ホワイトヘッド研究所フェローファンド

パート1：aRNAの標識：色素のアミノアリルカップリング<ol><li> 1.5ml微量遠心チューブにaRNAのサンプルの1μgのを追加。 </li><li>彼らは完全に乾燥されるまで低いかゼロの熱で試料をドライ真空。とすぐに乾燥しているとして、各チューブにフタを- 乾燥し過ぎたしないでください！ </li><li>各チューブに9μlカップリング緩衝液を加え、穏やかに1分間ボルテックスでaRNAを再懸濁します。チューブの底にサンプルを収集するために手短に遠心し、サンプルが氷の上に座ってみましょう。 </li><li> Cy3またはCy5色素の各チューブに22μlの高品質のDMSOを追加。染料の一管は十分な2サンプル用です。 Cy3標識色素は、参照試料を標識するためです、とCy5色素は、テストサンプルを標識するためです。 </li><li>渦染料が完全に混合する。使用する準備ができるまで暗闇の中で染料を保管してください。使用する前に、前の1時間より染料を用意しないでください。水がどの時点でも染料/ DMSO混合で取得しないことを確認します。 </li><li>各サンプルに準備DMSO / Cyの染料の11μlを追加。穏やかにボルテックスでよく混ぜる。 </li><li>室温で30〜45分インキュベートする。アルミホイルで試料を覆ったり、光への曝露を最小限に抑えるために引き出しに保管してください。 </li><li>インキュベーション後、反応をクエンチするために各サンプルに4.5μlhydroxlyamineを追加。穏やかにボルテックスでよく混ぜる。 </li><li>室温でさらに15分間インキュベートする。アルミホイルで試料を覆ったり、光への曝露を最小限に抑えるために引き出しに保管してください。 </li></ol>パート2：aRNAのクリーンアップ標識<ol><li>簡単に渦RNA結合ビーズを使用前であっても混合物を得ること。 </li><li>室温でaRNAの結合ミックスを準備します。（表1） </li><li>ボルテックスでよく混ぜる。 </li><li>少なくとも10分間50〜60℃で1.5mlチューブとインキュベートにaRNAの溶出バッファーをAliquote。 </li><li>各サンプルにaRNAの結合ミックスの70μlを追加し、3,4回上下にピペッティングしてよく混ぜる。 </li><li> PCRプレートから96ウェル丸底プレートにサンプルを移す。 </li><li>各サンプルに100％イソプロパノール50μlのを追加し、3,4回上下にピペッティングしてよく混ぜる。 </li><li>やさしく徹底的にサンプルを混ぜるために、少なくとも2分間オービタルシェーカー上でプレートを振る。 </li><li>磁気ビーズを捕捉する磁気スタンドにプレートを移動します。混合物が透明になり、結合ビーズをペレット化されるまで、スタンドにプレートを残す。 </li><li>慎重に磁気ビーズを乱すことなく真空アスピレーターで上清を吸引除去する。また、注意深くピペットで上清を除去し、上清を捨てる。上清は、明るいピンク色または非法人の色素分子のためにこの時点では明るい青のいずれかでなければなりません。 </li><li>磁気スタンドからプレートを取り外します。 </li><li>各ウェルに100μlのaRNAの洗浄液を追加し、適度なスピードでオービタルシェーカー上で1分間プレートを振る。ビーズは、完全にこの段階では分散されないことがあります。 </li><li>磁気ビーズを捕捉する磁気スタンドにプレートを移動します。 </li><li>慎重に磁気ビーズを乱すことなく真空アスピレーターで上清を吸引除去する。また、注意深くピペットで上清を除去し、上清を捨てる。 </li><li>磁気スタンドからプレートを取り外します。 </li><li> 100μlのaRNAの洗浄溶液で洗浄2回目のタイムを繰り返します。 </li><li>第2回洗浄した後、最高速度でオービタルシェーカー上で1分間プレートを振とうしてビーズを乾燥させる。サンプルを乾燥し過ぎたしないでください！ </li><li>各サンプルに20μlの予熱aRNAの溶出バッファーを添加することによりビーズからaRNAのを溶出する。 </li><li>精力的に3分間オービタルシェーカー上でプレートを横に振ると、磁性ビーズが十分に分散されている確認してください。されていない場合は、揺れ続ける。 </li><li>磁気ビーズが完全に分散した後、磁気ビーズを捕捉する磁気スタンドにプレートを移動します。上清は、クリーンアップ、ラベルされたaRNAのサンプルが含まれており、淡いピンクや淡いブルーのどちらかでなければなりません。 </li><li>慎重に新たなPCRプレート（またはPCRチューブ）に溶出されたaRNAを転送します。 </li><li> （オプションの手順）は、マイクロアレイのモジュールを使用して光度計分光光度計に1.5μlずつを測定することにより、サンプル中のRNAの濃度と色素の量を確認してください。 </li><li>あなたがハイブリダイゼーションのための準備が整うまではすぐに代わりにお好みのマイクロアレイプラットフォームにラベル付けaRNAをハイブリダイズする、または、あなたは、-80 ° Cで標識したaRNAを保存することができます。 </li></ol>表1 aRNAをバインドミックス<table border="1"><tbody><tr><td>試薬</td><td> 1反応量</td></tr><tr><td> RNA結合ビーズ* </td><td> 10μlの</td></tr><tr><td>ビーズの再懸濁ソリューション* </td><td> 4μl </td></tr><tr><td> 100％イソプロパノール** </td><td> 6μl </td></tr><tr><td> aRNAの結合バッファー濃縮液</td><td> 50μlの</td></tr></tbody></table> *とRNA結合ビーズをミックスビーズ懸濁液第一 **イソプロパノールを追加し、aRNAの結合バッファー濃縮液を添加する前によく混ぜる。

