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

Agradecemos o Dr. Jian-Horng Leu do Instituto de biologia marinha, Universidade Nacional de Taiwan oceano para fornecer 3 construções de plasmídeo. Esta pesquisa foi apoiada por Grant 106-2311-B-197-001 - do Ministério da ciência e tecnologia (a maioria).

1. preparações
<ol><li>Cultura de células de inseto<ol>
<li>Prepare-se 50 mL de meio de cultura celular. Para fazer isso, adicione 500 µ l de antibióticos (Anfotericina B = 0,25 µ g/mL, penicilina = 100 unidades/mL, estreptomicina = 100 µ g/mL) e 5 mL de soro de bovino fetal inactivadas pelo calor em meio de cultura celular isento de soro (sem FBS ou antibióticos). Nota: Aquece o soro bovino fetal a 65 ° C por 30 min em um banho de água antes da utilização.</li>
		<li>Manter a Spodop...

<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>

O conceito de sistema de células de pDHsp/V5-His/sf9 baseada em choque de calor foi primeiramente descrito por Clem et al em 19948. Comparação do promotor do gene de baculoviral (IE1) e Drosophila hsp70 mostrou que aquele hsp70 tinha uma eficiência mais elevada em células de mosquito10. Além disso, devido a indução de choque do calor, o momento da expressão da proteína pode ser controlado precisamente após o tratamento de choqu...

Dois sistemas de expressão da proteína tem sido comumente usados para a produção de proteínas: sistemas de expressão da proteína de procarionte (sistema de expressão de gene deEscherichia coli ) e sistemas de expressão da proteína eucariota. Um sistema de expressão de proteínas eucariota popular é a expressão de baculovirus vetor sistema (BEVS)1. Baculoviruses primeiro foram usados como agentes em todo o mundo controle biológico de produtos agrícolas e florestais pragas. Nas últimas décadas, baculoviruses foram desenvolvidas como ferramentas biotecnológicas para vetores da expressão da proteína também. Os genomas de baculoviruses consistem de DNA circular de dupla-hélice e envoltos envelopada2. Até à data, mais de setenta e oito baculovirus isolados foram sequenciados3. Baseado em cascata temporal de expressões de gene baculoviral em células de inseto hospedeiro, a transcrição do gene pode ser classificada em quatro cascatas temporais, incluindo imediata-início, início atrasado, atrasado e muito tarde genes4.
BEVSs, foram designados para que os promotores de genes muito tarde (ou seja, Poliedro ou p10 promotor) foram usados para conduzir os genes-alvo, enquanto o baculovirus recombinante foi gerado pelo recombination homologous. Expressão de proteínas extrangeiras em células de inseto pelo baculovirus recombinante é similar de proteínas de mamíferos em modificações borne-translational (adequadas para a produção de glicoproteína). Assim, o baculovirus tem sido amplamente utilizado5,6,7. No entanto, uma limitação é a presença de diferentes percursos de N-glicosilação em células de inseto7.
Portanto, um novo sistema de expressão de baculovirus, o sistema de expressão de gene transiente, foi desenvolvido. Este sistema expressa genes estrangeiros sob a unidade de baculoviral imediata-primeiros promotores (promotorou seja,-1 ) em células de inseto. Usando este sistema, a proteína do alvo pode ser imediatamente expressa sob o controle do promotor ou seja-1 ao modificar o caminho de N-glicosilação em células de inseto, resultando em melhor oligossacarídeos N-ligados7. Além disso, baculoviral imediata-primeiros genes são trascritos pela RNA polimerase II a pilha de anfitrião e não requerem qualquer fator viral para ativação4. Portanto, proteínas estranhas podem ser expressa em células de inseto dentro de um curto período de tempo. Até à data, o transitório, sistema de expressão de gene é uma das tecnologias mais importantes para a realização de ensaios funcionais da proteína do baculovirus em vitro sistema de cultura celular. O sistema pode ser aplicado para analisar a função de baculovirus ou proteínas estranhas. Um dos sistemas de expressão de gene transiente comercialmente disponível é baseado nos promotores de gene início imediato (IE) de medicamentos multicapsid de Orgyia pseudotsugata (OpMNPV) (promotores de OpIE2 e OpIE1).
No entanto, o menor nível de expressão de genes estrangeiros em células de inseto ainda era um problema quando o sistema de expressão de gene transiente baseado no promotor OpIE foi usado8,9,10. Assim, um outro sistema de expressão de gene transiente foi construído com base no promotor da drosófila calor choque proteína 70 (hsp70) gene8,9. O promotor da hsp70 funciona mais eficientemente do que o promotor baculoviral IE quando induzida por choque térmico em células de inseto10. Neste sistema, os genes-alvo foram expressos sob a unidade de Drosophila 70 (Dhsp70) promotor de calor choque. Genes estrangeiros podem ser facilmente clonados em plasmídeo de expressão do gene transitória por métodos de clonagem baseados em PCR. Além disso, o controle de sincronismo para a expressão do gene pode ser executado por indução de choque do calor.
Neste relatório, vamos seguir a abordagem e expressar três truncamentos diferentes do gene baculoviral (inibidor da apoptose 3, iap3 de mariposa Ksýlina MNPV) usando o sistema de expressão de proteína transiente baseada em choque de calor e aplicam-se ainda mais estas proteínas expressas na análise da atividade anti-apoptotic. Este sistema também pode expressar proteínas estranhas rapidamente ou ainda ser aplicado para a avaliação da atividade anti-apoptotic de proteína nas células sf9, tendo também o potencial para ser aplicado a outros ensaios de atividade da proteína.

