scholarly journals Enhancement by lithium of cAMP-induced CRE/CREB-directed gene transcription conferred by TORC on the CREB basic leucine zipper domain

2007 ◽  
Vol 408 (1) ◽  
pp. 69-77 ◽  
Author(s):  
Ulrike Böer ◽  
Julia Eglins ◽  
Doris Krause ◽  
Susanne Schnell ◽  
Christof Schöfl ◽  
...  
Keyword(s):  
Dna Binding ◽  
Gene Transcription ◽  
Leucine Zipper ◽  
Luciferase Reporter ◽  
Lithium Salts ◽  
Transactivation Domain ◽  
Camp Response Element ◽  
Basic Leucine Zipper ◽  
Response Element ◽  
Leucine Zipper Domain

The molecular mechanism of the action of lithium salts in the treatment of bipolar disorder is not well understood. As their therapeutic action requires chronic treatment, adaptive neuronal processes are suggested to be involved. The molecular basis of this are changes in gene expression regulated by transcription factors such as CREB (cAMP-response-element-binding protein). CREB contains a transactivation domain, in which Ser119 is phosphorylated upon activation, and a bZip (basic leucine zipper domain). The bZip is involved in CREB dimerization and DNA-binding, but also contributes to CREB transactivation by recruiting the coactivator TORC (transducer of regulated CREB). In the present study, the effect of lithium on CRE (cAMP response element)/CREB-directed gene transcription was investigated. Electrically excitable cells were transfected with CRE/CREB-driven luciferase reporter genes. LiCl (6 mM or higher) induced an up to 4.7-fold increase in 8-bromo-cAMP-stimulated CRE/CREB-directed transcription. This increase was not due to enhanced Ser119 phosphorylation or DNA-binding of CREB. Also, the known targets inositol monophosphatase and GSK3β (glycogen-synthase-kinase 3β) were not involved as specific GSK3β inhibitors and inositol replenishment did not mimic and abolish respectively the effect of lithium. However, lithium no longer enhanced CREB activity when the CREB-bZip was deleted or the TORC-binding site inside the CREB-bZip was specifically mutated (CREB-R300A). Otherwise, TORC overexpression conferred lithium responsiveness on CREB-bZip or the CRE-containing truncated rat somatostatin promoter. This indicates that lithium enhances cAMP-induced CRE/CREB-directed transcription, conferred by TORC on the CREB-bZip. We thus support the hypothesis that lithium salts modulate CRE/CREB-dependent gene transcription and suggest the CREB coactivator TORC as a new molecular target of lithium.

scholarly journals cAMP Response Element-Binding Protein Interacts With and Stimulates the Proteasomal Degradation of the Nuclear Receptor Coactivator GRIP1

Endocrinology ◽  
2013 ◽  
Vol 154 (4) ◽  
pp. 1513-1527 ◽  
Author(s):  
Tuyen Hoang ◽  
Ingvild S. Fenne ◽  
Andre Madsen ◽  
Olivera Bozickovic ◽  
Mona Johannessen ◽  
...  
Keyword(s):  
Nuclear Receptor ◽  
Leucine Zipper ◽  
Binding Protein ◽  
Proteasomal Degradation ◽  
Estrogen Receptor Α ◽  
Camp Response Element Binding ◽  
Camp Response Element ◽  
Basic Leucine Zipper ◽  
Response Element ◽  
Element Binding Protein

