Cellular proteins bind to the downstream component of the lytic origin of DNA replication of Epstein-Barr virus.
The lytic origin of DNA replication of Epstein-Barr virus, oriLyt, is a complex eukaryotic origin which is activated during the lytic phase of the viral life cycle. It consists of at least two independent cis-acting components, one of which plays a dual role in transcription and DNA replication. The binding of the viral factor BZLF1, a member of the AP1 family of transcription factors, to this upstream component is crucial for oriLyt function (A. Schepers, D. Pich, and W. Hammerschmidt, EMBO J. 12:3921-3929, 1993). The second cis-acting element, the downstream component of oriLyt, is equally indispensable; however, its function is unknown. In this study, the downstream component was found to be the binding target of several cellular proteins. One could be identified as Sp1 or as a related protein which binds twice to the downstream component of oriLyt. Mutational analysis indicated that Sp1 alone is not directly involved in mediating DNA replication; however, other factors which share the same binding sequence or bind closely to one of the Sp1 binding sites are likely candidates to contribute to a replication protein complex at the downstream component of oriLyt. The sequence requirements for the downstream component are remarkably stringent, indicating that at least one of the putative factors is a sequence-specific DNA-binding protein which is required for the activation of oriLyt.
Institut für Klinische Molekularbiologie und Tumorgenetik, GSF-Forschungszentrum für Umwelt und Gesundheit GmbH, Munich, Germany.
H
H
Gruffat
O
O
Renner
D
D
Pich
W
W
Hammerschmidt
D001483:Base Sequence; D004261:DNA Replication; D004279:DNA, Viral / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D015967:Gene Expression Regulation, Viral; D004854:Herpesvirus 4, Human / Q000235:genetics*; D006801:Humans; D006822:Hybrid Cells; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid; D016329:Sp1 Transcription Factor / Q000378:metabolism; D014779:Virus Replication
D004279:DNA, Viral; D004268:DNA-Binding Proteins; D009838:Oligodeoxyribonucleotides; D016329:Sp1 Transcription Factor