私たちは、ビデオ撮影の準備で彼女の助けと技術を実証するためのエイミー·チェンに感謝します。エニグマが行ったこの作品：遺伝子および分子集合体（http://enigma.lbl.gov）と生態系とネットワークの統合、ローレンスバークレー国立研究所の科学重点領域プログラム、科学局によってサポートされていました、生物のOfficeと契約番号DE-AC02-05CH11231下、米国エネルギー省の環境研究、。

<ol>
	<li>Galperin, M. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diversity+of+structure+and+function+of+response+regulator+output+domains.">Diversity of structure and function of response regulator output domains.</a> Curr Opin Microbiol. 13, 150-159 (2010).</li><li>Casino, P., Rubio, V., Marina, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+mechanism+of+signal+transduction+by+two-component+systems.">The mechanism of signal transduction by two-component systems.</a> Curr Opin Struct Biol. 20, 763-771 (2010).</li><li>Aparicio, O., Geisberg, J. V., Struhl, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chromatin+immunoprecipitation+for+determining+the+association+of+proteins+with+specific+genomic+sequences+in+vivo.">Chromatin immunoprecipitation for determining the association of proteins with specific genomic sequences in vivo.</a> Curr Protoc Cell Biol. 17 (17), (2004).</li><li>McCleary, W. R., Stock, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Acetyl+phosphate+and+the+activation+of+two-component+response+regulators.">Acetyl phosphate and the activation of two-component response regulators.</a> J Biol Chem. 269, 31567-31572 (1994).</li><li>Novichkov, P. S., 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=RegPrecise+web+services+interface:+programmatic+access+to+the+transcriptional+regulatory+interactions+in+bacteria+reconstructed+by+comparative+genomics.">RegPrecise web services interface: programmatic access to the transcriptional regulatory interactions in bacteria reconstructed by comparative genomics.</a> Nucleic Acids Res. 40, 604-608 (2012).</li><li>Studholme, D. J., Buck, M., Nixon, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+potential+sigma(N)-dependent+promoters+in+bacterial+genomes.">Identification of potential sigma(N)-dependent promoters in bacterial genomes.</a> Microbiology. 146 (12), 3021-3023 (2000).</li><li>Rajeev, L., 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=Systematic+mapping+of+two+component+response+regulators+to+gene+targets+in+a+model+sulfate+reducing+bacterium.">Systematic mapping of two component response regulators to gene targets in a model sulfate reducing bacterium.</a> Genome Biol. 12, 99 (2011).</li><li>Crooks, G. E., Hon, G., Chandonia, J. M., Brenner, S. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=WebLogo:+a+sequence+logo+generator.">WebLogo: a sequence logo generator.</a> Genome Res. 14, 1188-1190 (2004).</li><li>Barbieri, C. M., Mack, T. R., Robinson, V. L., Miller, M. T., Stock, A. M. <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+response+regulator+autophosphorylation+through+interdomain+contacts.">Regulation of response regulator autophosphorylation through interdomain contacts.</a> J Biol Chem. 285, 32325-32335 (2010).</li><li>Bourret, R. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Receiver+domain+structure+and+function+in+response+regulator+proteins.">Receiver domain structure and function in response regulator proteins.</a> Curr Opin Microbiol. 13, 142-149 (2010).</li><li>Gao, R., Stock, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+strategies+for+phosphorylation-mediated+regulation+of+response+regulator+activity.">Molecular strategies for phosphorylation-mediated regulation of response regulator activity.