title: Sequence-specific interaction of the Ets1 protein with the long terminal repeat of the human T-lymphotropic virus type I.
abstract: We recently demonstrated that members of the c-ets proto-oncogene family, Ets1 and Ets2, are sequence-specific transcriptional activators of the human T-lymphotropic virus type I (HTLV-I) long terminal repeat (LTR). We now report that the HTLV-I LTR contains two distinct Ets1-responsive regions, ERR-1 and ERR-2. Expression of Ets1 with reporter plasmids containing ERR-1 or ERR-2 upstream of a basal promoter resulted in an increase in transcriptional activity. By gel mobility shift assay, the interaction of Ets1 with the downstream ERR-1-binding region was found to be more stable than its interaction with the upstream ERR-2 region. By DNase I footprint, gel mobility shift, and methylation interference analyses, ERR-1 was found to contain two Ets1 binding sites, ERE-A and ERE-B. A recombinant Ets1 protein was found to bind with higher affinity to ERE-A than to ERE-B. Binding of Ets1 to these sites appears to result in a specific and sequential protection of a 37-nucleotide sequence of the HTLV-I LTR from -154 to -118. In view of the high-level expression of Ets1 in lymphoid cells, the c-ets proto-oncogenes encode transcription factors which could play an important role in both basal and Tax1-mediated HTLV-I transcription.
authors.affiliation: Laboratory of Molecular Virology, National Cancer Institute, Bethesda, Maryland 20892.
authors.forename: S D
authors.initials: SD
authors.lastname: Gitlin
authors.forename: R
authors.initials: R
authors.lastname: Bosselut
authors.forename: A
authors.initials: A
authors.lastname: Gégonne
authors.forename: J
authors.initials: J
authors.lastname: Ghysdael
authors.forename: J N
authors.initials: JN
authors.lastname: Brady
mesh_terms: D000818:Animals; D016367:Baculoviridae / Q000235:genetics; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D002467:Cell Nucleus / Q000502:physiology; D004279:DNA, Viral / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006367:HeLa Cells / Q000502:physiology; D015368:Human T-lymphotropic virus 1 / Q000235:genetics*; D006801:Humans; D015151:Immunoblotting; D007313:Insecta; D008969:Molecular Sequence Data; D005810:Multigene Family; D016297:Mutagenesis, Site-Directed; D000090063:Proto-Oncogene Mas; D050784:Proto-Oncogene Protein c-ets-1; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D050783:Proto-Oncogene Proteins c-ets; D011519:Proto-Oncogenes; D011994:Recombinant Proteins / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid; D012689:Sequence Homology, Nucleic Acid; D013379:Substrate Specificity; D014157:Transcription Factors
chemical_list: D004279:DNA, Viral; D004268:DNA-Binding Proteins; C494041:ETS1 protein, human; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D050784:Proto-Oncogene Protein c-ets-1; D011518:Proto-Oncogene Proteins; D050783:Proto-Oncogene Proteins c-ets; D011994:Recombinant Proteins; D014157:Transcription Factors