Name: transient expression of foreign genes in insect cells (sf9) for protein functional assay
Uploaded: 2018-02-22T13:00:00
Description: Watch this Scientific Journal Video about Transient Expression of Foreign Genes in Insect Cells sf9 for Protein Functional Assay at JoVE.com

Wij danken Dr. Jian-Horng Leu van Instituut van mariene biologie, National Taiwan Oceaan University voor het verstrekken van 3 plasmide constructies. Dit onderzoek werd gesteund door Grant 106-2311-B-197-001 - van het ministerie van wetenschap en technologie (MOST).

1. voorbereiding
<ol><li>Insect celkweek<ol>
<li>50 mL cel kweekmedium voor te bereiden. Om dit te doen, voeg 500 µL van antibiotica (Amfotericine B = 0,25 µg/mL penicilline = 100 eenheid/mL streptomycine = 100 µg/mL) en 5 mL van de warmte-geïnactiveerd foetale runderserum in cel serumvrij cultuurmedium (zonder FBS of antibiotica). Opmerking: Verwarm de foetale runderserum bij 65 ° C gedurende 30 minuten in een waterbad vóór gebruik.</li>
		<li>Spodoptera frugiperda handhaven (Lepido...

<ol>
	<li>Miller, L. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Baculoviruses+as+gene+expression+vectors.">Baculoviruses as gene expression vectors.</a> Annual Reviews in Microbiology. 42 (1), 177-199 (1988).</li><li>Theilmann, D. A., Fauquet, C. M., Mayo, M. A., Maniloff, J., Desselberger, U., Ball, L. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Family+Baculoviridae.">Family Baculoviridae.</a> Virus Taxonomy: Eighth Report of the International Committee on Taxonomy of Viruses. , 1129-1185 (2005).</li><li>Nai, Y. S., Huang, Y. F., Chen, T. H., Chiu, K. P., Wang, C. H., Shields, V. D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Determination+of+nucleopolyhedrovirus'+taxonomic+position.">Determination of nucleopolyhedrovirus' taxonomic position.</a> Biological Control of Pest and Vector Insects. , 169-200 (2017).</li><li>Friesen, P. D., Miller, L. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+of+baculovirus+early+gene+expression.">Regulation of baculovirus early gene expression.</a> The Baculoviruses. , 141-170 (1997).</li><li>Smith, G. E., Summers, M., Fraser, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Production+of+human+beta+interferon+in+insect+cells+infected+with+a+baculovirus+expression+vector.">Production of human beta interferon in insect cells infected with a baculovirus expression vector.</a> Mol. Cell. Biol. 3 (12), 2156-2165 (1983).</li><li>Luckow, V. A., Summers, M. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Trends+in+the+development+of+baculovirus+expression+vectors.">Trends in the development of baculovirus expression vectors.</a> Nature Biotechnol. 6 (1), 47-55 (1988).</li><li>Jarvis, D. L., Finn, E. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modifying+the+insect+cell+N-glycosylation+pathway+with+immediate+early+baculovirus+expression+vectors.">Modifying the insect cell N-glycosylation pathway with immediate early baculovirus expression vectors.</a> Nature Biotechnol. 14 (1996), 1288-1292 (1996).</li><li>Clem, R. J., Miller, L. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Control+of+programmed+cell+death+by+the+baculovirus+genes+p35+and+iap.">Control of programmed cell death by the baculovirus genes p35 and iap.</a> Mol. Cell. Biol. 14, 5212-5222 (1994).</li><li>Leu, J. H., Kuo, Y. C., Kou, G. H., Lo, C. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+cloning+and+characterization+of+an+inhibitor+of+apoptosis+protein+(IAP)+from+the+tiger+shrimp,+Penaeus+monodon.">Molecular cloning and characterization of an inhibitor of apoptosis protein (IAP) from the tiger shrimp, Penaeus monodon.</a> Dev. Comp. Immunol. 32, 121-133 (2008).</li><li>Zhao, Y. G., Eggleston, P. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+analysis+of+promoters+for+transient+gene+expression+in+cultured+mosquito+cells.">Comparative analysis of promoters for transient gene expression in cultured mosquito cells.</a> Insect Mol. Biol. 8 (1), 31-38 (1999).</li><li>Nai, Y. S., Yang, Y. T., Kim, J. S., Wu, C. Y., Chen, Y. W., Wang, C. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Baculoviral+IAP2+and+IAP3+encoded+by+Lymantria+xylina+multiple+nucleopolyhedrovirus+(LyxyMNPV)+suppress+insect+cell+apoptosis+in+a+transient+expression+assay.">Baculoviral IAP2 and IAP3 encoded by Lymantria xylina multiple nucleopolyhedrovirus (LyxyMNPV) suppress insect cell apoptosis in a transient expression assay.</a> Appl. Entomol. Zool. 51, 305-316 (2016).</li><li>Eslami, A., Lujan, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Western+Blotting:+Sample+Preparation+to+Detection.">Western Blotting: Sample Preparation to Detection.</a> J. Vis. Exp. (44), e2359 (2010).</li><li>. Basic Methods in Cellular and Molecular Biology. Separating Protein with SDS-PAGE Available from: <a target="_blank" href="https://www.jove.com/science-education/5058/separating-protein-with-sds-page">https://www.jove.com/science-education/5058/separating-protein-with-sds-page</a> (2017)</li><li>Vucic, D., Kaiser, W. J., Harvey, A. J., Miller, L. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inhibition+of+reaper-induced+apoptosis+by+interaction+with+inhibitor+of+apoptosis+proteins+(IAPs).">Inhibition of reaper-induced apoptosis by interaction with inhibitor of apoptosis proteins (IAPs).</a> Proc. Natl. Acad. Sci. USA. 94, 10183-10188 (1997).</li></ol>