</a> Curr Opin Microbiol. 13, 160-167 (2010).</li><li>Hung, D. C., 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=Oligomerization+of+the+response+regulator+ComE+from+Streptococcus+mutans+is+affected+by+phosphorylation.">Oligomerization of the response regulator ComE from Streptococcus mutans is affected by phosphorylation.</a> J Bacteriol. 194, 1127-1135 (2012).</li><li>Ladds, J. C., 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=The+response+regulator+Spo0A+from+Bacillus+subtilis+is+efficiently+phosphorylated+in+Escherichia+coli.">The response regulator Spo0A from Bacillus subtilis is efficiently phosphorylated in Escherichia coli.</a> FEMS Microbiol Lett. 223, 153-157 (2003).</li><li>Wen, Y., Feng, J., Scott, D. R., Marcus, E. A., Sachs, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Involvement+of+the+HP0165-HP0166+two-component+system+in+expression+of+some+acidic-pH-upregulated+genes+of+Helicobacter+pylori.">Involvement of the HP0165-HP0166 two-component system in expression of some acidic-pH-upregulated genes of Helicobacter pylori.</a> J Bacteriol. 188, 1750-1761 (2006).</li><li>Liu, X., Noll, D. M., Lieb, J. D., Clarke, N. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=DIP-chip:+rapid+and+accurate+determination+of+DNA-binding+specificity.">DIP-chip: rapid and accurate determination of DNA-binding specificity.</a> Genome Res. 15, 421-427 (2005).</li><li>Gossett, A. J., Lieb, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=DNA+Immunoprecipitation+(DIP)+for+the+Determination+of+DNA-Binding+Specificity.">DNA Immunoprecipitation (DIP) for the Determination of DNA-Binding Specificity.</a> CSH Protoc. 2008, (2008).</li><li>Mascher, T., 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=The+Streptococcus+pneumoniae+cia+regulon:+CiaR+target+sites+and+transcription+profile+analysis.">The Streptococcus pneumoniae cia regulon: CiaR target sites and transcription profile analysis.</a> J Bacteriol. 185, 60-70 (2003).</li><li>Park, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=ChIP-seq:+advantages+and+challenges+of+a+maturing+technology.">ChIP-seq: advantages and challenges of a maturing technology.</a> Nat Rev Genet. 10, 669-680 (2009).</li><li>Lefrancois, P., Zheng, W., Snyder, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=ChIP-Seq+using+high-throughput+DNA+sequencing+for+genome-wide+identification+of+transcription+factor+binding+sites.">ChIP-Seq using high-throughput DNA sequencing for genome-wide identification of transcription factor binding sites.</a> Methods Enzymol. 470, 77-104 (2010).</li><li>Ho, J. W., 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=ChIP-chip+versus+ChIP-seq:+lessons+for+experimental+design+and+data+analysis.">ChIP-chip versus ChIP-seq: lessons for experimental design and data analysis.</a> BMC Genomics. 12, 134 (2011).</li><li>Liu, X., Lee, C. K., Granek, J. A., Clarke, N. D., Lieb, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Whole-genome+comparison+of+Leu3+binding+in+vitro+and+in+vivo+reveals+the+importance+of+nucleosome+occupancy+in+target+site+selection.">Whole-genome comparison of Leu3 binding in vitro and in vivo reveals the importance of nucleosome occupancy in target site selection.</a> Genome Res. 16, 1517-1528 (2006).</li></ol>

