Repression of bovine papillomavirus type 1 transcription by the E1 replication protein.
Bovine papillomavirus type 1 (BPV-1) is the prototype virus for the study of papillomavirus gene regulation. The functions of the BPV-1 E2 proteins in transcriptional regulation have been well characterized. The BPV-1 E1 protein is required for viral DNA replication and can bind to the origin of replication alone or in a complex with the E2 transactivator protein. In this study, we demonstrated that the BPV-1 E1 protein is also involved in transcriptional regulation. The E1 protein significantly repressed E2-transactivated transcription from the major early promoter P89. This activity is consistent with the elevated level of P89 transcription observed in BPV-1 E1 open reading frame mutants. Transcriptional repression by E1 correlated with the ability of an E1-E2 protein complex to bind the replication origin but was not dependent on viral DNA replication. These studies identify a new mechanism involved in the regulation of papillomavirus transcription which has implications regarding expression of the viral transforming functions.
Laboratory of Tumor Virus Biology, National Cancer Institute, Bethesda, Maryland 20892.
A B
AB
Sandler
S B
SB
Vande Pol
B A
BA
Spalholz
D000818:Animals; D001483:Base Sequence; D052688:Bovine papillomavirus 1 / Q000235:genetics / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D015500:Chloramphenicol O-Acetyltransferase / Q000378:metabolism; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000378:metabolism*; D015967:Gene Expression Regulation, Viral; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D010957:Plasmids; D011994:Recombinant Proteins / Q000378:metabolism; D015183:Restriction Mapping; D012867:Skin; D015534:Trans-Activators / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection; D014764:Viral Proteins / Q000378:metabolism*
D004268:DNA-Binding Proteins; C069814:E1 protein, Bovine papillomavirus; D009838:Oligodeoxyribonucleotides; D011994:Recombinant Proteins; D015534:Trans-Activators; D014764:Viral Proteins; D015500:Chloramphenicol O-Acetyltransferase