scholarly journals Role of Regulatory Elements and the MAPK/ERK or p38 MAPK Pathways for Activation of Human Cytomegalovirus Gene Expression

2002 ◽  
Vol 76 (10) ◽  
pp. 4873-4885 ◽  
Author(s):  
Jiping Chen ◽  
Mark F. Stinski
Keyword(s):  
Gene Expression ◽  
Protein Kinase ◽  
P38 Mapk ◽  
Human Cytomegalovirus ◽  
Mapk Pathway ◽  
Regulatory Elements ◽  
Mitogen Activated Protein Kinase ◽  
Viral Gene ◽  
Mapk Pathways ◽  
Mitogen Activated Protein

ABSTRACT A series of recombinant viruses with either site-specific mutations or various deletions of the early UL4 promoter of human cytomegalovirus were used to determine the roles of regulatory elements and the effects of the mitogen-activated protein kinase (MAPK) pathways. Viral gene expression was regulated by upstream cis-acting sites and by basic promoter elements that respond to the MAPK signal transduction pathways. Inhibitors of either the mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway or the p38 MAPK pathway affected expression equally with either wild-type or mutant early UL4 promoters in the viral genome, indicating that the effects of the inhibitors are not exclusive for a single transcription factor. The minimal responsive element is the TATA box-containing early viral promoter.

scholarly journals APPL1 mediates adiponectin-stimulated p38 MAPK activation by scaffolding the TAK1-MKK3-p38 MAPK pathway

2011 ◽  
Vol 300 (1) ◽  
pp. E103-E110 ◽  
Author(s):  
Xiaoban Xin ◽  
Lijun Zhou ◽  
Caleb M. Reyes ◽  
Feng Liu ◽  
Lily Q. Dong
Keyword(s):  
Protein Kinase ◽  
P38 Mapk ◽  
Mapk Pathway ◽  
Adaptor Protein ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Scaffolding Protein ◽  
Mapk Activation ◽  
P38 Mapk Pathway ◽  
Mitogen Activated Protein

The adaptor protein APPL1 mediates the stimulatory effect of adiponectin on p38 mitogen-activated protein kinase (MAPK) signaling, yet the underlying mechanism remains unclear. Here we show that, in C2C12 cells, overexpression or suppression of APPL1 enhanced or suppressed, respectively, adiponectin-stimulated p38 MAPK upstream kinase cascade, consisting of transforming growth factor-β-activated kinase 1 (TAK1) and mitogen-activated protein kinase kinase 3 (MKK3). In vitro affinity binding and coimmunoprecipitation experiments revealed that TAK1 and MKK3 bind to different regions of APPL1, suggesting that APPL1 functions as a scaffolding protein to facilitate adiponectin-stimulated p38 MAPK activation. Interestingly, suppressing APPL1 had no effect on TNFα-stimulated p38 MAPK phosphorylation in C2C12 myotubes, indicating that the stimulatory effect of APPL1 on p38 MAPK activation is selective. Taken together, our study demonstrated that the TAK1-MKK3 cascade mediates adiponectin signaling and uncovers a scaffolding role of APPL1 in regulating the TAK1-MKK3-p38 MAPK pathway, specifically in response to adiponectin stimulation.

scholarly journals Both Binding and Activation of p38 Mitogen-Activated Protein Kinase (MAPK) Play Essential Roles in Regulation of the Nucleocytoplasmic Distribution of MAPK-Activated Protein Kinase 5 by Cellular Stress

2002 ◽  
Vol 22 (20) ◽  
pp. 6931-6945 ◽  
Author(s):  
Ole Morten Seternes ◽  
Bjarne Johansen ◽  
Beate Hegge ◽  
Mona Johannessen ◽  
Stephen M. Keyse ◽  
...  
Keyword(s):  
Protein Kinase ◽  
P38 Mapk ◽  
Nuclear Export ◽  
Fluorescent Protein ◽  
Mapk Pathway ◽  
Nuclear Export Signal ◽  
Mitogen Activated Protein Kinase ◽  
Protein Fusion ◽  
Translational Machinery ◽  
Mitogen Activated Protein

