Linked Life Data

2532611

Source:http://linkedlifedata.com/resource/pubmed/id/2532611

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1990-2-14
pubmed:abstractText
Nuclear factor E2F is a cellular protein that binds to the adenovirus E2 promoter and E1A enhancer regions and to the cellular c-myc P2 promoter region. The DNA binding activity of E2F, detected in vitro using nuclear extracts prepared from HeLa cells, is increased by adenovirus infection (termed E2F induction). We demonstrate here that a 19.5-kD protein, encoded by adenovirus early region 4 (E4) open reading frame (ORF) 6/7, is primarily responsible for the induction of E2F DNA binding activity to the E2 promoter region. Viral mutants that contain frame-shift mutations in E4 ORF 6/7 failed to induce E2F binding activity; a virus that carries an E4 ORF 6/7 cDNA in place of the E4-coding sequences induced E2F efficiently. Using gel mobility shift assays, we demonstrate that the E4 ORF 6/7 product induces the binding of E2F to the E2 promoter via a direct complex. The addition of a peptide-specific antiserum, directed against the E4 ORF 6/7 protein, to an in vitro E2F-binding reaction resulted in the formation of a DNA-protein complex with reduced gel mobility compared to the normal, adenovirus-induced E2F-E2 promoter complex. The formation of the E2F-E2 promoter-antibody complex was blocked by the addition of the cognate peptide used to generate the antiserum but not by a nonspecific peptide. Nuclear extracts prepared from adenovirus-infected HeLa cells were cleared of E2F binding activity using the ORF 6/7 peptide-specific serum, but not the preimmune serum, suggesting that E2F and the E4 ORF 6/7 product form a protein-protein complex in solution. The adenovirus E1A proteins are not absolutely required for the induction of E2F binding activity because the infection of HeLa cells with an E1A mutant, dl312, at high multiplicity resulted in E2F induction. Under these conditions of infection, the E4 ORF 6/7 product was synthesized. E2F binding activity was induced, but inefficiently, in cells infected with E4 ORF 6/7 mutants, indicating that an additional pathway may lead to E2F induction.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0890-9369
pubmed:author
pubmed:issnType
Print
pubmed:volume
3
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1699-710
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
The adenovirus early region 4 open reading frame 6/7 protein regulates the DNA binding activity of the cellular transcription factor, E2F, through a direct complex.
pubmed:affiliation
Department of Microbiology, State University of New York, Stony Brook 11794.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.