著者らは、開示することは、特別の利害関係はありません。

ここで説明DAPチップ方式が正常つが代表的結果として示されているのビブリオ尋常 Hildenborough 7におけるいくつかのRRのための遺伝子標的を決定するために使用された。 RR DVU3023、候補遺伝子ターゲットを選択することは簡単でした。 DVU3025は、RR遺伝子のすぐ下流に位置し、RRおよび標的遺伝子は、いくつかのビブリオ種において保存され、さらに、予測DVU3025 sigma54依存性...

生存し繁殖する細菌の能力は、それらが知覚とその環境における摂動に応答することができるどの程度に決定的に依存し、これは順番に、それらのシグナル伝達系に依存する。信号システム細菌エンコードの数は、その「微生物のIQ」と呼ばれているとその環境の変動と複数の信号を感知する能力を微調整その応答1の両方を示している可能性があり。二成分シグナル伝達系（TCS）細菌によって使用される最も普及しているシグナル伝達系であり、それらは外部信号を感知し、エフェクターレスポンスレギュレーター（RR）2リン酸化を介して送信するヒスチジンキナーゼ（HK）からなる。 RRは、出力領域の様々なため、異なるエフェクターのモードを持つことができますが、最も一般的な応答は、ドメイン1のDNA 結合を介した転写調節です。信号が感知され、VASの対応する機能のTCSsのT大半は不明のままである。 このようなChIPチップ等のインビボ方法は、日常的に、転写のゲノム結合部位の決定のために使用されているが3因子活性化状態または信号が既知である場合、それらは、細菌の二成分系資源レコードのために使用することができる。多くの場合、TCSをアクティブに環境手がかりは、その遺伝子標的よりも決定することが困難です。ここに記載したインビトロマイクロアレイに基づくアッセイは、効果的かつ迅速に遺伝子標的を決定し、のTCSsの機能を予測するために使用することができる。このアッセイは、RRがリン酸化され、従って、アセチルリン酸4などの小分子供与体を用いてインビトロで活性化することができるという事実を利用する。 この方法では、DNA-親和性精製チップ（ 図1）DAP-チップという、目的のRR遺伝子はE.でHisタグにクローニングする大腸菌 、そして続いて精製タグを付けたタンパク質を双方向に許可されているNDゲノムDNAをせん断した。タンパク質に結合したDNAは、その後、アフィニティー精製、濃縮し、入力DNAによって濃縮されて増幅され、蛍光標識されたが、一緒にプールし、カスタム目的の生物（ 図1）に対して行われるタイリングアレイにハイブリダイズ。マイクロアレイ実験は、アーチファクトを受けやすく、したがって、追加のステップは、アッセイを最適化するのに用いられる。一つのそのような工程は、（ 図2のワークフローを参照）を電気泳動移動度シフトアッセイ（EMSA）を用いて、研究中のRR毎にターゲットを決定しようとすることである。その後、ゲノムDNAおよびDAPステップに結合した後、タンパク質結合及び投入DNAは、このように最適な結合条件を確認し、正のターゲットは入力割合と比較して、タンパク質に結合した画分に濃縮されているかどうかを確認するために定量PCRによって調べられるRR（ 図2）。アレイハイブリダイゼーションの後、データは、ゲノム遺伝子座タンパク質hを示す高強度信号のピークを見つけるために分析される広告が結合した。関数が得られた遺伝子標的に基づいて、RRのために予測することができる。標的ゲノム遺伝子座を、次いで、実験的にEMSAを（ 図2）を用いて検証される結合部位モチーフを予測するために使用される。 RRのための機能的予測および遺伝子標的は、次いで密接に（ 図2）と類似の結合モチーフをそれらのゲノムをスキャンすることによってオーソロガスRRをコードする種が関連するように拡張することができる。 DAPチップ方式は、以前に何もありませんでしたTCSのための豊富な情報を提供することができます。この方法はまた、タンパク質を精製することができ、DNA結合条件を決定することができる場合、任意の転写調節のために使用され、ゲノム配列を有する関心対象の任意の生物に利用可能することができる。 <img alt="図1" fo:content-width="5in" src="/files/ftp_upload/51715/51715fig1highres.jpg" width="500" /> 図1。のDNAアフィニティー精製したチップ（DAP-チップ）戦略7。目的の生物からのRR遺伝子を大腸菌にカルボキシ末端Hisタグでクローン化される大腸菌発現株。精製されたHisタグ付きタンパク質は、アセチルリン酸とリン酸化により活性化され、剪断されたゲノムDNAと混合する。残りは、Ni-NTA樹脂を用いてアフィニティー精製を行っている間の結合反応のアリコートを、入力DNAとして保存される。入力およびRR-結合したDNAは、増幅全ゲノムであり、それぞれCy3およびCy5で標識。標識されたDNAを一緒にプールし、次いで、遺伝子標的を決定するために分析されたタイリングアレイにハイブリダイズされる。図は、修正され、7からクリエイティブコモンズライセンスを使用して復刻。 <img alt="図2" fo:content-width="5in" src="/files/ftp_upload/51715/51715fig2highres.jpg" width="500" /> 図2。ワークフローの概要。任意の精製されたタグが付いprotei用nは、EMSAを使用してターゲットを決定することから始めます。許可したゲノムDNAを結合して、DNA-アフィニティ精製するタンパク質（DAP）、全ゲノム（WGA）濃縮し、入力DNAを増幅する。遺伝子標的が既知である場合、公知の標的は、タンパク質結合画分中に濃縮されることを確実にするために定量PCRを使用する。標的が決定できなかった場合には、DNAの標識およびアレイハイブリダイゼーションに直接進む。定量PCRによる濃縮が観察されなかった場合には、結合タンパク質のgDNAと異なるタンパク質の量を使用してDAP-WGAステップを繰り返す。ピークを見つけ、遺伝子をターゲットにマップするために、配列解析を使用してください。結合部位モチーフを予測するために、標的遺伝子の上流領域を使用してください。 EMSAをを使用して実験的にモチーフを検証します。研究中のRRのオルソログをコードする近縁種のゲノムをスキャンし、同様にそれらの種で標的遺伝子を予測するモチーフを使用してください。得られた遺伝子標的に基づいて、RRおよびそのオーソログの生理学的機能を予測することができる。図は、創造的なCを使用して修正して復刻ommonsは7からライセンス。