<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

O sistema de expressão de gene transiente é uma das tecnologias mais importantes para a realização de análise funcional da proteína do baculovirus em vitro sistema de cultura celular. Este sistema foi desenvolvido para os genes expressam estrangeiros sob o controle do promotor baculoviral em plasmídeo de expressão transiente. Além disso, este sistema pode ser aplicado a um ensaio funcional de baculovirus em si ou proteínas estranhas. O sistema de expressão de gene transiente mais amplamente e comercialmente disponível é desenvolvido com base no promotor do gene imediata-início (IE) da Orgyia pseudotsugata multicapsid Membros (OpMNPV). No entanto, observou-se um nível de baixa expressão de genes estrangeiros em células de inseto. Portanto, um sistema de expressão de gene transiente foi construído para melhorar a expressão da proteína. Neste sistema, o plasmídeo recombinante foram construído para conter a sequência alvo sob o controle do promotor Drosophila calor choque 70 (Dhsp70). Este protocolo apresenta a aplicação deste calor baseada em choque pDHsp/V5-His (epítopo V5 com 6 histidina) /Spodoptera frugiperda celular sistema (sf9 celular); Este sistema está disponível não só para a expressão de gene, mas também para avaliar a atividade anti-apoptotic de proteínas de candidato em células de inseto. Além disso, este sistema pode também ser transfected com um plasmídeo recombinante ou transfectadas co dois funcionalmente potencialmente antagônico plasmídeo recombinante em células de inseto. O protocolo demonstra a eficiência deste sistema e fornece um caso prático desta técnica.

O comprimento total e outros dois truncamentos (domínios BIR e anel) de Ly-IAP3 de LyxyMNPV foram overexpressed em células sf9, baseia o calor baseada em choque pDHsp/V5-His /Spodoptera frugiperda celular sistema (sf9 celular). O pDHsp/V5-His contido uma drosófila calor choque proteína promotora, que impulsiona a expressão gênica a jusante a uma temperatura de 42 ° C condição usando celulares fatores transcricionais e a tradução sistema (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

Este protocolo descreve um calor induzida por choque proteína expressão (sistema pDHsp/V5-His/sf9 célula), que pode ser usado para expressar proteínas estranhas ou avaliando a atividade anti-apoptotic de potenciais proteínas estranhas e seus truncado amino ácidos em células de inseto.

Expressão transiente de estrangeiros Genes em células de inseto (sf9) para o ensaio funcional da proteína

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

Controlável Expressão Ion Canal através de transfecção transiente Induzível

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

Genética

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 Ensaio de bioluminescência para caracterizar o ritmo circadiano em células epiteliais mamárias

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

Determinação da localização cromossômica ideal para um elemento de DNA em Escherichia coli usando uma nova abordagem mediada por Transposon

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

Manutenção de culturas biológicas e medição de expressão gênica em Aphis nerii: um sistema Non-modelo de interações inseto-planta

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

Proteína endógena de marcação em humanos induzida por células-tronco pluripotentes usando 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

Reverter a transcrição Loop-mediada por amplificação isotérmica (RT-lâmpada) ensaio para vírus Zika e Housekeeping Genes em amostras de Mosquito, soro e urina

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

Identificação de eventos de recombinação homóloga em células-tronco embrionárias de camundongo usando Southern Blotting e reação em cadeia da polimerase

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

Determinação da taxa de fertilização do ovo de Bemisia tabaci usando uma técnica citogenética

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

Um ensaio para quantificar a ligação de RNA de proteína em bactérias

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

Protocolo in vitro para avaliação de níveis de MicroRNA, funções e genes alvo associados em células tumorais

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