Het concept van warmte schok gebaseerde pDHsp/V5-zijne/sf9 cel systeem werd voor het eerst beschreven door Clem et al. in 19948. Vergelijking van de baculoviral gen promotor (IE1) en Drosophila hsp70 toonde aan dat hsp70 had een hogere efficiëntie in mug cellen10. Bovendien, als gevolg van de hitte schok inductie, de timing van eiwit expressie kan worden gecontroleerd juist na de schok van de warmtebehandeling. Dit systeem werd vervolgen...

Twee eiwit expressiesystemen zijn meestal gebruikt voor de productie van eiwitten: prokaryote eiwit expressie (Escherichia coli gen expressie systeem) en eukaryote eiwit expressiesystemen. Een populaire eukaryote eiwit expressie systeem is de baculovirus expressie vector systeem (BEVS)1. Baculoviruses werden voor het eerst gebruikt als wereldwijd biologische bestrijders van landbouw en bosbouw van ongedierte. In de afgelopen decennia, werden baculoviruses ontwikkeld als biotechnologische instrumenten voor eiwit expressievectoren evenals. Het genoom van de baculoviruses bestaan uit circulaire dubbelstrengig DNA en omhuld nucleocapsids2. Tot op heden meer dan achtenzeventig baculovirus geweest isolaten gesequenceerd3. Op basis van de temporele cascade van baculoviral gen expressies in insect cellen van de gastheer, kan de transcriptie van het gen worden ingedeeld in vier temporele cascades, met inbegrip van direct-vroege, vertraagd-vroege, late en erg laat genen4.
BEVSs werden aangewezen, zodat het zeer laat gene initiatiefnemers (d.w.z., veelvlak of p10 promotor) werden gebruikt om te rijden de doelgenen, terwijl de recombinante baculovirus werd gegenereerd door homologe recombinatie. Uitdrukking van vreemde proteïnen in insect cellen door recombinant baculovirus is vergelijkbaar met die van zoogdieren eiwitten in posttranslationele modificaties (geschikt voor de productie van glycoproteïne). Aldus, is de baculovirus gebruikte5,6,7. Een beperking is echter de aanwezigheid van verschillende N-glycosylation routes in insect cellen7.
Daarom werd een nieuwe baculovirus expressie systeem, het voorbijgaande gen expressie systeem, ontwikkeld. Dit systeem geeft uiting aan buitenlandse genen onder de schijf van baculoviral onmiddellijk-vroege initiatiefnemers (dwz 1 promotor) in insect cellen. Met behulp van dit systeem, kan de doel-eiwit worden onmiddellijk uitgedrukt onder de controle van ie-1 promotor tijdens het wijzigen van de route van de N-glycosylation in insect cellen, wat resulteert in betere N-linked oligosacchariden7. Bovendien, baculoviral onmiddellijke-vroege genen worden getranscribeerd door de gastheercel RNA polymerase II en vereisen geen enige virale factor voor activering4. Daarom kunnen vreemde eiwitten worden uitgedrukt in insect cellen binnen een korte tijd. Tot op heden, de voorbijgaande is gen expressie systeem een van de belangrijkste technologieën voor het uitvoeren van functionele testen van eiwit in de baculovirus in vitro celcultuur. Het systeem kan worden toegepast om de functie van baculovirus of vreemde eiwitten te analyseren. Een van de verkrijgbare voorbijgaande gen expressiesystemen is gebaseerd op de onmiddellijke-vroege gen (IE) initiatiefnemers van Orgyia pseudotsugata multicapsid nucleopolyhedrovirus (OpMNPV) (OpIE2 en OpIE1 initiatiefnemers).
Het lagere niveau van de expressie van buitenlandse genen in insect cellen was echter nog steeds een probleem toen het OpIE promotor gebaseerde voorbijgaande gen expressie systeem gebruikte8,9,10. Dus, een ander voorbijgaande gen expressie systeem werd gebouwd op basis van de promotor van de Drosophila warmte schok eiwit 70 (hsp70) gen8,9. De promotor van hsp70 werkt efficiënter dan baculoviral IE promotor wanneer geïnduceerd door warmte schok in insect cellen10. In dit systeem, werden de doelgenen uitgedrukt onder het station van Drosophila warmte schok 70 (Dhsp70) promotor. Buitenlandse genen kunnen gemakkelijk worden gekloond in het voorbijgaande gen expressie plasmide door PCR-gebaseerde klonen methoden. Bovendien is de controle van de timing voor de expressie van genen kan worden uitgevoerd door warmte schok inductie.
In dit verslag, we volgen de aanpak en uiten van drie verschillende opschoningen van het baculoviral gen (remmer van apoptosis 3, iap3 vanaf Lymantria xylina MNPV) met behulp van de warmte schok gebaseerde voorbijgaande eiwit expressie systemen en Verder gelden deze uitgedrukte proteïnen op anti-apoptotic activiteit analyse. Dit systeem kan ofwel express vreemde eiwitten snel of verder worden toegepast op de evaluatie van eiwit anti-apoptotic activiteit in sf9 cellen, terwijl ook het potentieel om te worden toegepast op andere eiwit activiteit testen te hebben.

