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.

Ceramide and Cyclic Adenosine Monophosphate (cAMP) Induce cAMP Response Element Binding Protein Phosphorylation via Distinct Signaling Pathways While Having Opposite Effects on Myeloid Cell Survival

Blood ◽  
1999 ◽  
Vol 93 (1) ◽  
pp. 217-225 ◽  
Author(s):  
Michael P. Scheid ◽  
Ian N. Foltz ◽  
Peter R. Young ◽  
John W. Schrader ◽  
Vincent Duronio
Keyword(s):  
P38 Mapk ◽  
Binding Protein ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Camp Response Element Binding ◽  
Camp Response Element ◽  
Response Element ◽  
Creb Phosphorylation ◽  
Element Binding Protein ◽  
Induced Apoptosis

Abstract The role of ceramide as a second messenger is a subject of great interest, particularly since it is implicated in signaling in response to inflammatory cytokines. Ceramide induces apoptosis in both cytokine-dependent MC/9 cells and factor-independent U937 cells. Elevation of cyclic adenosine monophosphate (cAMP) levels inhibits apoptosis induced by ceramide and several other treatments. One target of cAMP-mediated signaling is the transcription factor CREB (cAMP response element binding protein), and recently CREB phosphorylation at an activating site has been shown to also be mediated by a cascade involving p38 mitogen-activated protein kinase (MAPK), one of the stress-activated MAP kinases. Because no role for p38 MAPK in apoptosis has been firmly established, we examined the relationship between p38 MAPK and CREB phosphorylation under various conditions. Ceramide, or sphingomyelinase, like tumor necrosis factor- (TNF-) or the hematopoietic growth factor, interleukin-3 (IL-3), was shown to activate p38 MAPK, which in turn activated MAPKAP kinase-2. Each of these treatments led to phosphorylation of CREB (and the related factor ATF-1). A selective p38 MAPK inhibitor, SB203580, blocked TNF-– or ceramide-induced CREB phosphorylation, but had no effect on the induction of apoptosis mediated by these agents. The protective agents cAMP and IL-3 also led to CREB phosphorylation, but this effect was independent of p38 MAPK, even though IL-3 was shown to activate both p38 MAPK and MAPKAP kinase-2. Therefore, the opposing effects on apoptosis observed with cAMP and IL-3, compared with ceramide and TNF-, could not be explained on the basis of phosphorylation of CREB. In addition, because SB203580 had no effect of TNF- or ceramide-induced apoptosis, our results strongly argue against a role for p38 MAPK in the induction of TNF-– or ceramide-induced apoptosis.

Ceramide and Cyclic Adenosine Monophosphate (cAMP) Induce cAMP Response Element Binding Protein Phosphorylation via Distinct Signaling Pathways While Having Opposite Effects on Myeloid Cell Survival

Blood ◽  
1999 ◽  
Vol 93 (1) ◽  
pp. 217-225 ◽  
Author(s):  
Michael P. Scheid ◽  
Ian N. Foltz ◽  
Peter R. Young ◽  
John W. Schrader ◽  
Vincent Duronio
Keyword(s):  
P38 Mapk ◽  
Binding Protein ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Camp Response Element Binding ◽  
Camp Response Element ◽  
Response Element ◽  
Creb Phosphorylation ◽  
Element Binding Protein ◽  
Induced Apoptosis

The role of ceramide as a second messenger is a subject of great interest, particularly since it is implicated in signaling in response to inflammatory cytokines. Ceramide induces apoptosis in both cytokine-dependent MC/9 cells and factor-independent U937 cells. Elevation of cyclic adenosine monophosphate (cAMP) levels inhibits apoptosis induced by ceramide and several other treatments. One target of cAMP-mediated signaling is the transcription factor CREB (cAMP response element binding protein), and recently CREB phosphorylation at an activating site has been shown to also be mediated by a cascade involving p38 mitogen-activated protein kinase (MAPK), one of the stress-activated MAP kinases. Because no role for p38 MAPK in apoptosis has been firmly established, we examined the relationship between p38 MAPK and CREB phosphorylation under various conditions. Ceramide, or sphingomyelinase, like tumor necrosis factor- (TNF-) or the hematopoietic growth factor, interleukin-3 (IL-3), was shown to activate p38 MAPK, which in turn activated MAPKAP kinase-2. Each of these treatments led to phosphorylation of CREB (and the related factor ATF-1). A selective p38 MAPK inhibitor, SB203580, blocked TNF-– or ceramide-induced CREB phosphorylation, but had no effect on the induction of apoptosis mediated by these agents. The protective agents cAMP and IL-3 also led to CREB phosphorylation, but this effect was independent of p38 MAPK, even though IL-3 was shown to activate both p38 MAPK and MAPKAP kinase-2. Therefore, the opposing effects on apoptosis observed with cAMP and IL-3, compared with ceramide and TNF-, could not be explained on the basis of phosphorylation of CREB. In addition, because SB203580 had no effect of TNF- or ceramide-induced apoptosis, our results strongly argue against a role for p38 MAPK in the induction of TNF-– or ceramide-induced apoptosis.

