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Archives of Virology

, Volume 146, Issue 3, pp 495–506 | Cite as

An element downstream of the transcription start site is required for activation of Bombyx mori nucleopolyhedrovirus bro-c promoter

  • M. G. Suzuki
  • W.-K. Kang
  • S. Maeda

Summary.

Bombyx mori nucleopolyhedrovirus (BmNPV) contains five baculovirus repeated ORF (bro) genes. We have previously reported that all of these genes (bro-a, b, c, d and e) are transcribed as early genes and require viral factor(s) for their expression. In this study, we investigated the mechanism of promoter activation of the bro-c gene. Transient expression assays using genomic libraries of BmNPV indicated that the baculoviral trans-regulator IE-1 is responsible for activating the bro-c promoter. To identify essential site(s) for promoter activation, mutations were introduced to the promoter region of bro-c. Interestingly, it was shown that the pentanucleotide sequence CACGC located 30 nucleotides downstream of the RNA start site was essential for bro-c promoter activation. In addition, the RNA start site and the spacing between the RNA start site and CACGC were also required for promoter activation. By introducing a CACGC sequence into the corresponding region of the bro-b promoter, which is not normally trans-activated by IE-1, we demonstrated that this pentanucleotide motif has the ability to confer trans-activation by IE-1 on a promoter. Gel retardation experiments also showed a sequence-specific DNA binding protein induced by baculovirus infection interacts with the CACGC motif.

Keywords

Promoter Activation Viral Factor Start Site Transcription Start Site Transcription Start 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag/Wien 2001

Authors and Affiliations

  • M. G. Suzuki
    • 1
  • W.-K. Kang
    • 1
  • S. Maeda
    • 1
  1. 1.Laboratory of Molecular Entomology and Baculovirology, RIKEN, Wako, JapanJP

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