<table>
	<tbody>
		<tr>
			<td>Antibiotic-Antimycotic, 100X</td>
			<td>Gibco</td>
			<td>15240-062</td>
			<td>for insect cell culture</td>
		</tr>
		<tr>
			<td>Certified Foetal Bovine Serum</td>
			<td>Bioind</td>
			<td>04-001-1A</td>
			<td></td>
		</tr>
		<tr>
			<td>Sf-900 II SFM</td>
			<td>Thermo Fisher</td>
			<td>10902096</td>
			<td>serum-free cell culture medium</td>
		</tr>
		<tr>
			<td>Sf9 cells</td>
			<td>ATCC</td>
			<td>CRL-1711</td>
			<td></td>
		</tr>
		<tr>
			<td>25cm2 cell culture flask</td>
			<td>Nunc, Thermo Fisher</td>
			<td>156340</td>
			<td></td>
		</tr>
		<tr>
			<td>Inverted light microscopy</td>
			<td>WHITED</td>
			<td>WHITED WI-400</td>
			<td></td>
		</tr>
		<tr>
			<td>RBC HIT Competent Cell</td>
			<td>Bioman</td>
			<td>RH618-J80</td>
			<td>Escherichia coli (DH5&#945;)</td>
		</tr>
		<tr>
			<td>L.B. Broth (Miller)</td>
			<td>Bioman</td>
			<td>LBL407</td>
			<td></td>
		</tr>
		<tr>
			<td>Agar, Bacteriological Grade</td>
			<td>Bioman</td>
			<td>AGR001</td>
			<td></td>
		</tr>
		<tr>
			<td>Zeocin</td>
			<td>Invitrogen</td>
			<td>ant-zn-1</td>
			<td>selection antibiotic</td>
		</tr>
		<tr>
			<td>PCR Master Mix (2X)</td>
			<td>ThermoFisher</td>
			<td>K0171</td>
			<td></td>
		</tr>
		<tr>
			<td>Geneaid Midi Plasmid Kit (Endotoxin Free)</td>
			<td>Geneaid</td>
			<td>PIE25</td>
			<td></td>
		</tr>
		<tr>
			<td>Actinomycin D</td>
			<td>SIGMA</td>
			<td>A9415</td>
			<td></td>
		</tr>
		<tr>
			<td>Corning 50 mL centrifuge tubes</td>
			<td>SIGMA</td>
			<td>CLS430829-500EA</td>
			<td>50 mL tubes</td>
		</tr>
		<tr>
			<td>Hemocytometer</td>
			<td>Gizmo Supply Co</td>
			<td>B-CNT-SLDE-V2</td>
			<td></td>
		</tr>
		<tr>
			<td>24-Well Multidish</td>
			<td>Nunc, Thermo Fisher</td>
			<td>142475</td>
			<td>24-well plate</td>
		</tr>
		<tr>
			<td>Cellfectin II Reagent</td>
			<td>Thermo Fisher</td>
			<td>10362100</td>
			<td>cell transfectin reagent</td>
		</tr>
		<tr>
			<td>PBS-Phosphate-Buffered Saline (10X) pH 7.4</td>
			<td>Thermo Fisher</td>
			<td>AM9624</td>
			<td></td>
		</tr>
		<tr>
			<td>4&#215;SDS Loading Dye</td>
			<td>Bioman</td>
			<td>P1001</td>
			<td></td>
		</tr>
		<tr>
			<td>Immobilon-P (PVDF Blotting Membranes)</td>
			<td>Merck Milipore</td>
			<td>IPVH00010</td>
			<td>PVDF membranes</td>
		</tr>
		<tr>
			<td>Mini Trans-Blot Cell system</td>
			<td>BIO-RED</td>
			<td>1703930</td>
			<td>Blotting device</td>
		</tr>
		<tr>
			<td>Ponceau S solution</td>
			<td>SIGMA</td>
			<td>6226-79-5</td>
			<td></td>
		</tr>
		<tr>
			<td>Anti-V5</td>
