scholarly journals Analysis of the Steroid Receptor Coactivator 1 (SRC1)-CREB Binding Protein Interaction Interface and Its Importance for the Function of SRC1

2001 ◽  
Vol 21 (1) ◽  
pp. 39-50 ◽  
Author(s):  
Hilary M. Sheppard ◽  
Janet C. Harries ◽  
Sagair Hussain ◽  
Charlotte Bevan ◽  
David M. Heery
Keyword(s):  
Binding Protein ◽  
Steroid Receptor ◽  
Creb Binding Protein ◽  
Interaction Domain ◽  
Steroid Receptor Coactivator ◽  
Helix Loop Helix ◽  
Rich Domain ◽  
Interaction Interface ◽  
Acetyltransferase Domain

ABSTRACT The transcriptional activity of nuclear receptors is mediated by coactivator proteins, including steroid receptor coactivator 1 (SRC1) and its homologues and the general coactivators CREB binding protein (CBP) and p300. SRC1 contains an activation domain (AD1) which functions via recruitment of CBP and and p300. In this study, we have used yeast two-hybrid and in vitro interaction-peptide inhibition experiments to map the AD1 domain of SRC1 to a 35-residue sequence potentially containing two α-helices. We also define a 72-amino-acid sequence in CBP necessary for SRC1 binding, designated the SRC1 interaction domain (SID). We show that in contrast to SRC1, direct binding of CBP to the estrogen receptor is weak, suggesting that SRC1 functions primarily as an adaptor to recruit CBP and p300. In support of this, we show that the ability of SRC1 to enhance ligand-dependent nuclear receptor activity in transiently transfected cells is dependent upon the integrity of the AD1 region. In contrast, the putative histone acetyltransferase domain, the Per-Arnt-Sim basic helix-loop-helix domain, the glutamine-rich domain, and AD2 can each be removed without loss of ligand-induced activity. Remarkably, a construct corresponding to residues 631 to 970, which contains only the LXXLL motifs and the AD1 region of SRC1, retained strong coactivator activity in our assays.

scholarly journals Cubitus interruptus Requires DrosophilaCREB-Binding Protein To Activate wingless Expression in theDrosophila Embryo

2000 ◽  
Vol 20 (5) ◽  
pp. 1616-1625 ◽  
Author(s):  
Yang Chen ◽  
R. H. Goodman ◽  
Sarah M. Smolik
Keyword(s):  
Transcriptional Activation ◽  
Target Genes ◽  
Binding Protein ◽  
Point Mutations ◽  
Creb Binding Protein ◽  
Wild Type ◽  
Interaction Domain ◽  
Cubitus Interruptus

ABSTRACT CREB-binding protein (CBP) serves as a transcriptional coactivator in multiple signal transduction pathways. The Drosophilahomologue of CBP, dCBP, interacts with the transcription factors Cubitus interruptus (CI), MAD, and Dorsal (DL) and functions as a coactivator in several signaling pathways during Drosophiladevelopment, including the hedgehog (hh),decapentaplegic (dpp), and Tollpathways. Although dCBP is required for the expression of thehh target genes, wingless (wg) andpatched (ptc) in vivo, and potentiatesci-mediated transcriptional activation in vitro, it is not known that ci absolutely requires dCBP for its activity. We used a yeast genetic screen to identify several ci point mutations that disrupt CI-dCBP interactions. These mutant proteins are unable to transactivate a reporter gene regulated by cibinding sites and have a lower dCBP-stimulated activity than wild-type CI. When expressed exogenously in embryos, the CI point mutants cannot activate endogenous wg expression. Furthermore, a CI mutant protein that lacks the entire dCBP interaction domain functions as a negative competitor for wild-type CI activity, and the expression of dCBP antisense RNAs can suppress CI transactivation in Kc cells. Taken together, our data suggest that dCBP function is necessary forci-mediated transactivation of wg duringDrosophila embryogenesis.

scholarly journals Nuclear Integration of Glucocorticoid Receptor and Nuclear Factor-κB Signaling by CREB-binding Protein and Steroid Receptor Coactivator-1

1998 ◽  
Vol 273 (45) ◽  
pp. 29291-29294 ◽  
Author(s):  
Kelly-Ann Sheppard ◽  
Kathleen M. Phelps ◽  
Amy J. Williams ◽  
Dimitris Thanos ◽  
Christopher K. Glass ◽  
...  
Keyword(s):  
Glucocorticoid Receptor ◽  
Binding Protein ◽  
Steroid Receptor ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Creb Binding Protein ◽  
Steroid Receptor Coactivator

scholarly journals Mad proteins contain a dominant transcription repression domain.

