scholarly journals Extracellular Signal-Regulated Kinase Induces the Megakaryocyte GPIIb/CD41 Gene through MafB/Kreisler

2004 ◽  
Vol 24 (10) ◽  
pp. 4534-4545 ◽  
Author(s):  
Joel R. Sevinsky ◽  
Anne M. Whalen ◽  
Natalie G. Ahn
Keyword(s):  
Gene Expression ◽  
Mammalian Cells ◽  
Transcriptional Start Site ◽  
Dominant Negative ◽  
Proximal Promoter ◽  
Specific Gene ◽  
Promoter Regulation ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Megakaryocyte Differentiation

ABSTRACT Extracellular signal-regulated kinase (ERK) facilitates cell cycle progression in most mammalian cells, but in certain cell types prolonged signaling through this pathway promotes differentiation and lineage-specific gene expression through mechanisms that are poorly understood. Here, we characterize the transcriptional regulation of platelet GPIIb integrin (CD41) by ERK during megakaryocyte differentiation. ERK-dependent transactivation involves the proximal promoter of GPIIb within 114 bp upstream of the transcriptional start site. GATA, Ets, and Sp1 consensus sequences within this region are each necessary and function combinatorially in ERK-activated transcription. MafB/Kreisler is induced in response to ERK and synergizes with GATA and Ets to enhance transcription from the proximal promoter. The requirement for MafB in promoter regulation is demonstrated by inhibition of transactivation following dominant-negative or antisense suppression of MafB function. Thus, ERK promotes megakaryocyte differentiation by coordinate regulation of nuclear factors that synergize in GPIIb promoter regulation. These results establish a novel role for MafB as a regulator of ERK-induced gene expression.

Phorbol ester-induced activation of mitogen-activated protein kinase/extracellular-signal-regulated kinase kinase and extracellular-signal-regulated protein kinase decreases glucose-6-phosphatase gene expression

2001 ◽  
Vol 357 (3) ◽  
pp. 867-873 ◽  
Author(s):  
Dieter SCHMOLL ◽  
Rolf GREMPLER ◽  
Andreas BARTHEL ◽  
Hans-Georg JOOST ◽  
Reinhard WALTHER
Keyword(s):  
Gene Expression ◽  
Protein Kinase ◽  
Phorbol Ester ◽  
Regulation Of Gene Expression ◽  
Insulin Response ◽  
Dominant Negative ◽  
Mitogen Activated Protein Kinase ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Mitogen Activated Protein

Glucose-6-phosphatase (G6Pase) plays a central role in blood glucose homoeostasis, and insulin suppresses G6Pase gene expression by the activation of phosphoinositide 3-kinase (PI 3-kinase). Here, we show that the phorbol ester PMA decreases both basal and dexamethasone/cAMP-induced expression of a luciferase gene under the control of the G6Pase promoter in transiently transfected H4IIE hepatoma cells. This regulation was suppressed by the inhibitors of the mitogen-activated protein kinase/extracellular-signal-regulated kinase kinase (MEK), PD98059 and U0126, but not by the inhibitor of PI 3-kinase, LY294002. The co-expression of a constitutively active mutant of MEK mimicked the regulation of G6Pase promoter activity by PMA. The effect of PMA on both basal and induced G6Pase gene transcription was impaired by the overexpression of a dominant negative MEK construct, as well as by the expression of mitogen-activated protein kinase phosphatase-1. The mutation of the forkhead-binding sites within the insulin-response unit of the G6Pase promoter, which decreases the effect of insulin on G6Pase gene expression, did not alter the regulation of gene expression by PMA. The data show that PMA decreases G6Pase gene expression by the activation of MEK and extracellular-signal regulated protein kinase. With that, PMA mimics the effect of insulin on G6Pase gene expression by a different signalling pathway.

scholarly journals Critical role of the extracellular signal–regulated kinase–MAPK pathway in osteoblast differentiation and skeletal development

