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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
8
|
| pubmed:dateCreated |
1995-1-3
|
| pubmed:abstractText |
One of the first steps during Ig heavy chain isotype switching to IgE is the IL-4 induced synthesis of IgE germline transcripts. To further characterize the molecular mechanism of the IL-4 action, the regulatory DNA elements involved in the control of expression of these transcripts were analyzed. Transient transfection of a B cell tumor line revealed the presence of a 15 bp IL-4 responsive cis-acting element (IL-4RE) highly homologous to an IL-4 response element in the human CD23b promoter. An IL-4 induced DNA binding protein specifically interacted with this sequence. Point mutations within that sequence not only abolished IL-4 inducibility of reporter constructs but also prevented binding of the nuclear factor to the mutated sequence. A stretch of 16 nucleotides just upstream of the IL-4RE contributed to IL-4 inducibility and formed nucleoprotein complexes with constitutive factors. All reporter constructs containing the functional IL-4RE were transcriptionally very weak but could be readily activated upon IL-4 induction. Transfection of constructs containing the mutated IL-4RE or plasmids lacking that sequence displayed a high constitutive promoter activity and were IL-4 unresponsive. These data suggest that in the absence of the cytokine the activity of the IgE germline promoter is actively repressed through the action of the IL-4RE. The same sequence appears to be critically involved in the IL-4 induced activation of the promoter via the binding of a cytokine induced transcription factor.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Aug
|
| pubmed:issn |
0953-8178
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
6
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
1143-51
|
| pubmed:dateRevised |
2008-11-21
|
| pubmed:meshHeading |
pubmed-meshheading:7981143-Base Sequence,
pubmed-meshheading:7981143-DNA-Binding Proteins,
pubmed-meshheading:7981143-Gene Expression Regulation,
pubmed-meshheading:7981143-Humans,
pubmed-meshheading:7981143-Immunoglobulin E,
pubmed-meshheading:7981143-Interleukin-4,
pubmed-meshheading:7981143-Molecular Sequence Data,
pubmed-meshheading:7981143-Promoter Regions, Genetic,
pubmed-meshheading:7981143-Regulatory Sequences, Nucleic Acid,
pubmed-meshheading:7981143-Transcription, Genetic,
pubmed-meshheading:7981143-Transcription Factors
|
| pubmed:year |
1994
|
| pubmed:articleTitle |
A bifunctional control element in the human IgE germline promoter involved in repression and IL-4 activation.
|
| pubmed:affiliation |
Sandoz Forschungsinstitut, Vienna, Austria.
|
| pubmed:publicationType |
Journal Article
|