scholarly journals Neutrophils Stimulated with a Variety of Chemoattractants Exhibit Rapid Activation of p21-Activated Kinases (Paks): Separate Signals Are Required for Activation and Inactivation of Paks

1998 ◽  
Vol 18 (12) ◽  
pp. 7130-7138 ◽  
Author(s):  
RiYun Huang ◽  
Jian P. Lian ◽  
Dwight Robinson ◽  
John A. Badwey
Keyword(s):  
G Proteins ◽  
Platelet Activating Factor ◽  
Cell Types ◽  
Mitogen Activated Protein Kinase ◽  
Transient Activation ◽  
Anaphylatoxin C5a ◽  
Mitogen Activated Protein ◽  
Fmlp Receptor ◽  
Rapid Activation ◽  
G Protein Coupled

ABSTRACT Activation of the p21-activated protein kinases (Paks) was compared in neutrophils stimulated with a wide variety of agonists that bind to receptors coupled to heterotrimeric G proteins. Neutrophils stimulated with sulfatide, a ligand for the L-selectin receptor, or the chemoattractant fMet-Leu-Phe (fMLP), platelet-activating factor, leukotriene B4, interleukin-8, or the chemokine RANTES exhibited a rapid and transient activation of the 63- and 69-kDa Paks. These kinases exhibited maximal activation with each of these agonists within 15 s followed by significant inactivation at 3 min. In contrast, neutrophils treated with the chemoattractant and anaphylatoxin C5a exhibited a prolonged activation (>15 min) of these Paks even though the receptor for this ligand may activate the same overall population of complex G proteins as the fMLP receptor. Addition of fMLP to neutrophils already stimulated with C5a resulted in the inactivation of the 63- and 69-kDa Paks. Optimal activation of Paks could be observed at concentrations of these agonists that elicited only shape changes and chemotaxis in neutrophils. While all of the agonists listed above triggered quantitatively similar activation of the 63- and 69-kDa Paks, fMLP was far superior to the other stimuli in triggering activation of the c-Jun N-terminal kinase (JNK) and the p38 mitogen-activated protein kinase (MAPK). These data indicate that separate signals are required for activation and inactivation of Paks and that, in contrast to other cell types, activated Pak does not trigger activation of JNK or p38-MAPK in neutrophils. These results are consistent with the recent hypothesis that G-protein-coupled receptors may initiate signals independent of those transmitted by the α and βγ subunits of complex G proteins.

Role of plasmalemmal caveolae in signal transduction

1998 ◽  
Vol 275 (5) ◽  
pp. L843-L851 ◽  
Author(s):  
Philip W. Shaul ◽  
Richard G. W. Anderson
Keyword(s):  
Signal Transduction ◽  
Buoyant Density ◽  
Cell Types ◽  
Mitogen Activated Protein Kinase ◽  
Multiple Components ◽  
Mitogen Activated Protein ◽  
Numerous Cell ◽  
Triton X ◽  
Oxide Synthase ◽  
G Protein Coupled

Caveolae are specialized plasmalemmal microdomains originally studied in numerous cell types for their involvement in the transcytosis of macromolecules. They are enriched in glycosphingolipids, cholesterol, sphingomyelin, and lipid-anchored membrane proteins, and they are characterized by a light buoyant density and resistance to solubilization by Triton X-100 at 4°C. Once the identification of the marker protein caveolin made it possible to purify this specialized membrane domain, it was discovered that caveolae also contain a variety of signal transduction molecules. This includes G protein-coupled receptors, G proteins and adenylyl cyclase, molecules involved in the regulation of intracellular calcium homeostasis, and their effectors including the endothelial isoform of nitric oxide synthase, multiple components of the tyrosine kinase-mitogen-activated protein kinase pathway, and numerous lipid signaling molecules. More recent work has indicated that caveolae further serve to compartmentalize, modulate, and integrate signaling events at the cell surface. This specialized plasmalemmal domain warrants direct consideration in future investigations of both normal and pathological signal transduction in pulmonary cell types.

scholarly journals Selective expression of the scaffold protein JSAP1 in spermatogonia and spermatocytes