2007 ◽  
Vol 176 (5) ◽  
pp. 709-718 ◽  
Author(s):  
Chunxi Ge ◽  
Guozhi Xiao ◽  
Di Jiang ◽  
Renny T. Franceschi
Keyword(s):  
Transcriptional Activity ◽  
Mapk Pathway ◽  
Skeletal Development ◽  
Critical Role ◽  
Dominant Negative ◽  
Mitogen Activated Protein Kinase ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal

The extracellular signal–regulated kinase (ERK)–mitogen-activated protein kinase (MAPK) pathway provides a major link between the cell surface and nucleus to control proliferation and differentiation. However, its in vivo role in skeletal development is unknown. A transgenic approach was used to establish a role for this pathway in bone. MAPK stimulation achieved by selective expression of constitutively active MAPK/ERK1 (MEK-SP) in osteoblasts accelerated in vitro differentiation of calvarial cells, as well as in vivo bone development, whereas dominant-negative MEK1 was inhibitory. The involvement of the RUNX2 transcription factor in this response was established in two ways: (a) RUNX2 phosphorylation and transcriptional activity were elevated in calvarial osteoblasts from TgMek-sp mice and reduced in cells from TgMek-dn mice, and (b) crossing TgMek-sp mice with Runx2+/− animals partially rescued the hypomorphic clavicles and undemineralized calvaria associated with Runx2 haploinsufficiency, whereas TgMek-dn; Runx2+/− mice had a more severe skeletal phenotype. This work establishes an important in vivo function for the ERK–MAPK pathway in bone that involves stimulation of RUNX2 phosphorylation and transcriptional activity.

scholarly journals The Hinge-Helix 1 Region of Peroxisome Proliferator-Activated Receptor γ1 (PPARγ1) Mediates Interaction with Extracellular Signal-Regulated Kinase 5 and PPARγ1 Transcriptional Activation: Involvement in Flow-Induced PPARγ Activation in Endothelial Cells

2004 ◽  
Vol 24 (19) ◽  
pp. 8691-8704 ◽  
Author(s):  
Masashi Akaike ◽  
Wenyi Che ◽  
Nicole-Lerner Marmarosh ◽  
Shinsuke Ohta ◽  
Masaki Osawa ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Adhesion Molecule ◽  
Critical Role ◽  
Physiological Role ◽  
Cellular Adhesion ◽  
Dominant Negative ◽  
Peroxisome Proliferator ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Cellular Adhesion Molecule

ABSTRACT Peroxisome proliferator-activated receptors (PPAR) are ligand-activated transcription factors that form a subfamily of the nuclear receptor gene family. Since both flow and PPARγ have atheroprotective effects and extracellular signal-regulated kinase 5 (ERK5) kinase activity is significantly increased by flow, we investigated whether ERK5 kinase regulates PPARγ activity. We found that activation of ERK5 induced PPARγ1 activation in endothelial cells (ECs). However, we could not detect PPARγ phosphorylation by incubation with activated ERK5 in vitro, in contrast to ERK1/2 and JNK, suggesting a role for ERK5 as a scaffold. Endogenous PPARγ1 was coimmunoprecipitated with endogenous ERK5 in ECs. By mammalian two-hybrid analysis, we found that PPARγ1 associated with ERK5a at the hinge-helix 1 region of PPARγ1. Expressing a hinge-helix 1 region PPARγ1 fragment disrupted the ERK5a-PPARγ1 interaction, suggesting a critical role for hinge-helix 1 region of PPARγ in the ERK5-PPARγ interaction. Flow increased ERK5 and PPARγ1 activation, and the hinge-helix 1 region of the PPARγ1 fragment and dominant negative MEK5β significantly reduced flow-induced PPARγ activation. The dominant negative MEK5β also prevented flow-mediated inhibition of tumor necrosis factor alpha-mediated NF-κB activation and adhesion molecule expression, including vascular cellular adhesion molecule 1 and E-selectin, indicating a physiological role for ERK5 and PPARγ activation in flow-mediated antiinflammatory effects. We also found that ERK5 kinase activation was required, likely by inducing a conformational change in the NH2-terminal region of ERK5 that prevented association of ERK5 and PPARγ1. Furthermore, association of ERK5a and PPARγ1 disrupted the interaction of SMRT and PPARγ1, thereby inducing PPARγ activation. These data suggest that ERK5 mediates flow- and ligand-induced PPARγ activation via the interaction of ERK5 with the hinge-helix 1 region of PPARγ.