<table><tbody><tr><td>HisTrapFF column (Ni-Sepharose column)</td><td>GE Lfe Sciences, Pittsburgh, PA, USA</td><td>17-5255-01</td><td></td></tr><tr><td>Akta explorer (FPLC instrument)</td><td>GE Lfe Sciences, Pittsburgh, PA, USA</td><td></td><td></td></tr><tr><td>HiPrep 26/10 Desalting column</td><td>GE Lfe Sciences, Pittsburgh, PA, USA</td><td>17-5087-01</td><td></td></tr><tr><td>Qiaquick Gel extraction kit</td><td>Qiagen Inc, Valencia, CA, USA</td><td>28704</td><td></td></tr><tr><td>Biotin-labeled oligonucleotides</td><td>Integrated DNA Technologies</td><td>N/A</td><td></td></tr><tr><td>6% polyacrylamide-0.5x TBE precast mini DNA retardation gel</td><td>Life Technologies, Grand Island, NY, USA</td><td>EC63652BOX</td><td>Alternately, you can pour your own gel.</td></tr><tr><td>Nylon membrane</td><td>EMD Millipore, Billerica, MA, USA</td><td>INYC00010</td><td></td></tr><tr><td>Trans-Blot SD Semi-dry electrophoretic transfer cell</td><td>Biorad, Hercules, CA, USA</td><td>170-3940</td><td></td></tr><tr><td>Extra thick blot paper, 8 x 13.5 cm</td><td>Biorad, Hercules, CA, USA</td><td>170-3967</td><td></td></tr><tr><td>UV crosslinker Model XL-1000</td><td>Fisher Scientific</td><td>11-992-89</td><td></td></tr><tr><td>Nucleic Acid chemiluminescent detection kit (Pierce)</td><td>Thermo fisher Scientific, Rockford, IL, USA</td><td>89880</td><td></td></tr><tr><td>Ni-NTA agarose resin</td><td>Qiagen Inc, Valencia, CA, USA</td><td>30210</td><td></td></tr><tr><td>GenomePlex Whole genome amplification kit (Fragmentation buffer, library preparation buffer, library stabilization solution, library preparation enzyme, 10x amplification master mix, WGA polymerase)</td><td>Sigma-Aldrich, St. Louis, MO, USA</td><td>WGA2-50RXN</td><td></td></tr><tr><td>Nanodrop ND-1000</td><td>Thermo Scientific, Wilmington, DE, USA</td><td>For quantitation of DNA</td><td></td></tr><tr><td>Perfecta Sybr Green SuperMix, with ROX</td><td>Quanta biosciences</td><td>95055-500</td><td>Any Sybr Green PCR mix may be used</td></tr><tr><td>PlateMax Ultra clear heat sealing film for qPCR</td><td>Axygen</td><td></td><td></td></tr><tr><td colspan="4">[header]</td></tr><tr><td>96-well clear low profile PCR microplate</td><td>Life Technologies, Grand Island, NY, USA</td><td>PCR-96-LP-AB-C</td><td></td></tr><tr><td>Applied Biosystems StepOne Plus Real time PCR system</td><td>Life Technologies, Grand Island, NY, USA</td><td>4376600</td><td>Any real time PCR system may be used</td></tr><tr><td>Qiaquick PCR purification kit</td><td>Qiagen Inc, Valencia, CA, USA</td><td>28104</td><td>Any PCR clean up kit may be used</td></tr><tr><td>Cy3/Cy5-labeled nonamers</td><td>Trilink biotechnologies, San Diego, CA, USA</td><td>N46-0001, N46-0002</td><td></td></tr><tr><td>Klenow polymerase 50,000 U/ml, 3&#039;-5&#039; exo&lt;sup&gt;-&lt;/sup&gt;</td><td>New England Biolabs, Ipswich, MA</td><td>M0212M</td><td></td></tr><tr><td>Hybridization system</td><td>Roche-Nimblegen, Madison, WI, USA</td><td>N/A</td><td>This company no longer makes arrays or related items, so alternate sources such as Agilent or Affymetrix will need to be used.</td></tr><tr><td>Custom printed microarrays and mixers</td><td>Roche-Nimblegen, Madison, WI, USA</td><td>N/A</td><td></td></tr><tr><td>Hybridization kit (2x Hybridization buffer, Hybridization component A, Alignment oligo)</td><td>Roche-Nimblegen, Madison, WI, USA</td><td>N/A</td><td></td></tr><tr><td>Wash buffer kit (10x Wash buffer I, II, III, 1 M DTT)</td><td>Roche-Nimblegen, Madison, WI, USA</td><td>N/A</td><td></td></tr><tr><td>GenePix 4200A microarray scanner</td><td>Molecular Devices, Sunnyvale CA, USA</td><td>This model has been replaced by superior ones</td><td></td></tr><tr><td>GenePix Pro microarray software</td><td>Molecular Devices, Sunnyvale CA, USA</td><td></td><td></td></tr><tr><td>Nimblescan v.2.4, ChIP-chip analysis software</td><td>Roche-Nimblegen, Madison, WI, USA</td><td>N/A</td><td></td></tr></tbody></table>

