scholarly journals Signaling through mitogen-activated protein kinase and Rac/Rho does not duplicate the effects of activated Ras on skeletal myogenesis.

1997 ◽  
Vol 17 (7) ◽  
pp. 3547-3555 ◽  
Author(s):  
M B Ramocki ◽  
S E Johnson ◽  
M A White ◽  
C L Ashendel ◽  
S F Konieczny ◽  
...  
Keyword(s):  
Map Kinase ◽  
Signaling Pathways ◽  
Transcriptional Activation ◽  
Intracellular Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Ras Signaling ◽  
Negative Effects ◽  
Intracellular Signaling Pathway ◽  
Helix Loop Helix ◽  
Mitogen Activated Protein

The ability of basic helix-loop-helix muscle regulatory factors (MRFs), such as MyoD, to convert nonmuscle cells to a myogenic lineage is regulated by numerous growth factor and oncoprotein signaling pathways. Previous studies have shown that H-Ras 12V inhibits differentiation to a skeletal muscle lineage by disrupting MRF function via a mechanism that is independent of the dimerization, DNA binding, and inherent transcriptional activation properties of the proteins. To investigate the intracellular signaling pathway(s) that mediates the inhibition of MRF-induced myogenesis by oncogenic Ras, we tested two transformation-defective H-Ras 12V effector domain variants for their ability to alter terminal differentiation. H-Ras 12V,35S retains the ability to activate the Raf/MEK/mitogen-activated protein (MAP) kinase cascade, whereas H-Ras 12V,40C is unable to interact directly with Raf-1 yet still influences other signaling intermediates, including Rac and Rho. Expression of each H-Ras 12V variant in C3H10T1/2 cells abrogates MyoD-induced activation of the complete myogenic program, suggesting that MAP kinase-dependent and -independent Ras signaling pathways individually block myogenesis in this model system. However, additional studies with constitutively activated Rac1 and RhoA proteins revealed no negative effects on MyoD-induced myogenesis. Similarly, treatment of Ras-inhibited myoblasts with the MEK1 inhibitor PD98059 revealed that elevated MAP kinase activity is not a significant contributor to the H-Ras 12V effect. These data suggest that an additional Ras pathway, distinct from the well-characterized MAP kinase and Rac/Rho pathways known to be important for the transforming function of activated Ras, is primarily responsible for the inhibition of myogenesis by H-Ras 12V.

scholarly journals TRAF6-Dependent Mitogen-Activated Protein Kinase Activation Differentially Regulates the Production of Interleukin-12 by Macrophages in Response to Toxoplasma gondii

2004 ◽  
Vol 72 (10) ◽  
pp. 5662-5667 ◽  
Author(s):  
Nicola J. Mason ◽  
Jim Fiore ◽  
Takashi Kobayashi ◽  
Katherine S. Masek ◽  
Yongwon Choi ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Toxoplasma Gondii ◽  
Signaling Pathways ◽  
Intracellular Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Interleukin 12 ◽  
Wild Type ◽  
Kinase Activation ◽  
Extracellular Signal ◽  
Mitogen Activated Protein

ABSTRACT The production of interleukin-12 (IL-12) is critical to the development of innate and adaptive immune responses required for the control of intracellular pathogens. Many microbial products signal through Toll-like receptors (TLR) and activate NF-κB family members that are required for the production of IL-12. Recent studies suggest that components of the TLR pathway are required for the production of IL-12 in response to the parasite Toxoplasma gondii; however, the production of IL-12 in response to this parasite is independent of NF-κB activation. The adaptor molecule TRAF6 is involved in TLR signaling pathways and associates with serine/threonine kinases involved in the activation of both NF-κB and mitogen-activated protein kinase (MAPK). To elucidate the intracellular signaling pathways involved in the production of IL-12 in response to soluble toxoplasma antigen (STAg), wild-type and TRAF6−/− mice were inoculated with STAg, and the production of IL-12(p40) was determined. TRAF6−/− mice failed to produce IL-12(p40) in response to STAg, and TRAF6−/− macrophages stimulated with STAg also failed to produce IL-12(p40). Studies using Western blot analysis of wild-type and TRAF6−/− macrophages revealed that stimulation with STAg resulted in the rapid TRAF6-dependent phosphorylation of p38 and extracellular signal-related kinase, which differentially regulated the production of IL-12(p40). The studies presented here demonstrate for the first time that the production of IL-12(p40) in response to toxoplasma is dependent upon TRAF6 and p38 MAPK.