<ol>
	<li>Rubins, K. H., Hensley, L. E., Bell, G. W., Wang, C., Lefkowitz, E. J., Brown, P. O., Relman, D. A. <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+viral+gene+expression+programs+during+poxvirus+infection:+a+transcriptional+map+of+the+vaccinia+and+monkeypox+genomes.">Comparative analysis of viral gene expression programs during poxvirus infection: a transcriptional map of the vaccinia and monkeypox genomes.</a> PLoS ONE. 3 (7), e2628-e2628 (2008).</li><li>Assarsson, E., Greenbaum, J. A., Sundstr&#246;m, M., Schaffer, L., Hammond, J. A., Pasquetto, V., Oseroff, C., Hendrickson, R. C., Lefkowitz, E. J., Tscharke, D. C., Sidney, J., Grey, H. M., Head, S. R., Peters, B., Sette, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Kinetic+analysis+of+a+complete+poxvirus+transcriptome+reveals+an+immediate-early+class+of+genes.">Kinetic analysis of a complete poxvirus transcriptome reveals an immediate-early class of genes.</a> Proc. Natl. Acad. Sci. 105 (6), 2140-2145 (2008).</li><li>Satheshkumar, P. S., Moss, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Poxvirus+transcriptome+analysis.">Poxvirus transcriptome analysis.</a> Proc. Natl. Acad. Sci. U.S.A. 105, E62-E62 (2008).</li><li>Assarsson, E., Greenbaum, J. A., Sundstr&#246;m, M., Schaffer, L., Hammond, J. A., Pasquetto, V., Oseroff, C., Hendrickson, R. C., Lefkowitz, E. J., Tscharke, D. C., Sidney, J., Grey, H. M., Head, S. R., Peters, B., Sette, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A.+Reply+to+Satheshkumar+and+Moss:+Poxvirus+transcriptome+analysis.">A. Reply to Satheshkumar and Moss: Poxvirus transcriptome analysis.</a> Proc. Natl. Acad. Sci. U.S.A. 105, E63-E64 (2008).</li><li>Guerra, S., L&#243;pez-Fern&#225;ndez, L. A., Pascual-Montano, A., Mu&#241;oz, M., Harshman, K., Esteban, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cellular+gene+expression+survey+of+vaccinia+virus+infection+of+human+HeLa+cells.">Cellular gene expression survey of vaccinia virus infection of human HeLa cells.</a> J Virol. 77 (11), 6493-6506 (2003).</li><li>Guerra, S., L&#243;pez-Fern&#225;ndez, L. A., Conde, R., Pascual-Montano, A., Harshman, K., Esteban, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microarray+analysis+reveals+characteristic+changes+of+host+cell+gene+expression+in+response+to+attenuated+modified+vaccinia+virus+Ankara+infection+of+human+HeLa+cells.">Microarray analysis reveals characteristic changes of host cell gene expression in response to attenuated modified vaccinia virus Ankara infection of human HeLa cells.</a> J Virol. 78 (11), 5820-5824 (2004).</li><li>Guerra, S., L&#243;pez-Fern&#225;ndez, L. A., Pascual-Montano, A., N&#225;jera, J. L., Zaballos, A., Esteban, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Host+response+to+the+attenuated+poxvirus+vector+NYVAC:+upregulation+of+apoptotic+genes+and+NF-kappaB-responsive+genes+in+infected+HeLa+cells.">Host response to the attenuated poxvirus vector NYVAC: upregulation of apoptotic genes and NF-kappaB-responsive genes in infected HeLa cells.</a> J Virol. 80 (2), 985-998 (2006).</li><li>Guerra, S., N&#225;jera, J. L., Gonz&#225;lez, J. M., L&#243;pez-Fern&#225;ndez, L. A., Climent, N., Gatell, J. M., Gallart, T., Esteban, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Distinct+gene+expression+profiling+after+infection+of+immature+human+monocyte-derived+dendritic+cells+by+the+attenuated+poxvirus+vectors+MVA+and+NYVAC.">Distinct gene expression profiling after infection of immature human monocyte-derived dendritic cells by the attenuated poxvirus vectors MVA and NYVAC.</a> 81 (16), 8707-8721 (2007).</li></ol>