dna-affinity-purified chip (dap-chip) method to determine gene targets for bacterial two component regulatory systems

このようなChIPチップインビボ方法において 、転写因子のためのグローバルな遺伝子標的を決定するために使用される十分に確立された技術である。しかし、彼らは特徴づけられていない活性化条件で、細菌の2成分の規制制度を模索中使用が制限されている。このようなシステムは、ユニークな信号の存在下で活性化する場合にのみ転写を調節する。これらの信号はしばしば不明であるので、このビデオ資料に記載のインビトロマイクロアレイベースの方法は、遺伝子標的および応答調節因子の結合部位を決定するために使用することができる。このDNA-アフィニティー精製チップ法は、配列決定されたゲノムを有する任意の生物の任意の精製されたレギュレータに使用されてもよい。プロトコルは、精製されたタグが付いたタンパク質は、カスタムタイリングアレイへのDNAとハイブリダイゼーションの蛍光標識に続いて、タンパク質に結合したDNAを剪断ゲノムDNAに結合して、親和性浄化することができますが含まれます。仕するためのアッセイを最適化するために使用され得る工程の前にCレギュレータはまた、記載されている。アレイデータの分析によって生成されたピークは、次いで、実験的に検証される結合部位モチーフを予測するために使用される。モチーフの予測は、さらに密接に関連した種にオルソロガス応答調節因子の遺伝子標的を決定するために使用することができる。私たちは、遺伝子標的を決定し、サイトのモチーフを結合し、このような環境細菌デスルホビブリオ尋常 Hildenborough中sigma54依存応答レギュレータDVU3023機能を予測することにより、この方法の適用可能性を実証する。

