The transcriptional activity of Pygopus is enhanced by its interaction with cAMP-response-element-binding protein (CREB)-binding protein

2009 ◽  
Vol 422 (3) ◽  
pp. 493-501 ◽  
Author(s):  
Phillip G. P. Andrews ◽  
Zhijian He ◽  
Cathy Popadiuk ◽  
Kenneth R. Kao
Keyword(s):  
Histone Acetylation ◽  
Transcriptional Activation ◽  
Transcriptional Activity ◽  
Target Genes ◽  
Histone Acetyltransferase ◽  
Binding Protein ◽  
Camp Response Element Binding ◽  
Creb Binding Protein ◽  
Hek 293 ◽  
Element Binding Protein

Pygopus is a core component of the β-catenin/TCF (T-cell factor) transcriptional activation complex required for the expression of canonical Wnt target genes. Recent evidence suggests that Pygopus could interpret histone methylation associated with target genes and it was shown to be required for histone acetylation. The involvement of a specific acetyltransferase, however, was not determined. In this report, we demonstrate that Pygopus can interact with the HAT (histone acetyltransferase) CBP [CREB (cAMP-responsive-element-binding protein)-binding protein]. The interaction is via the NHD (N-terminal homology domain) of Pygopus, which binds to two regions in the vicinity of the HAT domain of CBP. Transfected and endogenous hPygo2 (human Pygopus2) and CBP proteins co-immunoprecipitate in HEK-293 (human embryonic kidney 293) cells and both proteins co-localize in SW480 colorectal cancer cells. The interaction with CBP also enhances both DNA-tethered and TCF/LEF1 (lymphoid enhancing factor 1)-dependent transcriptional activity of Pygopus. Furthermore, immunoprecipitated Pygopus protein complexes displayed CBP-dependent histone acetyltransferase activity. Our data support a model in which the NHD region of Pygopus is required to augment TCF/β-catenin-mediated transcriptional activation by a mechanism that includes both transcriptional activation and histone acetylation resulting from the recruitment of the CBP histone acetyltransferase.

scholarly journals Transcriptional Activation by NF-κB Requires Multiple Coactivators

1999 ◽  
Vol 19 (9) ◽  
pp. 6367-6378 ◽  
Author(s):  
Kelly-Ann Sheppard ◽  
David W. Rose ◽  
Zaffar K. Haque ◽  
Riki Kurokawa ◽  
Eileen McInerney ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcriptional Activation ◽  
Histone Acetyltransferase ◽  
Binding Protein ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Creb Binding Protein ◽  
Element Binding Protein ◽  
Cyclic Amp Response Element ◽  
Coactivator Complex

ABSTRACT Nuclear factor-κB (NF-κB) plays a role in the transcriptional regulation of genes involved in inflammation and cell survival. In this report we demonstrate that NF-κB recruits a coactivator complex that has striking similarities to that recruited by nuclear receptors. Inactivation of either cyclic AMP response element binding protein (CREB)-binding protein (CBP), members of the p160 family of coactivators, or the CBP-associated factor (p/CAF) by nuclear antibody microinjection prevents NF-κB-dependent transactivation. Like nuclear receptor-dependent gene expression, NF-κB-dependent gene expression requires specific LXXLL motifs in one of the p160 family members, and enhancement of NF-κB activity requires the histone acetyltransferase (HAT) activity of p/CAF but not that of CBP. This coactivator complex is differentially recruited by members of the Rel family. The p50 homodimer fails to recruit coactivators, although the p50-p65 heterodimeric form of the transcription factor assembles the integrator complex. These findings provide new mechanistic insights into how this family of dimeric transcription factors has a differential effect on gene expression.

scholarly journals p300/cAMP-response-element-binding-protein ('CREB')-binding protein (CBP) modulates co-operation between myocyte enhancer factor 2A (MEF2A) and thyroid hormone receptor-retinoid X receptor

