Related Experiment Video
Updated: May 17, 2026
Transient Expression of Foreign Genes in Insect Cells (sf9) for Protein Functional Assay
Published on: February 22, 2018
Functional analysis of Spodoptera frugiperda nucleopolyhedrovirus late expression factors in Sf9 cells
Marcelo F Berretta1, M Gabriela López, Oscar Taboga
1Instituto de Microbiología y Zoología Agrícola, INTA Castelar, Castelar, Argentina. mberretta@cnia.inta.gov.ar
Abstract:
We used transient expression assays to assess the function of the baculovirus Spodoptera frugiperda M nucleopolyhedrovirus (SfMNPV) homologs of Autographa californica MNPV (AcMNPV) factors involved in late gene expression (lefs), in the Sf9 insect cell-line, which is permissive for both viruses. It is well-established that nineteen AcMNPV lefs support optimal levels of activity from a late promoter-reporter gene cassette in this assay. A subgroup of SfMNPV lefs predicted to function in transcription-specific events substituted the corresponding AcMNPV lefs very efficiently. When all SfMNPV lefs were assayed, including replication lefs, activity was low, but addition of two AcMNPV lefs not encoded in SfMNPV genome, resulted in augmented reporter activity. SfMNPV IE-1 was able to activate an early promoter cis-linked to an hr-derived element from SfMNPV but not from AcMNPV. However, the level of early promoter activation with SfMNPV IE-1 was lower compared to AcMNPV IE-1.
Insights
This study investigated baculovirus gene expression, finding that Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV) factors partially substitute for Autographa californica MNPV (AcMNPV) late expression factors (lefs). Adding specific AcMNPV lefs enhanced SfMNPV activity.
Area of Science:
- Virology
- Molecular Biology
- Insect Cell Culture
Background:
- Baculoviruses are essential tools in molecular biology and biotechnology.
- Understanding late gene expression is crucial for optimizing viral replication and gene delivery.
- Autographa californica MNPV (AcMNPV) late expression factors (lefs) are well-characterized.
Purpose of the Study:
- To assess the functional conservation of Spodoptera frugiperda M nucleopolyhedrovirus (SfMNPV) lefs compared to AcMNPV.
- To identify SfMNPV lefs that can substitute for AcMNPV lefs in transient expression assays.
- To investigate the role of specific SfMNPV and AcMNPV factors in regulating viral gene expression.
Main Methods:
- Transient expression assays in Sf9 insect cells.
- Utilizing a late promoter-reporter gene cassette.
- Assessing the functional substitution of AcMNPV lefs by SfMNPV homologs.
- Investigating the activity of SfMNPV IE-1 on early promoters.
Main Results:
- A subset of SfMNPV lefs efficiently substituted for AcMNPV lefs involved in transcription.
- Low reporter activity was observed when all SfMNPV lefs were assayed, but was enhanced by adding two AcMNPV-specific lefs.
- SfMNPV IE-1 activated an SfMNPV hr-derived early promoter, but less efficiently than AcMNPV IE-1.
Conclusions:
- SfMNPV lefs exhibit partial functional conservation with AcMNPV lefs.
- Specific AcMNPV lefs are required to augment SfMNPV late gene expression.
- SfMNPV IE-1 demonstrates distinct promoter activation capabilities compared to its AcMNPV counterpart.
More Related Videos
08:16Single-Molecule Analysis of Sf9 Purified Superprocessive Kinesin-3 Family Motors
Published on: July 27, 2022
12:18Expression of Functional Recombinant Hemagglutinin and Neuraminidase Proteins from the Novel H7N9 Influenza Virus Using the Baculovirus Expression System
Published on: November 6, 2013