The authors have nothing to disclose.

重要なステップアミノアリルカップリングを実行するとき、それはカップリングの前にすぐにDMSO（1時間未満）で色素を再懸濁し、それが染料でアクティブグループと反応するので、水が、染料/ DMSO混合に入ったことを確認するため、重要です。 RNAを（1 - 2uLではなく、完全に乾燥するまで乾燥することができます）乾燥し過ぎた、そしてカップリングバッファにうまく懸?...

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">	
		
		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>CyDye Post-Labeling Reactive Dye Pack</td>
<td>Reagent</td>
<td>GE Healthcare</td>
<td>RPN5661</td>
<td>Contains both Cy3 and Cy5 dyes</td>
</tr>
<tr>
<td>NanoDrop ND-1000 UV-VIS spectrophotometer</td>
<td>Other</td>
<td>NanoDrop</td>
<td>ND-1000</td>
<td>Or equivalent spectrophotometer</td>
</tr>		</tbody>
		</table>
		</div>

vaccinia virus infection &amp; temporal analysis of virus gene expression: part 3

家族の<em&gt;ポックスウイルス科</em&gt;感染細胞の細胞質中に独占的に複製するウイルスを含む大規模な二重鎖DNAで構成されています。のメンバー<em&gt;オルトポックス</em&gt;属インクルード天然痘、人間の天然痘、サル痘、およびワクシニア（VAC）の原因物質、ウイルスの家族の原型の一員。比較的大きな（〜200 KB）ワクシニアゲノムの中で、遺伝子の3つのクラスは、エンコードされています：初期、中間、および遅い。すべての3つのクラスがウイルスによりコードされたRNAポリメラーゼによって転写されていますが、各クラスには、ウイルスのライフサイクルの異なる機能を果たします。ポックスウイルスは感染時に宿主細胞環境の変調のための複数の戦略を利用する。両方のホストとウイルスの遺伝子発現の調節を理解するために、我々は、ウイルスと宿主細胞の両方から転写産物量を分析するためにゲノムワイドなアプローチを利用してきた。ここで、我々は、いくつかの時点感染後におけるワクシニアウイルスとサンプリングのRNAとHeLa細胞の経時的感染を示す。両方のホストとウイルスの全RNAを単離し、遺伝子発現の解析用マイクロアレイへのハイブリダイゼーションのために増幅されます。

Watch this Scientific Journal Video about Vaccinia Virus Infection & Temporal Analysis of Virus Gene Expression: Part 3 at JoVE.com

Vaccinia Virus Infection &amp; Temporal Analysis of Virus Gene Expression: Part 3

HeLa細胞と宿主とウイルスの遺伝子発現の解析のワクシニア感染のためのプロトコル。パート3は、蛍光色素のアミノアリルカップリングにより、両方のホストとウイルスのサンプルから増幅されたRNAを標識するプロセスを説明します。 3のパート3。

ワクシニアウイルス感染とウイルスの遺伝子発現の時間的解析：その3

The family Poxviridae consists of large double-stranded DNA containing viruses that replicate exclusively in the cytoplasm of infected cells.  Members of ...