scholarly journals MAP Kinase OsMEK2 and OsMPK1 Signaling for Ferroptotic Cell Death in Rice-Magnaporthe oryzae Interactions

2020 ◽  
Author(s):  
Sarmina Dangol ◽  
Raksha Singh ◽  
Khoa Nam Nguyen ◽  
Yafei Chen ◽  
Juan Wang ◽  
...  
Keyword(s):  
Cell Death ◽  
Map Kinase ◽  
Signaling Pathways ◽  
Magnaporthe Oryzae ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Microbial Pathogens ◽  
Blast Disease ◽  
Related Cell ◽  
Mitogen Activated Protein

ABSTRACTMitogen-activated protein kinase (MAPK) signaling is required for plant cell death responses to invading microbial pathogens. Ferric ions and reactive oxygen species (ROS) accumulate in rice (Oryza sativa) tissues undergoing cell death during Magnaporthe oryzae infection. Here, we report that rice MAP kinase (OsMEK2 and OsMPK1) signaling cascades are involved in iron- and ROS-dependent ferroptotic cell death responses of rice to M. oryzae infection. OsMEK2 interacted with OsMPK1 in the cytoplasm, and OsMPK1 moved from the cytoplasm into the nucleus to bind to the OsWRKY90 transcription factor. OsMEK2 expression may trigger OsMPK1-OsWRKY90 signaling pathways in the nucleus. Avirulent M. oryzae infection in ΔOsmek2 mutant rice did not trigger iron and ROS accumulation and lipid peroxidation, and also downregulated OsMPK1, OsWRKY90, OsRbohB, and OsPR-1b expression. However, OsMEK2 overexpression induced ROS-and iron-dependent cell death in rice during M. oryzae infection. The downstream MAP kinase (OsMPK1) overexpression induced ROS- and iron-dependent ferroptotic cell death in the compatible rice-M. oryzae interaction. These data suggest that the OsMEK2-OsMPK1-OsWRKY90 signaling cascade is involved in the ferroptotic cell death in rice. The small-molecule inducer erastin triggered iron- and lipid ROS-dependent, but OsMEK2-independent, ferroptotic cell death in ΔOsmek2 mutant plants during M. oryzae infection. Disease-related cell death was lipid ROS-dependent and iron-independent in the ΔOsmek2 mutant plants. These combined results suggest that OsMEK2 and OsMPK1 expression positively regulates iron- and ROS-dependent ferroptotic cell death via OsMEK2-OsMPK1-OsWRKY90 signaling pathways, and blast disease (susceptibility)-related cell death was ROS-dependent but iron-independent in rice-M. oryzae interactions.

scholarly journals ERK5 Is a Novel Type of Mitogen-Activated Protein Kinase Containing a Transcriptional Activation Domain

2000 ◽  
Vol 20 (22) ◽  
pp. 8382-8389 ◽  
Author(s):  
Herbert G. Kasler ◽  
Joseph Victoria ◽  
Omar Duramad ◽  
Astar Winoto
Keyword(s):  
T Cells ◽  
Map Kinase ◽  
Transcriptional Activation ◽  
Antigen Receptor ◽  
Mitogen Activated Protein Kinase ◽  
Calcium Flux ◽  
Activation Domain ◽  
Transcriptional Activation Domain ◽  
Mitogen Activated Protein

ABSTRACT Previous studies have shown that upregulation of the orphan steroid receptor Nur77 is required for the apoptosis of immature T cells in response to antigen receptor signals. Transcriptional upregulation of Nur77 in response to antigen receptor signaling involves two binding sites for the MEF2 family of transcription factors located in the Nur77 promoter. Calcium signals greatly increase the activity of MEF2D in T cells via a posttranslational mechanism. The mitogen-activated protein (MAP) kinase ERK5 was isolated in a yeast two-hybrid screen using the MADS-MEF2 domain of MEF2D as bait. ERK5 resembles the other MAP kinase family members in its N-terminal half, but it also contains a 400-amino-acid C-terminal domain of previously uncharacterized function. We report here that the C-terminal region of ERK5 contains a MEF2-interacting domain and, surprisingly, also a potent transcriptional activation domain. These domains are both required for coactivation of MEF2D by ERK5. The MEF2-ERK5 interaction was found to be activation dependent in vivo and inhibitable in vitro by the calcium-sensitive MEF2 repressor Cabin 1. The transcriptional activation domain of ERK5 is required for maximal MEF2 activity in response to calcium flux in T cells, and it can activate the endogenous Nur77 gene when constitutively recruited to the Nur77 promoter via MEF2 sites. These studies provide insights into a mechanism whereby MEF2 activity can respond to calcium signaling and suggest a novel, unexpected mechanism of MAP kinase function.

scholarly journals Characterization of a serum response factor-like protein in Saccharomyces cerevisiae, Rlm1, which has transcriptional activity regulated by the Mpk1 (Slt2) mitogen-activated protein kinase pathway.