Abstract The glucocorticoid receptor interacting protein (GRIP1) belongs to the p160 steroid receptor coactivator family that plays essential roles in nuclear receptor-dependent transcriptional regulation. Previously, we reported that the cAMP-dependent protein kinase (PKA) induces ubiquitination leading to degradation of GRIP1. Here we show that the cAMP response element-binding protein (CREB) downregulates GRIP1 and is necessary for the PKA-stimulated degradation of GRIP1, which leads to changes in the expression of a subset of genes regulated by estrogen receptor-α in MCF-7 breast cancer cells. Our data of domain-mapping and ubiquitination analyses suggest that CREB promotes the proteasomal breakdown of ubiquitinated GRIP1 through 2 functionally independent protein domains containing amino acids 347 to 758 and 1121 to 1462. We provide evidence that CREB interacts directly with GRIP1 and that CREB Ser-133 phosphorylation or transcriptional activity is not required for GRIP1 interaction and degradation. The basic leucine zipper domain (bZIP) of CREB is important for the interaction with GRIP1, and deletion of this domain led to an inability to downregulate GRIP1. We propose that CREB mediates the PKA-stimulated degradation of GRIP1 through protein-protein interaction and stimulation of proteasomal degradation of ubiquitinated GRIP1.

scholarly journals Consensus and Variant cAMP-regulated Enhancers Have Distinct CREB-binding Properties

2000 ◽  
Vol 276 (15) ◽  
pp. 11719-11728 ◽  
Author(s):  
Johanna C. Craig ◽  
Maria A. Schumacher ◽  
Steven E. Mansoor ◽  
David L. Farrens ◽  
Richard G. Brennan ◽  
...  
Keyword(s):  
Dna Binding ◽  
Binding Affinity ◽  
Leucine Zipper ◽  
Camp Response Element Binding ◽  
Camp Response Element ◽  
Basic Leucine Zipper ◽  
Binding Characteristics ◽  
Element Binding Protein ◽  
Dna Binding Affinity

Recent determination of the cAMP response element-binding protein (CREB) basic leucine zipper (bZIP) consensus CRE crystal structure revealed key dimerization and DNA binding features that are conserved among members of the CREB/CREM/ATF-1 family of transcription factors. Dimerization appeared to be mediated by a Tyr307–Glu312interhelical hydrogen bond and a Glu319–Arg314electrostatic interaction. An unexpected hexahydrated Mg2+ion was centered above the CRE in the dimer cavity. In the present study, we related these features to CREB dimerization and DNA binding. A Y307F substitution reduced dimer stability and DNA binding affinity, whereas a Y307R mutation produced a stabilizing effect. Mutation of Glu319to Ala or Lys attenuated dimerization and DNA binding. Mg2+ions enhanced the binding affinity of wild-type CREB to the palindromic CRE by ∼20-fold but did not do so for divergent CREs. Similarly, mutation of Lys304, which mediates the CREB interaction with the hydrated Mg2+, blocked CREB binding to the palindromic but not the variant CRE sequences. The distinct binding characteristics of the K304A mutants to the consensus and variant CRE sequences indicate that CREB binding to these elements is differentially regulated by Mg2+ions. We suggest that CREB binds the consensus and variant CRE sequences through fundamentally distinct mechanisms.

A cDNA for a human cyclic AMP response element-binding protein which is distinct from CREB and expressed preferentially in brain

1990 ◽  
Vol 10 (4) ◽  
pp. 1347-1357
Author(s):  
C J Kara ◽  
H C Liou ◽  
L B Ivashkiv ◽  
L H Glimcher
Keyword(s):  
Dna Binding ◽  
Cyclic Amp ◽  
Leucine Zipper ◽  
Binding Protein ◽  
Structural Similarity ◽  
Response Element ◽  
Cellular Genes ◽  
Viral Promoters ◽  
Element Binding Protein ◽  
Cyclic Amp Response Element

