G(alpha) peptides. A mutant AT(2) receptor D141A-R142L that is inactive in G(alpha) protein activation constitutively associates with SHP-1 and activates it. Together, these results indicate that G(alphas) alone, rather than exclusively in the form of G(alphabetagamma) heterotrimer may facilitate signal transduction for G protein-coupled receptors, suggesting a novel mechanism distinct from the classic paradigm of heterotrimeric G proteins. The AT(2)-mediated ITIM-independent activation of SHP-1 that is distinct from the conventional mode of activation, may represent a general paradigm for activation of SHP-1/2-class tyrosine phosphatases by G protein-coupled receptors.
...
PMID:Gbeta gamma -independent constitutive association of Galpha s with SHP-1 and angiotensin II receptor AT2 is essential in AT2-mediated ITIM-independent activation of SHP-1. 1222 Dec 92
T cells resistant to the immunosuppressive drug cyclosporin A (CsA) may be important mediators of chronic graft rejection. We previously reported that T cells activated in the presence of endothelial cells (EC) develop resistance to CsA, and initiate IL-2 secretion within 8-12 h of triggering. CsA normally blocks the
phosphatase
, calcineurin, thus preventing nuclear translocation of the transcription factor, NFAT. We find that in the presence but not the absence of EC, NFAT1 can be detected in the nuclei of CsA-treated T cells within 8 h of triggering, reaching a maximal level of 60% of control by 24 h. Glycogen synthase kinase-3beta (GSK-3beta), which rephosphorylates NFAT and promotes nuclear export, is inhibited by EC costimulation. GSK-3beta is a component of the wnt signaling pathway, and EC express wnt-5a and T cells express frizzled-5, a wnt-5a receptor. Wnt-5a promotes T cell NFAT nuclear accumulation in the presence of CsA, an effect mimicked by Li(+), a potent inhibitor of GSK-3beta. The protein kinase C agonist PMA dramatically synergizes with both EC and wnt-5a in stimulating T cell IL-2 synthesis, and inhibition of either protein kinase C by Ro-31-8425 or G-proteins by
pertussis
toxin effectively blocks the actions of wnt-5a on T cells. Finally, a secreted, dominant-negative form of frizzled-5 blocks EC-mediated CsA resistance. Thus, EC promote CsA-resistant nuclear localization of NFAT and subsequent IL-2 synthesis through a noncanonical wnt-dependent pathway.
...
PMID:Endothelial cells stimulate T cell NFAT nuclear translocation in the presence of cyclosporin A: involvement of the wnt/glycogen synthase kinase-3 beta pathway. 1224 65
Aging is associated with an impaired ability to maintain long-term potentiation (LTP), but the underlying cause of the impairment remains unclear. To gain a better understanding of the cellular and molecular mechanisms responsible for this impairment, the synaptic transmission and plasticity were studied in the CA1 region of hippocampal slices from adult (6-8 months) and poor-memory (PM)-aged (23-24 months) rats. The one-way inhibitory avoidance learning task was used as the behavioral paradigm to screen PM-aged rats. With intracellular recordings, CA1 neurons of PM-aged rats exhibited a more hyperpolarized resting membrane potential, reduced input resistance, and increased amplitude of afterhyperpolarization and spike threshold, compared with those in adult rats. Although a reduction in the size of excitatory synaptic response was observed in PM-aged rats, no obvious differences were found between adult and PM-aged rats in the pharmacological properties of excitatory synaptic response, paired-pulse facilitation, or frequency-dependent facilitation, which was tested with trains of 10 pulses at 1, 5, and 10 Hz. Slices from the PM-aged rats displayed significantly reduced early-phase long-term potentiation (E-LTP) and late-phase LTP (L-LTP), and the entire frequency-response curve of LTP and LTD is modified to favor LTD induction. The susceptibility of time-dependent reversal of LTP by low-frequency afferent stimulation was also facilitated in PM-aged rats. Bath application of the protein phosphatase inhibitor, calyculin A, enhanced synaptic response in slices from PM-aged, but not adult, rats. In contrast, application of the cAMP-dependent protein kinase inhibitors, Rp-8-CPT-cAMPS and KT5720, induced a decrease in synaptic transmission only in slices from the adult rats. Furthermore, the selective beta-adrenergic receptor agonist, isoproterenol, and
pertussis
toxin-sensitive G-protein inhibitor, N-ethylmaleimide, effectively restored the deficit in E-LTP and L-LTP of PM-aged rats. These results demonstrate that age-related impairments of synaptic transmission and LTP may result from alterations in the balance of protein kinase/
phosphatase
activities.