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 Nrf2 Neh5 domain is differentially utilized in the transactivation of cytoprotective genes

2007 ◽  
Vol 404 (3) ◽  
pp. 459-466 ◽  
Author(s):  
Jianyong Zhang ◽  
Tomonori Hosoya ◽  
Atsushi Maruyama ◽  
Keizo Nishikawa ◽  
Jonathan M. Maher ◽  
...  
Keyword(s):  
Target Genes ◽  
Mutational Analysis ◽  
Binding Protein ◽  
Human Kidney ◽  
Camp Response Element Binding ◽  
Related Factor ◽  
Activation Domains ◽  
Nrf2 Target Gene ◽  
Element Binding Protein

The transcription factor Nrf2 (nuclear factor erythroid 2-related factor 2) contains two transcription activation domains, Neh4 (Nrf2 ECH homology 4) and Neh5, which co-ordinately regulate transactivation of cytoprotective genes. In the present study we aimed to clarify the role of the Neh5 domain in Nrf2-mediated gene regulation. Deletion of the complete Neh5 domain reduces expression of endogenous Nrf2 target genes, such as HO-1 (haem oxygenase 1), NQO1 [NAD(P)H:quinone oxidoreductase 1] and GCLM (glutamate cysteine ligase modulatory subunit), in human kidney epithelial cells. Furthermore, the deletion of Neh5 markedly repressed CBP [CREB (cAMP-response-element-binding protein)-binding protein] and BRG1 (Brahma-related gene 1) from associating with Nrf2, diminishing their co-operative enhancement of HO-1 promoter activity. Mutational analysis of the Neh5 domain revealed a motif that shares significant homology with β-actin and ARP1 (actin-related protein 1). Mutagenesis of this motif selectively decreased HO-1, but not NQO1 and GCLM, expression. Taken together, these results indicate that the Neh5 domain has the ability to regulate Nrf2 target gene transcription, yet the role of the Neh5 domain in transcription varies from gene to gene.

Scutellarin Mitigates Cancer-Induced Bone Pain by Suppressing CaMKII/CREB Pathway in Rat Models

2019 ◽  
Vol 17 (3) ◽  
pp. 249-253
Author(s):  
Liu Chenglong ◽  
Liu Haihua ◽  
Zhang Fei ◽  
Zheng Jie ◽  
Wei Fang
Keyword(s):  
Protein Kinase ◽  
Bone Pain ◽  
Binding Protein ◽  
Camp Response Element Binding ◽  
Camp Response Element ◽  
Dependent Protein Kinase ◽  
Response Element ◽  
Protein Kinase Ii ◽  
Element Binding Protein ◽  
Dependent Protein

Cancer-induced bone pain is a severe and complex pain caused by metastases to bone in cancer patients. The aim of this study was to investigate the analgesic effect of scutellarin on cancer-induced bone pain in rat models by intrathecal injection of Walker 256 carcinoma cells. Mechanical allodynia was determined by paw withdrawal threshold in response to mechanical stimulus, and thermal hyperalgesia was indicated by paw withdrawal latency in response to noxious thermal stimulus. The paw withdrawal threshold and paw withdrawal latencies were significantly decreased after inoculation of tumor cells, whereas administration of scutellarin significantly attenuated tumor cell inoculation-induced mechanical and heat hyperalgesia. Tumor cell inoculation-induced tumor growth was also significantly abrogated by scutellarin. Ca2+/calmodulin-dependent protein kinase II is a multifunctional kinase with up-regulated activity in bone pain models. The activation of Ca2+/calmodulin-dependent protein kinase II triggers phosphorylation of cAMP-response element binding protein. Scutellarin significantly reduced the expression of phosphorylated-Ca2+/calmodulin-dependent protein kinase II and phosphorylated-cAMP-response element binding protein in cancer-induced bone pain rats. Collectively, our study demonstrated that scutellarin attenuated tumor cell inoculation-induced bone pain by down-regulating the expression of phosphorylated-Ca2+/calmodulin-dependent protein kinase II and phosphorylated-cAMP-response element binding protein. The suppressive effect of scutellarin on phosphorylated-Ca2+/calmodulin-dependent protein kinase II/phosphorylated-cAMP-response element binding protein activation may serve as a novel therapeutic strategy for CIBP management.

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