scholarly journals Analysis of mitogen-activated protein kinase pathways used by interleukin 1 in tissues in vivo: activation of hepatic c-Jun N-terminal kinases 1 and 2, and mitogen-activated protein kinase kinases 4 and 7

2001 ◽  
Vol 353 (2) ◽  
pp. 275-281 ◽  
Author(s):  
Andrew FINCH ◽  
W. DAVIS ◽  
Wayne G. CARTER ◽  
Jeremy SAKLATVALA
Keyword(s):  
Protein Kinase ◽  
Cultured Cells ◽  
Interleukin 1 ◽  
Mitogen Activated Protein Kinase ◽  
Signalling Pathways ◽  
Jnk Pathway ◽  
Mitogen Activated Protein ◽  
Jnk Isoforms ◽  
Fold Activation

The effects of interleukin 1 (IL-1) are mediated by the activation of protein kinase signalling pathways, which have been well characterized in cultured cells. We have investigated the activation of these pathways in rabbit liver and other tissues after the systemic administration of IL-1α. In liver there was 30Ő40-fold activation of c-Jun N-terminal kinase (JNK) and 5-fold activation of both JNK kinases, mitogen-activated protein kinase (MAPK) kinase (MKK)4 and MKK7. IL-1α also caused 2Ő3-fold activation of p38 MAPK and degradation of the inhibitor of nuclear factor κB (‘IκB’), although no activation of extracellular signal-regulated protein kinase (ERK) (p42/44 MAPK) was observed. The use of antibodies against specific JNK isoforms showed that, in liver, short (p46) JNK1 and long (p54) JNK2 are the predominant forms activated, with smaller amounts of long JNK1 and short JNK2. No active JNK3 was detected. A similar pattern of JNK activation was seen in lung, spleen, skeletal muscle and kidney. Significant JNK3 activity was detectable only in the brain, although little activation of the JNK pathway in response to IL-1α was observed in this tissue. This distribution of active JNK isoforms probably results from a different expression of JNKs within the tissues, rather than from a selective activation of isoforms. We conclude that IL-1α might activate a more restricted set of signalling pathways in tissues in vivo than it does in cultured cells, where ERK and JNK3 activation are often observed. Cultured cells might represent a ‘repair’ phenotype that undergoes a broader set of responses to the cytokine.

scholarly journals The MKK7 Gene Encodes a Group of c-Jun NH2-Terminal Kinase Kinases

1999 ◽  
Vol 19 (2) ◽  
pp. 1569-1581 ◽  
Author(s):  
Cathy Tournier ◽  
Alan J. Whitmarsh ◽  
Julie Cavanagh ◽  
Tamera Barrett ◽  
Roger J. Davis
Keyword(s):  
Protein Kinase ◽  
Protein Kinases ◽  
Cultured Cells ◽  
Biochemical Properties ◽  
Mitogen Activated Protein Kinase ◽  
Dual Specificity ◽  
Mitogen Activated Protein ◽  
Extracellular Stimuli ◽  
Jnk Activation

ABSTRACT The c-Jun NH2-terminal protein kinase (JNK) is a member of the mitogen-activated protein kinase (MAPK) group and is an essential component of a signaling cascade that is activated by exposure of cells to environmental stress. JNK activation is regulated by phosphorylation on both Thr and Tyr residues by a dual-specificity MAPK kinase (MAPKK). Two MAPKKs, MKK4 and MKK7, have been identified as JNK activators. Genetic studies demonstrate that MKK4 and MKK7 serve nonredundant functions as activators of JNK in vivo. We report here the molecular cloning of the gene that encodes MKK7 and demonstrate that six isoforms are created by alternative splicing to generate a group of protein kinases with three different NH2 termini (α, β, and γ isoforms) and two different COOH termini (1 and 2 isoforms). The MKK7α isoforms lack an NH2-terminal extension that is present in the other MKK7 isoforms. This NH2-terminal extension binds directly to the MKK7 substrate JNK. Comparison of the activities of the MKK7 isoforms demonstrates that the MKK7α isoforms exhibit lower activity, but a higher level of inducible fold activation, than the corresponding MKK7β and MKK7γ isoforms. Immunofluorescence analysis demonstrates that these MKK7 isoforms are detected in both cytoplasmic and nuclear compartments of cultured cells. The presence of MKK7 in the nucleus was not, however, required for JNK activation in vivo. These data establish that theMKK4 and MKK7 genes encode a group of protein kinases with different biochemical properties that mediate activation of JNK in response to extracellular stimuli.

