Signaling through the extracellular signal-regulated kinase 1/2 cascade in cardiac myocytes

2004 ◽  
Vol 82 (6) ◽  
pp. 603-609 ◽  
Author(s):  
Angela Clerk ◽  
Peter H Sugden
Keyword(s):  
Cardiac Myocytes ◽  
Intracellular Signaling ◽  
Regulation Of Transcription ◽  
Signal Integration ◽  
Extracellular Signal Regulated Kinase ◽  
Kinase C ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Protein Kinase C Isoforms ◽  
Activate Protein Kinase

The extracellular signal-regulated kinases 1/2 (ERK1/2) are particularly implicated in the growth response of cardiac myocytes. In these cells, the ERK1/2 pathway is potently activated by Gq protein-coupled receptor agonists (such as endothelin-1 or α-adrenergic agonists), which activate protein kinase C isoforms. Here, we review the mechanisms associated with the activation of the ERK1/2 pathway by these agonists with particular emphasis on signal integration into the pathway. Signaling to the nucleus and the regulation of transcription factor activity associated with ERK1/2 activation in cardiac myocytes are also discussed.Key words: mitogen-activated protein kinases, cardiac myocytes, intracellular signaling.

scholarly journals Involvement of Guanosine Triphosphatases and Phospholipase C-γ2 in Extracellular Signal–regulated Kinase, c-Jun NH2-terminal Kinase, and p38 Mitogen-activated Protein Kinase Activation by the B Cell Antigen Receptor

1998 ◽  
Vol 188 (7) ◽  
pp. 1287-1295 ◽  
Author(s):  
Ari Hashimoto ◽  
Hidetaka Okada ◽  
Aimin Jiang ◽  
Mari Kurosaki ◽  
Steven Greenberg ◽  
...  
Keyword(s):  
Protein Kinase ◽  
B Cell ◽  
Map Kinase ◽  
B Cell Antigen Receptor ◽  
Erk Activation ◽  
Extracellular Signal Regulated Kinase ◽  
Kinase C ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Pkc Activation

Mitogen-activated protein (MAP) kinase family members, including extracellular signal–regulated kinase (ERK), c-Jun NH2-terminal kinase (  JNK), and p38 MAP kinase, have been implicated in coupling the B cell antigen receptor (BCR) to transcriptional responses. However, the mechanisms that lead to the activation of these MAP kinase family members have been poorly elucidated. Here we demonstrate that the BCR-induced ERK activation is reduced by loss of Grb2 or expression of a dominant-negative form of Ras, RasN17, whereas this response is not affected by loss of Shc. The inhibition of the ERK response was also observed in phospholipase C (PLC)-γ2–deficient DT40 B cells, and expression of RasN17 in the PLC-γ2–deficient cells completely abrogated the ERK activation. The PLC-γ2 dependency of ERK activation was most likely due to protein kinase C (PKC) activation rather than calcium mobilization, since loss of inositol 1,4,5-trisphosphate receptors did not affect ERK activation. Similar to cooperation of Ras with PKC activation in ERK response, both PLC-γ2–dependent signal and GTPase are required for BCR-induced JNK and p38 responses. JNK response is dependent on Rac1 and calcium mobilization, whereas p38 response requires Rac1 and PKC activation.

scholarly journals Activation of the Mitogen-Activated Protein Kinase/Extracellular Signal-Regulated Kinase Pathway by Conventional, Novel, and Atypical Protein Kinase C Isotypes

1998 ◽  
Vol 18 (2) ◽  
pp. 790-798 ◽  
Author(s):  
Dorothee C. Schönwasser ◽  
Richard M. Marais ◽  
Christopher J. Marshall ◽  
Peter J. Parker
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Mapk Cascade ◽  
Mitogen Activated Protein Kinase ◽  
Extracellular Signal Regulated Kinase ◽  
Erk Mapk ◽  
Kinase C ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Stimulation Of