1997 ◽  
Vol 17 (5) ◽  
pp. 2615-2623 ◽  
Author(s):  
Y Watanabe ◽  
G Takaesu ◽  
M Hagiwara ◽  
K Irie ◽  
K Matsumoto
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Map Kinase ◽  
Transcriptional Activation ◽  
Transcriptional Activity ◽  
Mitogen Activated Protein Kinase ◽  
Dependent Manner ◽  
Mads Box ◽  
Mitogen Activated Protein

The Mpk1 (Slt2) mitogen-activated protein (MAP) kinase has been implicated in several biological processes in Saccharomyces cerevisiae. The Rlm1 protein, a member of the MADS box family of transcription factors, functions downstream of Mpk1 in the pathway. To characterize the role of Rlm1 in mediating the transcriptional activation by the Mpk1 pathway, we constructed a LexA-Rlm1 deltaN chimera in which sequences, including the MADS box domain of the Rlm1 protein, were replaced by the LexA DNA binding domain and tested the ability of this chimera to activate a LexA operator-controlled reporter gene. In this assay, the Rlm1 protein was found to activate transcription in a manner regulated by the Mpk1 pathway. The Mpk1 protein kinase phosphorylated Rlm1 deltaN in vitro and the LexA-Rlm1 deltaN chimera protein was phosphorylated in vivo in a Mpk1-dependent manner. These results suggest that Mpk1 regulates the transcriptional activity of Rlm1 by directly phosphorylating it. We identified a Mpk1-like protein kinase, Mlp1, as an Rlm1-associated protein by using the yeast two-hybrid system. Overexpression of MLP1 suppresses the caffeine-sensitive phenotype of the bck1 delta mutation. The additivity of the mlp1 delta defect with the Mpk1 delta defect with regard to the caffeine sensitivity, combined with the results of genetic epistasis experiments, suggested that the activity of Rlm1 is regulated independently by Mpk1 MAP kinase and the Mlp1 MAP kinase-like kinase.

scholarly journals Protein synthesis inhibitors reveal differential regulation of mitogen-activated protein kinase and stress-activated protein kinase pathways that converge on Elk-1.

1995 ◽  
Vol 15 (9) ◽  
pp. 4930-4938 ◽  
Author(s):  
R Zinck ◽  
M A Cahill ◽  
M Kracht ◽  
C Sachsenmaier ◽  
R A Hipskind ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Protein Synthesis ◽  
Protein Kinase ◽  
Signaling Pathways ◽  
Intracellular Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Early Gene ◽  
Immediate Early ◽  
Protein Synthesis Inhibitors ◽  
Mitogen Activated Protein

Inhibitors of protein synthesis, such as anisomycin and cycloheximide, lead to superinduction of immediate-early genes. We demonstrate that these two drugs activate intracellular signaling pathways involving both the mitogen-activated protein kinase (MAPK) and stress-activated protein kinase (SAPK) cascades. The activation of either pathway correlates with phosphorylation of the c-fos regulatory transcription factor Elk-1. In HeLa cells, anisomycin stabilizes c-fos mRNA when protein synthesis is inhibited to only 50%. Under these conditions, anisomycin, in contrast to cycloheximide, rapidly induces kinase activation and efficient Elk-1 phosphorylation. However, full inhibition of translation by either drug leads to prolonged activation of SAPK activity, while MAPK induction is transient. This correlates with prolonged Elk-1 phosphorylation and c-fos transcription. Elk-1 induction and c-fos activation are also observed in KB cells, in which anisomycin strongly induces SAPKs but not MAPKs. Purified p54 SAPK alpha efficiently phosphorylates the Elk-1 C-terminal domain in vitro and comigrates with anisomycin-activated kinases in in-gel kinase assays. Thus, Elk-1 provides a potential convergence point for the MAPK and SAPK signaling pathways. The activation of signal cascades and control of transcription factor function therefore represent prominent processes in immediate-early gene superinduction.