Role of extracellular signal-regulated kinase (ERK) signaling in nucleotide excision repair and genotoxicity in response to As(III) and Pb(II)

2008 ◽  
Vol 80 (12) ◽  
pp. 2735-2750
Author(s):  
Ju-Pi Li ◽  
Chun-Yu Wang ◽  
Yen-An Tang ◽  
Yun-Wei Lin ◽  
Jia-Ling Yang
Keyword(s):  
Signaling Pathways ◽  
Nucleotide Excision Repair ◽  
Mammalian Cells ◽  
Excision Repair ◽  
Erk Signaling ◽  
Erk Activation ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Nucleotide Excision

Arsenic and lead can induce genetic injuries and epigenetic signaling pathways in cultured mammalian cells. To test whether signaling pathways affect the extent of genetic injuries, we explored the impacts of extracellular signal-regulated kinase 1 and 2 (ERK) on nucleotide excision repair (NER), cytotoxicity, and genotoxicity following sodium arsenite [As(III)] and lead acetate [Pb(II)]. Sustained ERK activation was observed in human cells exposed to As(III) and Pb(II). As(III) inhibited the cellular NER synthesis capability; conversely, Pb(II) stimulated it. ERK activation contributed to the As(III)-induced NER inhibition and micronucleus formation. In contrast, this signal was required for inducing cellular NER activity and preventing mutagenesis following Pb(II). ERK activation by Pb(II) was dependent on protein kinase C (PKCα) that also exhibited anti-mutagenicity. Enforced expression of ERK signaling markedly elevated the cellular NER activity, which was suppressed by As(III). Nonetheless, ERK activation could counteract the cytotoxicity caused by these two metals. Together, the results indicate that pro-survival ERK signaling exhibits dual and opposing impacts on NER process following As(III) and Pb(II) exposures. The findings also suggest that ERK is an important epigenetic signaling in the determination of metal genotoxicity.

Non-autonomous regulation of a graded, PKA-mediated transcriptional activation signal for cell patterning

Development ◽  
1998 ◽  
Vol 125 (20) ◽  
pp. 3947-3954
Author(s):  
P. Balint-Kurti ◽  
G.T. Ginsburg ◽  
J. Liu ◽  
A.R. Kimmel
Keyword(s):  
Transcriptional Activation ◽  
Leucine Zipper ◽  
Gene Activation ◽  
Distal Segment ◽  
Dominant Negative ◽  
Regulatory Subunit ◽  
Specific Gene ◽  
Differentiated Cells ◽  
Extracellular Signal ◽  
Dependent Protein

The pseudoplasmodium or migrating slug of Dictyostelium is composed of non-terminally differentiated cells, organized along an anteroposterior axis. Cells in the anterior region of the slug define the prestalk compartment, whereas most of the posterior zone consists of prespore cells. We now present evidence that the cAMP-dependent protein kinase (PKA) and the RING domain/leucine zipper protein rZIP interact genetically to mediate a transcriptional activation gradient that regulates the differentiation of prespore cells within the posterior compartment of the slug. PKA is absolutely required for prespore differentiation. In contrast, rZIP negatively regulates prespore patterning; rzpA- cells, which lack rZIP, have reduced prestalk differentiation and a corresponding increase in prespore-specific gene expression. Using cell-specific markers and chimaeras of wild-type and rzpA- cells, we show that rZIP functions non-autonomously to establish a graded, prespore gene activation signal but autonomously to localize prespore expression. Overexpression of either the catalytic subunit or a dominant-negative regulatory subunit of PKA further demonstrates that PKA lies within the intracellular pathway that mediates the extracellular signal and regulates prespore patterning. Finally, we show that a 5′-distal segment within a prespore promoter that is responsive to a graded signal is also sensitive to PKA and rZIP, indicating that it acts directly at the level of prespore-specific gene transcription for regulation.