ABSTRACT The p38 mitogen-activated protein kinase (MAPK) pathway is an important mediator of cellular responses to environmental stress. Targets of p38 include transcription factors, components of the translational machinery, and downstream serine/threonine kinases, including MAPK-activated protein kinase 5 (MK5). Here we have used enhanced green fluorescent protein fusion proteins to analyze the subcellular localization of MK5. Although this protein is predominantly nuclear in unstimulated cells, MK5 shuttles between the nucleus and the cytoplasm. Furthermore, we have shown that the C-terminal domain of MK5 contains both a functional nuclear localization signal (NLS) and a leucine-rich nuclear export signal (NES), indicating that the subcellular distribution of this kinase reflects the relative activities of these two signals. In support of this, we have shown that stress-induced activation of the p38 MAPK stimulates the chromosomal region maintenance 1 protein-dependent nuclear export of MK5. This is regulated by both binding of p38 MAPK to MK5, which masks the functional NLS, and stress-induced phosphorylation of MK5 by p38 MAPK, which either activates or unmasks the NES. These properties may define the ability of MK5 to differentially phosphorylate both nuclear and cytoplasmic targets or alternatively reflect a mechanism whereby signals initiated by activation of MK5 in the nucleus may be transmitted to the cytoplasm.

Phosphorylation of Argonaute 2 at serine-387 facilitates its localization to processing bodies

2008 ◽  
Vol 413 (3) ◽  
pp. 429-436 ◽  
Author(s):  
Yan Zeng ◽  
Heidi Sankala ◽  
Xiaoxiao Zhang ◽  
Paul R. Graves
Keyword(s):  
Protein Kinase ◽  
P38 Mapk ◽  
Kinase Inhibitor ◽  
Mapk Pathway ◽  
Phosphorylation Site ◽  
Mitogen Activated Protein Kinase ◽  
Processing Bodies ◽  
Mitogen Activated Protein

Ago (Argonaute) proteins are essential effectors of RNA-mediated gene silencing. To explore potential regulatory mechanisms for Ago proteins, we examined the phosphorylation of human Ago2. We identified serine-387 as the major Ago2 phosphorylation site in vivo. Phosphorylation of Ago2 at serine-387 was significantly induced by treatment with sodium arsenite or anisomycin, and arsenite-induced phosphorylation was inhibited by a p38 MAPK (mitogen-activated protein kinase) inhibitor, but not by inhibitors of JNK (c-Jun N-terminal kinase) or MEK [MAPK/ERK (extracellular-signal-regulated kinase) kinase]. MAPKAPK2 (MAPK-activated protein kinase-2) phosphorylated bacterially expressed full-length human Ago2 at serine-387 in vitro, but not the S387A mutant. Finally, mutation of serine-387 to an alanine residue or treatment of cells with a p38 MAPK inhibitor reduced the localization of Ago2 to processing bodies. These results suggest a potential regulatory mechanism for RNA silencing acting through Ago2 serine-387 phosphorylation mediated by the p38 MAPK pathway.

scholarly journals JNK and p38 Mitogen-Activated Protein Kinase Pathways Contribute to Porcine Circovirus Type 2 Infection

2009 ◽  
Vol 83 (12) ◽  
pp. 6039-6047 ◽  
Author(s):  
Li Wei ◽  
Zhongwu Zhu ◽  
Jing Wang ◽  
Jue Liu
Keyword(s):  
Protein Kinase ◽  
P38 Mapk ◽  
Porcine Circovirus Type ◽  
Mitogen Activated Protein Kinase ◽  
Porcine Circovirus ◽  
Mapk Pathways ◽  
Mitogen Activated Protein ◽  
Pcv2 Replication ◽  
Specific Inhibitors

ABSTRACT Infection with a wide variety of viruses often perturbs host cell signaling pathways including the Jun NH2-terminal kinase/stress-activated kinase (JNK/SAPK) and the p38 mitogen-activated protein kinase (p38/MAPK), which are important components of cellular signal transduction pathways. The present study demonstrated for the first time that porcine circovirus type 2 (PCV2), which is the primary causative agent of an emerging swine disease, postweaning multisystemic wasting syndrome, can activate JNK1/2 and p38 MAPK pathways in PCV2-infected PK15 cells. However, PCV2 at an early stage of infection, as well as UV-irradiated PCV2, failed to activate these two MAPK families, which demonstrated that PCV2 replication was necessary for their activation. We further found that PCV2 activated the phosphorylation of JNK1/2 and p38 MAPK downstream targets c-Jun and ATF-2 with virus replication in the cultured cells. The roles of these kinases in PCV2 infection were further evaluated using specific inhibitors: the JNK inhibitor 1 for JNK1/2 and SB202190 for p38. Inhibition of JNK1/2 and p38 kinases by these specific inhibitors did result in significant reduction of PCV2 viral mRNA transcription and protein synthesis, viral progeny release, and blockage of PCV2-induced apoptotic caspase-3 activation in the infected cells. Taken together, these data suggest that JNK/SAPK and p38 MAPK pathways play important roles in the PCV2 replication and contribute to virus-mediated changes in host cells.

