Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the anterior pituitary, expression of the common glycoprotein hormone alpha-subunit (alphaGSU) is mediated in part by multiple response elements residing in the distal promoter (-435 bp). One such site is the gonadotrope-specific element (GSE), which is bound by the orphan nuclear receptor steroidogenic factor-1 (SF-1) and confers pituitary adenylate cyclase-activating polypeptide (PACAP)-stimulated alphaGSU expression. Here we investigated the functional importance of the GSE and SF-1 phosphorylation in both basal and stimulated alphaGSU transcription. Mutation of the GSE reduced basal and PACAP-stimulated alphaGSU promoter activity in the alphaT3-1 gonadotrope cell line. Overexpression of wild-type SF-1, but not an S203A mutant form of SF-1, enhanced basal and PACAP-stimulated alphaGSU promoter activity. The effect of PACAP on alphaGSU promoter activity was inhibited after overexpression of MAPK phosphatase. Helix assembly of the SF-1 ligand-binding domain was stimulated by PACAP in vitro via a MAPK-dependent pathway, as determined using a mammalian two-hybrid assay. PACAP quickly activated MAPK (within 5 min) and also resulted in elevated levels of phospho-cAMP response element-binding protein and phospho-SF-1, as judged by a specific antiphospho-S203 antibody; this effect was blocked by the MAPK kinase inhibitor, UO126. Collectively, these data demonstrate that SF-1 binds to the GSE and activates both basal and PACAP-stimulated alphaGSU transcription, which is further increased by phosphorylation at Ser203 via MAPK. These data suggest strongly that the induction of alphaGSU gene expression by peptide hormone signaling is coupled directly to the posttranslational status of SF-1.
Mol Endocrinol 2003 Nov
PMID:Steroidogenic factor-1 and the gonadotrope-specific element enhance basal and pituitary adenylate cyclase-activating polypeptide-stimulated transcription of the human glycoprotein hormone alpha-subunit gene in gonadotropes. 1292 Feb 32

The utility of morphine for the treatment of chronic pain is hindered by the development of tolerance. Fentanyl has been shown to be a potent analgesic with a lower propensity to produce tolerance and physical dependence in the clinical setting. Previous finding has shown that fentanyl induces mu opioid receptor gene expression in PC-12 cells (Brain Res 859:217-223, 2000). In this report, we aim to identify the molecular mechanism of mu-opioid receptor (MOR) gene regulation by fentanyl. We demonstrated that the 4.7-kilobase MOR promoter could be induced by fentanyl in PC-12 cells, and we defined a partial cAMP response element (CRE) located at -106/-111 in 5'-untranslated region of the MOR gene. In electrophoretic mobility shift assay, cAMP response element-binding protein (CREB) was found in the protein-DNA complex formed on the CRE box. CREB was phosphorylated after forskolin induction, and both CREB and CREB-binding protein (CBP) binding to the endogenous MOR promoter was increased by forskolin in chromatin immunoprecipitation assay. The functional role of CREB in the induction of MOR gene was further elucidated by an experiment in which a dominant-negative mutant CREB, CREB-S133A, abolished the forskolin-mediated MOR induction. Moreover, we found that this CRE box is conserved in mouse, rat, and human MOR gene, implying physiological relevance in different species. Collectively, this study demonstrated that fentanyl-triggered MOR gene induction was mediated by the sequential activation of CREB and the binding of CREB and CBP to MOR promoter, thus provides direct evidence for lower propensity of fentanyl to produce tolerance.
Mol Pharmacol 2003 Dec
PMID:Transcriptional regulation of mu opioid receptor gene by cAMP pathway. 1464 71

