ADP- and thapsigargin-evoked Ca2+ entry and protein-tyrosine phosphorylation are inhibited by the tyrosine kinase inhibitors genistein and methyl-2,5-dihydroxycinnamate in fura-2-loaded human platelets.

Oxidant-induced activation of phospholipase D (PLD) in bovine pulmonary artery endothelial cells (BPAEC) is independent of protein kinase C and calcium. In the present study, the effects of tyrosine kinase and protein tyrosine phosphatase (PTPase) inhibitors on hydrogen peroxide (H2O2)-induced PLD activation and protein tyrosine phosphorylation were examined in BPAEC. Pretreatment of BPAEC with putative tyrosine kinase inhibitors genistein, tyrphostin, and herbimycin attenuated H2O2 (1 mM)-induced PLD activation. The inhibitory effect of the tyrosine kinase inhibitors was highly specific for H2O2-induced modulation and showed no effect on PLD activation mediated by 12-O-tetradecanoylphorbol 13-acetate or bradykinin. Furthermore, addition of H2O2 increased in a time-dependent manner tyrosine phosphorylation of several proteins (17-200 kDa), as determined by immunoblot analysis with antiphosphotyrosine antibodies. H2O2-mediated protein tyrosine phosphorylation preceded PLD activation, and a good correlation was observed on the effect of genistein in H2O2-induced PLD activation and protein tyrosine phosphorylation. Addition of vanadate, a phosphotyrosine phosphatase inhibitor, synergistically increased both PLD activation and protein tyrosine phosphorylation mediated by H2O2. Moreover, vanadate by itself had minimal effect on basal PLD activity in BPAEC; however, at 10 microM vanadate, an increase in protein tyrosine phosphorylation was observed. In addition to vanadate, phenylarsine oxide and diamide potentiated H2O2-induced PLD activation. These results suggest that tyrosine kinase activation may be involved in H2O2-induced PLD activation in vascular endothelial cells.

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Fcγ receptor II stimulated formation of inositol phosphates in human platelets is blocked by tyrosine kinase inhibitors and associated with tyrosine phosphorylation of the receptor

FEBS Letters ◽

10.1016/0014-5793(94)80575-x ◽

1994 ◽

Vol 342 (1) ◽

pp. 15-18 ◽

Cited By ~ 25

Author(s):

Robert A. Blake ◽

Judith Asselin ◽

Trevor Walker ◽

Steve P. Watson

Keyword(s):

Tyrosine Kinase ◽

Tyrosine Phosphorylation ◽

Tyrosine Kinase Inhibitors ◽

Kinase Inhibitors ◽

Inositol Phosphates ◽

Human Platelets ◽

Fcγ Receptor

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Cell proliferation status, cytokine action and protein tyrosine phosphorylation modulate leukotriene biosynthesis in a basophil leukaemia and a mastocytoma cell line

Biochemical Journal ◽

10.1042/bj2990467 ◽

1994 ◽

Vol 299 (2) ◽

pp. 467-472 ◽

Cited By ~ 12

Author(s):

W Hagmann

Keyword(s):

Growth Factors ◽

Tyrosine Kinase ◽

Tyrosine Phosphorylation ◽

Protein Tyrosine Kinase ◽

Kinase Inhibitors ◽

Interleukin 4 ◽

Protein Tyrosine Phosphorylation ◽

Protein Tyrosine ◽

Herbimycin A ◽

Mastocytoma Cells

Mast cells, mastocytoma cells and basophil leukaemia cells are well-established producers of leukotrienes when grown and stimulated appropriately. I report that the cells' ability to produce leukotrienes is dependent on the cells' proliferative status or their provision with growth factors. Proliferating MC/9 and subconfluent RBL2H3 cells respond maximally to stimulation by 1 microM ionomycin with the production of 56 and 32 pmol of cysteinyl-leukotrienes/10(6) cells respectively. In contrast, confluent RBL2H3 or growth-arrested MC/9 cells lose their ability to generate leukotrienes in response to ionomycin treatment. This rapid down-regulation of leukotriene synthesis is also observed when proliferating RBL2H3 cells are transferred to growth-factor-free medium, wherein cellular leukotriene-synthesis capacity has an apparent half-lifetime of 60 min. Transfer back into growth medium results in the regeneration of leukotriene synthesis capacity within 6 h. In growth-arrested MC/9 cells, leukotriene production ability can at least partially be restored by priming the cells with interleukin 3, but not with interleukin 4. In RBL2H3 cells, pretreatment with protein tyrosine kinase inhibitors such as genistein (5 min, 37 microM), herbimycin A (6 h, 3 microM) or tyrphostin 25 (16 h, 100 microM) completely inhibits leukotriene generation, whereas okadaic acid (15 min, 0.5 microM) has no effect. Under these conditions, both genistein and herbimycin A strongly impair ionomycin-induced protein tyrosine phosphorylation. Our study indicates that leukotriene generation in these tumour cells is tightly regulated by their proliferation status and supply with growth factors, and cell stimulation towards leukotriene synthesis appears to involve protein tyrosine kinase activity.