scholarly journals Growth Arrest-Specific Gene 6 (Gas6)/Adhesion Related Kinase (Ark) Signaling Promotes Gonadotropin-Releasing Hormone Neuronal Survival via Extracellular Signal-Regulated Kinase (ERK) and Akt

1999 ◽  
Vol 13 (2) ◽  
pp. 191-201 ◽  
Author(s):  
Melissa P. Allen ◽  
Chan Zeng ◽  
Kristina Schneider ◽  
Xiaoyan Xiong ◽  
Mary Kay Meintzer ◽  
...  
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Neuronal Migration ◽  
Neuronal Development ◽  
Mek Inhibitor ◽  
Specific Gene ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Gnrh Neurons ◽  
Induced Apoptosis

Abstract We identified Ark, the mouse homolog of the receptor tyrosine kinase Axl (Ufo, Tyro7), in a screen for novel factors involved in GnRH neuronal migration by using differential-display PCR on cell lines derived at two windows during GnRH neuronal development. Ark is expressed in Gn10 GnRH cells, developed from a tumor in the olfactory area when GnRH neurons are migrating, but not in GT1–7 cells, derived from a tumor in the forebrain when GnRH neurons are postmigratory. Since Ark (Axl) signaling protects from programmed cell death in fibroblasts, we hypothesized that it may play an antiapoptotic role in GnRH neurons. Gn10 (Ark positive) GnRH cells were more resistant to serum withdrawal-induced apoptosis than GT1–7 (Ark negative) cells, and this effect was augmented with the addition of Gas6, the Ark (Axl) ligand. Gas6/Ark stimulated the extracellular signal-regulated kinase, ERK, and the serine-threonine kinase, Akt, a downstream component of the phosphoinositide 3-kinase (PI3-K) pathway. To determine whether ERK or Akt activation is required for the antiapoptotic effects of Gas6/Ark in GnRH neurons, cells were serum starved in the absence or presence of Gas6, with or without inhibitors of ERK and PI3-K signaling cascades. Gas6 rescued Gn10 cells from apoptosis, and this effect was blocked by coincubation of the cells with the mitogen-activated protein/ERK kinase (MEK) inhibitor, PD98059, or wortmannin (but not rapamycin). These data support an important role for Gas6/Ark signaling via the ERK and PI3-K (via Akt) pathways in the protection of GnRH neurons from programmed cell death across neuronal migration.

scholarly journals The Transcription Factor GATA4 Is Activated by Extracellular Signal-Regulated Kinase 1- and 2-Mediated Phosphorylation of Serine 105 in Cardiomyocytes

2001 ◽  
Vol 21 (21) ◽  
pp. 7460-7469 ◽  
Author(s):  
Qiangrong Liang ◽  
Russell J. Wiese ◽  
Orlando F. Bueno ◽  
Yan-Shan Dai ◽  
Bruce E. Markham ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Dna Binding ◽  
Phosphorylation Site ◽  
Dominant Negative ◽  
Site Directed Mutagenesis ◽  
Mitogen Activated Protein Kinase ◽  
Cardiomyocyte Hypertrophy ◽  
Hypertrophic Growth ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal

