Attenuation of CHOP-mediated Myocardial Apoptosis in Pressure-overloaded Dominant Negative p38α Mitogen-activated Protein Kinase Mice

AbstractThe Schizosaccharomyces pombe fbp1 gene, which encodes fructose-1,6-bis-phosphatase, is transcriptionally repressed by glucose through the activation of the cAMP-dependent protein kinase A (PKA) and transcriptionally activated by glucose starvation through the activation of a mitogen-activated protein kinase (MAPK). To identify transcriptional regulators acting downstream from or in parallel to PKA, we screened an adh-driven cDNA plasmid library for genes that increase fbp1 transcription in a strain with elevated PKA activity. Two such clones express amino-terminally truncated forms of the S. pombe tup12 protein that resembles the Saccharomyces cerevisiae Tup1p global corepressor. These clones appear to act as dominant negative alleles. Deletion of both tup12 and the closely related tup11 gene causes a 100-fold increase in fbp1-lacZ expression, indicating that tup11 and tup12 are redundant negative regulators of fbp1 transcription. In strains lacking tup11 and tup12, the atf1-pcr1 transcriptional activator continues to play a central role in fbp1-lacZ expression; however, spc1 MAPK phosphorylation of atf1 is no longer essential for its activation. We discuss possible models for the role of tup11- and tup12-mediated repression with respect to signaling from the MAPK and PKA pathways. A third clone identified in our screen expresses the php5 protein subunit of the CCAAT-binding factor (CBF). Deletion of php5 reduces fbp1 expression under both repressed and derepressed conditions. The CBF appears to act in parallel to atf1-pcr1, although it is unclear whether or not CBF activity is regulated by PKA.

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Synergistic Activation of Mitogen-Activated Protein Kinase by Cyclic AMP and Myeloid Growth Factors Opposes Cyclic AMP’s Growth-Inhibitory Effects

Blood ◽

10.1182/blood.v93.2.537 ◽

1999 ◽

Vol 93 (2) ◽

pp. 537-553 ◽

Cited By ~ 26

Author(s):

Angel Wai-mun Lee

Keyword(s):

Protein Kinase ◽

Cyclic Amp ◽

Cell Line ◽

Mapk Pathway ◽

Dominant Negative ◽

Mitogen Activated Protein Kinase ◽

Erk Activation ◽

Mitogen Activated Protein ◽

Erk Activity ◽

Myeloid Progenitors

Abstract Colony-stimulating factors (CSFs) promote the proliferation, differentiation, commitment, and survival of myeloid progenitors, whereas cyclic AMP (cAMP)-mediated signals frequently induce their growth arrest and apoptosis. The ERK/mitogen-activated protein kinase (MAPK) pathway is a target for both CSFs and cAMP. We investigated how costimulation by cAMP and colony-stimulating factor-1 (CSF-1) or interleukin-3 (IL-3) modulates MAPK in the myeloid progenitor cell line, 32D. cAMP dramatically increased ERK activity in the presence of CSF-1 or IL-3. IL-3 also synergized with cAMP to activate ERK in another myeloid cell line, FDC-P1. The increase in ERK activity was transmitted to a downstream target, p90rsk. cAMP treatment of 32D cells transfected with oncogenic Ras was found to recapitulate the superactivation of ERK seen with cAMP and CSF-1 or IL-3. ERK activation in the presence of cAMP did not appear to involve any of the Raf isoforms and was blocked by expression of dominant-negative MEK1 or treatment with a MEK inhibitor, PD98059. Although cAMP had an overall inhibitory effect on CSF-1–mediated proliferation and survival, the inhibition was markedly increased if ERK activation was blocked by PD98059. These findings suggest that upregulation of the ERK pathway is one mechanism induced by CSF-1 and IL-3 to protect myeloid progenitors from the growth-suppressive and apoptosis-inducing effects of cAMP elevations.

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Regulation of Cyclooxygenase 2 mRNA Stability by the Mitogen-Activated Protein Kinase p38 Signaling Cascade

Molecular and Cellular Biology ◽

10.1128/mcb.20.12.4265-4274.2000 ◽

2000 ◽

Vol 20 (12) ◽

pp. 4265-4274 ◽

Cited By ~ 290

Author(s):

Marina Lasa ◽

Kamal R. Mahtani ◽

Andrew Finch ◽

Gary Brewer ◽

Jeremy Saklatvala ◽

...