			<td>SIGMA</td>
			<td>V8137</td>
			<td>rabbit anti-V5 antibody</td>
		</tr>
		<tr>
			<td>Goat anti-rabbit IgG-horseradish peroxidase (HRP)</td>
			<td>Jackson</td>
			<td>111-035-003</td>
			<td></td>
		</tr>
		<tr>
			<td>Tween 20</td>
			<td>Merck</td>
			<td>817072</td>
			<td></td>
		</tr>
		<tr>
			<td>6-Well Multidish</td>
			<td>Nunc, Thermo Fisher</td>
			<td>145380</td>
			<td></td>
		</tr>
		<tr>
			<td>0.4 % trypan blue solution</td>
			<td>AMRESCO</td>
			<td>K940-100ML</td>
			<td></td>
		</tr>
		<tr>
			<td>P10 pipetman</td>
			<td>Gilson</td>
			<td>F144802</td>
			<td></td>
		</tr>
		<tr>
			<td>P1000 pipetman</td>
			<td>Gilson</td>
			<td>F123602</td>
			<td></td>
		</tr>
		<tr>
			<td>Tape</td>
			<td>Symbio</td>
			<td>PPS7</td>
			<td>24 well tape ( 19 mm&#215;36 M)</td>
		</tr>
	</tbody>
</table>

transient expression of foreign genes in insect cells (sf9) for protein functional assay

Het voorbijgaande gen expressie systeem is een van de belangrijkste technologieën voor het uitvoeren van de functionaalanalyse eiwit in de baculovirus in vitro celcultuur. Dit systeem werd ontwikkeld om de uitdrukkelijke buitenlandse genen onder de controle van de promotor van de baculoviral in voorbijgaande expressie plasmiden. Dit systeem kan bovendien worden toegepast op een functionele test van de baculovirus zelf of vreemde eiwitten. Het meest algemeen en commercieel beschikbare voorbijgaande gen expressie systeem is ontwikkeld op basis van de promotor van de onmiddellijke-vroege gen (IE) van Orgyia pseudotsugata multicapsid nucleopolyhedrovirus (OpMNPV). Echter werd een lage expressie niveau van buitenlandse genen in insect cellen waargenomen. Dus werd een voorbijgaande gen expressie systeem gebouwd om eiwituitdrukking te verbeteren. In dit systeem, werden recombinante plasmiden gebouwd om bevatten de volgorde van de doelgroep onder de controle van de Drosophila warmte schok 70 (Dhsp70) promotor. Dit protocol stelt de toepassing van deze warmte schok gebaseerde pDHsp/V5-Hsi (V5 epitoop met 6 histidine) /Spodoptera frugiperda cel (sf9 cel) systeem; Dit systeem is niet alleen beschikbaar voor de expressie van genen maar ook voor de evaluatie van de activiteiten van de anti-apoptotic van kandidaat-eiwitten in insect cellen. Bovendien, dit systeem ofwel kan zijn transfected met één recombinant plasmide of mede twee potentieel functioneel antagonistische recombinante plasmiden in insect cellen transfected. Het protocol toont de doeltreffendheid van dit systeem en biedt een praktisch voorbeeld van deze techniek.

