Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
52
pubmed:dateCreated
2005-12-26
pubmed:abstractText
The transcription factor Egr-1 regulates the expression of numerous genes involved in differentiation, growth, and in response to environmental signals. Egr-1 activity is modulated in part through the binding of corepressors Nab1 and Nab2. Nab2 appears crucial for controlling Egr-1-mediated transactivation because it is a delayed early response gene, induced by the same stimuli that induce the immediate early gene Egr-1. To identify important elements regulating Nab2 expression, we cloned the human Nab2 gene and investigated the 5'-region. The TATA- and initiator-less Nab2 promoter, located from -679 to -74 bp, contains a total of 11 Egr binding sites, including a cluster of multiple overlapping Egr/Sp1 sites between -329 and -260 bp. This region is critical for basal promoter activity as well as for maximum induction by phorbol esters. Electromobility shifts show that Sp1 binds to this region in normal and stimulated cells, whereas stimulation induces binding of Egr-1. In addition Egr-1 activates the Nab2 promoter in a pattern similar to phorbol esters, suggesting that Egr-1 is a major inducer of protein kinase C-mediated Nab2 induction. Depletion of Egr-1 by each of two distinct Egr-1 short-interfering RNAs reduces Nab2 expression and inducibility, confirming that Egr-1 is an important regulator of Nab2 expression. Transfection experiments show that Egr-1-induced Nab2 promoter activity is itself repressed by Nab2. These results indicate that Egr-1 mediates the induction of its own repressor, thereby preventing a permanent transactivation of Egr-1 target genes and a damaging overreaction in response to environmental signals.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
280
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
42785-93
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:16260776-Base Sequence, pubmed-meshheading:16260776-Binding Sites, pubmed-meshheading:16260776-Cell Differentiation, pubmed-meshheading:16260776-Cell Line, pubmed-meshheading:16260776-Cell Line, Tumor, pubmed-meshheading:16260776-Cell Nucleus, pubmed-meshheading:16260776-Cloning, Molecular, pubmed-meshheading:16260776-DNA, Complementary, pubmed-meshheading:16260776-Dose-Response Relationship, Drug, pubmed-meshheading:16260776-Early Growth Response Protein 1, pubmed-meshheading:16260776-Feedback, Physiological, pubmed-meshheading:16260776-Gene Deletion, pubmed-meshheading:16260776-Genes, Reporter, pubmed-meshheading:16260776-Genome, pubmed-meshheading:16260776-HeLa Cells, pubmed-meshheading:16260776-Humans, pubmed-meshheading:16260776-Luciferases, pubmed-meshheading:16260776-Models, Genetic, pubmed-meshheading:16260776-Molecular Sequence Data, pubmed-meshheading:16260776-Neoplasm Proteins, pubmed-meshheading:16260776-Phorbol Esters, pubmed-meshheading:16260776-Promoter Regions, Genetic, pubmed-meshheading:16260776-Protein Binding, pubmed-meshheading:16260776-Protein Kinase C, pubmed-meshheading:16260776-RNA, Small Interfering, pubmed-meshheading:16260776-Repressor Proteins, pubmed-meshheading:16260776-Reverse Transcriptase Polymerase Chain Reaction, pubmed-meshheading:16260776-Time Factors, pubmed-meshheading:16260776-Transcription, Genetic, pubmed-meshheading:16260776-Transcriptional Activation, pubmed-meshheading:16260776-Transfection
pubmed:year
2005
pubmed:articleTitle
Egr-1 induces the expression of its corepressor nab2 by activation of the nab2 promoter thereby establishing a negative feedback loop.
pubmed:affiliation
Institute for Immunology, University of Munich, Munich 80336, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't