Keyword(s):

Protein Kinase ◽

Mrna Stability ◽

Active Form ◽

Cyclooxygenase 2 ◽

Dominant Negative ◽

Mitogen Activated Protein Kinase ◽

Signaling Cascade ◽

Mitogen Activated Protein ◽

Cox 2 ◽

Constitutively Active

ABSTRACT A tetracycline-regulated reporter system was used to investigate the regulation of cyclooxygenase 2 (Cox-2) mRNA stability by the mitogen-activated protein kinase (MAPK) p38 signaling cascade. The stable β-globin mRNA was rendered unstable by insertion of the 2,500-nucleotide Cox-2 3′ untranslated region (3′ UTR). The chimeric transcript was stabilized by a constitutively active form of MAPK kinase 6, an activator of p38. This stabilization was blocked by SB203580, an inhibitor of p38, and by two different dominant negative forms of MAPK-activated protein kinase 2 (MAPKAPK-2), a kinase lying downstream of p38. Constitutively active MAPKAPK-2 was also able to stabilize chimeric β-globin–Cox-2 transcripts. The MAPKAPK-2 substrate hsp27 may be involved in stabilization, as β-globin–Cox-2 transcripts were partially stabilized by phosphomimetic mutant forms of hsp27. A short (123-nucleotide) fragment of the Cox-2 3′ UTR was necessary and sufficient for the regulation of mRNA stability by the p38 cascade and interacted with a HeLa protein immunologically related to AU-rich element/poly(U) binding factor 1.

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Akt-Dependent Phosphorylation Specifically Regulates Cot Induction of NF-κB-Dependent Transcription

Molecular and Cellular Biology ◽

10.1128/mcb.22.16.5962-5974.2002 ◽

2002 ◽

Vol 22 (16) ◽

pp. 5962-5974 ◽

Cited By ~ 113

Author(s):

Lawrence P. Kane ◽

Marianne N. Mollenauer ◽

Zheng Xu ◽

Christoph W. Turck ◽

Arthur Weiss

Keyword(s):

Protein Kinase ◽

Signaling Pathways ◽

Cellular Transformation ◽

Dominant Negative ◽

Mitogen Activated Protein Kinase ◽

Iκb Kinase ◽

Ikk Complex ◽

Mitogen Activated Protein ◽

Tumor Necrosis Factor Induction ◽

Necrosis Factor

ABSTRACT The Akt (or protein kinase B) and Cot (or Tpl-2) serine/threonine kinases are associated with cellular transformation. These kinases have also been implicated in the induction of NF-κB-dependent transcription. As a member of the mitogen-activated protein kinase kinase kinase (MAP3K) family, Cot can also activate MAP kinase signaling pathways that target AP-1 and NFAT family transcription factors. Here we show that Akt and Cot physically associate and functionally cooperate. Akt appears to function upstream of Cot, as Akt can enhance Cot induction of NF-κB-dependent transcription, and dominant-negative Cot blocks the activation of this element by Akt. Furthermore, deletion analysis shows that binding to Akt is critical for Cot function. The regulation of NF-κB-dependent transcription by Cot requires Akt-dependent phosphorylation of serine 400 (S400), near the carboxy terminus of Cot. However, phosphorylation at this site is not required for Cot kinase activity or AP-1 induction, suggesting it specifically regulates Cot effector function at the level of the NF-κB pathway. Mutation of S400 in Cot does indeed abolish its ability to activate IκB-kinase (IKK) complexes, but paradoxically it allows for increased Cot association with the IKK complex. This mutated form of Cot also acts as a dominant negative for T-cell antigen receptor/CD28- or Akt/phorbol myristate acetate-induced NF-κB induction, while having relatively little effect on tumor necrosis factor induction of NF-κB. These findings suggest that the activation of different signaling pathways by MAP3Ks may be regulated separately and may provide evidence for how such discrimination by one member of this kinase family occurs.

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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

Biochemical Journal ◽

10.1042/bj3570867 ◽

2001 ◽

Vol 357 (3) ◽

pp. 867-873 ◽

Cited By ~ 9

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.

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EphA kinase activation regulates HGF-induced epithelial branching morphogenesis

The Journal of Cell Biology ◽

10.1083/jcb.200304018 ◽

2003 ◽

Vol 162 (7) ◽

pp. 1281-1292 ◽

Cited By ~ 58

Author(s):

Hui Miao ◽

Christian H. Nickel ◽

Lloyd G. Cantley ◽

Leslie A. Bruggeman ◽

Laura N. Bennardo ◽

...