Effects of exercise and insulin on mitogen-activated protein kinase signaling pathways in rat skeletal muscle

1996 ◽  
Vol 271 (2) ◽  
pp. E403-E408 ◽  
Author(s):  
L. J. Goodyear ◽  
P. Y. Chang ◽  
D. J. Sherwood ◽  
S. D. Dufresne ◽  
D. E. Moller
Keyword(s):  
Skeletal Muscle ◽  
Protein Kinase ◽  
Map Kinase ◽  
Signaling Pathways ◽  
Mammalian Cells ◽  
Mitogen Activated Protein Kinase ◽  
Kinase Signaling ◽  
Rat Skeletal Muscle ◽  
Map Kinase Signaling ◽  
Mitogen Activated Protein

Studies in mammalian cells have established the existence of at least three distinct mitogen-activated protein kinase (MAP kinase) signaling pathways that are activated by a variety of growth factors and/or environmental stressors. We determined whether physical exercise, a physiological stressor, and insulin, a metabolic stimulator and growth factor, activate the c-jun NH2-terminus kinase (JNK), the p38 kinase, and/or the extracellular regulatory kinases (ERK; p42MAPK and p44MAPK) signaling pathways in rat skeletal muscle. Animals were studied immediately after running on a motorized treadmill for 10-60 min (20 m/min, 10% grade) or 5-30 min after an intraperitoneal injection of insulin (20 U/rat). Exercise increased skeletal muscle JNK activity by two- to threefold throughout the time course studied, whereas insulin did not significantly increase JNK activity. The p38 activity was slightly stimulated by exercise and not by insulin. The ERK kinase pathway, as assessed by ribosomal S6 kinase-2 activity assays and phosphospecific p42MAPK/p4NAPK immunoblotting, was stimulated by both exercise and insulin. These data are the first demonstration of exercise stimulating multiple intracellular signaling pathways in skeletal muscle. Activation of these MAP kinase signaling pathways may mediate changes in skeletal muscle growth and metabolism that occur in response to exercise.

scholarly journals Investigation of effects of the <i>MKK3</i> and <i>MKK6</i> genes on meat production traits in the pig (Brief Report)

2010 ◽  
Vol 53 (2) ◽  
pp. 242-245 ◽  
Author(s):  
H. Wu ◽  
S. Zhao ◽  
B. Fan
Keyword(s):  
Intracellular Signaling ◽  
Muscle Development ◽  
Mapk Pathway ◽  
Mitogen Activated Protein Kinase ◽  
Meat Production ◽  
Production Traits ◽  
Association Analyses ◽  
Helix Loop Helix ◽  
Mitogen Activated Protein ◽  
Temporal Expressions

Abstract. Skeletal muscle development is a complexity process involved in spatial and temporal expressions of numerous muscle differentiation-specific genes, which are controlled by a series of basic helix-loop-helix myogenic regulatory factors (MRFs) (HOUBA and TE PAS 2004). The recent studies have demonstrated that the p38 mitogen-activated protein kinase (MAPK) pathway is probably one of the major intracellular signaling pathways affecting myogenesis (KEREN et al. 2006, LIUÍS et al. 2006). The p38 MAPKs regulate the transcriptional activities of MRFs and function in the remodeling of chromatin at specific muscle-regulatory regions (LI et al. 2000, ZARUBIN et al. 2005). The genes involved in the p38 MAPK pathway have been poorly studied in pigs. The primary work on SNP discovery and association analyses of two important MAPK kinases encoding genes MKK3 (MAP2K3) and MKK6 (MAP2K6) was presented in the study, so as to identify the potential genetic markers useful for marker assisted selection (MAS) improving lean meat production.

scholarly journals Cyclic AMP Selectively Uncouples Mitogen-Activated Protein Kinase Cascades from Activating Signals

2006 ◽  
Vol 26 (8) ◽  
pp. 3039-3047 ◽  
Author(s):  
Gray W. Pearson ◽  
Svetlana Earnest ◽  
Melanie H. Cobb
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Map Kinase ◽  
Signaling Pathways ◽  
Cellular Response ◽  
Mitogen Activated Protein Kinase ◽  
Extracellular Signal ◽  
Mitogen Activated Protein