Reproduction ◽  
2006 ◽  
Vol 131 (4) ◽  
pp. 711-719 ◽  
Author(s):  
Munkhuu Bayarsaikhan ◽  
Akiko Shiratsuchi ◽  
Davaakhuu Gantulga ◽  
Yoshinobu Nakanishi ◽  
Katsuji Yoshioka
Keyword(s):  
Protein Kinase ◽  
Western Blotting ◽  
Cell Types ◽  
Mapk Signaling ◽  
Scaffold Protein ◽  
Mitogen Activated Protein Kinase ◽  
Interacting Protein ◽  
Early Postnatal Development ◽  
Mitogen Activated Protein ◽  
Signaling Modules

Scaffold proteins of mitogen-activated protein kinase (MAPK) intracellular signal transduction pathways mediate the efficient and specific activation of the relevant MAPK signaling modules. Previously, our group and others have identified c-Jun NH2-terminal kinase (JNK)/stress-activated protein kinase-associated protein 1 (JSAP1, also known as JNK-interacting protein 3) as a scaffold protein for JNK MAPK pathways. Although JSAP1 is expressed in the testis in adults, its expression during development has not been investigated. In addition, it is unknown which types of cells in the testis express the scaffold protein. Here, we examined the expression of JSAP1 in the testis of mice aged 14 days, 20 days, 6 weeks, and 12 weeks by immunohistochemistry and Western blotting. The specificity of the anti-JSAP1 antibody was evaluated from its reactivity to exogenously expressed JSAP1 and a structurally related protein, and by antigen-absorption experiments. The immunohistochemical analyses with the specific antibody showed that the JSAP1 protein was selectively expressed in the spermatogonia and spermatocytes, but not in other cell types, including spermatids and somatic cells, during development. However, not all spermatogonia and spermatocytes were immunopositive either, especially in the 12-week-old mouse testis. Furthermore, we found by Western blotting that the expression levels of JSAP1 protein vary during development; there is high expression until 6 weeks after birth, which approximately corresponds to the end of the first wave of spermatogenesis. Collectively, these results suggest that JSAP1 function may be important in spermatogenic cells during early postnatal development.

scholarly journals Rapid activation of phosphorylated mitogen-activated protein kinase after sexual stimulation in male mice

Neuroreport ◽  
2011 ◽  
Vol 22 (6) ◽  
pp. 294-298 ◽  
Author(s):  
Mélanie Taziaux ◽  
Matthieu Keller ◽  
Jacques Balthazart ◽  
Julie Bakker
Keyword(s):  
Protein Kinase ◽  
Mitogen Activated Protein Kinase ◽  
Male Mice ◽  
Sexual Stimulation ◽  
Mitogen Activated Protein ◽  
Rapid Activation

AMPK, MAPK and Bax in the heart: some questions answered

2008 ◽  
Vol 412 (2) ◽  
pp. e15-e16 ◽  
Author(s):  
Vilmante Borutaite
Keyword(s):  
Protein Kinase ◽  
Mitogen Activated Protein Kinase ◽  
Wide Field ◽  
Biochemical Journal ◽  
Mitogen Activated Protein ◽  
Isolated Cardiac Myocytes ◽  
And Migration ◽  
Induced Apoptosis ◽  
Amp Activated Protein Kinase ◽  
Rapid Activation

The question of how Bax is activated during apoptosis to perform its role in permeabilization of mitochondrial membranes is intriguing for investigators in the wide field of cell death research. In their paper published in the Biochemical Journal in 2006, Capano and Crompton presented their discovery that simulated ischaemia causes rapid activation of AMPK (AMP-activated protein kinase) which phosphorylates and activates p38 MAPK (mitogen-activated protein kinase) leading to Bax activation and translocation to mitochondria in isolated cardiac myocytes. This was the first report on the molecular mechanism of Bax activation and migration during ischaemia-induced apoptosis in cardiomyocytes.

scholarly journals Cdk5 Modulation of Mitogen-activated Protein Kinase Signaling Regulates Neuronal Survival