Keyword(s):

Protein Kinase ◽

Mdck Cells ◽

Branching Morphogenesis ◽

Dominant Negative ◽

Mitogen Activated Protein Kinase ◽

Protein Kinase Activity ◽

Kinase Activation ◽

Cell Protrusion ◽

Mitogen Activated Protein

Eph kinases and their ephrin ligands are widely expressed in epithelial cells in vitro and in vivo. Our results show that activation of endogenous EphA kinases in Madin-Darby canine kidney (MDCK) cells negatively regulates hepatocyte growth factor/scatter factor (HGF)–induced branching morphogenesis in collagen gel. Cotreatment with HGF and ephrin-A1 reduced sprouting of cell protrusions, an early step in branching morphogenesis. Moreover, addition of ephrin-A1 after HGF stimulation resulted in collapse and retraction of preexisting cell protrusions. In a newly developed assay that simulates the localized interactions between Ephs and ephrins in vivo, immobilized ephrin-A1 suppressed HGF-induced MDCK cell scattering. Ephrin-A1 inhibited basal ERK1/2 mitogen-activated protein kinase activity; however, the ephrin-A1 effect on cell protrusion was independent of the mitogen-activated protein kinase pathway. Ephrin-A1 suppressed HGF-induced activation of Rac1 and p21-activated kinase, whereas RhoA activation was retained, leading to the preservation of stress fibers. Moreover, dominant-negative RhoA or inhibitor of Rho-associated kinase (Y27632) substantially negated the inhibitory effects of ephrin-A1. These data suggest that interfering with c-Met signaling to Rho GTPases represents a major mechanism by which EphA kinase activation inhibits HGF-induced MDCK branching morphogenesis.

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Coordinate Regulation of IκB Kinases by Mitogen-Activated Protein Kinase Kinase Kinase 1 and NF-κB-Inducing Kinase

Molecular and Cellular Biology ◽

10.1128/mcb.18.12.7336 ◽

1998 ◽

Vol 18 (12) ◽

pp. 7336-7343 ◽

Cited By ~ 181

Author(s):

Shino Nemoto ◽

Joseph A. DiDonato ◽

Anning Lin

Keyword(s):

Protein Kinase ◽

Interleukin 1 ◽

Dominant Negative ◽

Mitogen Activated Protein Kinase ◽

Dominant Negative Mutant ◽

Necrosis Factor Alpha ◽

Tnf Α ◽

Ikk Complex ◽

Mitogen Activated Protein ◽

Protein Kinase Kinase

ABSTRACT IκB kinases (IKKα and IKKβ) are key components of the IKK complex that mediates activation of the transcription factor NF-κB in response to extracellular stimuli such as inflammatory cytokines, viral and bacterial infection, and UV irradiation. Although NF-κB-inducing kinase (NIK) interacts with and activates the IKKs, the upstream kinases for the IKKs still remain obscure. We identified mitogen-activated protein kinase kinase kinase 1 (MEKK1) as an immediate upstream kinase of the IKK complex. MEKK1 is activated by tumor necrosis factor alpha (TNF-α) and interleukin-1 and can potentiate the stimulatory effect of TNF-α on IKK and NF-κB activation. The dominant negative mutant of MEKK1, on the other hand, partially blocks activation of IKK by TNF-α. MEKK1 interacts with and stimulates the activities of both IKKα and IKKβ in transfected HeLa and COS-1 cells and directly phosphorylates the IKKs in vitro. Furthermore, MEKK1 appears to act in parallel to NIK, leading to synergistic activation of the IKK complex. The formation of the MEKK1-IKK complex versus the NIK-IKK complex may provide a molecular basis for regulation of the IKK complex by various extracellular signals.

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Differential inhibition of signaling pathways by dominant-negative SH2/SH3 adapter proteins.

Molecular and Cellular Biology ◽

10.1128/mcb.15.12.6829 ◽

1995 ◽

Vol 15 (12) ◽

pp. 6829-6837 ◽

Cited By ~ 173

Author(s):

M Tanaka ◽

R Gupta ◽

B J Mayer

Keyword(s):