De volledige lengte en andere twee opschoningen (BIR en RING domeinen) van Ly-IAP3 van LyxyMNPV werden overexpressie in sf9 cellen, op basis van de warmte schok gebaseerde pDHsp/V5-Hsi /Spodoptera frugiperda cel (sf9 cel) systeem. De pDHsp/V5-Hsi bevatte een Drosophila warmte schok eiwit promotor, die downstream genexpressie bij een temperatuur van 42 ° C aandoening rijdt met behulp van cellulaire transcriptionele factoren en de vertaling systeem (F...

Watch this Scientific Journal Video about Transient Expression of Foreign Genes in Insect Cells sf9 for Protein Functional Assay at JoVE.com

Transient Expression of Foreign Genes in Insect Cells sf9 for Protein Functional Assay

Dit protocol beschrijft een warmte schok-geïnduceerde proteïne expressie systeem (pDHsp/V5-zijne/sf9 cel), die kan worden gebruikt voor het uitdrukken van vreemde proteïnen of evaluatie van de anti-apoptotic activiteit van potentiële buitenlandse eiwitten en hun afgeknotte amino zuren in insect cellen.

Voorbijgaande expressie van buitenlandse genen in Insect cellen (sf9) voor eiwit functionele Assay

The transient gene expression system is one of the most important technologies for performing protein functional analysis in the baculovirus in vitro cell ...