2003 ◽  
Vol 369 (3) ◽  
pp. 477-484 ◽  
Author(s):  
Antonio De LUCA ◽  
Anna SEVERINO ◽  
Paola De PAOLIS ◽  
Giuliano COTTONE ◽  
Luca De LUCA ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Binding Protein ◽  
Camp Response Element Binding ◽  
Creb Binding Protein ◽  
Camp Response Element ◽  
Response Element ◽  
Adenovirus E1a ◽  
Element Binding Protein ◽  
Enhancer Factor

Thyroid hormone receptors (TRs) and members of the myocyte enhancer factor 2 (MEF2) family are involved in the regulation of muscle-specific gene expression during myogenesis. Physical interaction between these two factors is required to synergistically activate gene transcription. p300/cAMP-response-element-binding-protein ('CREB')-binding protein (CBP) interacting with transcription factors is able to increase their activity on target gene promoters. We investigated the role of p300 in regulating the TR—MEF2A complex. To this end, we mapped the regions of these proteins involved in physical interactions and we evaluated the expression of a chloramphenicol acetyltransferase (CAT) reporter gene in U2OS cells under control of the α-myosin heavy chain promoter containing the thyroid hormone response element (TRE). Our results suggested a role of p300/CBP in mediating the transactivation effects of the TR—retenoid X receptor (RxR)—MEF2A complex. Our findings showed that the same C-terminal portion of p300 binds the N-terminal domains of both TR and MEF2A, and our in vivo studies demonstrated that TR, MEF2A and p300 form a ternary complex. Moreover, by the use of CAT assays, we demonstrated that adenovirus E1A inhibits activation of transcription by TR—RxR—MEF2A—p300 but not by TR—RxR—MEF2A. Our data suggested that p300 can bind and modulate the activity of TR—RxR—MEF2A at TRE. In addition, it is speculated that p300 might modulate the activity of the TR—RxR—MEF2A complex by recruiting a hypothetical endogenous inhibitor which may act like adenovirus E1A.

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.

Ankyrin repeats-containing cofactors interact with ADA3 and modulate its co-activator function

2008 ◽  
Vol 413 (2) ◽  
pp. 349-357 ◽  
Author(s):  
Chia-Wei Li ◽  
Gia Khanh Dinh ◽  
Aihua Zhang ◽  
J. Don Chen
Keyword(s):  
Nuclear Receptors ◽  
Transcriptional Activation ◽  
Histone Deacetylases ◽  
Binding Protein ◽  
Camp Response Element Binding ◽  
Transactivation Domain ◽  
Ankyrin Repeats ◽  
Camp Response Element ◽  
Element Binding Protein

ANCO (ankyrin repeats-containing cofactor)-1 and ANCO-2 are a family of unique transcriptional co-regulators with dual properties: they interact with both the co-activators and the co-repressors [Zhang, Yeung, Li, Tsai, Dinh, Wu, Li and Chen (2004) J. Biol. Chem. 279, 33799–33805]. Specifically, ANCO-1 is thought to recruit HDACs (histone deacetylases) to the p160 co-activator to repress transcriptional activation by nuclear receptors. In the present study, we provide new evidence to suggest further that ANCO-1 and ANCO-2 also interact with the co-activator ADA3 (alteration/deficiency in activation 3). The interaction occurs between the conserved C-terminal domain of ANCO-1 and the N-terminal transactivation domain of ADA3. Several subunits of the P/CAF {p300/CBP [CREB (cAMP-response-element-binding protein)-binding protein]-associated factor} complex, including ADA3, ADA2α/β and P/CAF, showed co-localization with ANCO-1 nuclear dots, indicating an in vivo association of ANCO-1 with the P/CAF complex. Furthermore, a transient reporter assay revealed that both ANCO-1 and ANCO-2 repress ADA3-mediated transcriptional co-activation on nuclear receptors, whereas ANCO-1 stimulated p53-mediated transactivation. These data suggest that ADA3 is a newly identified target of the ANCO proteins, which may modulate co-activator function in a transcription-factor-specific manner.

scholarly journals Transcriptional regulation of the human glycoprotein hormone common α subunit gene by cAMP-response-element-binding protein (CREB)-binding protein (CBP)/p300 and p53