Essential components of a signal-transduction pathway regulating activity-dependent neuropeptide gene transcription have been identified. Proenkephalin (PEnk) gene activation after depolarization of chromaffin cells with 40 mM KCl was blocked by the voltage-sensitive calcium-channel blocker methoxyverapamil (D600) (30 microM) and by calcineurin inhibition with 100 nM cyclosporin A or ascomycin but not by inhibiting new protein synthesis with 0.5 microg/ml cycloheximide. KCl-induced elevation of PEnk mRNA was distinct from activation of the PEnk gene by either cAMP or protein kinase C. Twenty-five micromolar forskolin- and 100 nM phorbol 12-myristate 13-acetate-induced elevations of PEnk mRNA were cycloheximide-sensitive and were not blocked by cyclosporin A or ascomycin. KCl stimulated Ser-133 phosphorylation of cAMP response element-binding protein (CREB) in chromaffin cells, and CREB phosphorylation was blocked by both ascomycin and D600. A reporter gene containing 193 bases of the PEnk gene 5' flank driving luciferase gene expression (pENK12-Luc) transfected into chromaffin cells was transcriptionally activated by KCl depolarization. Activation was blocked by both ascomycin and D600 and required an intact CREB binding site (ENKCRE2). An oligonucleotide containing the PEnk cAMP response element-2 was gel-shifted by both unstimulated and potassium-stimulated chromaffin cell nuclear extracts into a prominent complex supershifted by CREB antibodies. Finally, stimulation of transcription of the pENK12-Luc reporter by KCl in chromaffin cells was blocked by coexpression of the CREB antagonist A-CREB but not by the AP-1 antagonist A-Fos. Stimulus-transcription coupling after depolarization in chromaffin cells occurs via calcineurin-dependent activation of CREB, a pathway distinct from cAMP- or protein kinase C-initiated signaling and independent of immediate early gene regulation.
Mol Pharmacol 2003 Dec
PMID:A calcium-initiated signaling pathway propagated through calcineurin and cAMP response element-binding protein activates proenkephalin gene transcription after depolarization. 1464 81

In recently published studies, we show that angiotensin II (AII) generated from an engineered rat angiotensinogen cDNA, and maintained intracellularly, is growth stimulatory for a rat hepatoma cell line. In the present study, we report that co-expression of AII fused to cyan fluorescent protein (ECFP/AII) and angiotensin type I receptor fused to yellow fluorescent protein (AT1R/EYFP) enhances proliferation of COS-7 and CHO-K1 cells by 59% and 64%, respectively, compared to cells expressing the corresponding independent proteins (P < 0.001 for both). This effect is inhibited by losartan, suggesting (as in our previous published studies) that losartan is internalized by the cells, via receptor-mediated endocytosis, and thus inhibits intracellular receptor-ligand interaction. The growth effect is independent of anti-AII antibodies suggesting that it does not reflect AII secretion into the culture media; AII is also undetectable in the media. Expression of AT1R/EYFP with ECFP/AIIC (control scrambled sequence AII fused to ECFP) has no effect upon cell proliferation. ECFP/AII also alters the cellular localization of AT1R/EYFP. ECFP/AII is concentrated in the nucleus, but shows diffuse cytoplasmic fluorescence as well. AT1R/EYFP, expressed independently, is visible in the endoplasmic reticulum and Golgi apparatus of COS-7 and CHO-K1 cells as early as 24-h post-transfection. At 72 h, it is visibly associated with the plasma membrane. By 144 h, 85% of the cells show detectable circumferential fluorescence. In contrast, in cells that express AT1R/EYFP and ECFP/AII, both proteins accumulate in the nucleus and only 13% of the cells show visible plasma membrane-associated yellow fluorescence at 144 h (P < 0.001). Furthermore, co-expression of ECFP/AII with AT1R/EYFP stimulates cAMP response element-binding protein (CREB) activity in CHO-K1 and COS-7 cells. Exogenous AII similarly significantly increases CREB activation in AT1R/EYFP-stably transfected CHO-K1 and COS-7 cells.
J Mol Cell Cardiol 2004 Jan
PMID:Intracellular angiotensin II fusion protein alters AT1 receptor fusion protein distribution and activates CREB. 1473 50

Barbiturates are frequently used for the treatment of intracranial hypertension after brain injury but their application is associated with a profound increase in the infection rate. The mechanism of barbiturate-induced failure of protective immunity is still unknown. We provide evidence that nuclear factor of activated T cells (NFAT), an essential transcription factor in T cell activation, is a target of barbiturate-mediated immunosuppression in human T lymphocytes. Treatment of primary CD3+ lymphocytes with barbiturates inhibited the PMA and ionomycin induced increase in DNA binding of NFAT, whereas the activity of other transcription factors, such as Oct-1, SP-1, or the cAMP response element-binding protein, remained unaffected. Moreover, barbiturates suppressed the expression of a luciferase reporter gene under control of NFAT (stably transfected Jurkat T cells), and of the cytokine genes interleukin-2 and interferon-gamma that contain functional binding motifs for NFAT within their regulatory promotor domains (human peripheral blood CD3+ lymphocytes). Neither GABA receptor-initiated signaling nor direct interactions of barbiturates with nuclear proteins affected the activity of NFAT. In contrast, barbiturates suppressed the calcineurin-dependent dephosphorylation of NFAT in intact T cells and also inhibited the enzymatic activity of calcineurin in a cell-free system, excluding upstream regulation. Thus, our results demonstrate a novel mechanism of direct inhibition of the calcineurin/calmodulin complex that may explain some of the known immunosuppressive effects associated with barbiturate treatment.
Mol Pharmacol 2004 Feb
PMID:Barbiturates directly inhibit the calmodulin/calcineurin complex: a novel mechanism of inhibition of nuclear factor of activated T cells. 1474 77