2007 ◽  
Vol 18 (2) ◽  
pp. 404-413 ◽  
Author(s):  
Ya-Li Zheng ◽  
Bing-Sheng Li ◽  
Jyotshna Kanungo ◽  
Sashi Kesavapany ◽  
Niranjana Amin ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Cortical Neurons ◽  
Neuronal Cell ◽  
Mitogen Activated Protein Kinase ◽  
Significant Shift ◽  
Kinase Signaling ◽  
Small Interference Rna ◽  
Transient Activation ◽  
Mitogen Activated Protein ◽  
Protein Kinase Signaling

Cdk5, a cyclin-dependent kinase, is critical for neuronal development, neuronal migration, cortical lamination, and survival. Its survival role is based, in part, on “cross-talk” interactions with apoptotic and survival signaling pathways. Previously, we showed that Cdk5 phosphorylation of mitogen-activated protein kinase kinase (MEK)1 inhibits transient activation induced by nerve growth factor (NGF) in PC12 cells. To further explore the nature of this inhibition, we studied the kinetics of NGF activation of extracellular signal-regulated kinase (Erk)1/2 in cortical neurons with or without roscovitine, an inhibitor of Cdk5. NGF alone induced an Erk1/2-transient activation that peaked in 15 min and declined rapidly to baseline. Roscovitine, alone or with NGF, reached peak Erk1/2 activation in 30 min that was sustained for 48 h. Moreover, the sustained Erk1/2 activation induced apoptosis in cortical neurons. Significantly, pharmacological application of the MEK1 inhibitor PD98095 to roscovitine-treated cortical neurons prevented apoptosis. These results were also confirmed by knocking down Cdk5 activity in cortical neurons with Cdk5 small interference RNA. Apoptosis was correlated with a significant shift of phosphorylated tau and neurofilaments from axons to neuronal cell bodies. These results suggest that survival of cortical neurons is also dependent on tight Cdk5 modulation of the mitogen-activated protein kinase signaling pathway.

scholarly journals An ultrasensitive fiveplex activity assay for cellular kinases

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Christian M. Smolko ◽  
Kevin A. Janes
Keyword(s):  
Protein Kinase ◽  
Protein Interactions ◽  
Posttranslational Modifications ◽  
Large Scale ◽  
Cell Types ◽  
Mitogen Activated Protein Kinase ◽  
Activity Measurement ◽  
Kinase Substrate ◽  
Iκb Kinase ◽  
Mitogen Activated Protein

AbstractProtein kinases are enzymes whose abundance, protein-protein interactions, and posttranslational modifications together determine net signaling activity in cells. Large-scale data on cellular kinase activity are limited, because existing assays are cumbersome, poorly sensitive, low throughput, and restricted to measuring one kinase at a time. Here, we surmount the conventional hurdles of activity measurement with a multiplexing approach that leverages the selectivity of individual kinase-substrate pairs. We demonstrate proof of concept by designing an assay that jointly measures activity of five pleiotropic signaling kinases: Akt, IκB kinase (IKK), c-jun N-terminal kinase (JNK), mitogen-activated protein kinase (MAPK)-extracellular regulated kinase kinase (MEK), and MAPK-activated protein kinase-2 (MK2). The assay operates in a 96-well format and specifically measures endogenous kinase activation with coefficients of variation less than 20%. Multiplex tracking of kinase-substrate pairs reduces input requirements by 25-fold, with ~75 µg of cellular extract sufficient for fiveplex activity profiling. We applied the assay to monitor kinase signaling during coxsackievirus B3 infection of two different host-cell types and identified multiple differences in pathway dynamics and coordination that warrant future study. Because the Akt–IKK–JNK–MEK–MK2 pathways regulate many important cellular functions, the fiveplex assay should find applications in inflammation, environmental-stress, and cancer research.

scholarly journals The AngFus3 Mitogen-Activated Protein Kinase Controls Hyphal Differentiation and Secondary Metabolism in Aspergillus niger

