scholarly journals Gα12 Structural Determinants of Hsp90 Interaction Are Necessary for Serum Response Element–Mediated Transcriptional Activation

2014 ◽  
Vol 85 (4) ◽  
pp. 586-597 ◽  
Author(s):  
Ellyn R. Montgomery ◽  
Brenda R. S. Temple ◽  
Kimberly A. Peters ◽  
Caitlin E. Tolbert ◽  
Brandon K. Booker ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
Serum Response Element ◽  
Structural Determinants ◽  
Response Element ◽  
Serum Response

scholarly journals Cas Mediates Transcriptional Activation of the Serum Response Element by Src

1999 ◽  
Vol 19 (10) ◽  
pp. 6953-6962 ◽  
Author(s):  
Yaron Hakak ◽  
G. Steven Martin
Keyword(s):  
Transcriptional Activation ◽  
Tyrosine Phosphatase ◽  
Sh3 Domain ◽  
Dominant Negative ◽  
Mitogen Activated Protein Kinase ◽  
Adapter Protein ◽  
Binding Region ◽  
Serum Response Element ◽  
Response Element ◽  
Serum Response

ABSTRACT The Src substrate p130Cas is a docking protein containing an SH3 domain, a substrate domain that contains multiple consensus SH2 binding sites, and a Src binding region. We have examined the possibility that Cas plays a role in the transcriptional activation of immediate early genes (IEGs) by v-Src. Transcriptional activation of IEGs by v-Src occurs through distinct transcriptional control elements such as the serum response element (SRE). An SRE transcriptional reporter was used to study the ability of Cas to mediate Src-induced SRE activation. Coexpression of v-Src and Cas led to a threefold increase in SRE-dependent transcription over the level induced by v-Src alone. Cas-dependent activation of the SRE was dependent on the kinase activity of v-Src and the Src binding region of Cas. Signaling to the SRE is promoted by a serine-rich region within Cas and inhibited by the Cas SH3 domain. Cas-dependent SRE activation was accompanied by an increase in the level of active Ras and in the activity of the mitogen-activated protein kinase (MAPK) Erk2; these changes were blocked by coexpression of dominant-negative mutants of the adapter protein Grb2. SRE activation was abrogated by coexpression of dominant-negative mutants of Ras, MAPK kinase (Mek1), and Grb2. Coexpression of Cas with v-Src enhanced the association of Grb2 with the adapter protein Shc and the protein tyrosine phosphatase Shp-2; coexpression of Shc or Shp-2 mutants significantly reduced SRE activation by Cas and v-Src. Cas-induced Grb2 association with Shp-2 and Shc may account for the Cas-dependent activation of the Ras/Mek/Erk pathway and SRE-dependent transcription. 14-3-3 proteins may also play a role in Cas-mediated signaling to the SRE. Overexpression of Cas was found to modestly enhance epidermal growth factor (EGF)-induced activation of the SRE. A Cas mutant lacking the Src binding region did not potentiate the EGF response, suggesting that Cas enhances EGF signaling by binding to endogenous cellular Src or another Src family member. These observations implicate Cas as a mediator of Src-induced transcriptional activation.

scholarly journals Two pathways for serum regulation of the c-fos serum response element require specific sequence elements and a minimal domain of serum response factor.

1994 ◽  
Vol 14 (9) ◽  
pp. 5920-5928 ◽  
Author(s):  
F E Johansen ◽  
R Prywes
Keyword(s):  
Transcriptional Activation ◽  
Serum Response Factor ◽  
Mitogen Activated Protein Kinase ◽  
Response Factor ◽  
Serum Response Element ◽  
Specific Sequence ◽  
Response Element ◽  
Transcriptional Activation Domain ◽  
Central Sequence ◽  
Serum Response