The cyclic AMP response element (CRE) is found in many cellular genes regulated by cyclic AMP, and similar elements are present in the early genes of adenovirus that are activated by E1A. The transcription factor CREB has previously been shown to bind this site, and cDNAs for CREB have recently been characterized. We report here the isolation of a cDNA encoding a human DNA-binding protein that also recognizes this motif in cellular and viral promoters. This protein, HB16, displays structural similarity to CREB and to c-Jun and c-Fos, which bind the related 12-O-tetradecanoylphorbol-13-acetate response element (TRE). HB16 contains a highly basic, putative DNA-binding domain and a leucine zipper structure thought to be involved in dimerization. Deletional analysis of HB16 demonstrated that the leucine zipper is required for its interaction with DNA. In addition, HB16 could form a complex with c-Jun but not with c-Fos. Despite its structural similarity to c-Jun and c-Fos and its interaction with c-Jun, HB16 had approximately a 10-fold-lower affinity for the TRE sequence than for the CRE sequence. Although HB16 and CREB both recognized the CRE motif, an extensive binding analysis of HB16 revealed differences in the fine specificity of binding of the two proteins. HB16 mRNA was found at various levels in many human tissues but was most abundant in brain, where its expression was widespread. The existence of more than one CRE-binding protein suggests that the CRE motif could serve multiple regulatory functions.

Identification of transactivation and repression functions of the dioxin receptor and its basic helix-loop-helix/PAS partner factor Arnt: inducible versus constitutive modes of regulation

1994 ◽  
Vol 14 (12) ◽  
pp. 8343-8355
Author(s):  
M L Whitelaw ◽  
J A Gustafsson ◽  
L Poellinger
Keyword(s):  
Transcription Factor ◽  
Dna Binding ◽  
Ligand Binding ◽  
Transactivation Domain ◽  
Response Element ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
C Terminus ◽  
Heterodimeric Complex ◽  
Dioxin Receptor

Gene regulation by dioxins is mediated via the dioxin receptor, a ligand-dependent basic helix-loop-helix (bHLH)/PAS transcription factor. The latent dioxin receptor responds to dioxin signalling by forming an activated heterodimeric complex with a specific bHLH partner, Arnt, an essential process for target DNA recognition. We have analyzed the transactivating potential within this heterodimeric complex by dissecting it into individual subunits, replacing the dimerization and DNA-binding bHLH motifs with heterologous zinc finger DNA-binding domains. The uncoupled Arnt chimera, maintaining 84% of Arnt residues, forms a potent and constitutive transcription factor. Chimeric proteins show that the dioxin receptor also harbors a strong transactivation domain in the C terminus, although this activity was silenced by inclusion of 82 amino acids from the central ligand-binding portion of the dioxin receptor. This central repression region conferred binding of the molecular chaperone hsp90 upon otherwise constitutive chimeras in vitro, indicating that hsp90 has the ability to mediate a cis-repressive function on distant transactivation domains. Importantly, when the ligand-binding domain of the dioxin receptor remained intact, the ability of this hsp90-binding activity to confer repression became conditional rather than irreversible. Our data are consistent with a model in which crucial activities of the dioxin receptor, such as dimerization with Arnt and transactivation, are conditionally repressed by the central ligand- and-hsp90-binding region of the receptor. In contrast, the Arnt protein appears to be free from any repressive activity. Moreover, within the context of the dioxin response element (xenobiotic response element), the C terminus of Arnt conferred a potent, dominating transactivation function onto the native bHLH heterodimeric complex. Finally, the relative transactivation potencies of the individual dioxin receptor and Arnt chimeras varied with cell type and promoter architecture, indicating that the mechanisms for transcriptional activation may differ between these two subunits and that in the native complex the transactivation pathway may be dependent upon cell-specific and promoter contexts.

scholarly journals Dexamethasone represses cAMP rapid upregulation of TRH gene transcription: identification of a composite glucocorticoid response element and a cAMP response element in TRH promoter

2005 ◽  
Vol 34 (1) ◽  
pp. 177-197 ◽  
Author(s):  
A Cote-Vélez ◽  
L Pérez-Martínez ◽  
M Y Díaz-Gallardo ◽  
C Pérez-Monter ◽  
A Carreón-Rodríguez ◽  
...  
Keyword(s):  
Luciferase Reporter ◽  
Transcriptional Level ◽  
Mrna Levels ◽  
Mobility Shift ◽  
Camp Response Element ◽  
Glucocorticoid Response Element ◽  
Response Element ◽  
Nuclear Extracts ◽  
Glucocorticoid Response ◽  
Hypothalamic Cells