ABSTRACT Cells integrate signals to select the appropriate response from an array of possible outcomes. Signal integration causes the reorganization of signaling pathways by undescribed events. To analyze the molecular changes in signaling pathways that elicit different responses, we focused on the interaction between cyclic AMP (cAMP) and growth factors. We show that the activation of extracellular signal-regulated kinase 5 (ERK5), but not ERK1/2, by growth factors is disrupted by cAMP through cAMP-dependent protein kinase (PKA). Activation of MEKK2, a mitogen-activated protein (MAP) kinase kinase kinase upstream of ERK5 that is required for growth factor activation of ERK5, is also disrupted by PKA. Transcription of c-Jun is induced by ERK5, and like ERK5, c-Jun induction is also blocked by cAMP. Transcription from the serum response element, like activation of ERK1/2, is not blocked by cAMP. Collectively, these results support a model in which cAMP shapes the growth factor-induced cellular response through PKA-dependent uncoupling of selected MAP kinase cascades from activating signals.

scholarly journals Post-Translational Regulation of the Activity of ERK/MAPK and PI3K/AKT Signaling Pathways in Neuroblastoma Cancer

2021 ◽  
Author(s):  
Aysegul Yildiz ◽  
Yesim Kaya
Keyword(s):  
Signaling Pathways ◽  
Intracellular Signaling ◽  
Translational Regulation ◽  
Akt Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Erk Mapk ◽  
Mitogen Activated Protein ◽  
Apoptotic Effect ◽  
Cancer Types ◽  
Effective Diagnosis

Pathogenesis of cancer is a multi-step process containing a number of cellular alterations such as post-translational dysregulation of intracellular signaling proteins. These alterations control several functions in carcinogenesis such as angiogenesis, metastasis, evading growth suppressors, and sustaining proliferative signaling. Data of various studies has demonstrated that Phosphatidylinositol 3-kinase (PI3K/AKT) and Mitogen-activated protein kinase (ERK/MAPK) pathways are both abnormally activated in many cancer types, including neuroblastoma. ERK/MAPK and PI3K/AKT signaling pathways that are regulated by sequential phosphorylation upon extracellular stimulation have many important functions in cell cycle, migration, proliferation and apoptosis. Besides their aberrant phosphorylation/activation, there is a crosstalk between these two pathways resulting in an anti-apoptotic effect. In this chapter, carcinogenetic abnormalities in post-translational regulation of the activity of ERK/MAPK and PI3K/AKT pathways in neuroblastoma and other cancers will be summarized. In addition, several crosstalk nodes between two pathways will be briefly explained. All these concepts are not only crucial for thoroughly understanding the molecular basis of carcinogenesis but also choosing the appropriate molecular targets for effective diagnosis and treatment.

scholarly journals A Misexpression Screen Identifies Genes That Can Modulate RAS1 Pathway Signaling in Drosophila melanogaster

Genetics ◽  
2000 ◽  
Vol 156 (3) ◽  
pp. 1219-1230 ◽  
Author(s):  
Audrey M Huang ◽  
Gerald M Rubin
Keyword(s):  
Signaling Pathways ◽  
Dominant Negative ◽  
Mitogen Activated Protein Kinase ◽  
Ras Signaling ◽  
Ras Pathway ◽  
Novel Proteins ◽  
Kinase Suppressor Of Ras ◽  
Mitogen Activated Protein ◽  
Sevenless Receptor Tyrosine Kinase ◽  
Protein Kinase Signaling

Abstract Differentiation of the R7 photoreceptor cell is dependent on the Sevenless receptor tyrosine kinase, which activates the RAS1/mitogen-activated protein kinase signaling cascade. Kinase suppressor of Ras (KSR) functions genetically downstream of RAS1 in this signal transduction cascade. Expression of dominant-negative KSR (KDN) in the developing eye blocks RAS pathway signaling, prevents R7 cell differentiation, and causes a rough eye phenotype. To identify genes that modulate RAS signaling, we screened for genes that alter RAS1/KSR signaling efficiency when misexpressed. In this screen, we recovered three known genes, Lk6, misshapen, and Akap200. We also identified seven previously undescribed genes; one encodes a novel rel domain member of the NFAT family, and six encode novel proteins. These genes may represent new components of the RAS pathway or components of other signaling pathways that can modulate signaling by RAS. We discuss the utility of gain-of-function screens in identifying new components of signaling pathways in Drosophila.

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