scholarly journals Proteinase-activated receptor-1 and -2 induce the release of chemokine GRO/CINC-1 from rat astrocytes via differential activation of JNK isoforms, evoking multiple protective pathways in brain

2006 ◽  
Vol 401 (1) ◽  
pp. 65-78 ◽  
Author(s):  
Yingfei Wang ◽  
Weibo Luo ◽  
Georg Reiser
Keyword(s):  
Protein Kinase ◽  
Mitogen Activated Protein Kinase ◽  
Signalling Pathways ◽  
Receptor Subtypes ◽  
Neural Cells ◽  
Loss Of Function ◽  
Mitogen Activated Protein ◽  
Rat Astrocytes ◽  
Induced Apoptosis ◽  
Jnk Isoforms

Activation of both PAR-1 (proteinase-activated receptor-1) and PAR-2 resulted in release of the chemokine GRO (growth-regulated oncogene)/CINC-1 (cytokine-induced neutrophil chemoattractant-1), a functional counterpart of human interleukin-8, from rat astrocytes. Here, we investigate whether the two PAR receptor subtypes can signal separately. PAR-2-induced GRO/CINC-1 release was independent of protein kinase C, phosphoinositide 3-kinase and MEK (mitogen-activated protein kinase kinase)-1/2 activation, whereas these three kinases were involved in PAR-1-induced GRO/CINC-1 release. Despite such clear differences between PAR-1 and PAR-2 signalling pathways, JNK (c-Jun N-terminal kinase) was identified in both signalling pathways to play a pivotal role. By isoform-specific loss-of-function studies using small interfering RNA against JNK1–3, we demonstrate that different JNK isoforms mediated GRO/CINC-1 secretion, when it was induced by either PAR-1 or PAR-2 activation. JNK2 and JNK3 isoforms were both activated by PAR-1 and essential for chemokine GRO/CINC-1 secretion, whereas PAR-1-mediated JNK1 activation was mainly responsible for c-Jun phosphorylation, which was not involved in GRO/CINC-1 release. In contrast, PAR-2-induced JNK1 activation, which failed to phosphorylate c-Jun, uniquely contributed to GRO/CINC-1 release. Therefore our results show for the first time that JNK-mediated chemokine GRO/CINC-1 release occurred in a JNK isoform-dependent fashion and invoked PAR subtype-specific mechanisms. Furthermore, here we demonstrate that activation of PAR-2, as well as PAR-1, rescued astrocytes from ceramide-induced apoptosis via regulating chemokine GRO/CINC-1 release. Taken together, our results suggest that PAR-1 and PAR-2 have overlapping functions, but can activate separate pathways under certain pathological conditions to rescue neural cells from cell death. This provides new functional insights into PAR/JNK signalling and the protective actions of PARs in brain.

scholarly journals Interaction of a Mitogen-Activated Protein Kinase Signaling Module with the Neuronal Protein JIP3

2000 ◽  
Vol 20 (3) ◽  
pp. 1030-1043 ◽  
Author(s):  
Nyaya Kelkar ◽  
Shashi Gupta ◽  
Martin Dickens ◽  
Roger J. Davis
Keyword(s):  
Protein Kinase ◽  
Cultured Cells ◽  
Mitogen Activated Protein Kinase ◽  
Jnk Pathway ◽  
Molecular Scaffold ◽  
Mapk Kinase ◽  
Mitogen Activated Protein ◽  
Kinase Cascade ◽  
Jnk Activation ◽  
Protein Kinase Signaling

ABSTRACT The c-Jun NH2-terminal kinase (JNK) group of mitogen-activated protein kinases (MAPKs) is activated in response to the treatment of cells with inflammatory cytokines and by exposure to environmental stress. JNK activation is mediated by a protein kinase cascade composed of a MAPK kinase and a MAPK kinase kinase. Here we describe the molecular cloning of a putative molecular scaffold protein, JIP3, that binds the protein kinase components of a JNK signaling module and facilitates JNK activation in cultured cells. JIP3 is expressed in the brain and at lower levels in the heart and other tissues. Immunofluorescence analysis demonstrated that JIP3 was present in the cytoplasm and accumulated in the growth cones of developing neurites. JIP3 is a member of a novel class of putative MAPK scaffold proteins that may regulate signal transduction by the JNK pathway.

scholarly journals Interleukin 1 alpha activates two forms of p54 alpha mitogen-activated protein kinase in rabbit liver.