The c-fos serum response element (SRE) is necessary and sufficient for induction of the c-fos gene in response to serum and growth factors. This activation is dependent upon serum response factor (SRF), a transcriptional activator which binds the SRE. A factor, p62TCF, which binds in conjunction with SRF to the SRE and which is activated by mitogen-activated protein kinase, has also been implicated in c-fos regulation. By using a reporter gene system with weak SRE mutations that is dependent upon overexpression of SRF for serum induction, we have found that there are at least two pathways for serum induction that converge on the SRE. Loss of TCF binding by mutations in SRF and the SRE did not reduce serum induction of the reporter genes. We have found a pathway for serum induction that is sensitive to mutations in the A/T-containing central sequence of the SRE and which is independent of TCF. When this pathway was mutated, activation was dependent upon TCF binding, demonstrating that TCF can also function in serum induction. Both of the signalling pathways required a minimal domain of SRF. This domain, spanning SRF's DNA binding domain, was sufficient for serum induction when fused to a heterologous transcriptional activation domain.

Homer-3 regulates activation of serum response element in T cells via its EVH1 domain

Blood ◽  
2004 ◽  
Vol 103 (6) ◽  
pp. 2248-2256 ◽  
Author(s):  
Kazuhiro Ishiguro ◽  
Ramnik Xavier
Keyword(s):  
Signal Transduction ◽  
T Cells ◽  
T Cell ◽  
Transcriptional Activation ◽  
Cell Receptor ◽  
Synaptic Activity ◽  
Jurkat Cells ◽  
Serum Response Element ◽  
Response Element ◽  
Serum Response

Abstract Drosophila enabled/vasodilator-stimulated phosphoprotein (Ena/VASP) homology 1 (EVH1) domain proteins regulate signal transduction at the neuronal and immunologic synapse. Despite shared cell biologic machinery at these synapses, the regulation of client proteins that transmit synaptic activity to the nucleus is likely to be different. Homer-3, a member of the EVH1 family, is expressed in the thymus, suggesting a role for this protein in T-cell signal transduction. Upon T-cell receptor (TCR) engagement, Homer-3 was recruited to the contact area of Jurkat cells to anti-CD3 and CD28 antibody–coated beads prior to actin accumulation and was subsequently translocated into the nucleus. Overexpression of Homer-3 reduced transcriptional activation via the serum response element (SRE) in response to anti-CD3 antibody, phorbol ester, or dominant active Ha-Ras. Consistent with these results, knockdown of Homer-3 increased SRE activation. Homer-3 coprecipitated with CCAAT/enhancer binding protein β (C/EBPβ), one of the transcription factors that binds to the SRE and has a consensus motif binding to EVH1 domain. Moreover, Homer-3 and its EVH1 domain fragment reduced transcriptional activation of C/EBPβ. These findings suggest that Homer-3 may be involved in the regulation of SRE activation in T cells via interaction between its EVH1 domain and C/EBPβ.

Two pathways for serum regulation of the c-fos serum response element require specific sequence elements and a minimal domain of serum response factor

1994 ◽  
Vol 14 (9) ◽  
pp. 5920-5928
Author(s):  
F E Johansen ◽  
R Prywes
Keyword(s):  
Transcriptional Activation ◽  
Serum Response Factor ◽  
Mitogen Activated Protein Kinase ◽  
Response Factor ◽  
Serum Response Element ◽  
Specific Sequence ◽  
Response Element ◽  
Transcriptional Activation Domain ◽  
Central Sequence ◽  
Serum Response

The c-fos serum response element (SRE) is necessary and sufficient for induction of the c-fos gene in response to serum and growth factors. This activation is dependent upon serum response factor (SRF), a transcriptional activator which binds the SRE. A factor, p62TCF, which binds in conjunction with SRF to the SRE and which is activated by mitogen-activated protein kinase, has also been implicated in c-fos regulation. By using a reporter gene system with weak SRE mutations that is dependent upon overexpression of SRF for serum induction, we have found that there are at least two pathways for serum induction that converge on the SRE. Loss of TCF binding by mutations in SRF and the SRE did not reduce serum induction of the reporter genes. We have found a pathway for serum induction that is sensitive to mutations in the A/T-containing central sequence of the SRE and which is independent of TCF. When this pathway was mutated, activation was dependent upon TCF binding, demonstrating that TCF can also function in serum induction. Both of the signalling pathways required a minimal domain of SRF. This domain, spanning SRF's DNA binding domain, was sufficient for serum induction when fused to a heterologous transcriptional activation domain.

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