The overall goal of this heat shock-induced protein expression system is to evaluate protein anti-apoptotic activity in two potentially functionally antagonistic proteins in insect cells. This method can help answer key questions about the functions and activities of candidate proteins in biotechnology and proteomics, such as their anti-apoptotic activities and protein interactions. The main advantage of this technique is that the timing of gene expression is controlled by heat shock induction.So this method can provide insight into protein functional status. It can also be applied to other systems, such as mammalian protein expression. The Spodoptera frugiperda, or Sf9, insect cells used in this protocol are grown in cell culture medium in 25 square centimeter cell culture flasks at 28 degrees Celsius.Shake the cell culture flask to detach the cells from the flask. Then check under a light microscope to make sure that about 80%of the cells are detached. Transfer 50%of the cell suspension to a new 25 square centimeter cell culture flask, and allow the cells to attach at room temperature for 15 minutes.After 15 minutes, replace the medium with five milliliters of fresh culture medium, and grow in an incubator at 28 degrees Celsius. Depending on the cell growth, passage the cells every two to three days. Prior to harvesting the Sf9 cells, it is important to check the cells under the light microscope to make sure that there is no contamination by bacteria or other microorganisms.To harvest the Sf9 cells, shake the culture flask to detach the cells, and then transfer the cell suspension to a 15-milliliter tube. Using a P10 pipette, transfer 10 microliters of the cell suspension to a hemacytometer, and count the cell number under the light microscope. Plate three times 10 to the fifth cells into each well of a 24-well plate, and leave at room temperature for 15 minutes.After 15 minutes, replace the medium with 0.5 milliliters of plating medium. Prepare the cell transfection regent. For each transfection, dilute eight microliters of cell transfection reagent with 100 microliters of serum-free cell culture medium, and vortex for one second to mix.In this study, three different truncations of the baculoviral gene, inhibitor of apoptosis 3, or IAP3, will be expressed under the control of the Drosophila heat shock 70 promoter, the full-length IAP3, a truncation lacking the RING domain, and a truncation lacking the BIR domain. Add two micrograms of each plasmid DNA into 100 microliters of serum-free cell culture medium, and mix by vortexing for one second. Prepare a positive control as well.Combine the diluted plasmid DNA and diluted cell transfection reagent, and mix by vortexing. Incubate at room temperature for 30 minutes. Using a P1000 pipette, add 210 microliters of each DNA transfection reagent mixture dropwise onto the cells.Incubate at 28 degrees Celsius for five hours. After five hours, replace the plating medium with 0.5 milliliters of cell culture medium, and then seal the 24-well plate with tape. Incubate at 28 degrees.On the following day, heat shock to induce protein expression by floating the plate in a 42 degree Celsius water bath for 30 minutes. After 30 minutes, return the 24-well plate to the 28 degree Celsius incubator. Protein expression is subsequently confirmed by Western blot as described in the text protocol.To examine gene-induced cell apoptosis, first prepare Sf9 cells as demonstrated earlier. Next, transfect the cells in the same manner as before, but include one microgram of a plasmid containing an apoptosis inducer gene in each transfection reaction. Incubate at 28 degrees Celsius for five hours, replace the medium, and incubate for 16 hours.Heat shock the transfected cells at 42 degrees Celsius for 30 minutes. Incubate the cells at 28 degrees Celsius for five hours before conducting the cell viability assay. For chemical-induced cell apoptosis, plate one times 10 to the six Sf9 cells into each well of a six-well plate.Leave at room temperature for 15 minutes, and then replace the medium with one milliliter of plating medium. Transfect the cells with four micrograms of each plasmid DNA. After five hours, replace the plating medium with one milliliter of cell culture medium, and incubate the cells at 28 degrees Celsius for 16 hours.Then heat shock at 42 degrees Celsius for 30 minutes. Incubate the cells at 28 degrees Celsius for five hours post-heat shock. Then treat the transfected cells with actinomycin D to induce apoptosis.Incubate at 28 degrees Celsius for 16 hours before conducting the cell viability assay. Begin this procedure by washing the treated cells. Remove the medium from each well, add one milliliter of PBS, and leave for one minute.Wash the cells three times with PBS in this manner. Resuspend the cells in each well with one milliliter of PBS containing 04%trypan blue, and stain at room temperature for three minutes. Transfer the cell suspension into a 1.5 milliliter microfuge tube.Transfer 10 microliters of the trypan blue-stained cell suspension to a hemacytometer, and count the viable intact cells under a light microscope. Finally, perform statistical analysis as described in the text protocol. The full length and two truncations of IAP3 from Lymantria xylina MNPV were overexpressed in Sf9 cells, and Western blot was performed on cell lysates to confirm protein expression.The anti-apoptotic protein Ac-P35 was included as a positive control. All proteins could be detected in transfected cells at either one hour or five hours post-heat shock, with a higher expression at five hours. This system can be adapted to evaluate anti-apoptotic activity.For gene-induced cell apoptosis, the apoptosis inducer Drosophila Reaper was co-transfected with target gene plasmid constructs into Sf9 cells, which were subsequently heat shocked to activate gene expression. Compared to the vector Drosophila Reaper, the positive control showed high anti-apoptotic activity, reaching up to 80%of the viability rate. The other constructs showed various effects on anti-apoptotic activity.For chemical-induced cell apoptosis, only one construct was transfected into Sf9 cells, and actinomycin D was added five hours post-heat shock. Compared to the positive control or the negative control, the other constructs showed various effects on anti-apoptotic activity. Once mastered, this technique can be done in two to three days if it is performed properly.While attempting this procedure, it's important to remember to obey the operation rules of cell culture in laminar flow and check the status of cells diligently. Following this procedure, other methods, such as co-immunoprecipitation, can be performed to answer additional questions, like whether there is any interaction between the two proteins co-expressed in the insect cells. After its development, this technique paved the way for researchers in the field of biotechnology to explore protein functions in animal or microorganisms.After watching this video, you should have a good understanding of how to use this system to express foreign protein or evaluate potentially functionally antagonistic proteins in insect cells. Don't forget that working with some chemicals, like actinomycin D, can be extremely hazardous, and precautions, such as wearing gloves, should always be taken while performing this procedure.

