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The transcription factors AP-1 and Ets are regulators of C3a receptor expression

Schaefer, Myriam; Konrad, Stephanie; Thalmann, Jessica; Rheinheimer, Claudia; Johswich, Kay; Sohns, Bettina and Klos, Andreas (2005) In Journal of Biological Chemistry 280(51). p.42113-42123
Abstract
The anaphylatoxin C3a is a proinflammatory mediator generated during complement activation. The tight control of C3a receptor (C3aR) expression is crucial for the regulation of anaphylatoxin-mediated effects. Key factors regulating constitutive expression of the C3aR in the mast cell line HMC-1 and receptor induction by dibutyryl-cAMP in monomyeloblastic U937 cells were determined by functional characterization of the C3aR promoter. Nucleotides -18 to -285 upstream of the translational start site proved to be critical for promoter activity in HMC-1 cells. Binding sites for the transcription factors AP-1 and Ets could be located. Overexpressed c-Jun/c-Fos (AP-1) and Ets-1 led synergistically to increased promoter activity that was... (More)
The anaphylatoxin C3a is a proinflammatory mediator generated during complement activation. The tight control of C3a receptor (C3aR) expression is crucial for the regulation of anaphylatoxin-mediated effects. Key factors regulating constitutive expression of the C3aR in the mast cell line HMC-1 and receptor induction by dibutyryl-cAMP in monomyeloblastic U937 cells were determined by functional characterization of the C3aR promoter. Nucleotides -18 to -285 upstream of the translational start site proved to be critical for promoter activity in HMC-1 cells. Binding sites for the transcription factors AP-1 and Ets could be located. Overexpressed c-Jun/c-Fos (AP-1) and Ets-1 led synergistically to increased promoter activity that was substantially reduced by site-directed mutagenesis of the corresponding elements within the C3aR promoter. In HMC-1 cells, Ets interacted directly with the predicted binding motif of the C3aR promoter as determined by electromobility shift assays. AP-1 binding to the C3aR promoter was augmented during C3aR induction in U937 cells. A retroviral gene transfer system was used to express a dominant negative mutant of Ets-1 in these cells. The resulting cells failed to up-regulate the C3aR after stimulation with dibutyryl-cAMP and showed decreased AP-1 binding, suggesting that Ets acts here indirectly. Thus, it was established that Ets and the AP-1 element mediates dibutyryl-cAMP induction of C3aR promoter activity, hence providing a mechanistic explanation of dibutyryl-cAMP-dependent up-regulation of C3aR expression. In conclusion, this study demonstrates an important role of AP-1 and a member of the Ets family in the transcriptional regulation of C3aR expression, a prerequisite for the ability of C3a to participate in immunomodulation and inflammation. (Less)
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author
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Biological Chemistry
volume
280
issue
51
pages
42113 - 42123
publisher
ASBMB
external identifiers
  • pmid:16253992
  • scopus:29644447200
ISSN
1083-351X
DOI
10.1074/jbc.M508146200
language
English
LU publication?
no
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e1d71579-19d5-4373-bfca-a4ff9afdb547 (old id 1133804)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/16253992
http://www.jbc.org/content/280/51/42113.long
date added to LUP
2013-10-16 15:14:53
date last changed
2017-01-01 04:22:02
@article{e1d71579-19d5-4373-bfca-a4ff9afdb547,
  abstract     = {The anaphylatoxin C3a is a proinflammatory mediator generated during complement activation. The tight control of C3a receptor (C3aR) expression is crucial for the regulation of anaphylatoxin-mediated effects. Key factors regulating constitutive expression of the C3aR in the mast cell line HMC-1 and receptor induction by dibutyryl-cAMP in monomyeloblastic U937 cells were determined by functional characterization of the C3aR promoter. Nucleotides -18 to -285 upstream of the translational start site proved to be critical for promoter activity in HMC-1 cells. Binding sites for the transcription factors AP-1 and Ets could be located. Overexpressed c-Jun/c-Fos (AP-1) and Ets-1 led synergistically to increased promoter activity that was substantially reduced by site-directed mutagenesis of the corresponding elements within the C3aR promoter. In HMC-1 cells, Ets interacted directly with the predicted binding motif of the C3aR promoter as determined by electromobility shift assays. AP-1 binding to the C3aR promoter was augmented during C3aR induction in U937 cells. A retroviral gene transfer system was used to express a dominant negative mutant of Ets-1 in these cells. The resulting cells failed to up-regulate the C3aR after stimulation with dibutyryl-cAMP and showed decreased AP-1 binding, suggesting that Ets acts here indirectly. Thus, it was established that Ets and the AP-1 element mediates dibutyryl-cAMP induction of C3aR promoter activity, hence providing a mechanistic explanation of dibutyryl-cAMP-dependent up-regulation of C3aR expression. In conclusion, this study demonstrates an important role of AP-1 and a member of the Ets family in the transcriptional regulation of C3aR expression, a prerequisite for the ability of C3a to participate in immunomodulation and inflammation.},
  author       = {Schaefer, Myriam and Konrad, Stephanie and Thalmann, Jessica and Rheinheimer, Claudia and Johswich, Kay and Sohns, Bettina and Klos, Andreas},
  issn         = {1083-351X},
  language     = {eng},
  number       = {51},
  pages        = {42113--42123},
  publisher    = {ASBMB},
  series       = {Journal of Biological Chemistry},
  title        = {The transcription factors AP-1 and Ets are regulators of C3a receptor expression},
  url          = {http://dx.doi.org/10.1074/jbc.M508146200},
  volume       = {280},
  year         = {2005},
}