ABSTRACT The zinc finger-containing transcription factor GATA4 has been implicated as a critical regulator of multiple cardiac-expressed genes as well as a regulator of inducible gene expression in response to hypertrophic stimulation. Here we demonstrate that GATA4 is itself regulated by the mitogen-activated protein kinase signaling cascade through direct phosphorylation. Site-directed mutagenesis and phospho-specific GATA4 antiserum revealed serine 105 as the primary site involved in agonist-induced phosphorylation of GATA4. Infection of cultured cardiomyocytes with an activated MEK1-expressing adenovirus induced robust phosphorylation of serine 105 in GATA4, while a dominant-negative MEK1-expressing adenovirus blocked agonist-induced phosphorylation of serine 105, implicating extracellular signal-regulated kinase (ERK) as a GATA4 kinase. Indeed, bacterially purified ERK2 protein directly phosphorylated purified GATA4 at serine 105 in vitro. Phosphorylation of serine 105 enhanced the transcriptional potency of GATA4, which was sensitive to U0126 (MEK1 inhibitor) but not SB202190 (p38 inhibitor). Phosphorylation of serine 105 also modestly enhanced the DNA binding activity of bacterially purified GATA4. Finally, induction of cardiomyocyte hypertrophy with an activated MEK1-expressing adenovirus was blocked with a dominant-negative GATA4-engrailed-expressing adenovirus. These results suggest a molecular pathway whereby MEK1-ERK1/2 signaling regulates cardiomyocyte hypertrophic growth through the transcription factor GATA4 by direct phosphorylation of serine 105, which enhances DNA binding and transcriptional activation.

Homocysteine-responsive ATF3 gene expression in human vascular endothelial cells: activation of c-Jun NH2-terminal kinase and promoter response element

Blood ◽  
2000 ◽  
Vol 96 (6) ◽  
pp. 2140-2148 ◽  
Author(s):  
Yong Cai ◽  
Chun Zhang ◽  
Tigre Nawa ◽  
Teijiro Aso ◽  
Makiko Tanaka ◽  
...  
Keyword(s):  
Gene Expression ◽  
Endothelial Cells ◽  
Protein Kinase ◽  
Transcriptional Start Site ◽  
Dominant Negative ◽  
Mitogen Activated Protein Kinase ◽  
Transcriptional Level ◽  
Appreciable Effect ◽  
Responsive Element ◽  
Atf3 Expression

Abstract Activating transcription factor (ATF) 3 is a member of ATF/cyclic adenosine monophosphate (cAMP)–responsive element binding protein (ATF/CREB) family of transcription factors and functions as a stress-inducible transcriptional repressor. To understand the stress-induced gene regulation by homocysteine, we investigated activation of the ATF3 gene in human endothelial cells. Homocysteine caused a rapid induction of ATF3 at the transcriptional level. This induction was preceded by a rapid and sustained activation of c-Jun NH2-terminal kinase/stress-activated protein kinase (JNK/SAPK), and dominant negative mitogen-activated protein kinase kinase 4 and 7 abolished these effects. The effect of homocysteine appeared to be specific, because cysteine or homocystine had no appreciable effect, but it was mimicked by dithiothreitol and β-mercaptoethanol as well as tunicamycin. The homocysteine effect was not inhibited by an active oxygen scavenger. Deletion analysis of the 5′ flanking sequence of the ATF3 gene promoter revealed that one of the major elements responsible for the induction by homocysteine is an ATF/cAMP responsive element (CRE) located at −92 to −85 relative to the transcriptional start site. Gel shift, immunoprecipitation, and cotransfection assays demonstrated that a complex (or complexes) containing ATF2, c-Jun, and ATF3 increased binding to the ATF/CRE site in the homocysteine-treated cells and activated the ATF3 gene expression, while ATF3 appeared to repress its own promoter. These data together suggested a novel pathway by which homocysteine causes the activation of JNK/SAPK and subsequent ATF3 expression through its reductive stress. Activation of JNK/SAPK and ATF3 expression in response to homocysteine may have a functional role in homocysteinemia-associated endothelial dysfunction.

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