vaccinia-virus-infection-temporal-analysis-virus-gene-expression-part

Research

JoVE Journal

Biology

8.1K ビュー.  MIT - Massachusetts Institute of Technology. HeLa細胞と宿主とウイルスの遺伝子発現の解析のワクシニア感染のためのプロトコル。パート3は、蛍光色素のアミノアリルカップリングにより、両方のホストとウイルスのサンプルから増幅されたRNAを標識するプロセスを説明します。 3のパート3。

ビデオ: Vaccinia Virus Infection & Temporal Analysis of Virus Gene Expression: Part 3

Bacterial Gene Expression Analysis Using Microarrays

マイクロアレイを用いた細菌の遺伝子発現解析

生物学

The Preparation of Primary Hematopoietic Cell Cultures From Murine Bone Marrow for Electroporation

It is becoming increasingly apparent that electroporation is the most effective way to introduce plasmid DNA or siRNA into primary cells. The Gene Pulser MXcell  electroporation system and Gene Pulser  electroporation buffer were specifically developed to transfect nucleic acids into mammalian cells and difficult-to-transfect cells, such as primary and stem cells.This video demonstrates how to establish primary hematopoietic cell cultures from murine bone marrow, and then prepare them for electroporation in the MXcell system. We begin by isolating femur and tibia. Bone marrow from both femur and tibia are then harvested and cultures are established. Cultured bone marrow cells are then transfected and analyzed.

This procedure describes how to establish primary hematopoietic cell cultures from murine bone marrow and is followed by transfection using the Gene Pulser MXCell electroporation system.

エレクトロポレーションのためのマウス骨髄からの一次造血細胞培養の準備

It is becoming increasingly apparent that electroporation is the most effective way to introduce plasmid DNA or siRNA into primary cells. The Gene Pulser ...

Vaccinia Virus Infection &amp; Temporal Analysis of Virus Gene Expression: Part 1

The family Poxviridae consists of large double-stranded DNA containing viruses that replicate exclusively in the cytoplasm of infected cells. Members of the orthopox genus include variola, the causative agent of human small pox, monkeypox, and vaccinia (VAC), the prototypic member of the virus family. Within the relatively large (~ 200 kb) vaccinia genome, three classes of genes are encoded: early, intermediate, and late. While all three classes are transcribed by virally-encoded RNA polymerases, each class serves a different function in the life cycle of the virus. Poxviruses utilize multiple strategies for modulation of the host cellular environment during infection. In order to understand regulation of both host and virus gene expression, we have utilized genome-wide approaches to analyze transcript abundance from both virus and host cells. Here, we demonstrate time course infections of HeLa cells with Vaccinia virus and sampling RNA at several time points post-infection. Both host and viral total RNA is isolated and amplified for hybridization to microarrays for analysis of gene expression.

Protocol for Vaccinia infection of HeLa cells and analysis of host and viral gene expression. Part 1 of 3.

ワクシニアウイルス感染とウイルスの遺伝子発現の時間的解析：その1

Vaccinia Virus Infection &amp; Temporal Analysis of Virus Gene Expression: Part 2

The family Poxviridae consists of large double-stranded DNA containing viruses that replicate exclusively in the cytoplasm of infected cells. Members of the orthopox genus include variola, the causative agent of human small pox, monkeypox, and vaccinia (VAC), the prototypic member of the virus family. Within the relatively large (~ 200 kb) vaccinia genome, three classes of genes are encoded: early, intermediate, and late. While all three classes are transcribed by virally-encoded RNA polymerases, each class serves a different function in the life cycle of the virus. Poxviruses utilize multiple strategies for modulation of the host cellular environment during infection. In order to understand regulation of both host and virus gene expression, we have utilized genome-wide approaches to analyze transcript abundance from both virus and host cells. Here, we demonstrate time course infections of HeLa cells with Vaccinia virus and sampling RNA at several time points post-infection. Both host and viral total RNA is isolated and amplified for hybridization to microarrays for analysis of gene expression.

Protocol for Vaccinia infection of HeLa cells and analysis of host and viral gene expression. Part 2 of 3.