Long-term depression (LTD) induction relies upon receptor cross-talk between group I and group II metabotropic glutamate receptors (mGluRs) in perirhinal cortex. The molecular mechanism of this mGluR interplay is not clear. Here, we show that the mGluR subtypes postulated to be involved in this mechanism are developmentally regulated and mGluR2 has a preferential role over mGluR3 in the synergistic interaction with mGluR5. We have identified a >70% reduction in basal cAMP levels following mGluR2 stimulation, which could lead to increased mGluR5 function via reduced PKA mediated phosphorylation and decreased desensitisation of mGluR5. To further investigate the roles of mGluRs in downstream intracellular signalling, we have examined the effects of mGluRs on the phosphorylation state of cAMP response element-binding protein (CREB). Both group I and group II agonists increased the phosphorylation of CREB, which indicates a cAMP- and PKA-independent signalling mechanism. These results suggest a convergence of signalling mechanisms from surface mGluRs to CREB-mediated transcription.
Mol Cell Neurosci 2004 Feb
PMID:Metabotropic glutamate receptor signalling in perirhinal cortical neurons. 1501 44

Little is known about molecular mechanisms for long-lasting neuroadaptation related to the rewarding effects of methamphetamine (MAP). In the present study, we examined the intracellular signaling that is associated with the expression of conditioned place preference (CPP) induced by MAP in rats. Rats were given MAP or saline (control group) for conditioning to the CPP test. MAP-treated and control animals were killed immediately after the CPP test [CPP(+)]. Some of the MAP-treated rats were killed without the CPP test [CPP(-)]. Hyperphosphorylation of mitogen-activated protein kinase (MAPK) ERK1/2, but not p38 and c-Jun N-terminal kinase/stress-activated protein kinase, was found in the nucleus accumbens (NAc) and striatum but not in other brain areas of MAP-treated CPP(+) animals. No such phosphorylation was seen in control and MAP-treated CPP(-) animals. Moreover, the transcription factor ets-like gene-1 (Elk-1), but not cAMP response element-binding protein, also showed a similar hyperphosphorylation in the same regions of MAP-treated CPP(+). Tyrosine kinase receptors, including tyrosine kinase B, were not activated in any brain regions examined in all groups. Both the dopamine D1 receptor antagonist R-(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine (SCH23390) and the D2 receptor antagonist raclopride inhibited the expression of CPP as well as the activation of ERK1/2 in MAP-treated CPP(+) animals, when they were injected before the CPP test. The microinjection of 2'-amino-3'-methoxyflavone (PD98059), a selective MAPK kinase inhibitor, into the NAc before the test, abolished the MAP-induced ERK1/2 activation and decreased the expression of MAP-induced CPP. These results suggest the importance of the ERK1/2 signaling pathway through activation of dopamine D1 and D2 receptors in the expression of CPP induced by MAP.
Mol Pharmacol 2004 May
PMID:Regulations of methamphetamine reward by extracellular signal-regulated kinase 1/2/ets-like gene-1 signaling pathway via the activation of dopamine receptors. 1510 58

