scholarly journals The Phosphoinositide-dependent Kinase, PDK-1, Phosphorylates Conventional Protein Kinase C Isozymes by a Mechanism That Is Independent of Phosphoinositide 3-Kinase

2001 ◽  
Vol 276 (48) ◽  
pp. 45289-45297 ◽  
Author(s):  
Erica Dutil Sonnenburg ◽  
Tianyan Gao ◽  
Alexandra C. Newton
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Kinase C ◽  
Phosphoinositide 3 Kinase ◽  
Phosphoinositide Dependent Kinase

Platelet P-selectin expression: requirement for protein kinase C, but not protein tyrosine kinase or phosphoinositide 3-kinase

2003 ◽  
Vol 89 (06) ◽  
pp. 1016-1023 ◽  
Author(s):  
Danielle Libersan ◽  
Yahye Merhi
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Tyrosine Kinase ◽  
Protein Tyrosine Kinase ◽  
Human Platelet ◽  
The Novel ◽  
Protein Tyrosine ◽  
Kinase C ◽  
Activated Platelets ◽  
Phosphoinositide 3 Kinase

SummaryP-selectin is translocated from the α-granules to the surface of activated platelets where it participates in thrombosis and inflammation. We investigated the signaling pathways involved in thrombin-induced human platelet P-selectin expression. Assessed by flow cytometry, inhibition of protein kinase C (PKC) with chelerythrine reduced P-selectin expression by 66%, platelet/neutrophil binding, GPIIb/IIIa activation and aggregation (p<0.05). Gö 6976, an inhibitor of the conventional PKCs (α and β), did not alter P-selectin expression. However, rottlerin inhibited by 50% its expression (p<0.05), but only at doses that interfere with the novel (є, η) and atypical (ζ) PKCs. Inhibition of protein tyrosine kinase (PTK) and phosphoinositide 3-kinase (PI3-K) did not significantly affect P-selectin expression. In conclusion, thrombin-induced P-selectin expression is PKC-sensitive, but PTK and PI3-K-insensitive. The novel є and η and atypical ζ, but not the conventional α and β and the novel θ PKCs, may be involved in this process.

Cross-talk between receptors with intrinsic tyrosine kinase activity and α1b-adrenoceptors

2000 ◽  
Vol 350 (2) ◽  
pp. 413-419 ◽  
Author(s):  
Luz DEL CARMEN MEDINA ◽  
José VÁZQUEZ-PRADO ◽  
J. Adolfo GARCÍA-SÁINZ
Keyword(s):  
Protein Kinase C ◽  
Growth Factors ◽  
Growth Factor ◽  
Protein Kinase ◽  
Tyrosine Kinase ◽  
Functional Coupling ◽  
Kinase C ◽  
Epidermal Growth ◽  
Phosphoinositide 3 Kinase ◽  
And Function

The effect of epidermal growth factor (EGF) and platelet-derived growth factor (PDGF) on the phosphorylation and function of α1b-adrenoceptors transfected into Rat-1 fibroblasts was studied. EGF and PDGF increased the phosphorylation of these adrenoceptors. The effect of EGF was blocked by tyrphostin AG1478 and that of PDGF was blocked by tyrphostin AG1296, inhibitors of the intrinsic tyrosine kinase activities of the receptors for these growth factors. Wortmannin, an inhibitor of phosphoinositide 3-kinase, blocked the α1b-adrenoceptor phosphorylation induced by EGF but not that induced by PDGF. Inhibition of protein kinase C blocked the adrenoceptor phosphorylation induced by EGF and PDGF. The ability of noradrenaline to increase [35S]guanosine 5´-[γ-thio]triphosphate ([35S]GTP[S]) binding in membrane preparations was used as an index of the functional coupling of the α1b-adrenoceptors and G-proteins. Noradrenaline-stimulated [35S]GTP[S] binding was markedly decreased in membranes from cells pretreated with EGF or PDGF. Our data indicate that: (i) activation of EGF and PDGF receptors induces phosphorylation of α1b-adrenoceptors, (ii) phosphatidylinositol 3-kinase is involved in the EGF response, but does not seem to play a major role in the action of PDGF, (iii) protein kinase C mediates this action of both growth factors and (iv) the phosphorylation of α1b-adrenoceptors induced by EGF and PDGF is associated with adrenoceptor desensitization.

scholarly journals The Lipid Products of Phosphoinositide 3-Kinase Increase Cell Motility through Protein Kinase C

