Transcriptional repression by human adenovirus E1A N terminus/conserved domain 1 polypeptides in vivo and in vitro in the absence of protein synthesis.
The human adenovirus E1A 243R protein (243 residues) transcriptionally represses a set of cellular genes that regulate cellular growth and differentiation. We describe two lines of evidence that E1A repression does not require cellular protein synthesis but instead involves direct interaction with a cellular protein(s). First, E1A 243R protein represses an E1A-repressible promoter in the presence of inhibitors of protein synthesis, as shown by cell microinjection-in situ hybridization. Second, E1A 243R protein strongly represses transcription in vitro from promoters of the E1A-repressible genes, human collagenase, and rat insulin type II. Repression in vitro is promoter-specific, and an E1A polypeptide containing only the N-terminal 80 residues is sufficient for strong repression both in vivo and in vitro. By use of a series of E1A 1-80 deletion proteins, the E1A repression function was found to require two E1A sequence elements, one within the nonconserved E1A N terminus, and the second within a portion of conserved region 1 (40-80). These domains have been reported to possess binding sites for several cellular transcription regulators, including p300, Dr1, YY1, and the TBP subunit of TFIID. The in vitro transcription-repression system described here provides a powerful tool for the further analysis of molecular mechanism and the possible role of these cellular factors.
Song
C Z
CZ
Institute for Molecular Virology, Saint Louis University School of Medicine, Missouri, USA.
Tierney
C J
CJ
Loewenstein
P M
PM
Pusztai
R
R
Symington
J S
JS
Tang
Q Q
QQ
Toth
K
K
Nishikawa
A
A
Bayley
S T
ST
Green
M
M
D017500:Adenovirus E1A Proteins / Q000235:genetics*; D000260:Adenoviruses, Human / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D017364:Collagenases / Q000235:genetics; D017124:Conserved Sequence; D017931:DNA Primers / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D066298:In Vitro Techniques; D007328:Insulin / Q000235:genetics; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000235:genetics; D011401:Promoter Regions, Genetic; D014176:Protein Biosynthesis; D051381:Rats; D012097:Repressor Proteins / Q000235:genetics; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
D017500:Adenovirus E1A Proteins; D017931:DNA Primers; D007328:Insulin; D010446:Peptide Fragments; D012097:Repressor Proteins; D014157:Transcription Factors; D017364:Collagenases