A brain dopamine receptor that modulates phosphatidylinositol (PI) metabolism via the activation of phospholipase Cbeta (PLCbeta) has been described previously. The present study aims to define the downstream signaling cascade initiated by the PI-linked dopamine receptor. Incubation of rat brain frontal cortical slices with 6-chloro-7,8-dihydroxy-3-methyl-1-(3-methylphenyl)-2,3,4,5-tetrahydro-1H-3-benzazepine (SKF83959), a recently identified selective agonist of the PI-linked D1-like dopamine receptor, elicited transient time- and dose-dependent stimulations of cyclin-dependent kinase 5 (cdk5) and calcium/calmodulin-dependent protein kinase II (CaMK II) activities. The stimulation of these kinases is blocked by 20 microM R-(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine (SCH23390) or the PLCbeta antagonist 1-[6-[[17beta-methoxyestra-1,3,5(10)-trien-17-yl]amino]hexyl]-1H-pyrrole-2,5-dione (U-73122) and is attenuated by the protein kinase inhibitor calphostin C or by the intracellular calcium chelator BAPTA, indicating that SKF83959 stimulates cdk5 and CaMK II activities via a PI-linked D1-like dopamine receptor, and PLCbeta and is dependent on protein kinase C and calcium. Although cdk5 and CaMK II are physically associated in native brain tissue, no change in this association was observed in response to SKF83959 stimulation or to the inhibition of either cdk5 by roscovitine or of CaMK by 2-[N-(2-hydroxyethyl)]-N-(4-methoxybenzenesulfonyl)]amino-N-(4-chlorocinnamyl)-N-methylbenzylamine) (KN93), suggesting that SKF83959-mediated stimulation of cdk5 or CaMK II is independent of the other kinase and that the association of the two kinases is not modulated by change of kinase activity. Moreover, we found that cdk5 phosphorylates dopamine and cAMP-regulated phosphoprotein at Thr75, whereas CaMK II is responsible for the activation of cAMP response element-binding protein in response to SKF83959 stimulation. The present data provide the first insight into the signaling mechanism for the PI-linked dopamine receptor. This information, in turn, may help in exploring the functional consequences of stimulation of this brain receptor.
Mol Pharmacol 2004 Dec
PMID:Regulation of cyclin-dependent kinase 5 and calcium/calmodulin-dependent protein kinase II by phosphatidylinositol-linked dopamine receptor in rat brain. 1528 9

The present study investigated whether the expression of the cAMP response element-binding protein (CREB) in the rat brain is altered following an acute self-limited seizure induced by pentylenetetrazol (PTZ). Male rats were injected intraperitoneally with a single convulsive dose (45 mg/kg) of PTZ, and the matched controls were given saline. For immunohistochemistry, animals were perfused with 4% parafomaldehyde at 24 h following PTZ seizures, and CREB immunoreactivity was examined in rat brain. For real-time RT-PCR, animals were sacrificed at 2 and 24 h and 1 week following PTZ seizures. Tissues from different rat brain regions were micropunched and subjected to real-time RT-PCR using Taqman probe. The CREB immunoreactive profiles were significantly decreased in CA3 and dentate gyrus of hippocampal formation, sensory cerebral cortex and thalamus at 24 h after PTZ seizures. Consistent with changes in CREB immunoreactivity, levels of CREB mRNA were significantly decreased in the hippocampus, cerebral cortex, amygdala and thalamus at 24 h after PTZ seizures. No significant change was found for CREB mRNA expression in these regions at 2 h or 1 week following PTZ seizures. These results show that a brief seizure caused a decline in CREB expression up to 24 h later.
Brain Res Mol Brain Res 2004 Aug 23
PMID:Decreased expression of brain cAMP response element-binding protein gene following pentylenetetrazol seizure. 1530 21

Glucose-6-phosphatase (Glc6Pase) is the last enzyme of gluconeogenesis and is only expressed in the liver, kidney, and small intestine. In these tissues, the mRNA and its activity are increased when cAMP levels increased (e.g. in fasting or diabetes). We first report that a proximal region (within -200 bp relative to the transcription start site) and a distal region (-694/-500 bp) are both required for a potent cAMP and a protein kinase A (PKA) responsiveness of the Glc6Pase promoter. Using different molecular approaches, we demonstrate that hepatocyte nuclear factor (HNF4alpha), CAAT/enhancer-binding protein-alpha (C/EBPalpha), C/EBPbeta, and cAMP response element-binding protein (CREB) are involved in the potentiated PKA responsiveness: in the distal region, via one HNF4alpha- and one C/EBP-binding sites, and in the proximal region, via two HNF4alpha and two CREB-binding sites. We also show that HNF4alpha, C/EBPalpha, and C/EBPbeta are constitutively bound to the endogenous Glc6Pase gene, whereas CREB and CREB-binding protein (CBP) will be bound to the gene upon stimulation by cAMP. These data strongly suggest that the cAMP responsiveness of the Glc6Pase promoter requires a tight cooperation between a proximal and a distal region, which depends on the presence of several HNF4alpha-, C/EBP-, and CREB-binding sites, therefore involving an intricate association of hepatic and ubiquitous transcription factors.
Mol Endocrinol 2005 Jan
PMID:A distal region involving hepatocyte nuclear factor 4alpha and CAAT/enhancer binding protein markedly potentiates the protein kinase A stimulation of the glucose-6-phosphatase promoter. 1538 92


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