1997 ◽  
Vol 272 (10) ◽  
pp. 6465-6470 ◽  
Author(s):  
Melanie P. Derman ◽  
Alex Toker ◽  
John H. Hartwig ◽  
Katherine Spokes ◽  
J. R. Falck ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Cell Motility ◽  
Kinase C ◽  
Increase Cell Motility ◽  
Phosphoinositide 3 Kinase

scholarly journals Relaxin Stimulates Protein Kinase C ζ Translocation: Requirement for Cyclic Adenosine 3′,5′-Monophosphate Production

2005 ◽  
Vol 19 (4) ◽  
pp. 1012-1023 ◽  
Author(s):  
Bao T. Nguyen ◽  
Carmen W. Dessauer
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Time Course ◽  
Kinase Inhibitors ◽  
Mesangial Cells ◽  
Camp Production ◽  
Protein Levels ◽  
Kinase C ◽  
Phosphoinositide 3 Kinase ◽  
Stimulation Of

Abstract Relaxin is a polypeptide hormone that activates the leucine-rich repeat containing G protein-coupled receptors, LGR7 and LGR8. In an earlier study, we reported that relaxin produces a biphasic time course and the second wave of cAMP is highly sensitive to phosphoinositide-3 kinase inhibitors (LY294002 and wortmannin). LY294002 inhibits relaxin-mediated increases in cAMP production by 40–50% across a large range of relaxin concentrations. Here we show that protein kinase C ζ (PKCζ) is a component of relaxin signaling in THP-1 cells. Sphingomyelinase increases cAMP production due to the release of ceramide, a direct activator of PKCζ. Chelerythrine chloride (a general PKC inhibitor) inhibits relaxin induced cAMP production to the same degree (∼40%) as LY294002. Relaxin stimulates PKCζ translocation to the plasma membrane in THP-1, MCF-7, pregnant human myometrial 1–31, and mouse mesangial cells, as shown by immunocytochemistry. PKCζ translocation is phosphoinositide-3 kinase dependent and independent of cAMP production. Antisense PKCζ oligodeoxynucleotides (PKCζ-ODNs) deplete both PKCζ transcript and protein levels in THP-1 cells. PKCζ-ODNs abolish relaxin-mediated PKCζ translocation and inhibit relaxin stimulation of cAMP by 40%, as compared with mock and random ODN controls. Treatment with LY294002 in the presence of PKCζ-ODNs results in little further inhibition. In summary, we present a novel role for PKCζ in relaxin-mediated stimulation of cAMP.

Activation of endothelial VEGFR-2 stimulates release of SFLT-1 via a phosphoinositide 3-kinase/protein kinase c? Dependent and AKT-independent pathway

2006 ◽  
Vol 45 (3) ◽  
pp. e139-e140
Author(s):  
Melissa Cudmore ◽  
Shakil Ahmad ◽  
Heather Coxall ◽  
Sakae Tanaka ◽  
Motoi Ohba ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Kinase C ◽  
Phosphoinositide 3 Kinase

scholarly journals α1B-Adrenergic receptor phosphorylation and desensitization induced by transforming growth factor-β

2002 ◽  
Vol 368 (2) ◽  
pp. 581-587 ◽  
Author(s):  
M. Teresa ROMERO-ÁVILA ◽  
C. Fabián FLORES-JASSO ◽  
J. Adolfo GARCÍA-SÁINZ
Keyword(s):  
Protein Kinase C ◽  
Growth Factor ◽  
Protein Kinase ◽  
Adrenergic Receptors ◽  
Adrenergic Receptor ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Receptor Phosphorylation ◽  
Kinase C ◽  
Phosphoinositide 3 Kinase

Transforming growth factor-β (TGF-β) induced α1B-adrenergic receptor phosphorylation in Rat-1 fibroblasts stably expressing these adrenoceptors. This effect of TGF-β was rapid, reaching a maximum within 30min and decreasing thereafter, and concentration-dependent (EC50 0.3pM). The phosphoinositide 3-kinase inhibitors wortmannin and LY294002, and the protein kinase C inhibitors staurosporine, Ro 318220 and bisindolylmaleimide, blocked the effect of this growth factor. α1B-Adrenergic receptor phosphorylation was associated with desensitization, as indicated by a reduction in the adrenergic-mediated production of [3H]inositol phosphates. Phosphorylation of α1B-adrenergic receptors by TGF-β was also observed in Cos-1 cells transfected with the receptor. Co-transfection of the dominant-negative mutant of the regulatory subunit of phosphoinositide 3-kinase (Δp85) inhibited the phosphorylation of α1B-adrenergic receptors induced by TGF-β. Our results indicate that activation of TGF-β receptors induces α1B-adrenergic receptor phosphorylation and desensitization. The data suggest that phosphoinositide 3-kinase and protein kinase C play key roles in this effect of TGF-β.

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