scholarly journals Extracellular Signal-Regulated Kinase (ERK) Activity During Sleep Consolidates Cortical Plasticity In Vivo

2013 ◽  
Vol 25 (2) ◽  
pp. 507-515 ◽  
Author(s):  
Michelle C. Dumoulin ◽  
Sara J. Aton ◽  
Adam J. Watson ◽  
Leslie Renouard ◽  
Tammi Coleman ◽  
...  
Keyword(s):  
Cortical Plasticity ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Erk Activity

Extracellular signal-regulated kinase pathway is differentially involved in β-agonist-induced hypertrophy in slow and fast muscles

2007 ◽  
Vol 292 (5) ◽  
pp. C1681-C1689 ◽  
Author(s):  
H. Shi ◽  
C. Zeng ◽  
A. Ricome ◽  
K. M. Hannon ◽  
A. L. Grant ◽  
...  
Keyword(s):  
Fiber Type ◽  
Erk Signaling ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Slow Twitch ◽  
Fast Twitch ◽  
Erk Activity ◽  
Fast Muscles ◽  
Slow And Fast Muscles

The molecular mechanisms controlling β-adrenergic receptor agonist (BA)-induced skeletal muscle hypertrophy are not well known. We presently report that BA exerts a distinct muscle- and muscle fiber type-specific hypertrophy. Moreover, we have shown that pharmacologically or genetically attenuating extracellular signal-regulated kinase (ERK) signaling in muscle fibers resulted in decreases ( P < 0.05) in fast but not slow fiber type-specific reporter gene expressions in response to BA exposure in vitro and in vivo. Consistent with these data, forced expression of MAPK phosphatase 1, a nuclear protein that dephosphorylates ERK1/2, in fast-twitch skeletal muscle ablated ( P < 0.05) the hypertrophic effects of BA feeding (clenbuterol, 20 parts per million in water) in vivo. Further analysis has shown that BA-induced phosphorylation and activation of ERK occurred to a greater ( P < 0.05) extent in fast myofibers than in slow myofibers. Analysis of the basal level of ERK activity in slow and fast muscles revealed that ERK1/2 is activated to a greater extent in fast- than in slow-twitch muscles. These data indicate that ERK signaling is differentially involved in BA-induced hypertrophy in slow and fast skeletal muscles, suggesting that the increased abundance of phospho-ERK1/2 and ERK activity found in fast-twitch myofibers, compared with their slow-twitch counterparts, may account, at least in part, for the fiber type-specific hypertrophy induced by BA stimulation. These data suggest that fast myofibers are pivotal in the adaptation of muscle to environmental cues and that the mechanism underlying this change is partially mediated by the MAPK signaling cascade.

scholarly journals Signal Pathways Which Promote Invasion and Metastasis: Critical and Distinct Contributions of Extracellular Signal-Regulated Kinase and Ral-Specific Guanine Exchange Factor Pathways

2001 ◽  
Vol 21 (17) ◽  
pp. 5958-5969 ◽  
Author(s):  
Yvona Ward ◽  
Warner Wang ◽  
Elisa Woodhouse ◽  
Ilona Linnoila ◽  
Lance Liotta ◽  
...  
Keyword(s):  
Dominant Negative ◽  
Signal Pathways ◽  
Nucleotide Exchange ◽  
3T3 Cells ◽  
Invasion And Metastasis ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Erk Activity

ABSTRACT Approximately 50% of metastatic tumors contain Ras mutations. Ras proteins can activate at least three downstream signaling cascades mediated by the Raf–MEK–extracellular signal-regulated kinase family, phosphatidylinositol-3 (PI3) kinase, and Ral-specific guanine nucleotide exchange factors (RalGEFs). Here we investigated the contribution of RalGEF and ERK activation to the development of experimental metastasis in vivo and associated invasive properties in vitro. Each pathway contributes distinct properties to the metastatic phenotype. Following lateral tail vein injection, 3T3 cells transformed by constitutively active Raf or MEK produced lung metastasis that displayed circumscribed, noninfiltrating borders. In contrast, 3T3 cells transformed by Ras(12V,37G), a Ras effector mutant that activates RalGEF but not Raf or P13 kinase, formed aggressive, infiltrative metastasis. Dominant negative RalB inhibited Ras(12V,37G)-activated invasion and metastasis, demonstrating the necessity of the RalGEF pathway for a fully transformed phenotype. Moreover, 3T3 cells constitutively expressing a membrane-associated form of RalGEF (RalGDS-CAAX) formed invasive tumors as well, demonstrating that activation of a RalGEF pathway is sufficient to initiate the invasive phenotype. Despite the fact that Ras(12V,37G) expression does not elevate ERK activity, inhibition of this kinase by a conditionally expressed ERK phosphatase demonstrated that ERK activity was necessary for Ras(12V,37G)-transformed cells to express matrix-degrading activity in vitro and tissue invasiveness in vivo. Therefore, these experiments have revealed a hitherto-unknown but essential interaction of the RalGEF and ERK pathways to produce a malignant phenotype. The generality of the role of the RalGEF pathway in metastasis is supported by the finding that Ras(12V,37G) increased the invasiveness of epithelial cells as well as fibroblasts.

