| Title |
Promoter Analysis of Bombyx mori Nucleopolyhedrovirus Ubiquitin Gene |
| Author |
Xu’ai Lin1,2, Yin Chen2,3, Yongzhu Yi2, Jie Yan1, and Zhifang Zhang2* |
| Address |
1Department of Medical Microbiology and Parasitology, School of Medicine, Zhejiang University, Hangzhou 310058, P. R. China, 2Biotechnology Research Institute, National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, P. R. China, 3Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310009, P. R. China |
| Bibliography |
Journal of Microbiology, 46(4),429-435, 2008,
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| DOI |
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| Key Words |
baculovirus, ubiquitin promoter, transient expression, mutation, enhancer hr3 |
| Abstract |
The aim of this study was to analyze the characteristics of Bombyx mori nucleopolyhedrovirus (BmNPV) ubiquitin gene promoter and the effects of conserved motifs, such as TAAG, TATA, and CAAT, along with baculovirus enhancer homologous region 3 (hr3), on promoter activity. Ubiquitin gene of BmNPV was expressed during the late phase of virus infection. In the presence of viral factors, significant reduction of promoter activity was observed by deletion of -382 to -124 bp upstream of ATG. The fragment between -187 and -383 bp upstream of ATG, including distal TAAG, CAAT motif, and TATA box, could also drive expression of the reporter gene. The mutation of cis-elements TATA boxes and TAAG motifs significantly decreased the promoter’s activity, while CAAT mutations enhanced promoter activity by 2- or 3-fold, as compared with the native promoter. In the presence of BmNPV, hr3, both located downstream of the reporter gene of the same vector, and separate vector, could significantly enhance transcription activity of ubiquitin promoter as compared to the control. We concluded that BmNPV ubiquitin gene might be regulated by dual sets of promoter elements, where TAAG and TATA box may positively regulate the expression of ubiquitin, while CAAT motif functions as a negative regulator. Viral factor(s) play an important role in the co-activation of hr3 and promoter. |