...
PMID:Alterations in the balance of protein kinase and phosphatase activities and age-related impairments of synaptic transmission and long-term potentiation. 1254 30
Signalling via m3 and m2 receptors in smooth muscles involved activation of two G-protein-dependent pathways by each receptor. m2 receptors were coupled via Gbetagammai3 with activation of phospholipase C-beta3, phosphoinositide 3-kinase and Cdc42/Rac1 (where Cdc stands for cell division cycle) and p21-activated kinase 1 (PAK1), resulting in phosphorylation and inactivation of myosin light chain kinase (MLCK). Each step was inhibited by methoctramine and
pertussis
toxin. PAK1 activity was abolished in cells expressing both Cdc42-DN (where DN stands for dominant negative) and Rac1-DN. MLCK phosphorylation was inhibited by PAK1 antibody, and in cells expressing Cdc42-DN and Rac1-DN. m3 receptors were coupled via Galpha(q/11) with activation of phospholipase C-beta1 and via RhoA with activation of Rho-associated kinase (Rho kinase), phospholipase D and protein kinase C (PKC). Rho kinase and phospholipase D activities were inhibited by C3 exoenzyme and in cells expressing RhoA-DN. PKC activity was inhibited by bisindolylmaleimide, and in cells expressing RhoA-DN; PKC activity was also inhibited partly by Y27632 (44+/-5%). PKC-induced phosphorylation of PKC-activated 17 kDa inhibitor protein of type 1
phosphatase
(CPI-17) at Thr38 was abolished by bisindolylmaleimide and inhibited partly by Y27632 (28+/-3%). Rho-kinase-induced phosphorylation of myosin phosphatase targeting subunit (MYPT1) and was abolished by Y27632. Sustained phosphorylation of 20 kDa regulatory light chain of myosin II (MLC20) and contraction were abolished by bisindolylmaleimide Y27632 and C3 exoenzyme and in cells expressing RhoA-DN. The results suggest that Rho-kinase-dependent phosphorylation of MYPT1 and PKC-dependent phosphorylation and enhancement of CPI-17 binding to the catalytic subunit of MLC
phosphatase
(MLCP) act co-operatively to inhibit MLCP activity, leading to sustained stimulation of MLC20 phosphorylation and contraction. Because Y27632 inhibited both Rho kinase and PKC activities, it could not be used to ascertain the contribution of MYPT1 to inhibition of MLCP activity. m2-dependent phosphorylation and inactivation of MLCK precluded its involvement in sustained MLC20 phosphorylation and contraction.
...
PMID:Differential signalling by muscarinic receptors in smooth muscle: m2-mediated inactivation of myosin light chain kinase via Gi3, Cdc42/Rac1 and p21-activated kinase 1 pathway, and m3-mediated MLC20 (20 kDa regulatory light chain of myosin II) phosphorylation via Rho-associated kinase/myosin phosphatase targeting subunit 1 and protein kinase C/CPI-17 pathway. 1273 88
Cannabinoids activate several members of the mitogen-activated protein kinase superfamily including p44 and p42 extracellular signal-regulated kinase (ERK). We used N1E-115 neuroblastoma cells and the cannabinoid receptor agonist WIN 55,212-2 (WIN) to examine the signal transduction pathways leading to the activation of ERK. ERK phosphorylation (activation) was measured by Western blot. The EC50 for stimulation of ERK phosphorylation was 10 nm, and this effect was blocked by
pertussis
toxin and the CB1 (cannabinoid) receptor antagonist SR141716A. The MEK inhibitors PD 98059 and U0126 blocked ERK phosphorylation, as did the adenylate cyclase activator forskolin. The phosphatidylinositol (PI) 3-kinase inhibitor LY 294002 and the Src kinase inhibitor PP2 partially occluded the response but also decreased basal levels of phospho-ERK. The PI 3-kinase and Src pathways are known to promote cell survival in many systems; therefore, MTT (1-(4,5-dimethylthiazol-2-yl)-3,5-diphenylformazan) conversion was used to examine the effects of these inhibitors on cellular viability. LY 294002 decreased the number of viable cells after 18 h of treatment; therefore, the inhibition of ERK by this inhibitor is probably because of cytotoxicity. Forskolin blocked ERK phosphorylation with an EC50 of <3 microm, and the protein kinase A (PKA) inhibitor H-89 enhanced ERK phosphorylation. c-Raf phosphorylation at an inhibitory PKA-regulated site (Ser259) was also reduced by WIN. This is probably due to constitutive
phosphatase
activity because WIN did not directly stimulate PP1 or PP2A activity when measured using 6,8-difluoro-4-methylumbelliferyl phosphate as a fluorogenic substrate. These data implicate the inhibition of PKA as the predominant pathway for ERK activation by CB1 receptors in N1E-115 cells. PI 3-kinase and Src appear to contribute to ERK activation by maintaining activation of kinases, which prime the pathway and maintain cellular viability.
