scholarly journals Distinct signalling pathways mediate the cAMP response element (CRE)-dependent activation of the calcitonin gene-related peptide gene promoter by cAMP and nerve growth factor

2000 ◽  
Vol 345 (2) ◽  
pp. 233-238 ◽  
Author(s):  
Karen FREELAND ◽  
Yu-Zhen LIU ◽  
David S. LATCHMAN
Keyword(s):  
Nerve Growth Factor ◽  
Growth Factor ◽  
Protein Kinase ◽  
Mapk Pathway ◽  
Mitogen Activated Protein Kinase ◽  
Signalling Pathways ◽  
Camp Response Element ◽  
Response Element ◽  
Calcitonin Gene ◽  
Mitogen Activated Protein

The gene encoding the calcitonin gene-related peptide (CGRP) is activated in neuronal cells by treatment with cAMP and nerve growth factor (NGF). Both stimuli induce the phosphorylation of the cAMP response element (CRE)-binding protein (CREB) transcription factor on Ser-133 and require the CRE in the CGRP promoter to stimulate transcription. However, whereas the CRE is necessary and sufficient for promoter activation by cAMP, it is necessary but not sufficient for activation by NGF. We show that this difference is paralleled by a difference in the signalling pathways which are required for each stimulus to activate the CGRP promoter. Thus whilst cAMP-mediated activation requires the protein kinase A pathway, NGF-mediated stimulation requires the Ras/Raf mitogen-activated protein kinase kinase-1 (MEK-1)/p42/p44 mitogen-activated protein kinase (MAPK) pathway. Although NGF can activate the protein kinase C, p38 MAPK and c-Jun N-terminal kinase (JNK) pathways, these pathways are not involved in its effect on the CGRP promoter. The effect of the p42/p44 MAPK pathway on CREB and associated transcription factors, and the manner in which this results in activation of the CGRP promoter is discussed.

scholarly journals Estrogen Activation of Cyclic Adenosine 5′-Monophosphate Response Element-Mediated Transcription Requires the Extracellularly Regulated Kinase/Mitogen-Activated Protein Kinase Pathway

Endocrinology ◽  
2003 ◽  
Vol 144 (3) ◽  
pp. 832-838 ◽  
Author(s):  
Christian B. Wade ◽  
Daniel M. Dorsa
Keyword(s):  
Protein Kinase ◽  
Mapk Pathway ◽  
Camp Response Element Binding ◽  
Mitogen Activated Protein Kinase ◽  
Camp Response Element ◽  
Response Element ◽  
Creb Phosphorylation ◽  
Mitogen Activated Protein ◽  
Element Binding Protein

The ability of estrogen to rapidly initiate a variety of signal transduction cascades is increasingly recognized as playing an important role in a number of tissue-specific transcriptional actions of the hormone. In vivo, estrogen rapidly elicits phosphorylation of cAMP response element-binding protein (CREB). We have previously shown that both ERα and ERβ are capable of activating the MAPK pathway in response to a low dose of 17β-estradiol. In the present study, the ability of estrogen to act through both ERα and ERβ to increase CREB phosphorylation was evaluated in an immortalized hippocampal cell line stably expressing either receptor. Estrogen treatment promoted rapid CREB phosphorylation, reaching a maximum by 15 min. This activation is completely blocked by the antiestrogen ICI 182,780, suggesting an estrogen receptor-dependent mechanism. The addition of the mitogen/ERK kinase-1 inhibitor, PD98059, also blocked the ability of estrogen to signal to CREB phosphorylation. Estrogen also caused an increase in p90Rsk activity, a critical mediator of MAPK effects. Surprisingly, blockade of the protein kinase A pathway in cells treated with estrogen did not affect estrogen-mediated CREB phosphorylation. Thus, MAPK and p90Rsk appear to be the primary mediators of estrogen-induced gene transcription through ERα and ERβ.

scholarly journals IGF-I and vasoactive intestinal peptide (VIP) regulate cAMP-response element-binding protein (CREB)-dependent transcription via the mitogen-activated protein kinase (MAPK) pathway in pituitary cells: requirement of Rap1

2005 ◽  
Vol 34 (3) ◽  
pp. 699-712 ◽  
Author(s):  
M Fernández ◽  
F Sánchez-Franco ◽  
N Palacios ◽  
I Sánchez ◽  
L Cacicedo
Keyword(s):  
Protein Kinase ◽  
Vasoactive Intestinal Peptide ◽  
Mapk Pathway ◽  
Binding Protein ◽  
Mitogen Activated Protein Kinase ◽  
Pituitary Cells ◽  
Camp Response Element ◽  
Response Element ◽  
Igf I ◽  
Mitogen Activated Protein