2002 ◽  
Vol 368 (1) ◽  
pp. 191-201 ◽  
Author(s):  
Xian ZHANG ◽  
Roger J.A. GRAND ◽  
Christopher J. McCABE ◽  
Jayne A. FRANKLYN ◽  
Phillip H. GALLIMORE ◽  
...  
Keyword(s):  
Binding Capacity ◽  
Binding Protein ◽  
Camp Response Element Binding ◽  
Creb Binding Protein ◽  
Camp Response Element ◽  
Glycoprotein Hormone ◽  
Response Element ◽  
Α Subunit ◽  
P53 Expression ◽  
Element Binding Protein

We have investigated the functional interactions between adenovirus early region 1A (AdE1A) protein, the co-activators cAMP-response-element-binding protein (CREB)-binding protein (CBP)/p300 and SUG1, and the transcriptional repressor retinoblastoma (Rb) in mediating T3-dependent repression. Utilizing the human glycoprotein hormone common α-subunit (α-subunit) promoter and AdE1A mutants with selective binding capacity to these molecules we have determined an essential role for CBP/p300. In normal circumstances, wild-type 12S AdE1A inhibited α-subunit activity. In contrast, adenovirus mutants that retain both the SUG1- and Rb-binding sites, but lack the CBP/p300-binding site, were unable to repress promoter activity. We have also identified a role for the tumour-suppressor gene product p53 in regulation of the α-subunit promoter. Akin to 12S AdE1A, exogenous p53 expression repressed α-subunit activity. This function resided in the ability of p53 to interact with CBP/p300; an N-terminal mutant incapable of interacting with CBP/p300 did not inhibit α-subunit activity. Stabilization of endogenous p53 by UV irradiation also correlated positively with reduced α-subunit activity. Intriguingly, T3 stimulated endogenous p53 transcriptional activity, implicating p53 in T3-dependent signalling pathways. These data indicate that CBP/p300 and p53 are key regulators of α-subunit activity.

scholarly journals Co-activator SRC-1 is dispensable for transcriptional control by STAT3

2009 ◽  
Vol 420 (1) ◽  
pp. 123-132 ◽  
Author(s):  
Helena Cvijic ◽  
Kay Bauer ◽  
Dennis Löffler ◽  
Gabriele Pfeifer ◽  
Conny Blumert ◽  
...  
Keyword(s):  
Transcriptional Control ◽  
Target Genes ◽  
Binding Protein ◽  
Myeloma Cell ◽  
Camp Response Element Binding ◽  
Signal Transducer ◽  
Il Interleukin ◽  
Element Binding Protein ◽  
Induced Apoptosis ◽  
Microarray Expression

SRC (steroid receptor co-activator)-1 has been reported to interact with and to be an essential co-activator for several members of the STAT (signal transducer and activator of transcription) family, including STAT3, the major signal transducer of IL (interleukin)-6. We addressed the question of whether SRC-1 is crucial for IL-6- and STAT3-mediated physiological responses such as myeloma cell survival and acute-phase protein induction. In fact, silencing of SRC-1 by RNA interference rapidly induced apoptosis in IL-6-dependent INA-6 human myeloma cells, comparable with what was observed upon silencing of STAT3. Using chromatin immunoprecipitation at STAT3 target regions of various genes, however, we observed constitutive binding of SRC-1 that decreased when INA-6 cells were treated with IL-6. The same held true for STAT3 target genes analysed in HepG2 human hepatocellular carcinoma cells. SRC-1-knockdown studies demonstrated that STAT3-controlled promoters require neither SRC-1 nor the other p160 family members SRC-2 or SRC-3 in HepG2 cells. Furthermore, microarray expression profiling demonstrated that the responsiveness of IL-6 target genes is not affected by SRC-1 silencing. In contrast, co-activators of the CBP [CREB (cAMP-response element-binding protein)-binding protein]/p300 family proved functionally important for the transactivation potential of STAT3 and bound inducibly to STAT3 target regions. This recruitment did not depend on the presence of SRC-1. Altogether, this suggests that functional impairment of STAT3 is not involved in the induction of myeloma cell apoptosis by SRC-1 silencing. We therefore conclude that STAT3 transactivates its target genes by the recruitment of CBP/p300 co-activators and that this process generally does not require the contribution of SRC-1.

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