Identification of factors that activate expression from baculovirus delayed early promoters /
The protein product of the 39k gene of Autographa californica multiple nuclear polyhedrosis virus (ACNPV) is thought to be important for viral replication because of its association with the virogenic matrix and its role in activation of late gene expression. The significance to study the regulatio...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1996.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=739363811&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | The protein product of the 39k gene of Autographa californica multiple nuclear polyhedrosis virus (ACNPV) is thought to be important for viral replication because of its association with the virogenic matrix and its role in activation of late gene expression. The significance to study the regulation of the delayed early promoter of the 39k gene is to build a model for the regulation of all genes expressed during the delayed early phase. A subtractive transient expression assay was used to identify factors that regulate 39k expression. In this method, a reporter plasmid p39cat was cotransfected with a library of DNA clones that overlap the entire ACNPV genome. Clones were individually subtracted from the transient expression assays to determine whether the clones encode factors that positively or negatively regulate expression of the 39k promoter. By using this method, we identified P35 and P6.7 as factors that positively regulate expression from 39k promoter. P35 was identified as an inhibitor of programmed cell death (apoptosis) which is induced by ACNPV infection. Our studies suggested that P35 also functions to regulate 39k gene expression. In transient expression assays, P35 requires IE1 to activate 39k, but P35 does not stimulate expression from the iel promoter. P35 appeared to regulate 39k expression at the level of transcription. Our studies showed that p6.7 encodes a small basic polypeptide, P6.7, with molecular weight of 6.7 kD. P6.7 alone increases iel expression, and the activation is even more dramatic in the presence of IE1. This suggests that P6.7 stimulates 39k expression by upregulation of iel. Activation of 39k by IE2 and P6.7 is additive, while activation by IE2 (or P6.7) and P35 is synergistic. Our model for the regulation of 39k is a network in which multiple factors are involved. IE1 plays a key role in the network of regulation by directly transactivating the 39k promoter. When a cis-linked enhancer element is present, IE1 binds to the enhancer element as a dimer and increases 39k expression 1000- fold. P35 requires IE1 to activate 39k transcription. IE2 and P6.7, individually upregulate 39k expression by stimulating iel expression. |
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| Item Description: | Vita. "Major Subject: Microbiology". |
| Physical Description: | xi,108 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references: pages 94-106. |