2015 ◽  
Vol 14 (6) ◽  
pp. 602-615 ◽  
Author(s):  
Bert-Ewald Priegnitz ◽  
Ulrike Brandt ◽  
Khomaizon A. K. Pahirulzaman ◽  
Jeroen S. Dickschat ◽  
André Fleißner
Keyword(s):  
Aspergillus Niger ◽  
Map Kinase ◽  
Secondary Metabolism ◽  
Filamentous Fungi ◽  
Cell Types ◽  
Growth Conditions ◽  
Mitogen Activated Protein Kinase ◽  
Content Type ◽  
Mitogen Activated Protein ◽  
Upstream Kinase

ABSTRACTAdaptation to a changing environment is essential for the survival and propagation of sessile organisms, such as plants or fungi. Filamentous fungi commonly respond to a worsening of their growth conditions by differentiation of asexually or sexually produced spores. The formation of these specialized cell types is, however, also triggered as part of the general life cycle by hyphal age or density. Spores typically serve for dispersal and, therefore, translocation but can also act as resting states to endure times of scarcity. Eukaryotic differentiation in response to environmental and self-derived signals is commonly mediated by three-tiered mitogen-activated protein (MAP) kinase signaling cascades. Here, we report that the MAP kinase Fus3 of the black moldAspergillus niger(AngFus3) and its upstream kinase AngSte7 control vegetative spore formation and secondary metabolism. Mutants lacking these kinases are defective in conidium induction in response to hyphal density but are fully competent in starvation-induced sporulation, indicating that conidiation inA. nigeris triggered by various independent signals. In addition, the mutants exhibit an altered profile of volatile metabolites and secrete dark pigments into the growth medium, suggesting a dysregulation of the secondary metabolism. By assigning the AngFus3 MAP kinase pathway to the transduction of a potentially self-derived trigger, this work contributes to the unraveling of the intricate signaling networks controlling fungal differentiation. Moreover, our data further support earlier observations that differentiation and secondary metabolism are tightly linked in filamentous fungi.

Diacylglycerol and ceramide formation induced by dopamine D2S receptors via Gβγ-subunits in Balb/c-3T3 cells

2003 ◽  
Vol 284 (3) ◽  
pp. C640-C648 ◽  
Author(s):  
Gele Liu ◽  
Mohammad H. Ghahremani ◽  
Behzad Banihashemi ◽  
Paul R. Albert
Keyword(s):  
Cell Growth ◽  
Phospholipase C ◽  
G Protein ◽  
G Proteins ◽  
Second Messengers ◽  
Mitogen Activated Protein Kinase ◽  
Fibroblast Cells ◽  
Induced Responses ◽  
3T3 Cells ◽  
Mitogen Activated Protein

Diacylglycerol (DAG) and ceramide are important second messengers affecting cell growth, differentiation, and apoptosis. Balb/c-3T3 fibroblast cells expressing dopamine-D2S (short) receptors (Balb-D2S cells) provide a model of G protein-mediated cell growth and transformation. In Balb-D2S cells, apomorphine (EC50= 10 nM) stimulated DAG and ceramide formation by 5.6- and 4.3-fold, respectively, maximal at 1 h and persisting over 6 h. These actions were blocked by pretreatment with pertussis toxin (PTX), implicating Gi/Goproteins. To address which G proteins are involved, Balb-D2S clones expressing individual PTX-insensitive Gαiproteins were treated with PTX and tested for apomorphine-induced responses. Neither PTX-insensitive Gαi2nor Gαi3rescued D2S-induced DAG or ceramide formation. Both D2S-induced DAG and ceramide signals required Gβγ-subunits and were blocked by inhibitors of phospholipase C [1-(6-[([17β]-3-methoxyestra-1,2,3[10]-trien- 17yl)amino]hexyl)-1H-pyrrole-2,5-dione (U-73122) and partially by D609]. The similar G protein specificity of D2S-induced calcium mobilization, DAG, and ceramide formation indicates a common Gβγ-dependent phospholipase C-mediated pathway. Both D2 agonists and ceramide specifically induced mitogen-activated protein kinase (ERK1/2), suggesting that ceramide mediates a novel pathway of D2S-induced ERK1/2 activation, leading to cell growth.

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