Gene expression from the delayed early 39K promoter of Autographa californica nuclear polyhedrosis virus (AcNPV) is regulated by both a trans-activating viral factor and a cis-acting enhancer. The trans-activating factor is IE1, an immediate early gene product absolutely required for 39K expression in a transient assay analysis, but insufficient for optimal expression under certain conditions. When the concentration of IE1 is limiting, a viral enhancer element cis-linked to the 39K promoter is also required. Enhancer function is also dependent upon IE1. Thus, the IE1 gene product plays two roles in the regulation of this delayed early gene; in trans-activates both the 39K promoter and the viral enhancer that cis-activates the 39k promoter. The mechanism of action of the enhancer-dependent and enhancer-independent regulation of 39K will be defined. Specifically, this work includes five parts: (1) identification of the enhancer sequences which influence the interactions between viral DNA and trans- activating host and viral factors, (2) the identification of factors which bind the viral enhancer in normal Spodoptera frugiperda cells (host specific factors) and in cells which express the viral IE1 gene (IE1-specific factors), (3) analysis of the 39K promoter sequences that are important for transcription in the presence and absence of the cis-linked enhancer, (4) identification of factors which bind the 39K promoter in normal and in IE1- expressing cells, and (5) confirmation of in vitro binding analysis by transient assay analysis and in vivo susceptibility of viral DNA to chemical and enzymatic probes.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
First Independent Research Support & Transition (FIRST) Awards (R29)
Project #
5R29AI027450-05
Application #
2063860
Study Section
Experimental Virology Study Section (EVR)
Project Start
1989-03-01
Project End
1996-02-29
Budget Start
1993-03-01
Budget End
1996-02-29
Support Year
5
Fiscal Year
1993
Total Cost
Indirect Cost
Name
Texas A&M University
Department
Zoology
Type
Schools of Earth Sciences/Natur
DUNS #
City
College Station
State
TX
Country
United States
Zip Code
77845
Choi, J; Guarino, L A (1995) Expression of the IE1 transactivator of Autographa californica nuclear polyhedrosis virus during viral infection. Virology 209:99-107
Choi, J; Guarino, L A (1995) A temperature-sensitive IE1 protein of Autographa californica nuclear polyhedrosis virus has altered transactivation and DNA binding activities. Virology 209:90-8
Xu, B; Yoo, S; Guarino, L A (1995) Differential transcription of baculovirus late and very late promoters: fractionation of nuclear extracts by phosphocellulose chromatography. J Virol 69:2912-7
Hang, X; Dong, W; Guarino, L A (1995) The lef-3 gene of Autographa californica nuclear polyhedrosis virus encodes a single-stranded DNA-binding protein. J Virol 69:3924-8
Choi, J; Guarino, L A (1995) The baculovirus transactivator IE1 binds to viral enhancer elements in the absence of insect cell factors. J Virol 69:4548-51
Guarino, L A; Dong, W (1994) Functional dissection of the Autographa california nuclear polyhedrosis virus enhancer element hr5. Virology 200:328-35
Gong, M; Guarino, L A (1994) Expression of the 39k promoter of Autographa californica nuclear polyhedrosis virus is increased by the apoptotic suppressor P35. Virology 204:38-44
Reilly, L M; Guarino, L A (1994) The pk-1 gene of Autographa californica multinucleocapsid nuclear polyhedrosis virus encodes a protein kinase. J Gen Virol 75 ( Pt 11):2999-3006
Kovacs, G R; Choi, J; Guarino, L A et al. (1992) Functional dissection of the Autographa californica nuclear polyhedrosis virus immediate-early 1 transcriptional regulatory protein. J Virol 66:7429-37
Guarino, L A; Dong, W; Xu, B et al. (1992) Baculovirus phosphoprotein pp31 is associated with virogenic stroma. J Virol 66:7113-20

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