1994 ◽  
Vol 180 (6) ◽  
pp. 2017-2025 ◽  
Author(s):  
M Kracht ◽  
O Truong ◽  
N F Totty ◽  
M Shiroo ◽  
J Saklatvala
Keyword(s):  
Protein Kinase ◽  
Map Kinases ◽  
Interleukin 1 ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Phosphorylation Site ◽  
Mitogen Activated Protein Kinase ◽  
Systemic Injection ◽  
Mitogen Activated Protein

We have identified in rabbits two hepatic forms of T669 peptide kinases that are very strongly activated after systemic injection with the inflammatory cytokine interleukin 1 (IL-1). The T669 peptide contains a major phosphorylation site of the epidermal growth factor receptor, threonine 699 and is a substrate for mitogen-activated protein (MAP) kinases. The kinases were purified to homogeneity and corresponded to 50- and 55-kD proteins on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Amino acid sequencing of 12 tryptic peptides of both kinases identified them as p54 MAP kinase alpha. This kinase belongs to the novel family of stress-activated protein kinases. This is the first evidence of IL-1 activating a specific protein kinase in vivo.

scholarly journals Synergistic activation of stress-activated protein kinase 1/c-Jun N-terminal kinase (SAPK1/JNK) isoforms by mitogen-activated protein kinase kinase 4 (MKK4) and MKK7

2000 ◽  
Vol 352 (1) ◽  
pp. 145-154 ◽  
Author(s):  
Yvonne FLEMING ◽  
Christopher G. ARMSTRONG ◽  
Nick MORRICE ◽  
Andrew PATERSON ◽  
Michel GOEDERT ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Specific Protein ◽  
Mitogen Activated Protein Kinase ◽  
Tyrosine Residue ◽  
Hek 293 ◽  
Mitogen Activated Protein ◽  
Jnk Isoforms ◽  
Protein Kinase Kinase

Stress-activated protein kinase 1 (SAPK1), also called c-Jun N-terminal kinase (JNK), becomes activated in vivo in response to pro-inflammatory cytokines or cellular stresses. Its full activation requires the phosphorylation of a threonine and a tyrosine residue in a Thr-Pro-Tyr motif, which can be catalysed by the protein kinases mitogen-activated protein kinase kinase (MKK)4 and MKK7. Here we report that MKK4 shows a striking preference for the tyrosine residue (Tyr-185), and MKK7 a striking preference for the threonine residue (Thr-183) in three SAPK1/JNK1 isoforms tested (JNK1α1, JNK2α2 and JNK3α1). For this reason, MKK4 and MKK7 together produce a synergistic increase in the activity of each SAPK1/JNK isoform in vitro. The MKK7β variant, which is several hundred-fold more efficient in activating all three SAPK1/JNK isoforms than is MKK7α´, is equally specific for Thr-183. MKK7 also phosphorylates JNK2α2 at Thr-404 and Ser-407 in vitro, Ser-407 being phosphorylated much more rapidly than Thr-183 in vitro. Thr-404/Ser-407 are phosphorylated in unstimulated human KB cells and HEK-293 cells, and phosphorylation is increased in response to an osmotic stress (0.5M sorbitol). However, in contrast with Thr-183 and Tyr-185, the phosphorylation of Thr-404 and Ser-407 is not increased in response to other agonists that activate MKK7 and SAPK1/JNK, suggesting that phosphorylation of these residues is catalysed by another protein kinase, such as CK2, which also phosphorylates Thr-404 and Ser-407 in vitro. MKK3, MKK4 and MKK6 all show a strong preference for phosphorylation of the tyrosine residue of the Thr-Gly-Tyr motifs in their known substrates SAPK2a/p38, SAPK3/p38γ and SAPK4/p38δ. MKK7 also phosphorylates SAPK2a/p38 at a low rate (but not SAPK3/p38γ or SAPK4/p38δ), and phosphorylation occurs exclusively at the tyrosine residue, demonstrating that MKK7 is intrinsically a ‘dual-specific’ protein kinase.

scholarly journals Leptin Signaling in the Hypothalamus of Normal Rats in Vivo**This work was supported in part by a Boston Obesity Nutrition Research Center Grant (to J.C.C.), NIH Grant DK-50411 (to R.J.S.), and NIH Diabetes and Endocrinology Center Grant DK-36836 (to R.J.S.).

