Involvement of the cyclic AMP-responsive element binding protein in bovine leukemia virus expression in vivo.
The TAR element (Tax-responsive element; also called TxRE) is a major determinant of the regulation of bovine leukemia virus (BLV) expression. In order to gain insight into the mechanisms of viral expression, complexes formed between proteins and the TAR enhancer DNA were analyzed by gel retardation assays. We report here that nuclear lysates from ex vivo-isolated B lymphocytes contain proteins that specifically bind to TAR. An antibody directed toward the cyclic AMP-responsive element binding (CREB) protein supershifted a complex (C1) present only in BLV-infected B lymphocytes. The CREB protein thus appears to be a major transcription factor involved in BLV expression in vivo.
Adam
E
E
Department of Molecular Biology, University of Brussels, Rhode-St-Genèse, Belgium.
Kerkhofs
P
P
Mammerickx
M
M
Kettmann
R
R
Burny
A
A
Droogmans
L
L
Willems
L
L
D000818:Animals; D001402:B-Lymphocytes / Q000502:physiology; D001483:Base Sequence; D002417:Cattle; D000242:Cyclic AMP / Q000502:physiology*; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D004742:Enhancer Elements, Genetic; D015967:Gene Expression Regulation, Viral; D001909:Leukemia Virus, Bovine / Q000235:genetics*; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism; D009838:Oligodeoxyribonucleotides / Q000378:metabolism; D011953:Receptors, Cyclic AMP / Q000502:physiology*; D012045:Regulatory Sequences, Nucleic Acid; D012091:Repetitive Sequences, Nucleic Acid
D017362:Cyclic AMP Response Element-Binding Protein; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D009838:Oligodeoxyribonucleotides; D011953:Receptors, Cyclic AMP; D000242:Cyclic AMP