scholarly journals Transcriptional Coregulation by the Cell Integrity Mitogen-Activated Protein Kinase Slt2 and the Cell Cycle Regulator Swi4

2001 ◽  
Vol 21 (19) ◽  
pp. 6515-6528 ◽  
Author(s):  
Kristin Baetz ◽  
Jason Moffat ◽  
Jennifer Haynes ◽  
Michael Chang ◽  
Brenda Andrews
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Cell Wall ◽  
Transcription Factor ◽  
Protein Kinase ◽  
Mapk Pathway ◽  
Mitogen Activated Protein Kinase ◽  
Regulatory Subunit ◽  
Cell Integrity ◽  
Mitogen Activated Protein

ABSTRACT In Saccharomyces cerevisiae, the heterodimeric transcription factor SBF (for SCB binding factor) is composed of Swi4 and Swi6 and activates gene expression at the G1/S-phase transition of the mitotic cell cycle. Cell cycle commitment is associated not only with major alterations in gene expression but also with highly polarized cell growth; the mitogen-activated protein kinase (MAPK) Slt2 is required to maintain cell wall integrity during periods of polarized growth and cell wall stress. We describe experiments aimed at defining the regulatory pathway involving the cell cycle transcription factor SBF and Slt2-MAPK. Gene expression assays and chromatin immunoprecipitation experiments revealed Slt2-dependent recruitment of SBF to the promoters of the G1 cyclinsPCL1 and PCL2 after activation of the Slt2-MAPK pathway. We performed DNA microarray analysis and identified other genes whose expression was reduced in both SLT2and SWI4 deletion strains. Genes that are sensitive to both Slt2 and Swi4 appear to be uniquely regulated and reveal a role for Swi4, the DNA-binding component of SBF, which is independent of the regulatory subunit Swi6. Some of the Swi4- and Slt2-dependent genes do not require Swi6 for either their expression or for Swi4 localization to their promoters. Consistent with these results, we found a direct interaction between Swi4 and Slt2. Our results establish a new Slt2-dependent mode of Swi4 regulation and suggest roles for Swi4 beyond its prominent role in controlling cell cycle transcription.

scholarly journals Posttranslational Regulation of Tristetraprolin Subcellular Localization and Protein Stability by p38 Mitogen-Activated Protein Kinase and Extracellular Signal-Regulated Kinase Pathways

2006 ◽  
Vol 26 (6) ◽  
pp. 2408-2418 ◽  
Author(s):  
Matthew Brook ◽  
Carmen R. Tchen ◽  
Tomas Santalucia ◽  
Joanne McIlrath ◽  
J. Simon C. Arthur ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Subcellular Localization ◽  
Protein Stability ◽  
P38 Mapk ◽  
Mapk Pathway ◽  
Mitogen Activated Protein Kinase ◽  
Extracellular Signal Regulated Kinase ◽  
P38 Mapk Pathway ◽  
Extracellular Signal ◽  
Mitogen Activated Protein

ABSTRACT The p38 mitogen-activated protein kinase (MAPK) signaling pathway, acting through the downstream kinase MK2, regulates the stability of many proinflammatory mRNAs that contain adenosine/uridine-rich elements (AREs). It is thought to do this by modulating the expression or activity of ARE-binding proteins that regulate mRNA turnover. MK2 phosphorylates the ARE-binding and mRNA-destabilizing protein tristetraprolin (TTP) at serines 52 and 178. Here we show that the p38 MAPK pathway regulates the subcellular localization and stability of TTP protein. A p38 MAPK inhibitor causes rapid dephosphorylation of TTP, relocalization from the cytoplasm to the nucleus, and degradation by the 20S/26S proteasome. Hence, continuous activity of the p38 MAPK pathway is required to maintain the phosphorylation status, cytoplasmic localization, and stability of TTP protein. The regulation of both subcellular localization and protein stability is dependent on MK2 and on the integrity of serines 52 and 178. Furthermore, the extracellular signal-regulated kinase (ERK) pathway synergizes with the p38 MAPK pathway to regulate both stability and localization of TTP. This effect is independent of kinases that are known to be synergistically activated by ERK and p38 MAPK. We present a model for the actions of TTP and the p38 MAPK pathway during distinct phases of the inflammatory response.