Protein Kinase ◽

Signaling Pathways ◽

Tyrosine Kinases ◽

Egf Receptor ◽

Sh3 Domain ◽

Sh2 Domain ◽

Dominant Negative ◽

Mitogen Activated Protein Kinase ◽

Erk Activation ◽

Mitogen Activated Protein

SH2/SH3 adapters are thought to function in signal transduction pathways by coupling inputs from tyrosine kinases to downstream effectors such as Ras. Members of the mitogen-activated protein kinase family are known to be activated by a variety of mitogenic stimuli, including tyrosine kinases such as Abl and the epidermal growth factor (EGF) receptor. We have used activation of the mitogen-activated protein kinase Erk-1 as a model system with which to examine whether various dominant-negative SH2/SH3 adapters (Grb2, Crk, and Nck) could block signaling pathways leading to Erk activation. Activation of Erk-1 by oncogenic Abl was effectively inhibited by Grb2 with mutations in either its SH2 or SH3 domain or by Crk-1 with an SH3 domain mutation. The Crk-1 SH2 mutant was less effective, while Nck SH2 and SH3 mutants had little or no effect on Erk activation. These results suggest that both Crk and Grb2 may contribute to the activation of Erk by oncogenic Abl, whereas Nck is unlikely to participate in this pathway. Next we examined whether combinations of these dominant-negative adapters could inhibit Erk activation more effectively than each mutant alone. When combinations of Crk-1 and Grb2 mutants were analyzed, the combination of the Crk-1 SH3 mutant plus the Grb2 SH3 mutant gave a striking synergistic effect. This finding suggests that in Abl-transformed cells, more than one class of tyrosine-phosphorylated sites (those that bind the Grb2 SH2 domain and those that bind the Crk SH2 domain) can lead to Ras activation. In contrast to results with Abl, Erk activation by EGF was strongly inhibited only by Grb2 mutants; Crk and Nck mutants had little or no effect. This finding suggests that Grb2 is the only adapter involved in the activation of Erk by EGF. Dominant-negative adaptors provide a novel means to identify binding interactions important in vivo for signaling in response to a variety of stimuli.

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Dominant-Negative Notch3 Receptor Inhibits Mitogen-Activated Protein Kinase Pathway and the Growth of Human Lung Cancers

Cancer Research ◽

10.1158/0008-5472.can-04-3132 ◽

2005 ◽

Vol 65 (9) ◽

pp. 3555-3561 ◽

Cited By ~ 112

Author(s):

Nobuhiro Haruki ◽

Keiko S. Kawaguchi ◽

Shannon Eichenberger ◽

Pierre P. Massion ◽

Sandra Olson ◽

...

Keyword(s):

Protein Kinase ◽

Human Lung ◽

Dominant Negative ◽

Mitogen Activated Protein Kinase ◽

Lung Cancers ◽

Mitogen Activated Protein ◽

Kinase Pathway

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Contrasting effects of ERK on tight junction integrity in differentiated and under-differentiated Caco-2 cell monolayers

Biochemical Journal ◽

10.1042/bj20100249 ◽

2010 ◽

Vol 433 (1) ◽

pp. 51-63 ◽

Cited By ~ 26

Author(s):

Sudhir Aggarwal ◽

Takuya Suzuki ◽

William L. Taylor ◽

Aditi Bhargava ◽

Radhakrishna K. Rao

Keyword(s):

Protein Kinase ◽

Tight Junction ◽

Tight Junctions ◽

Kinase Inhibitor ◽

Dominant Negative ◽

Mitogen Activated Protein Kinase ◽

Cell Monolayers ◽

Differentiated Cells ◽

Extracellular Signal ◽

Mitogen Activated Protein

ERK (extracellular-signal-regulated kinase) activation leads to disruption of tight junctions in some epithelial monolayers, whereas it prevents disruption of tight junctions in other epithelia. The factors responsible for such contrasting influences of ERK on tight junction integrity are unknown. The present study investigated the effect of the state of cell differentiation on ERK-mediated regulation of tight junctions in Caco-2 cell monolayers. EGF (epidermal growth factor) potentiated H2O2-induced tight junction disruption in under-differentiated cell monolayers, which was attenuated by the MEK [MAPK (mitogen-activated protein kinase)/ERK kinase] inhibitor U0126. In contrast, EGF prevented H2O2-induced disruption of tight junctions in differentiated cell monolayers, which was also attenuated by U0126. Knockdown of ERK1/2 enhanced tight junction integrity and accelerated assembly of tight junctions in under-differentiated cell monolayers, whereas it had the opposite effect in differentiated cell monolayers. Regulated expression of wild-type and constitutively active MEK1 disrupted tight junctions, and the expression of dominant-negative MEK1 enhanced tight junction integrity in under-differentiated cells, whereas contrasting responses were recorded in differentiated cells. EGF prevented both H2O2-induced association of PP2A (protein phosphatase 2A), and loss of association of PKCζ (protein kinase Cζ), with occludin by an ERK-dependent mechanism in differentiated cell monolayers, but not in under-differentiated cell monolayers. Active ERK was distributed in the intracellular compartment in under-differentiated cell monolayers, whereas it was localized mainly in the perijunctional region in differentiated cell monolayers. Thus ERK may exhibit its contrasting influences on tight junction integrity in under-differentiated and differentiated epithelial cells by virtue of differences in its subcellular distribution and ability to regulate the association of PKCζ and PP2A with tight junction proteins.

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