1996 ◽  
Vol 16 (10) ◽  
pp. 5772-5781 ◽  
Author(s):  
D E Ayer ◽  
C D Laherty ◽  
Q A Lawrence ◽  
A P Armstrong ◽  
R N Eisenman
Keyword(s):  
Dna Binding ◽  
Transcriptional Repression ◽  
Binding Domain ◽  
Full Length ◽  
Dna Binding Domain ◽  
Interaction Domain ◽  
Transcription Repression ◽  
Helix Loop Helix ◽  
Repression Domain

Transcription repression by the basic region-helix-loop-helix-zipper (bHLHZip) protein Mad1 requires DNA binding as a ternary complex with Max and mSin3A or mSin3B, the mammalian orthologs of the Saccharomyces cerevisiae transcriptional corepressor SIN3. The interaction between Mad1 and mSin3 is mediated by three potential amphipathic alpha-helices: one in the N terminus of Mad (mSin interaction domain, or SID) and two within the second paired amphipathic helix domain (PAH2) of mSin3A. Mutations that alter the structure of the SID inhibit in vitro interaction between Mad and mSin3 and inactivate Mad's transcriptional repression activity. Here we show that a 35-residue region containing the SID represents a dominant repression domain whose activity can be transferred to a heterologous DNA binding region. A fusion protein comprising the Mad1 SID linked to a Ga14 DNA binding domain mediates repression of minimal as well as complex promoters dependent on Ga14 DNA binding sites. In addition, the SID represses the transcriptional activity of linked VP16 and c-Myc transactivation domains. When fused to a full-length c-Myc protein, the Mad1 SID specifically represses both c-Myc's transcriptional and transforming activities. Fusions between the GAL DNA binding domain and full-length mSin3 were also capable of repression. We show that the association between Mad1 and mSin3 is not only dependent on the helical SID but is also dependent on both putative helices of the mSin3 PAH2 region, suggesting that stable interaction requires all three helices. Our results indicate that the SID is necessary and sufficient for transcriptional repression mediated by the Mad protein family and that SID repression is dominant over several distinct transcriptional activators.

scholarly journals The CREB-binding protein inhibitor ICG-001: a promising therapeutic strategy in sporadic meningioma with NF2 mutations

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Jiaojiao Deng ◽  
Lingyang Hua ◽  
Tao Han ◽  
Mi Tian ◽  
Daijun Wang ◽  
...  
Keyword(s):  
Binding Protein ◽  
Gene Mutations ◽  
Therapeutic Effects ◽  
Creb Binding Protein ◽  
Cycle Arrest ◽  
Large Patient ◽  
Wide Range ◽  
Patient Series ◽  
Responsive Element

Abstract Background Meningiomas with Neurofibromin 2 gene mutations (NF2-mutant meningiomas) account for ~40% of the sporadic meningiomas. However, there is still no effective drug treatment for the disease. Methods Expression profile of Merlin protein was explored through immunohistochemistry in a meningioma patient cohort (n = 346). A 20-agent library covering a wide range of meningioma relevant targets was tested using meningioma cell lines IOMM-Lee (NF2 wildtype) and CH157-MN (NF2 deficient). Therapeutic effects and biological mechanisms of the identified compound, ICG-001, in NF2-mutant meningiomas were further characterized in vitro and in patient-derived xenograft (PDX) models. Results Low Merlin expression was associated with meningioma proliferation and poor clinical outcomes in a large patient series. ICG-001, a cAMP-responsive element binding (CREB)-binding protein (CBP) inhibitor, selectively suppressed tumor growth of cells with low Merlin expression. Besides, ICG-001 mediated CH157-MN and IOMM-Lee growth inhibition primarily through robust induction of the G1 cell-cycle arrest. Treatment with ICG-001 alone significantly reduced the growth of NF2-mutant xenografts in mice, as well. We also provide further evidence that ICG-001 inhibits proliferation of NF2-mutant meningioma cells at least partly through attenuating the FOXM1-mediated Wnt/β-catenin signaling. Conclusions This study highlights the importance of ligand-mediated Wnt/β-catenin signaling as well as its drugable potency in NF2-mutant meningioma.