Hypothalamic proTRH mRNA levels are rapidly increased (at 1 h) in vivo by cold exposure or suckling, and in vitro by 8Br-cAMP or glucocorticoids. The aim of this work was to study whether these effects occurred at the transcriptional level. Hypothalamic cells transfected with rat TRH promoter (− 776/+85) linked to the luciferase reporter showed increased transcription by protein kinase (PK) A and PKC activators, or by dexamethasone (dex), but co-incubation with dex and 8Br-cAMP decreased their stimulatory effect (as observed for proTRH mRNA levels). These effects were also observed in NIH-3T3-transfected cells supporting a characteristic of TRH promoter and not of hypothalamic cells. Transcriptional regulation by 8Br-cAMP was mimicked by noradrenaline which increased proTRH mRNA levels, but not in the presence of dex. PKA inhibition by H89 avoided 8Br-cAMP or noradrenaline stimulation. TRH promoter sequences, cAMP response element (CRE)-like (− 101/− 94 and − 59/− 52) and glucocorticoid response element (GRE) half-site (− 210/− 205), were analyzed by electrophoretic mobility shift assays with nuclear extracts from hypothalamic or neuroblastoma cultures. PKA stimulation increased binding to CRE (− 101/− 94) but not to CRE (− 59/− 52); dex or 12-O-tetradecanoylphorbol-13-acetate (TPA) increased binding to GRE, a composite site flanked by a perfect and an imperfect activator protein (AP-1) site in the complementary strand. Interference was observed in the binding of CRE or GRE with nuclear extracts from cells co-incubated for 3 h with 8Br-cAMP and dex; from cells incubated for 1 h, only the binding to GRE showed interference. Rapid cross-talk of glucocorticoids with PKA signaling pathways regulating TRH transcription constitutes another example of neuroendocrine integration.

scholarly journals A cDNA for a human cyclic AMP response element-binding protein which is distinct from CREB and expressed preferentially in brain.

1990 ◽  
Vol 10 (4) ◽  
pp. 1347-1357 ◽  
Author(s):  
C J Kara ◽  
H C Liou ◽  
L B Ivashkiv ◽  
L H Glimcher
Keyword(s):  
Dna Binding ◽  
Cyclic Amp ◽  
Leucine Zipper ◽  
Binding Protein ◽  
Structural Similarity ◽  
Response Element ◽  
Cellular Genes ◽  
Viral Promoters ◽  
Element Binding Protein ◽  
Cyclic Amp Response Element

The cyclic AMP response element (CRE) is found in many cellular genes regulated by cyclic AMP, and similar elements are present in the early genes of adenovirus that are activated by E1A. The transcription factor CREB has previously been shown to bind this site, and cDNAs for CREB have recently been characterized. We report here the isolation of a cDNA encoding a human DNA-binding protein that also recognizes this motif in cellular and viral promoters. This protein, HB16, displays structural similarity to CREB and to c-Jun and c-Fos, which bind the related 12-O-tetradecanoylphorbol-13-acetate response element (TRE). HB16 contains a highly basic, putative DNA-binding domain and a leucine zipper structure thought to be involved in dimerization. Deletional analysis of HB16 demonstrated that the leucine zipper is required for its interaction with DNA. In addition, HB16 could form a complex with c-Jun but not with c-Fos. Despite its structural similarity to c-Jun and c-Fos and its interaction with c-Jun, HB16 had approximately a 10-fold-lower affinity for the TRE sequence than for the CRE sequence. Although HB16 and CREB both recognized the CRE motif, an extensive binding analysis of HB16 revealed differences in the fine specificity of binding of the two proteins. HB16 mRNA was found at various levels in many human tissues but was most abundant in brain, where its expression was widespread. The existence of more than one CRE-binding protein suggests that the CRE motif could serve multiple regulatory functions.

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