Endocrinology ◽  
1998 ◽  
Vol 139 (11) ◽  
pp. 4442-4447 ◽  
Author(s):  
Karen C. McCowen ◽  
Jesse C. Chow ◽  
Robert J. Smith
Keyword(s):  
Protein Kinase ◽  
Cultured Cells ◽  
Signaling Molecules ◽  
Janus Kinase ◽  
Mitogen Activated Protein Kinase ◽  
Leptin Signaling ◽  
Stat3 Phosphorylation ◽  
Mitogen Activated Protein ◽  
Plasma Leptin

Abstract Leptin has been shown to activate multiple signaling molecules in cultured cells, including Janus kinase-2, STAT (signal transducer and activator of transcription) proteins, and mitogen-activated protein kinase, and to stimulate the DNA-binding activity of STAT3 in mouse hypothalamus. In this study, the activation of candidate leptin signaling molecules in the hypothalamus of normal rats in vivo was investigated. Fasted male Sprague-Dawley rats were injected iv with recombinant murine leptin or vehicle. Plasma leptin concentrations were determined at defined time points, and the phosphorylation of signaling proteins was assessed in hypothalamic lysates. There was a marked increase in plasma leptin concentration at 2 min and a gradual decline by 45 min after leptin injection. Immunoblotting analysis of hypothalamic lysates with a phosphospecific STAT3 antibody demonstrated a time-dependent stimulation of STAT3 tyrosine phosphorylation. STAT3 phosphorylation was first evident at 5 min and was maximal at 30 min after leptin injection. By contrast, leptin did not increase the phosphorylation of Janus kinase proteins, mitogen-activated protein kinase, or STAT1 and -5 despite abundant expression of these signaling molecules in the hypothalamus. These results differ from findings in cultured cells and in vitro systems. It remains unclear how signaling is propagated downstream from the leptin receptor to STAT3, but this may involve novel signaling intermediates.

scholarly journals Anti-inflammatory Mechanism of Rhein in Treating Asthma Based on Network Pharmacology

2020 ◽  
Author(s):  
Junfang Feng ◽  
Ou Chen ◽  
Yibiao Wang
Keyword(s):  
Protein Kinase ◽  
Signalling Pathway ◽  
Mitogen Activated Protein Kinase ◽  
Signalling Pathways ◽  
Network Pharmacology ◽  
Active Growth ◽  
Inflammatory Mechanism ◽  
Mitogen Activated Protein ◽  
Anti Inflammatory

Abstract Background: Network pharmacological methods were used to predict the anti-inflammatory targets and related pathways of rhein in the treatment of asthma, and to elucidate its mechanism of action. In addition, we validated the anti-inflammatory effects of rhein in human bronchial epithelial (HBE) cells.Methods: The corresponding targets of rhein were obtained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform 2.3 (TCMSP), and molecular docking was also performed. A network of predicted rhein targets was established and analysed with Cytoscape 3.7.1. The anti-inflammatory targets in the Therapeutic Target Database 2020 (TTD) were searched to build a protein-protein interaction network (PPI), which was merged with the ingredient-target network to screen anti-inflammatory targets associated with rhein. A network of anti-inflammatory rhein targets during the in vivo treatment of asthma was constructed to screen the anti-inflammatory targets related to asthma. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis was performed with the Enrichr database and Cytoscape 3.7.1. The expression levels of proteins in the mitogen-activated protein kinase / nuclear factor kappa-B (MAPK/NF-κB) signalling pathway were assessed by western blot analysis.Results: Altogether, Eighty-three targets were obtained. Epidermal active growth factor receptor (EGFR), E-selecting (E-SELE), macrophage migration inhibitory factor (MIF), and mitogen-activated protein kinase 14 (MAPK14) might be important anti-inflammatory targets of rhein during asthma treatment. We selected the MAPK signalling pathway to determine the anti-inflammatory effects of rhein.Conclusion: The anti-inflammatory mechanism of the treatment of asthma with rhein may be related to MAPK14, EGFR, E-SELE and MIF as well as their signalling pathways. To prevent the exacerbation of asthma, instead of targeting a single pathway or a single target, all these targets and their signalling pathways should be controlled holistically. Rhein may reduce inflammation by inhibiting the MAPK/NF-κB pathway.