...
PMID:A predominant role for inhibition of the adenylate cyclase/protein kinase A pathway in ERK activation by cannabinoid receptor 1 in N1E-115 neuroblastoma cells. 1451 12
The roles of extracellular regulated kinase (ERK) activation and mitogen-activated protein kinase
phosphatase
-1 (MKP-1) were examined in sphingosine-1-phosphate (S1P)-mediated inhibition of apoptosis in C3H10T 1/2 fibroblast cells. Apoptosis induced by the ceramide analog, C8-ceramine, was inhibited by S1P (ceramine/S1P). Stress activated protein kinase or c-Jun N-terminal kinase (SAPK/JNK) activation was significantly higher after ceramine and ceramine/S1P treatments. Ceramine/S1P treatment also significantly increased ERK activation and MKP-1 protein levels. ERK activation was required for the inhibition of apoptosis by S1P as shown using the mitogen-activated protein kinase kinase inhibitor, PD98059. Transfection with a dominant negative mutant construct of the MKP-1 gene prevented S1P inhibition of apoptosis and resulted in sustained SAPK/JNK activity. The MKP-1 mutant did not affect ERK activity, indicating that MKP-1 preferentially down-regulates SAPK/JNK in C3H10T 1/2 cells. Finally, the S1P activation of ERK and inhibition of apoptosis were reduced by
pertussis
toxin treatment, suggesting that G-protein-coupled receptors, such as the endothelial differentiation gene (EDG) receptor, play a role. Thus, both ERK activation and MKP-1, which down-regulates SAPK/JNK, are required for S1P-mediated inhibition of apoptosis.
...
PMID:Sphingosine-1-phosphate inhibition of apoptosis requires mitogen-activated protein kinase phosphatase-1 in mouse fibroblast C3H10T 1/2 cells. 1460 42
Aim of the present study was to elucidate the regulation of the mitogen activated protein (MAP) kinase cascades as well as the cross-talk between the various MAP kinase isoforms (ERK1/2, SAPK and p38) after stimulation of vascular smooth muscle cells (VSMC) with low density lipoprotein (LDL), 100 microg/ml or lysophosphatidic acid (LPA), 5 microg/ml. Furthermore, the role of the intracellular free Ca(2+) concentration ([Ca(2+)](i)) on the activation of the MAP kinase isoforms as well as on the protein expression of MAP kinase
phosphatase
(MKP)-1 was investigated. The methods used were Western blot analysis, immunoprecipitation and LDL isolation. Involvement of G(i)-proteins on LDL- and LPA-induced activation of the MAP kinase isoforms was examined by treatment of VSMC with
pertussis
toxin (PTX),100 ng/ml. LDL as well as LPA induced an activation of SAPK and p38 MAP kinase in a PTX-sensitive manner. The ERK1/2, SAPK and p38 MAP kinase activation was a Ca(2+)-dependent process, most likely regulated through modulation of MKP-1 protein expression. Inhibition of ERK1/2 by PD 98059 completely abolished LDL- and LPA-induced activation of SAPK, whereas the activation of p38 MAP kinase was not affected. We conclude, that [Ca(2+)](i) regulates the PTX-sensitive LDL- and LPA-induced stimulation of the MAP kinase cascades, probably via inhibition of the MKP-1 protein expression.
...
PMID:Regulation of mitogen-activated protein kinase cascades by low density lipoprotein and lysophosphatidic acid. 1510 93
<< Previous
1
2
3
4
5
6
7
8
9
Next >>