ワクシニアウイルス感染とウイルスの遺伝子発現の時間的解析：その2

Virus-induced Gene Silencing (VIGS) in Nicotiana benthamiana and Tomato

RNA interference (RNAi) is a highly specific gene-silencing phenomenon triggered by dsRNA1. This silencing mechanism uses two major classes of RNA regulators: microRNAs, which are produced from non-protein coding genes and short interfering RNAs (siRNAs). Plants use RNAi to control transposons and to exert tight control over developmental processes such as flower organ formation and leaf development2,3,4. Plants also use RNAi to defend themselves against infection by viruses. Consequently, many viruses have evolved suppressors of gene silencing to allow their successful colonization of their host5.
Virus-induced gene silencing (VIGS) is a method that takes advantage of the plant RNAi-mediated antiviral defense mechanism. In plants infected with unmodified viruses the mechanism is specifically targeted against the viral genome. However, with virus vectors carrying sequences derived from host genes, the process can be additionally targeted against the corresponding host mRNAs. VIGS has been adapted for high-throughput functional genomics in plants by using the plant pathogen Agrobacterium tumefaciens to deliver, via its Ti plasmid, a recombinant virus carrying the entire or part of the gene sequence targeted for silencing. Systemic virus spread and the endogenous plant RNAi machinery take care of the rest. dsRNAs corresponding to the target gene are produced and then cleaved by the ribonuclease Dicer into siRNAs of 21 to 24 nucleotides in length. These siRNAs ultimately guide the RNA-induced silencing complex (RISC) to degrade the target transcript2.
Different vectors have been employed in VIGS and one of the most frequently used is based on tobacco rattle virus (TRV). TRV is a bipartite virus and, as such, two different A. tumefaciens strains are used for VIGS. One carries pTRV1, which encodes the replication and movement viral functions while the other, pTRV2, harbors the coat protein and the sequence used for VIGS6,7. Inoculation of Nicotiana benthamiana and tomato seedlings with a mixture of both strains results in gene silencing. Silencing of the endogenous phytoene desaturase (PDS) gene, which causes photobleaching, is used as a control for VIGS efficiency. It should be noted, however, that silencing in tomato is usually less efficient than in N. benthamiana. RNA transcript abundance of the gene of interest should always be measured to ensure that the target gene has efficiently been down-regulated. Nevertheless, heterologous gene sequences from N. benthamiana can be used to silence their respective orthologs in tomato and vice versa8.

Virus-induced Gene Silencing VIGS in Nicotiana benthamiana and Tomato

Description of a virus-induced gene silencing (VIGS) method for knock-down of gene expression in Nicotiana benthamiana and tomato.

ウイルス誘導ジーンサイレンシング（VIGS）でタバコbenthamianaとトマト

RNA interference (RNAi) is a highly specific gene-silencing phenomenon triggered by dsRNA1. This silencing mechanism uses two major classes of RNA ...

Using the Gene Pulser MXcell Electroporation System to Transfect Primary Cells with High Efficiency

It is becoming increasingly apparent that electroporation is the most effective way to introduce plasmid DNA or siRNA into primary cells. The Gene Pulser MXcell electroporation system and Gene Pulser electroporation buffer (Bio-Rad) were specifically developed to easily transfect nucleic acids into mammalian cells and difficult-to-transfect cells, such as primary and stem cells. We will demonstrate how to perform a simple experiment to quickly identify the best electroporation conditions. We will demonstrate how to run several samples through a range of electroporation conditions so that an experiment can be conducted at the same time as optimization is performed. We will also show how optimal conditions identified using 96-well electroporation plates can be used with standard electroporation cuvettes, facilitating the switch from electroporation plates to electroporation cuvettes while maintaining the same electroporation efficiency. In the video, we will also discuss some of the key factors that can lead to the success or failure of electroporation experiments.

This procedure shows how to use the Gene Pulser MXcell electroporation system to rapidly and easily identify the best electroporation conditions for mouse embryonic fibroblasts (MEFs) or other primary cells. Considerations for troubleshooting are also discussed in the associated video.