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Tyrosine phosphorylation / dephosphorylation balance is involved in thrombin-evoked microtubular reorganisation in human platelets

Thrombosis and Haemostasis ◽

10.1160/th07-01-0061 ◽

2007 ◽

Vol 98 (08) ◽

pp. 375-384 ◽

Cited By ~ 20

Author(s):

Aicha Bouaziz ◽

Nidhal Ben Amor ◽

Geoffrey Woodard ◽

Hanen Zibidi ◽

José López ◽

...

Keyword(s):

Platelet Aggregation ◽

Tyrosine Kinase ◽

Tyrosine Phosphorylation ◽

Tyrosine Kinases ◽

Human Platelets ◽

Protein Tyrosine Phosphorylation ◽

Tyrosine Phosphatases ◽

Protein Tyrosine ◽

Atp Secretion ◽

Initial Decrease

SummaryWe have investigated the intracellular mechanisms involved in microtubular remodelling by thrombin and its possible involvement in platelet aggregation and secretion. Platelet stimulation with thrombin induces a time- and concentration-dependent regulation of the microtubular content, which was found to be maximally effective at the concentration 0.1 U/ml. Thrombin (0.1 U/ml) evoked an initial decrease in the microtubule content detectable at 5 seconds (sec) and reached a minimum 10 sec after stimulation.The microtubular content then increased, exceeding basal levels again approximately 30 sec after stimulation. Inhibition of tyrosine phosphatases using vanadate abolished thrombin-induced microtubular depolymerisation while inhibition of tyrosine kinases by methyl-2,5-dihydroxycinnamate prevented microtubule polymerisation.Thrombin activates the cytosolic Brutons tyrosine kinase (Btk) and Src proteins. Inhibition of Btk or Src by LFM-A13 or PP1, respectively, abolished thrombin-induced microtubular polymerisation, while maintaining intact its ability to induce initial depolymerisation. Microtubular disruption by colchicine significantly reduced thrombin induced platelet aggregation and ATP secretion. Similar results were observed after inhibition of microtubular disassembly by paclitaxel.These findings indicate that thrombin induces microtubular remodelling by modifying the balance between protein tyrosine phosphorylation and dephosphorylation. The former seems to be required for microtubular polymerisation, while tyrosine dephosphorylation is required for microtubular depolymerisation. Both, initial microtubular disassembly and subsequent polymerisation are required for thrombin-induced platelet aggregation and secretion in human platelets.

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The role of protein tyrosine phosphorylation in integrin-mediated gene induction in monocytes.

The Journal of Cell Biology ◽

10.1083/jcb.126.6.1585 ◽

1994 ◽

Vol 126 (6) ◽

pp. 1585-1593 ◽

Cited By ~ 72

Author(s):

T H Lin ◽

A Yurochko ◽

L Kornberg ◽

J Morris ◽

J J Walker ◽

...

Keyword(s):

Cell Adhesion ◽

Tyrosine Kinase ◽

Tyrosine Phosphorylation ◽

Kinase Inhibitors ◽

Cell Types ◽

Gene Induction ◽

Protein Tyrosine Phosphorylation ◽

Protein Tyrosine ◽

Dose Dependent Fashion ◽

Beta 1 Integrin

Integrin-mediated cell adhesion, or cross-linking of integrins using antibodies, often results in the enhanced tyrosine phosphorylation of certain intracellular proteins, suggesting that integrins may play a role in signal transduction processes. In fibroblasts, platelets, and carcinoma cells, a novel tyrosine kinase termed pp125FAK has been implicated in integrin-mediated tyrosine phosphorylation. In some cell types, integrin ligation or cell adhesion has also been shown to result in the increased expression of certain genes. Although it seems reasonable to hypothesize that integrin-mediated tyrosine phosphorylation and integrin-mediated gene induction are related, until now, there has been no direct evidence supporting this hypothesis. In the current report, we explore the relationship between integrin-mediated tyrosine phosphorylation and gene induction in human monocytes. We demonstrate that monocyte adherence to tissue culture dishes or to extracellular matrix proteins is followed by a rapid and profound increase in tyrosine phosphorylation, with the predominant phosphorylated component being a protein of 76 kD (pp76). Tyrosine phosphorylation of pp76 and other monocyte proteins can also be triggered by incubation of monocytes with antibodies to the integrin beta 1 subunit, or by F(ab')2 fragments of such antibodies, but not by F(ab) fragments. The ligation of beta 1 integrins with antibodies or F(ab')2 fragments also induces the expression of immediate-early (IE) genes such as IL-1 beta. When adhering monocytes are treated with the tyrosine kinase inhibitors genistein or herbimycin, both phosphorylation of pp76 and induction of IL-1 beta message are blocked in a dose-dependent fashion. Similarly, treatment with genistein or herbimycin can block tyrosine phosphorylation of pp76 and IL-1 beta message induction mediated by ligation of beta 1 integrin with antibodies. These observations suggest that protein tyrosine phosphorylation is an important aspect of integrin-mediated IE gene induction in monocytes. The cytoplasmic tyrosine kinase pp125FAK, although important in integrin signaling in other cell types, seems not to play a role in monocytes because this protein could not be detected in these cells.

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