scholarly journals PI3Kγ controls oxidative bursts in neutrophils via interactions with PKCα and p47phox

2009 ◽  
Vol 419 (3) ◽  
pp. 603-610 ◽  
Author(s):  
Katja Lehmann ◽  
Jörg P. Müller ◽  
Bernhard Schlott ◽  
Philipp Skroblin ◽  
Dagmar Barz ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Kinase Activity ◽  
Direct Interaction ◽  
Protein Kinase Activity ◽  
Ros Production ◽  
Oxygen Species ◽  
Regulatory Module ◽  
Protein Kinase Cα ◽  
Inflammatory Immune Response ◽  
Phosphoinositide 3 Kinase

Neutrophils release reactive oxygen species (ROS) as part of the innate inflammatory immune response. Phosphoinositide 3-kinase γ (PI3Kγ), which is induced by the bacterial peptide N-formylmethionyl-leucyl-phenylalanine (fMLP), has been identified as an essential intracellular mediator of ROS production. However, the complex signalling reactions that link PI3Kγ with ROS synthesis by NADPH oxidase have not yet been described in detail. We found that activation of neutrophils by fMLP triggers the association of PI3Kγ with protein kinase Cα (PKCα). Specific inhibition of PI3Kγ suppresses fMLP-mediated activation of PKCα activity and ROS production, suggesting that the protein kinase activity of PI3Kγ is involved. Our data suggest that the direct interaction of PI3Kγ with PKCα forms a discrete regulatory module of fMLP-dependent ROS production in neutrophils.

scholarly journals Protein Kinase Activity of Phosphoinositide 3-Kinase Regulates Cytokine-Dependent Cell Survival

PLoS Biology ◽  
2013 ◽  
Vol 11 (3) ◽  
pp. e1001515 ◽  
Author(s):  
Daniel Thomas ◽  
Jason A. Powell ◽  
Benjamin D. Green ◽  
Emma F. Barry ◽  
Yuefang Ma ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Cell Survival ◽  
Kinase Activity ◽  
Protein Kinase Activity ◽  
Dependent Cell ◽  
Phosphoinositide 3 Kinase

Phosphoinositide 3-kinase: the protein kinase that time forgot

2004 ◽  
Vol 32 (2) ◽  
pp. 330-331 ◽  
Author(s):  
L.C. Foukas ◽  
P.R. Shepherd
Keyword(s):  
Protein Kinase ◽  
Kinase Activity ◽  
Class I ◽  
Protein Kinase Activity ◽  
Lipid Kinase ◽  
Vast Amount ◽  
Lipid Kinases ◽  
Phosphoinositide 3 Kinase ◽  
In Cells

Class I phosphoinositide 3-kinases were originally characterized as lipid kinases, although more than 10 years ago they were also found to phosphorylate protein serine residues. However, while there is a vast amount of data on the function of this lipid kinase activity, relatively little is known about the function of the protein kinase activity. We discuss the evidence that suggests that the protein kinase activity of phosphoinositide 3-kinases mediates important signalling functions in cells.

Protein kinase activity of phosphoinositide 3-kinase regulates β-adrenergic receptor endocytosis

2005 ◽  
Vol 7 (8) ◽  
pp. 785-796 ◽  
Author(s):  
Sathyamangla V. Naga Prasad ◽  
Arundathi Jayatilleke ◽  
Aasakiran Madamanchi ◽  
Howard A. Rockman
Keyword(s):  
Protein Kinase ◽  
Adrenergic Receptor ◽  
Kinase Activity ◽  
Protein Kinase Activity ◽  
Receptor Endocytosis ◽  
Phosphoinositide 3 Kinase

scholarly journals Specific binding of the Akt-1 protein kinase to phosphatidylinositol 3,4,5-trisphosphate without subsequent activation

1996 ◽  
Vol 315 (3) ◽  
pp. 709-713 ◽  
Author(s):  
Stephen R. JAMES ◽  
C. Peter DOWNES ◽  
Roy GIGG ◽  
Simon J. A. GROVE ◽  
Andrew B. HOLMES ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Surface Plasmon Resonance ◽  
Protein Kinase ◽  
Association Constant ◽  
Kinase Activity ◽  
Specific Binding ◽  
Protein Kinase Activity ◽  
L6 Myotubes ◽  
Subsequent Activation ◽  
Phosphoinositide 3 Kinase

