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Updated: May 16, 2026
Transient Expression of Foreign Genes in Insect Cells (sf9) for Protein Functional Assay
Published on: February 22, 2018
[Functional analysis of the late expression factor genes of plutella xylostella granulovirus]
1Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan 430079, China.
Abstract:
Plutella xylostella granulovirus (PlxyGV) contains homologs of 15 Autographa californica MNPV (AcMNPV) late expression factor (lef) genes. The prospective products of 14 PlxyGV lef genes (ie-0 is not included) share 13%-53% amino acid similarity with their corresponding homologs of AcMNPV, among which LEF-9, LEF-8 and P47, three subunits of the virus-encoded RNA polymerase, share 49%, 53% and 46% sequence identity, respectively. In this study, an established transient expression system was used to test the ability of the PlxyGV LEFs to activate an AcMNPV vp39 promoter-driven reporter gene in SF9 cells. It was shown that PlxyGV le f-2 replaced the corresponding AcMNPV gene and exhibited partial activity in the context of the remaining set of AcMNPV le fs. PlxyGV LEF-2 was found to contain additional 100aa and 70aa at the C-terminus in comparison with the LEF-2 of other GVs and lepidopteran NPVs respectively.
Insights
Plutella xylostella granulovirus (PlxyGV) LEF-2 partially activates a reporter gene, replacing its Autographa californica MNPV (AcMNPV) counterpart. This study reveals unique C-terminal extensions in PlxyGV LEF-2, impacting its function in viral gene expression.
Area of Science:
- Virology
- Molecular Biology
- Insect Pathology
Background:
- Plutella xylostella granulovirus (PlxyGV) shares homologous late expression factor (lef) genes with Autographa californica MNPV (AcMNPV).
- LEF proteins are crucial for regulating viral gene expression in baculoviruses.
- LEF-9, LEF-8, and P47 from PlxyGV show significant sequence similarity to AcMNPV subunits of viral RNA polymerase.
Purpose of the Study:
- To investigate the functional activity of PlxyGV LEF proteins in activating viral gene expression.
- To determine if PlxyGV LEF genes can functionally replace their AcMNPV homologs.
- To characterize unique structural features of PlxyGV LEF-2.
Main Methods:
- Utilized a transient expression system in SF9 cells.
- Tested the ability of PlxyGV LEFs to activate an AcMNPV vp39 promoter-driven reporter gene.
- Analyzed sequence identity and structural differences between PlxyGV and AcMNPV LEF proteins.
Main Results:
- PlxyGV LEF-2 demonstrated partial functional activity when replacing the AcMNPV LEF-2 gene.
- PlxyGV LEF-2 contains unique C-terminal extensions (100aa and 70aa) compared to other GVs and lepidopteran NPVs.
- The study confirmed functional conservation and divergence in LEF gene homologs between PlxyGV and AcMNPV.
Conclusions:
- PlxyGV LEF-2 possesses partial functional activity and unique structural characteristics.
- LEF gene homologs between different NPVs can exhibit both conserved and divergent functions.
- Further research is needed to fully elucidate the role of PlxyGV LEF-2 and its unique domains in viral replication.
