cAMP Response Element (camp + response_element)

Distribution by Scientific Domains
Life Sciences75%

Terms modified by cAMP Response Element

  • camp response element binding protein
    		•

    Selected Abstracts

    Characterization of the mouse adenylyl cyclase type VIII gene promoter: regulation by cAMP and CREB

    EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2002
    Jennifer R. Chao
    Abstract Adenylyl cyclase (AC) type VIII has been implicated in several forms of neural plasticity, including drug addiction and learning and memory. In the present study, we directly examined the role for the transcription factor CREB (cAMP response element binding protein) in regulating ACVIII expression by cloning a 5.2 kilobase region upstream of the translation start site of the mouse ACVIII gene. Analysis of this fragment revealed consensus elements for several transcription factors, including a canonical cAMP response element (CRE) in close proximity to the transcription initiation region. Next, ACVIII promoter activity was studied in two neural-derived cell lines and in primary cultures of rat striatal neurons. Activation of the cAMP pathway by forskolin treatment increased promoter activity, and a series of deletion and point mutants demonstrated that this activation is mediated specifically via the canonical CRE site. Gel shift assays confirmed that this site can bind CREB and several CREB family proteins. Further, activation of the ACVIII promoter by forskolin was potentiated by expression of a constitutively active form of CREB, CREB-VP16, whereas it was inhibited by expression of a dominant-negative form of CREB, A-CREB. Finally, over-expression of CREB in vivo, by viral-mediated gene transfer, induced ACVIII promoter activity in the brains of ACVIII-LacZ transgenic mice. These results suggest that the ACVIII gene is regulated by CREB in vitro and in vivo and that this regulation may contribute to CREB-dependent neural plasticity. [source]

    Heregulin and forskolin-induced cyclin D3 expression in Schwann cells: Role of a CCAAT promoter element and CCAAT enhancer binding protein

    GLIA, Issue 3 2004
    Luis Fuentealba
    Abstract Heregulin, a polypeptide growth factor, and forskolin, an adenylyl cyclase activator, synergistically stimulate expression of cyclin D3 and cell division in Schwann cells. Heregulin induces expression in Schwann cells of a luciferase reporter gene linked to the cyclin D3 promoter. Forskolin markedly augments reporter expression in the presence of heregulin. Deletion analysis identified several promoter sites that contribute to high-level reporter expression in heregulin- and forskolin-treated Schwann cells. A promoter fragment that contains 103 bp of 5,-flanking sequence produced significant reporter expression in heregulin- and forskolin-stimulated cells. Deletion of a consensus CCAAT site within this promoter fragment caused a nearly complete loss of reporter expression. Similar results were obtained when CCAAT site mutations were introduced into the promoter. Heregulin and forskolin increased steady-state levels of CCAAT/enhancer binding protein-, (C/EBP,) in Schwann cells. Mobility shift assays identified proteins in Schwann cell nuclear extracts that formed stable complexes with the cyclin D3 CCAAT promoter element and were disrupted by anti-C/EBP, antibody. Transfection of Schwann cells with C/EBP, cDNA increased cyclin D3 reporter expression. In contrast to these results, mutation of a cAMP response element in the cyclin D3 promoter had only a modest effect on heregulin- and forskolin-stimulated reporter expression. These findings demonstrate that C/EBP, plays a key role in the heregulin and cAMP-dependent regulation of cyclin D3 expression in Schwann cells. © 2003 Wiley-Liss, Inc. [source]

    Regulation of GTP cyclohydrolase I gene transcription by basic region leucine zipper transcription factors

    JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 5 2005
    Jude Al Sarraj
    Abstract Tetrahydrobiopterin is an essential cofactor for the phenylalanine, tyrosine and tryptophan hydroxylases, and the family of nitric oxide synthases. The initial and rate-limiting enzyme in the biosynthesis of tetrahydrobiopterin is GTP cyclohydrolase I. The proximal promoter of the human GTP cyclohydrolase I gene contains the sequence motif 5,-TGACGCGA-3,, resembling a cAMP response element (CRE). The objective of this study was to analyze the regulation of GTP cyclohydrolase I gene transcription by basic region leucine zipper (bZIP) transcription factors. A constitutively active mutant of the cAMP response element binding (CREB) protein strongly stimulated GTP cyclohydrolase I promoter activity, indicating that the CRE in the context of the GTP cyclohydrolase I gene is functional. Likewise, GTP cyclohydrolase I promoter/luciferase gene transcription was stimulated following nuclear expression of the catalytic subunit of cAMP-dependent protein kinase. Constitutively active mutants of activating transcription factor 2 (ATF2) and c-Jun additionally stimulated GTP cyclohydrolase I promoter activity, but to a lesser extent than the constitutively active CREB mutant. The fact that stress-activated protein kinases target the GTP cyclohydrolase I gene was corroborated by expression experiments involving p38 and MEKK1 protein kinases. We conclude that signaling pathways involving either the cAMP-dependent protein kinase or stress-activated protein kinases converge to the GTP cyclohydrolase I gene. Hence, enzymatic reactions that require tetrahydrobiopterin as cofactor are therefore indirectly controlled by signaling cascades involving the signal-responsive transcription factors CREB, c-Jun, and ATF2. J. Cell. Biochem. © 2005 Wiley-Liss, Inc. [source]

    Ethanol Uses cAMP-Independent Signal Transduction Mechanisms to Activate Proenkephalin Promoter Activity in Rat C6 Glioma Cells

    ALCOHOLISM, Issue 7 2000
    Xiaoju Yang
    Background: Previous in vivo studies show that acute ethanol exposure sequentially increases protein kinase A (PKA) activity, the phosphorylation of the adenosine 3,:5,-cyclic monophosphate (cAMP) dependent transcription factor, CREB, and finally proenkephalin gene expression. The present study was conducted to determine if ethanol could activate directly the adenylyl cyclase pathway and thus enhance proenkephalin promoter activity. Methods: Cultured rat C6 glioma cells stably transfected with a segment of the five prime flanking region of rat proenkephalin promoter (nucleotide -2700 + 53) ligated to the chloramphenicol acetyltransferase (CAT) reporter gene were employed to study the effects of ethanol on proenkephalin promoter activity. This region of proenkephalin promoter contains two cAMP response elements (CRE-1 and CRE-2) and one AP2 site located in the region upstream of the TATA box. Cultures were exposed to ethanol, isoproterenol, and phorbol-12, myristate 13-acetate (PMA) alone and in combination, in the presence and absence of PKA and protein kinase C (PKC) inhibitors. Results: Ethanol and isoproterenol increased proenkephalin promoter activity in a dose-dependent manner. Ethanol had an additive effect on maximal isoproterenol-stimulated proenkephalin promoter activity, which suggested that ethanol used a cAMP-independent signai transduction pathway to increase proenkephalin promoter activation. In contrast with isoproterenol, ethanol exposure did not increase cAMP accumulation, PKA activity, or the phosphorylated form of CREB. However, ethanol exposure modestly increased PKC activity. The PKA-specific inhibitor, Rp-cAMP, dampened isoproterenol-induced activation of CAT activity but did not alter ethanol's ability to increase CAT activity. However, the PKC inhibitors, chelerthyrine and G07874, abrogated ethanol's effect of CAT activity but did not alter isoproterenol's effects. Conclusions: Ethanol enhanced proenkephalin promoter activity and potentiated isoproterenol stimulated promoter activity through a cAMP-independent pathway. [source]