高効率で初代培養細胞をトランスフェクトするためにジーンパルサーMXcellのエレクトロポレーションシステムの使用

Using an Automated Cell Counter to Simplify Gene Expression Studies: siRNA Knockdown of IL-4 Dependent Gene Expression in Namalwa Cells

The use of siRNA mediated gene knockdown is continuing to be an important tool in studies of gene expression.  siRNA studies are being conducted not only to study the effects of downregulating single genes, but also to interrogate signaling pathways and other complex interaction networks.  These pathway analyses require both the use of relevant cellular models and methods that cause less perturbation to the cellular physiology.  Electroporation is increasingly being used as an effective way to introduce siRNA and other nucleic acids into difficult to transfect cell lines and primary cells without altering the signaling pathway under investigation. There are multiple critical steps to a successful siRNA experiment, and there are ways to simplify the work while improving the data quality at several experimental stages.  To help you get started with your siRNA mediated gene knockdown project, we will demonstrate how to perform a pathway study complete from collecting and counting the cells prior to electroporation through post transfection real-time PCR gene expression analysis.  The following study investigates the role of the transcriptional activator STAT6 in IL-4 dependent gene expression of CCL17 in a Burkitt lymphoma cell line (Namalwa).  The techniques demonstrated are useful for a wide range of siRNA-based experiments on both adherent and suspension cells.  We will also show how to streamline cell counting with the TC10 automated cell counter, how to electroporate multiple samples simultaneously using the MXcell electroporation system, and how to simultaneously assess RNA quality and quantity with the Experion automated electrophoresis system.

This procedure describes a quick and easy workflow to introduce siRNA into difficult to transfect cell lines and follow gene expression by real-time PCR. Use of an automated cell counter, multi-well electroporation plate, and automated electrophoresis station provide quick and reliable results without the need for expensive robotic handling.

ナマルバ細胞におけるIL - 4依存性遺伝子発現のsiRNAのノックダウン：遺伝子発現研究を簡素化する自動化セルカウンターの使い方

The use of siRNA mediated gene knockdown is continuing to be an important tool in studies of gene expression.  siRNA studies are being conducted not only ...

In vitro Reconstitution of the Active T. castaneum Telomerase

Efforts to isolate the catalytic subunit of telomerase, TERT, in sufficient quantities for structural studies, have been met with limited success for more than a decade. Here, we present methods for the isolation of the recombinant Tribolium castaneum TERT (TcTERT) and the reconstitution of the active T. castaneum telomerase ribonucleoprotein (RNP) complex in vitro.
Telomerase is a specialized reverse transcriptase1 that adds short DNA repeats, called telomeres, to the 3' end of linear chromosomes2 that serve to protect them from end-to-end fusion and degradation. Following DNA replication, a short segment is lost at the end of the chromosome3 and without telomerase, cells continue dividing until eventually reaching their Hayflick Limit4. Additionally, telomerase is dormant in most somatic cells5 in adults, but is active in cancer cells6 where it promotes cell immortality7.
The minimal telomerase enzyme consists of two core components: the protein subunit (TERT), which comprises the catalytic subunit of the enzyme and an integral RNA component (TER), which contains the template TERT uses to synthesize telomeres8,9. Prior to 2008, only structures for individual telomerase domains had been solved10,11. A major breakthrough in this field came from the determination of the crystal structure of the active12, catalytic subunit of T. castaneum telomerase, TcTERT1.
Here, we present methods for producing large quantities of the active, soluble TcTERT for structural and biochemical studies, and the reconstitution of the telomerase RNP complex in vitro for telomerase activity assays. An overview of the experimental methods used is shown in Figure 1.

In vitro Reconstitution of the Active T. castaneum Telomerase

Efforts to isolate the catalytic subunit of telomerase, TERT, in sufficient quantities for structural studies, have been met with limited success for more than a decade. Here, we present methods for the isolation of the recombinant Tribolium castaneum TERT (TcTERT) and the reconstitution of the active T. castaneum telomerase ribonucleoprotein (RNP) complex in vitro.

アクティブT.の試験管内再構成でcastaneumのテロメラーゼ

Efforts to isolate the catalytic subunit of telomerase, TERT, in sufficient quantities for structural studies, have been met with limited success for more ...