In previous studies we demonstrated that vasoactive intestinal peptide (VIP) mediation, and interactions between mitogen-activated protein kinase (MAPK) and cAMP/protein kinase A (PKA) signaling pathways are implicated in insulin-like growth factor I (IGF-I)- and VIP-induced lactotroph proliferation. These facts led us to investigate the intracellular mechanisms involved in IGF-I- and VIP-induced lactotroph proliferation. Exposure of cultured male rat pituitary cells to IGF-I (10−7 M) or VIP (10−7 M) stimulated the MAPK cascade. Studies in GH4C1 cells, with an expression vector for Rap1 GTPase-activating protein (Rap1 GAP1), demonstrated reduced VIP-induced MAPK activation, indicating that VIP-dependent activation of the extracellular signal-regulated kinase (ERK) pathway requires PKA-Rap1 signaling. IGF-I induced cAMP-response element (CRE)-binding protein (CREB) phosphorylation through the Ras-MAPK pathway, whereas VIP phosphorylated CREB directly via PKA. The mechanisms that regulate IGF-I-and VIP-CREB-dependent gene transcription were examined using GH4C1 cells transiently transfected with a CRE reporter gene. IGF-I and VIP stimulation of CRE-mediated transcription required activation of both Ras-MAPK and cAMP/PKA signaling. This activation was blocked in the presence of Rap1 GAP1. In summary, we showed that IGF-I and VIP stimulated MAPK activity and the phosphorylation of CREB in pituitary cells. Furthermore, VIP-dependent activation of PKA-Rap1-ERK pathways mediated VIP and IGF-I effects on CREB-dependent transcription in GH4C1 cells. Thus, it is possible that VIP- and IGF-I-induced lactotroph proliferation may involve Rap1.

Involvement of Ras/MAP Kinase in the Regulation of Ca2+ Channels in Adult Bullfrog Sympathetic Neurons by Nerve Growth Factor

1998 ◽  
Vol 80 (3) ◽  
pp. 1352-1361 ◽  
Author(s):  
Saobo Lei ◽  
William F. Dryden ◽  
Peter A. Smith
Keyword(s):  
Nerve Growth Factor ◽  
Growth Factor ◽  
Protein Kinase ◽  
Map Kinase ◽  
Kinase Inhibitors ◽  
Sympathetic Neurons ◽  
Mitogen Activated Protein Kinase ◽  
Nerve Growth ◽  
Channel Current ◽  
Mitogen Activated Protein

Lei, Saobo, William F. Dryden, and Peter A. Smith. Involvement of Ras/MAP kinase in the regulation of Ca2+ channels in adult bullfrog sympathetic neurons by nerve growth factor. J. Neurophysiol. 80: 1352–1361, 1998. The cellular mechanisms that underlie nerve growth factor (NGF) induced increase in Ca2+-channel current in adult bullfrog sympathetic B-neurons were examined by whole cell recording techniques. Cells were maintained at low density in neuron-enriched, defined-medium, serum-free tissue culture for 6 days in the presence or absence of NGF (200 ng/ml). The increase in Ba2+ current ( I Ba) density induced by NGF was attenuated by the RNA synthesis inhibitor cordycepin (20 μM), by the DNA transcription inhibitor actinomycin D (0.01 μg/ml), by inhibitors of Ras isoprenylation (perillic acid 0.1–1.0 mM or α-hydroxyfarnesylphosphonic acid 10–100 μM), by tyrosine kinase inhibitors genistein (20 μM) or lavendustin A (1 μM), and by PD98059 (10–100 μM), an inhibitor of mitogen-activated protein kinase kinase. Inhibitors of the phosphatidylinositol 3-kinase (PI3K) pathway (wortmannin, 100 nM, or LY29400, 100 μM) were ineffective as were inhibitors of phospholipase Cγ (U73122 or neomycin, both 100 μM). The effect of NGF persisted in Ca2+-free medium that contained 1.8 mM Mg2+ and 2 mM ethylene glycol-bis(β-aminoethyl ether)- N, N, N′, N′-tetraacetic acid. It was mimicked by a Trk antibody that was capable of inducing neurite outgrowth in explant cultures of bullfrog sympathetic ganglion. Antibodies raised against the low-affinity p75 neurotrophin receptor were ineffective in blocking the effect of NGF on I Ba. These results suggest that NGF-induced increase in Ca2+ channel current in adult sympathetic neurons results, at least in part, from new channel synthesis after Trk activation of Ras and mitogen activated protein kinase by a mechanism that is independent of extracellular Ca2+.

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