scholarly journals The regulatory mechanism by which interleukin-6 stimulates GH-gene expression in rat GH3 cells

2006 ◽  
Vol 190 (2) ◽  
pp. 397-406 ◽  
Author(s):  
Feng-ying Gong ◽  
Yi-fan Shi ◽  
Jie-ying Deng
Keyword(s):  
Gene Expression ◽  
Protein Kinase ◽  
P38 Mapk ◽  
Mitogen Activated Protein Kinase ◽  
Gh3 Cells ◽  
Luciferase Reporter ◽  
Luciferase Expression ◽  
Gh Secretion ◽  
Rat Pituitary ◽  
Mitogen Activated Protein

The present study was performed to elucidate the effect of interleukin (IL)-6 on the human GH (hGH)-gene expression in GH3 rat pituitary tumor cells using stable transfection of the hGH promoter fused to a luciferase reporter gene. Our results showed that IL-6 (102–104 U/ml) stimulated GH secretion and synthesis, and promoted the luciferase expression in stably transfected GH3 cells with the maximal action of 1.99 times above the control by 104 U/ml IL-6. Among the inhibitors of signaling transduction pathways, mitogen-activated protein kinase kinase (MAPKK/MEK) inhibitor PD98059 (40 μM) and p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580 (5 μM) completely blocked the stimulatory effect of IL-6. Western blot analysis demonstrated that IL-6 indeed increased the activation of phosphorylated MEK and p38 MAPK in GH3 cells. Neither overexpression of Pit-1 nor inhibiting Pit-1 expression affected IL-6 induction of hGH-promoter activity. To identify the DNA sequence that mediated the effect of IL-6, six deletion constructs of hGH promoter were created. The stimulatory effect of IL-6 was abolished following deletion of the −196 to −132 bp fragment. In conclusion, our data show that IL-6 promotes GH secretion and synthesis by rat pituitary GH3 cells. The stimulatory effect of IL-6 on hGH-gene promoter appears to require the activation of MEK and p38 MAPK, and a fragment of promoter sequence that spans the −196 to −132 bp of the gene, but may be unrelated to Pit-1 protein.

scholarly journals Cross talk between cAMP and p38 MAPK pathways in the induction of leptin by hCG in human placental syncytiotrophoblasts

Reproduction ◽  
2011 ◽  
Vol 142 (2) ◽  
pp. 369-375 ◽  
Author(s):  
Y C Ge ◽  
J N Li ◽  
X T Ni ◽  
C M Guo ◽  
W S Wang ◽  
...  
Keyword(s):  
Protein Kinase ◽  
P38 Mapk ◽  
Cross Talk ◽  
Mrna Level ◽  
Underlying Mechanism ◽  
Mitogen Activated Protein Kinase ◽  
Mapk Pathways ◽  
Mitogen Activated Protein ◽  
Leptin Expression ◽  
In Pregnancy

Leptin produced by the placental syncytiotrophoblasts participates in a number of processes in pregnancy including implantation, proliferation of the cytotrophoblasts, and nutrient transfer across the placenta. Despite the functional significance of leptin in pregnancy, the regulation of leptin synthesis is poorly understood in human placental syncytiotrophoblasts. In this study, we investigated the role of endogenous human chorionic gonadotropin (hCG) in the regulation of leptin production as well as the underlying mechanism involving the cross talk between cAMP and p38 mitogen-activated protein kinase (MAPK) pathways. We found that neutralization of endogenous hCG with its antibody dose dependently decreased leptin mRNA level and secretion, whereas exogenous hCG increased leptin mRNA level and secretion. Activation of the cAMP pathway with dibutyryl cAMP (db cAMP) or forskolin recapitulated the stimulatory effect of hCG on leptin expression. Inhibition of protein kinase A with H89 not only reduced the basal leptin expression but also attenuated the induced leptin expression by hCG. Treatment of the syncytiotrophoblasts with db cAMP and hCG phosphorylated p38 MAPK. Inhibition of p38 MAPK with SB203580 not only reduced the basal leptin production but also attenuated the leptin-induced production by both hCG and db cAMP. These data suggest that endogenous hCG plays a significant role in maintaining leptin production in human placental syncytiotrophoblasts, and this effect involves a cross talk between cAMP and p38 MAPK pathways.