A novel vasculo-angiogenic effect of cilostazol mediated by cross-talk between multiple signalling pathways including the ERK/p38 MAPK signalling transduction cascade

2012 ◽  
Vol 123 (3) ◽  
pp. 147-159 ◽  
Author(s):  
Ting-Hsing Chao ◽  
Shih-Ya Tseng ◽  
Yi-Heng Li ◽  
Ping-Yen Liu ◽  
Chung-Lung Cho ◽  
...  
Keyword(s):  
Protein Kinase ◽  
P38 Mapk ◽  
Umbilical Vein ◽  
Tube Formation ◽  
Mitogen Activated Protein Kinase ◽  
Signalling Pathways ◽  
No Production ◽  
Angiogenic Effect

Cilostazol is an anti-platelet agent with vasodilatory activity that acts by increasing intracellular concentrations of cAMP. Recent reports have suggested that cilostazol may promote angiogenesis. In the present study, we have investigated the effect of cilostazol in promoting angiogenesis and vasculogenesis in a hindlimb ischaemia model and have also examined its potential mechanism of action in vitro and in vivo. We found that cilostazol treatment significantly increased colony formation by human early EPCs (endothelial progenitor cells) through a mechanism involving the activation of cAMP/PKA (protein kinase A), PI3K (phosphoinositide 3-kinase)/Akt/eNOS (endothelial NO synthase) and ERK (extracellular-signal-regulated kinase)/p38 MAPK (mitogen-activated protein kinase) signalling pathways. Cilostazol also enhanced proliferation, chemotaxis, NO production and vascular tube formation in HUVECs (human umbilical vein endothelial cells) through activation of multiple signalling pathways downstream of PI3K/Akt/eNOS. Cilostazol up-regulated VEGF (vascular endothelial growth factor)-A165 expression and secretion of VEGF-A in HUVECs through activation of the PI3K/Akt/eNOS pathway. In a mouse hindlimb ischaemia model, recovery of blood flow ratio (ipsilateral/contralateral) 14 days after surgery was significantly improved in cilostazol-treated mice (10 mg/kg of body weight) compared with vehicle-treated controls (0.63±0.07 and 0.43±0.05 respectively, P<0.05). Circulating CD34+ cells were also increased in cilostazol-treated mice (3614±670 compared with 2151±608 cells/ml, P<0.05). Expression of VEGF and phosphorylation of PI3K/Akt/eNOS and ERK/p38 MAPK in ischaemic muscles were significantly enhanced by cilostazol. Our data suggest that cilostazol produces a vasculo-angiogenic effect by up-regulating a broad signalling network that includes the ERK/p38 MAPK, VEGF-A165, PI3K/Akt/eNOS and cAMP/PKA pathways.

scholarly journals Cross-talk between IRAK-4 and the NADPH oxidase1

2007 ◽  
Vol 403 (3) ◽  
pp. 451-461 ◽  
Author(s):  
Sandrine Pacquelet ◽  
Jennifer L. Johnson ◽  
Beverly A. Ellis ◽  
Agnieszka A. Brzezinska ◽  
William S. Lane ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Nadph Oxidase ◽  
P38 Mapk ◽  
Interleukin 1 ◽  
Mitogen Activated Protein Kinase ◽  
Free System ◽  
Mitogen Activated Protein ◽  
A Cell ◽  
Tlr4 Activation

Exposure of neutrophils to LPS (lipopolysaccharide) triggers their oxidative response. However, the relationship between the signalling downstream of TLR4 (Toll-like receptor 4) after LPS stimulation and the activation of the oxidase remains elusive. Phosphorylation of the cytosolic factor p47phox is essential for activation of the NADPH oxidase. In the present study, we examined the hypothesis that IRAK-4 (interleukin-1 receptor-associated kinase-4), the main regulatory kinase downstream of TLR4 activation, regulates the NADPH oxidase through phosphorylation of p47phox. We show that p47phox is a substrate for IRAK-4. Unlike PKC (protein kinase C), IRAK-4 phosphorylates p47phox not only at serine residues, but also at threonine residues. Target residues were identified by tandem MS, revealing a novel threonine-rich regulatory domain. We also show that p47phox is phosphorylated in granulocytes in response to LPS stimulation. LPS-dependent phosphorylation of p47phox was enhanced by the inhibition of p38 MAPK (mitogen-activated protein kinase), confirming that the kinase operates upstream of p38 MAPK. IRAK-4-phosphorylated p47phox activated the NADPH oxidase in a cell-free system, and IRAK-4 overexpression increased NADPH oxidase activity in response to LPS. We have shown that endogenous IRAK-4 interacts with p47phox and they co-localize at the plasma membrane after LPS stimulation, using immunoprecipitation assays and immunofluorescence microscopy respectively. IRAK-4 was activated in neutrophils in response to LPS stimulation. We found that Thr133, Ser288 and Thr356, targets for IRAK-4 phosphorylation in vitro, are also phosphorylated in endogenous p47phox after LPS stimulation. We conclude that IRAK-4 phosphorylates p47phox and regulates NADPH oxidase activation after LPS stimulation.

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