scholarly journals The N-Terminal Domain of p73 Interacts with the CH1 Domain of p300/CREB Binding Protein and Mediates Transcriptional Activation and Apoptosis

2000 ◽  
Vol 20 (4) ◽  
pp. 1299-1310 ◽  
Author(s):  
Xiaoya Zeng ◽  
Xiaorong Li ◽  
Ashley Miller ◽  
Zhimin Yuan ◽  
Wuchao Yuan ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
Binding Protein ◽  
Small Cell Lung Carcinoma ◽  
Creb Binding Protein ◽  
Cell Lung Carcinoma ◽  
Cell Extracts ◽  
N Terminus ◽  
Mcf 7

ABSTRACT The newly identified p53 homolog p73 mimics the transcriptional function of p53. We have investigated the regulation of p73's transcriptional activity by p300/CREB binding protein (CBP). p73-p300 complexes were identified in HeLa cell extracts by cofractionation and coimmunoprecipitation assays. The p73-p300 interaction was confirmed in vitro by glutathione S-transferase–protein association assays and in vivo by coimmunoprecipitating the overexpressed p300 and p73 in human p53-free small-cell lung carcinoma H1299 or osteosarcoma Saos-2 cells. The N terminus but not the N-terminal truncation of p73 bound to the CH1 domain (amino acids [aa] 350 to 450) of p300/CBP. Accordingly, this p73 N-terminal deletion was unable to activate transcription or to induce apoptosis. Overexpression of either p300 or CBP stimulated transcription mediated by p73 but not its N-terminally deleted mutant in vivo. The N-terminal fragment from aa 19 to 597, but not the truncated fragment from aa 242 to 1700 of p300, reduced p73-mediated transcription markedly. p73-dependent transcription or apoptosis was partially impaired in either p300- or CBP-deficient human breast carcinoma MCF-7 or H1299 cells, suggesting that both coactivators mediate transcription by p73 in cells. These results demonstrate that the N terminus of p73 directly interacts with the N-terminal CH1 domain of p300/CBP to activate transcription.

scholarly journals Mediator and p300/CBP-Steroid Receptor Coactivator Complexes Have Distinct Roles, but Function Synergistically, during Estrogen Receptor α-Dependent Transcription with Chromatin Templates

2003 ◽  
Vol 23 (1) ◽  
pp. 335-348 ◽  
Author(s):  
Mari Luz Acevedo ◽  
W. Lee Kraus
Keyword(s):  
Estrogen Receptor ◽  
Rna Polymerase Ii ◽  
Transcriptional Activation ◽  
Steroid Receptor ◽  
Estrogen Receptor Α ◽  
Preinitiation Complex ◽  
Transcription System ◽  
Steroid Receptor Coactivator ◽  
Transcription Reinitiation

ABSTRACT Ligand-dependent transcriptional activation by nuclear receptors involves the recruitment of various coactivators to the promoters of hormone-regulated genes assembled into chromatin. Nuclear receptor coactivators include histone acetyltransferase complexes, such as p300/CBP-steroid receptor coactivator (SRC), as well as the multisubunit mediator complexes (“Mediator”), which may help recruit RNA polymerase II to the promoter. We have used a biochemical approach, including an in vitro chromatin assembly and transcription system, to examine the functional role for Mediator in the transcriptional activity of estrogen receptor α (ERα) with chromatin templates, as well as functional interplay between Mediator and p300/CBP during ERα-dependent transcription. Using three different approaches to functionally inactivate Mediator (immunoneutralization, immunodepletion, and inhibitory polypeptides), we find that Mediator is required for maximal transcriptional activation by ligand-activated ERα. In addition, we demonstrate synergism between Mediator and p300/CBP-SRC during ERα-dependent transcription with chromatin templates, but not with naked DNA. This synergism is important for promoting the formation of a stable transcription preinitiation complex leading to the initiation of transcription. Interestingly, we find that Mediator has an additional distinct role during ERα-dependent transcription not shared by p300/CBP-SRC: namely, to promote preinitiation complex formation for subsequent rounds of transcription reinitiation. These results suggest that one functional consequence of Mediator-ERα interactions is the stimulation of multiple cycles of transcription reinitiation. Collectively, our results indicate an important role for Mediator, as well as its functional interplay with p300/CBP-SRC, in the enhancement of ERα-dependent transcription with chromatin templates.

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