Research

JoVE Journal

Genetics

Transient Expression of Foreign Genes in Insect Cells (sf9) for Protein Functional Assay

Controllable Ion Channel Expression through Inducible Transient Transfection

Controleerbaar Ion Channel Expression door middel Induceerbare tijdelijke transfectie

Transfection, the delivery of foreign nucleic acids into a cell, is a powerful tool in protein research. Through this method, ion channels can be ...

In Vitro Bioluminescence Assay to Characterize Circadian Rhythm in Mammary Epithelial Cells

In Vitro Bioluminescence Assay to Characterize Circadian Rhythm in Mammary Epithelial Cells

In Vitro Bioluminescentie Assay te karakteriseren Circadian Rhythm in borstklier epitheliale cellen

The circadian rhythm is a fundamental physiological process present in all organisms that regulates biological processes ranging from gene expression to ...

Determination of the Optimal Chromosomal Location(s) for a DNA Element in Escherichia coli Using a Novel Transposon-mediated Approach

Determination of the Optimal Chromosomal Locations for a DNA Element in Escherichia coli Using a Novel Transposon-mediated Approach

Bepaling van de optimale chromosomale locatie (s) voor een DNA Element in Escherichia coli met behulp van een nieuwe benadering van Transposon-gemedieerde

The optimal chromosomal position(s) of a given DNA element was/were determined by transposon-mediated random insertion followed by fitness selection. In ...

Maintaining Biological Cultures and Measuring Gene Expression in Aphis nerii: A Non-model System for Plant-insect Interactions

Maintaining Biological Cultures and Measuring Gene Expression in Aphis nerii: A Non-model System for Plant-insect Interactions

Behoud van de biologische culturen en meten van de genexpressie in Aphis Oleanderpijlstaart: een Non-modelsysteem voor Plant-insect interacties

Aphids are excellent experimental models for a variety of biological questions ranging from the evolution of symbioses and the development of polyphenisms ...

Endogenous Protein Tagging in Human Induced Pluripotent Stem Cells Using CRISPR/Cas9

Endogene eiwit Tagging in mens geïnduceerde pluripotente stamcellen met behulp van CRISPR/Cas9

A protocol is presented for generating human induced pluripotent stem cells (hiPSCs) that express endogenous proteins fused to in-frame&#160;N- or ...

Reverse Transcription-Loop-mediated Isothermal Amplification (RT-LAMP) Assay for Zika Virus and Housekeeping Genes in Urine, Serum, and Mosquito Samples

Reverse Transcription-Loop-mediated Isothermal Amplification RT-LAMP Assay for Zika Virus and Housekeeping Genes in Urine, Serum, and Mosquito Samples

Reverse transcriptie-lus-gemedieerde isotherme amplificatie (RT-LAMP) Assay voor Zika-Virus en huishouden genen in Urine, Serum en Mosquito monsters

Infection with Zika virus (ZIKV) can be asymptomatic in adults, however, infection during pregnancy can lead to miscarriage and severe neurological birth ...

Identification of Homologous Recombination Events in Mouse Embryonic Stem Cells Using Southern Blotting and Polymerase Chain Reaction

Identificatie van homologe recombinatie gebeurtenissen in muis embryonale stamcellen met behulp van Southern Blotting en de Kettingreactie van de Polymerase

Relative to the issues of off-target effects and the difficulty of inserting a long DNA fragment in the application of designer nucleases for genome ...

Determining the Egg Fertilization Rate of Bemisia tabaci Using a Cytogenetic Technique

Determining the Egg Fertilization Rate of Bemisia tabaci Using a Cytogenetic Technique

Bepaling van het tarief van de bevruchting ei van Bemisia tabaci met behulp van een cytogenetische techniek

A few species of sap-sucking whiteflies are some of the most damaging terrestrial pests worldwide because of the crop damage they inflict and plant ...

An Assay for Quantifying Protein-RNA Binding in Bacteria

Een test voor het kwantificeren van eiwit-RNA-binding bij bacteriën

In the initiation step of protein translation, the ribosome binds to the initiation region of the mRNA. Translation initiation can be blocked by binding ...

An In Vitro Protocol for Evaluating MicroRNA Levels, Functions, and Associated Target Genes in Tumor Cells

Een in vitro protocol voor het evalueren van MicroRNA-niveaus, functies en geassocieerde doel genen in tumor cellen

MicroRNAs (miRNAs) are small regulatory RNAs which are recognized to modulate numerous intracellular signaling pathways in several diseases including ...