ABSTRACT Phorbol ester treatment of quiescent Swiss 3T3 cells leads to cell proliferation, a response thought to be mediated by protein kinase C (PKC), the major cellular receptor for this class of agents. We demonstrate here that this proliferation is dependent on the activation of the extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) cascade. It is shown that dominant-negative PKC-α inhibits stimulation of the ERK/MAPK pathway by phorbol esters in Cos-7 cells, demonstrating a role for PKC in this activation. To assess the potential specificity of PKC isotypes mediating this process, constitutively active mutants of six PKC isotypes (α, β1, δ, ɛ, η, and ζ) were employed. Transient transfection of these PKC mutants into Cos-7 cells showed that members of all three groups of PKC (conventional, novel, and atypical) are able to activate p42 MAPK as well as its immediate upstream activator, the MAPK/ERK kinase MEK-1. At the level of Raf, the kinase that phosphorylates MEK-1, the activation cascade diverges; while conventional and novel PKCs (isotypes α and η) are potent activators of c-Raf1, atypical PKC-ζ cannot increase c-Raf1 activity, stimulating MEK by an independent mechanism. Stimulation of c-Raf1 by PKC-α and PKC-η was abrogated for RafCAAX, which is a membrane-localized, partially active form of c-Raf1. We further established that activation of Raf is independent of phosphorylation at serine residues 259 and 499. In addition to activation, we describe a novel Raf desensitization induced by PKC-α, which acts to prevent further Raf stimulation by growth factors. The results thus demonstrate a necessary role for PKC and p42 MAPK activation in 12-O-tetradecanoylphorbol-13-acetate induced mitogenesis and provide evidence for multiple PKC controls acting on this MAPK cascade.

scholarly journals Up-Regulation of Interleukin-8 by Novel Small Cytoplasmic Molecules of Nontypeable Haemophilus influenzae via p38 and Extracellular Signal-Regulated Kinase Pathways

2003 ◽  
Vol 71 (10) ◽  
pp. 5523-5530 ◽  
Author(s):  
Beinan Wang ◽  
P. Patrick Cleary ◽  
Haidong Xu ◽  
Jian-Dong Li
Keyword(s):  
Protein Kinase ◽  
Haemophilus Influenzae ◽  
Intracellular Signaling ◽  
Interleukin 8 ◽  
Mitogen Activated Protein Kinase ◽  
Akt Pathway ◽  
Chronic Obstructive ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Mitogen Activated Protein

ABSTRACT Nontypeable Haemophilus influenzae (NTHI) is an important etiological agent of otitis media (OM) and of exacerbated chronic obstructive pulmonary diseases (COPD). Inflammation is a hallmark of both diseases. Interleukin-8 (IL-8), one of the important inflammatory mediators, is induced by NTHI and may play a significant role in the pathogenesis of these diseases. Our studies demonstrated that a soluble cytoplasmic fraction (SCF) from NTHI induced much greater IL-8 expression by human epithelial cells than did NTHI lipooligosaccharides and envelope proteins. The IL-8-inducing activity was associated with molecules of ≤3 kDa from SCF and was peptidase and lipase sensitive, suggesting that small lipopeptides are responsible for the strong IL-8 induction. Moreover, multiple intracellular signaling pathways were activated in response to cytoplasmic molecules. The results indicated that the p38 mitogen-activated protein kinase (MAPK) and Src-dependent Raf-1-Mek1/2-extracellular signal-regulated kinase mitogen-activated protein kinase (ERK MAPK) pathways are required for NTHI-induced IL-8 production. In contrast, the phosphatidylinositol 3-kinase (PI3K)-Akt pathway did not affect IL-8 expression, although this pathway was concomitantly activated upon exposure to NTHI SCF. The PI3K-Akt pathway was also directly activated by IL-8 and significantly inhibited by an antagonist of IL-8 receptors during NTHI stimulation. These results indicated that the PI3K-Akt pathway is activated in response to IL-8 that is induced by NTHI and may lead to other important epithelial cell responses. This work provides insight into essential molecular and cellular events that may impact on the pathogenesis of OM and COPD and identifies rational targets for anti-inflammatory intervention.

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