Dissertation/ Thesis
A comprehensive library of mutations of Epstein-Barr virus and mutational analyses of the genes that are involved in viral lytic development
| العنوان: | A comprehensive library of mutations of Epstein-Barr virus and mutational analyses of the genes that are involved in viral lytic development |
|---|---|
| Alternate Title: | EB病毒突變株庫的建立與分析調控EB病毒溶裂發展的基因 |
| المؤلفون: | Ya-Fang Chiu, 邱亞芳 |
| Thesis Advisors: | Shih-Tung Liu, 劉世東 |
| سنة النشر: | 2008 |
| المجموعة: | National Digital Library of Theses and Dissertations in Taiwan |
| الوصف: | 97 Epstein-Barr virus (EBV) is a human herpesvirus that is often implicated in lymphoid and epithelial malignancies. This virus has a large genome, which makes the investigation of the virus difficult. In this study, a mutant library of 249 mutants with mutations that span the entire EBV genome was generated by transposition with EZ::TN and insertion with an apramycin-resistance gene by a PCR-targeting method. This study also demonstrates the feasibility of generating deletions and site-specific mutations in the BRLF1 promoter on the EBV genome to determine the regions in the promoter that are crucial to transcription. The analysis revealed that the proximal Zta-response element in the BRLF1 promoter is crucial to BRLF1 transcription from the EBV genome, despite the fact that another work demonstrated that this site was unimportant in transient transfection analysis. Analyzing BZLF1 and BRLF1 mutants revealed that these two genes regulate the transcription of EBV lytic genes differently, but both of them are critical for EBV lytic development. Furthermore, mutants with a mutation in BDLF1 and BORF1 cannot assemble the viral capsid. This study also shows that BDLF1 and BORF1 are the minor capsid proteins of EBV. By screening the mutant library to identify the genes that are involved in EBV maturation, this study found that BBLF1 is necessary for the production of EBV particles. Although proteins encoded by BBLF1 and HSV-1 UL11 do not have a sequence homology, both proteins contain a predicted N-myristoylation and palmitoylation signal, which are necessary for proper targeting of the protein to the Golgi apparatus and plasma membrane. BBLF1 also has a tyrosine-based motif, two acidic clusters, two dileucine motifs and a CKII phophorylation site, which are typically present in the trafficking proteins that are involved in the retrieval of proteins from the plasma membrane to the Golgi apparatus. Therefore, this investigation predicts that the BBLF1 protein and UL11 have similar functions and are critical to the envelopment and egress of the viral nucleocapsid. Coimmunoprecipitation and indirect immunofluorescence studies revealed that BBLF1 not only interacts with BDLF1 and gp350/220, but also a cellular protein, PACS-1, which is required for the trafficking of proteins containing acidic motifs from the early endosome to the trans-Golgi network. These observations suggest that the BBLF1-BDLF1 interaction may be required for the egress of EBV nucleocapsid to cross the nuclear membrane and transport from the cytoplasm to the Golgi apparatus. Additionally, since gp350/220, which is present abundantly on the plasma membrane, cannot be incorporated in the EBV virion, the PACS-1-BBLF1 and BBLF1-gp350/220 interaction are likely important for the retrieval of gp350/220 during the final envelopment. This investigation demonstrates the usefulness of a comprehensive mutant library in genetic analyses of EBV, which will lead to a better understanding on the maturation process of EBV. |
| Original Identifier: | 097CGU05114001 |
| نوع الوثيقة: | 學位論文 ; thesis |
| وصف الملف: | 98 |
| الاتاحة: | http://ndltd.ncl.edu.tw/handle/86504086298414540504 |
| رقم الانضمام: | edsndl.TW.097CGU05114001 |
| قاعدة البيانات: | Networked Digital Library of Theses & Dissertations |
| الوصف غير متاح. |