Potentiation of nitric oxide-induced apoptosis in p53−/− vascular smooth muscle cells

2002 ◽  
Vol 282 (3) ◽  
pp. C625-C634 ◽  
Author(s):  
Melina R Kibbe ◽  
Jianrong Li ◽  
Suhua Nie ◽  
Byung Min Choi ◽  
Imre Kovesdi ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Smooth Muscle ◽  
Protein Kinase ◽  
Vascular Smooth Muscle ◽  
P38 Mapk ◽  
Mitogen Activated Protein Kinase ◽  
Mapk Pathways ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Induced Apoptosis

The functional role of p53 in nitric oxide (NO)-mediated vascular smooth muscle cell (VSMC) apoptosis remains unknown. In this study, VSMC from p53−/− and p53+/+ murine aortas were exposed to exogenous or endogenous sources of NO. Unexpectedly, p53−/− VSMC were much more sensitive to the proapoptotic effects of NO than were p53+/+ VSMC. Furthermore, this paradox appeared to be specific to NO, because other proapoptotic agents did not demonstrate this differential effect on p53−/− cells. NO-induced apoptosis in p53−/− VSMC occurred independently of cGMP generation. However, mitogen-activated protein kinase (MAPK) pathways appeared to play a significant role. Treatment of the p53−/− VSMC with S-nitroso- N-acetylpenicillamine resulted in a marked activation of p38 MAPK and, to a lesser extent, of c-Jun NH2-terminal kinase, mitogen-activated protein kinase kinase (MEK) 1/2, and p42/44 (extracellular signal-regulated kinase, ERK). Furthermore, basal activity of the MEK-p42/44 (ERK) pathway was increased in the p53+/+ VSMC. Inhibition of p38 MAPK with SB-203580 or of MEK1/2 with PD-98059 blocked NO-induced apoptosis. Therefore, p53 may protect VSMC against NO-mediated apoptosis, in part, through differential regulation of MAPK pathways.

scholarly journals Modulation of the p38 MAPK (mitogen-activated protein kinase) pathway through Bcr/Abl: implications in the cellular response to Ara-C

2005 ◽  
Vol 387 (1) ◽  
pp. 231-238 ◽  
Author(s):  
Víctor Javier SÁNCHEZ-ARÉVALO LOBO ◽  
Clara Isabel ACEVES LUQUERO ◽  
Luis ÁLVAREZ-VALLINA ◽  
Alex J. TIPPING ◽  
Juan Guinea VINIEGRA ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Chronic Myeloid Leukaemia ◽  
Myeloid Leukaemia ◽  
P38 Mapk ◽  
Cellular Response ◽  
Mapk Pathway ◽  
K562 Cells ◽  
Mitogen Activated Protein Kinase ◽  
P38 Mapk Pathway ◽  
Mitogen Activated Protein

The chimaeric protein Bcr/Abl, the hallmark of chronic myeloid leukaemia, has been connected with several signalling pathways, such as those involving protein kinase B/Akt, JNK (c-Jun N-terminal kinase) or ERKs (extracellular-signal-regulated kinases) 1 and 2. However, no data about the p38 MAPK (mitogen-activated protein kinase) have been reported. Here, we present evidence showing that Bcr/Abl is able to modulate this signalling pathway. Transient transfection experiments indicated that overexpression of Bcr/Abl in 293T cells is able to activate p38 MAPK or induce p73 stabilization, suggesting that c-Abl and Bcr/Abl share some biological substrates. Interestingly, the control exerted by Bcr/Abl on the p38 MAPK pathway was not only mediated by the tyrosine kinase activity of Bcr/Abl, as the use of STI571 demonstrated. In fact, Bcr alone was able to induce p38 MAPK activation specifically through MKK3 (MAP kinase kinase 3). Supporting these observations, chronic myeloid leukaemia-derived K562 cells or BaF 3 cells stably transfected with Bcr/Abl showed higher levels of phosphorylated p38 MAPK compared with Bcr/Abl-negative cells. While Bcr/Abl-negative cells activated p38 MAPK in response to Ara-C (1-β-D-arabinofuranosylcytosine), Bcr/Abl-positive cells were unable to activate p38 MAPK, suggesting that the p38 MAPK pathway is not sensitive to Abl-dependent stimuli in Bcr/Abl-positive cells. Our results demonstrate that the involvement of Bcr/Abl in the p38 MAPK pathway is a key mechanism for explaining resistance to Ara-C, and could provide a clue for new therapeutic approaches based on the use of specific Abl inhibitors.

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