Recent evidence has suggested that activation of phosphoinositide 3-kinase (PI 3-kinase) is required for the activation of Akt-1 by growth factors and insulin. Here we demonstrate by two independent methods that Akt-1 from L6 myotubes binds to PtdIns(3,4,5)P3, PtdIns(3,4)P2 and PtdIns(4,5)P2 when presented against a background of phosphatidylserine (PtdSer) or a 1:1 mixture of PtdSer and phosphatidylcholine (PtdCho). No binding was observed with the lipids PtdIns(3,5)P2, PtdIns4P and PtdIns3P or background lipids. Activated, hyperphosphorylated forms of Akt-1 from insulin-stimulated L6 myotubes bound to PtdIns(3,4,5)P3 in a similar manner as inactive Akt-1. Quantitative analysis using surface plasmon resonance showed that the equilibrium association constant for the binding of Akt-1 to PtdIns(3,4,5)P3 was submicromolar and that PtdIns(3,4)P2 and PtdIns(4,5)P2 bound to Akt-1 with 3- and 6-fold lower affinities respectively. Interaction of Akt-1 with PtdIns(3,4,5)P3 did not activate the protein kinase activity, either before or after incubation with MgATP. A model is presented in which PtdIns(3,4,5)P3 may prime Akt-1 for activation by another protein kinase, perhaps by recruiting it to the plasma membrane.

scholarly journals Modulatory effect of curcumin on ketamine-induced toxicity in rat thymocytes: Involvement of reactive oxygen species (ROS) and the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathway

2018 ◽  
Vol 18 (4) ◽  
pp. 320-327 ◽  
Author(s):  
Svetlana Pavlovic ◽  
Zorica Jovic ◽  
Radmila Karan ◽  
Dane Krtinic ◽  
Gorana Rankovic ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Flow Cytometry ◽  
Protein Kinase ◽  
Caspase 3 ◽  
Protein Kinase B ◽  
Akt Signaling ◽  
Ros Production ◽  
Oxygen Species ◽  
Akt Signaling Pathway ◽  
Phosphoinositide 3 Kinase

Ketamine is a widely used anesthetic in pediatric clinical practice. Previous studies have demonstrated that ketamine induces neurotoxicity and has a modulatory effect on the cells of the immune system. Here, we evaluated the potential protective effect and underlying mechanisms of natural phenolic compound curcumin against ketamine-induced toxicity in rat thymocytes. Rat thymocytes were exposed to 100 µM ketamine alone or combined with increasing concentrations of curcumin (0.3, 1, and 3 μM) for 24 hours. Cell viability was analyzed with CCK-8 assay kit. Apoptosis was analyzed using flow cytometry and propidium iodide as well as Z-VAD-FMK and Z-LEHD-FMK inhibitors. Reactive oxygen species (ROS) production and mitochondrial membrane potential [MMP] were measured by flow cytometry. Colorimetric assay with DEVD-pNA substrate was used for assessing caspase-3 activity. Involvement of phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway was tested with Wortmannin inhibitor. Ketamine induced toxicity in cells, increased the number of hypodiploid cells, caspase-3 activity and ROS production, and inhibited the MMP. Co-incubation of higher concentrations of curcumin (1 and 3 μM) with ketamine markedly decreased cytotoxicity, apoptosis rate, caspase-3 activity, and ROS production in rat thymocytes, and increased the MMP. Application of Z-VAD-FMK (a pan caspase inhibitor) or Z-LEHD-FMK (caspase-9 inhibitor) with ketamine effectively attenuated the ketamine-induced apoptosis in rat thymocytes. Administration of Wortmannin (a PI3K inhibitor) with curcumin and ketamine significantly decreased the protective effect of curcumin on rat thymocytes. Our results indicate that ketamine-induced toxicity in rat thymocytes mainly occurs through the mitochondria-mediated apoptotic pathway and that the PI3K/Akt signaling pathway is involved in the anti-apoptotic effect of curcumin.

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