scholarly journals Intercellular propagation of extracellular signal-regulated kinase activation revealed by in vivo imaging of mouse skin

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Toru Hiratsuka ◽  
Yoshihisa Fujita ◽  
Honda Naoki ◽  
Kazuhiro Aoki ◽  
Yuji Kamioka ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Mouse Skin ◽  
Egf Receptors ◽  
M Cell ◽  
Erk Activation ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Erk Activity

Extracellular signal-regulated kinase (ERK) is a key effector of many growth signalling pathways. In this study, we visualise epidermal ERK activity in living mice using an ERK FRET biosensor. Under steady-state conditions, the epidermis occasionally revealed bursts of ERK activation patterns where ERK activity radially propagated from cell to cell. The frequency of this spatial propagation of radial ERK activity distribution (SPREAD) correlated with the rate of epidermal cell division. SPREADs and proliferation were stimulated by 12-O-tetradecanoylphorbol 13-acetate (TPA) in a manner dependent on EGF receptors and their cognate ligands. At the wounded skin, ERK activation propagated as trigger wave in parallel to the wound edge, suggesting that ERK activation propagation can be superimposed. Furthermore, by visualising the cell cycle, we found that SPREADs were associated with G2/M cell cycle progression. Our results provide new insights into how cell proliferation and transient ERK activity are synchronised in a living tissue.

cAMP and Extracellular Signal-Regulated Kinase Signaling in Response to d-Amphetamine and Methylphenidate in the Prefrontal Cortex in Vivo: Role of β1-Adrenoceptors

2005 ◽  
Vol 68 (2) ◽  
pp. 421-429 ◽  
Author(s):  
Vincent Pascoli ◽  
Emmanuel Valjent ◽  
Anne-Gaëlle Corbillé ◽  
Jean-Christophe Corvol ◽  
Jean-Pol Tassin ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Kinase Signaling ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal

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 RACK1 Targets the Extracellular Signal-Regulated Kinase/Mitogen-Activated Protein Kinase Pathway To Link Integrin Engagement with Focal Adhesion Disassembly and Cell Motility

2007 ◽  
Vol 27 (23) ◽  
pp. 8296-8305 ◽  
Author(s):  
Tomas Vomastek ◽  
Marcin P. Iwanicki ◽  
Hans-Joerg Schaeffer ◽  
Adel Tarcsafalvi ◽  
J. Thomas Parsons ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Focal Adhesion ◽  
Focal Adhesions ◽  
Mitogen Activated Protein Kinase ◽  
Erk Pathway ◽  
Large Measure ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Erk Activity

ABSTRACT The extracellular signal-regulated kinase (ERK) cascade is activated in response to a multitude of extracellular signals and converts these signals into a variety of specific biological responses, including cell differentiation, cell movement, cell division, and apoptosis. The specificity of the biological response is likely to be controlled in large measure by the localization of signaling, thus enabling ERK activity to be directed towards specific targets. Here we show that the RACK1 scaffold protein functions specifically in integrin-mediated activation of the mitogen-activated protein kinase/ERK cascade and targets active ERK to focal adhesions. We found that RACK1 associated with the core kinases of the ERK pathway, Raf, MEK, and ERK, and that attenuation of RACK1 expression resulted in a decrease in ERK activity in response to adhesion but not in response to growth factors. RACK1 silencing also caused a reduction of active ERK in focal adhesions, an increase in focal adhesion length, a decreased rate of focal adhesion disassembly, and decreased motility. Our data further suggest that focal adhesion kinase is an upstream activator of the RACK1/ERK pathway. We suggest that RACK1 tethers the ERK pathway core kinases and channels signals from upstream activation by integrins to downstream targets at focal adhesions.

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