Agrobacterium-Mediated Virus-Induced Gene Silencing Assay In Cotton

Cotton (Gossypium hirsutum) is one of the most important crops worldwide. Considerable efforts have been made on molecular breeding of new varieties. The large-scale gene functional analysis in cotton has been lagged behind most of the modern plant species, likely due to its large size of genome, gene duplication and polyploidy, long growth cycle and recalcitrance to genetic transformation1. To facilitate high throughput functional genetic/genomic study in cotton, we attempt to develop rapid and efficient transient assays to assess cotton gene functions.
Virus-Induced Gene Silencing (VIGS) is a powerful technique that was developed based on the host Post-Transcriptional Gene Silencing (PTGS) to repress viral proliferation2,3. Agrobacterium-mediated VIGS has been successfully applied in a wide range of dicots species such as Solanaceae, Arabidopsis and legume species, and monocots species including barley, wheat and maize, for various functional genomic studies3,4. As this rapid and efficient approach avoids plant transformation and overcomes functional redundancy, it is particularly attractive and suitable for functional genomic study in crop species like cotton not amenable for transformation.
In this study, we report the detailed protocol of Agrobacterium-mediated VIGS system in cotton. Among the several viral VIGS vectors, the tobacco rattle virus (TRV) invades a wide range of hosts and is able to spread vigorously throughout the entire plant yet produce mild symptoms on the hosts5. To monitor the silencing efficiency, GrCLA1, a homolog gene of Arabidopsis Cloroplastos alterados 1 gene (AtCLA1) in cotton, has been cloned and inserted into the VIGS binary vector pYL156. CLA1 gene is involved in chloroplast development6, and previous studies have shown that loss-of-function of AtCLA1 resulted in an albino phenotype on true leaves7, providing an excellent visual marker for silencing efficiency. At approximately two weeks post Agrobacterium infiltration, the albino phenotype started to appear on the true leaves, with 100% silencing efficiency in all replicated experiments. The silencing of endogenous gene expression was also confirmed by RT-PCR analysis. Significantly, silencing could potently occur in all the cultivars we tested, including various commercially grown varieties in Texas. This rapid and efficient Agrobacterium-mediated VIGS assay provides a very powerful tool for rapid large-scale analysis of gene functions at genome-wide level in cotton.

We present the detailed protocol for Agrobacterium-mediated virus-induced gene silencing (VIGS) assay in cotton. The tobacco rattle virus (TRV)-derived VIGS vectors were deployed to induce RNA silencing of cotton GrCLA1, Cloroplastos alterados 1 gene. The albino phenotype caused by silencing GrCLA1 was observed at the seedling stage within 2 weeks after inoculation.

コットンでアグロバクテリウムを介したウイルス誘発遺伝子サイレンシングアッセイ

Cotton (Gossypium hirsutum) is one of the most important crops worldwide. Considerable efforts have been made on molecular breeding of new varieties.  The ...

The MultiBac Protein Complex Production Platform at the EMBL

Proteomics research revealed the impressive complexity of eukaryotic proteomes in unprecedented detail. It is now a commonly accepted notion that proteins in cells mostly exist not as isolated entities but exert their biological activity in association with many other proteins, in humans ten or more, forming assembly lines in the cell for most if not all vital functions.1,2 Knowledge of the function and architecture of these multiprotein assemblies requires their provision in superior quality and sufficient quantity for detailed analysis. The paucity of many protein complexes in cells, in particular in eukaryotes, prohibits their extraction from native sources, and necessitates recombinant production. The baculovirus expression vector system (BEVS) has proven to be particularly useful for producing eukaryotic proteins, the activity of which often relies on post-translational processing that other commonly used expression systems often cannot support.3 BEVS use a recombinant baculovirus into which the gene of interest was inserted to infect insect cell cultures which in turn produce the protein of choice. MultiBac is a BEVS that has been particularly tailored for the production of eukaryotic protein complexes that contain many subunits.4 A vital prerequisite for efficient production of proteins and their complexes are robust protocols for all steps involved in an expression experiment that ideally can be implemented as standard operating procedures (SOPs) and followed also by non-specialist users with comparative ease. The MultiBac platform at the European Molecular Biology Laboratory (EMBL) uses SOPs for all steps involved in a multiprotein complex expression experiment, starting from insertion of the genes into an engineered baculoviral genome optimized for heterologous protein production properties to small-scale analysis of the protein specimens produced.5-8 The platform is installed in an open-access mode at EMBL Grenoble and has supported many scientists from academia and industry to accelerate protein complex research projects.

Protein complexes catalyze key cellular functions. Detailed functional and structural characterization of many essential complexes requires recombinant production. MultiBac is a baculovirus/insect cell system particularly tailored for expressing eukaryotic proteins and their complexes. MultiBac was implemented as an open-access platform, and standard operating procedures developed to maximize its utility.

EMBLでMultiBacタンパク質複合体生産プラットフォーム

Proteomics  research revealed the impressive complexity of eukaryotic proteomes in  unprecedented detail. It is now a commonly accepted notion that ...