上記の方法は、 デスルホビブリオ尋常 Hildenborough 7細菌を減らすモデル硫酸でRRの全体的な遺伝子ターゲットを特定するために適用した。この生物は、それが感知して応答することができる信号の多種多様を示し、70以上のRRで表されるのTCSsが多数ある。 インビボでは 、これらの信号システムの機能について解析し、それらの信号ので、実行するのは難しいので、それら...

Watch this Scientific Journal Video about DNA-affinity-purified Chip DAP-chip Method to Determine Gene Targets for Bacterial Two component Regulatory Systems at JoVE.com

DNA-affinity-purified Chip DAP-chip Method to Determine Gene Targets for Bacterial Two component Regulatory Systems

このビデオの記事は、遺伝子標的と2成分系の応答調節因子の結合部位を決定するためのin vitroのマイクロアレイベースの方法を説明します。

細菌のための2つの成分​​規制システムを遺伝子標的を決定するために、DNA親和性精製チップ（DAP-チップ）方法

In vivo methods such as ChIP-chip are well-established techniques used to determine global gene targets for transcription factors. However, they are of ...

dna-affinity-purified-chip-dap-chip-method-to-determine-gene-targets

Universidad de Cartagena UDEC

Research

JoVE Journal

Biology

DNA-affinity-purified Chip (DAP-chip) Method to Determine Gene Targets for Bacterial Two component Regulatory Systems

16.7K ビュー.  Lawrence Berkeley National Laboratory. このビデオの記事は、遺伝子標的と2成分系の応答調節因子の結合部位を決定するためのin vitroのマイクロアレイベースの方法を説明します。 

ビデオ: DNA-affinity-purified Chip DAP-chip Method to Determine Gene Targets for Bacterial Two component Regulatory Systems

A Chromatin Immunoprecipitation Assay to Identify Novel NFAT2 Target Genes in Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL) is characterized by the expansion of malignant B cell clones and represents the most common leukemia in western countries. The majority of CLL patients show an indolent course of the disease as well as an anergic phenotype of their leukemia cells, referring to a B cell receptor unresponsive to external stimulation. We have recently shown that the transcription factor NFAT2 is a crucial regulator of anergy in CLL. A major challenge in the analysis of the role of a transcription factor in different diseases is the identification of its specific target genes. This is of&#160;great significance for the elucidation of pathogenetic mechanisms and potential therapeutic interventions. Chromatin immunoprecipitation (ChIP) is a classic technique to demonstrate protein-DNA interactions and can, therefore, be used to identify direct target genes of transcription factors in mammalian cells. Here, ChIP was used to identify LCK as a direct target gene of NFAT2 in human CLL cells. DNA and associated proteins are crosslinked using formaldehyde and subsequently sheared by sonication into DNA fragments of approximately 200-500 base pairs (bp). Cross-linked DNA fragments associated with NFAT2 are then selectively immunoprecipitated from cell debris using an &#945;NFAT2 antibody. After purification, associated DNA fragments are detected via quantitative real-time PCR (qRT-PCR). DNA sequences with evident enrichment represent regions of the genome which are targeted by NFAT2 in vivo. Appropriate shearing of the DNA and the selection of the required antibody are particularly crucial for the successful application of this method. This protocol is ideal for the demonstration of direct interactions of NFAT2 with target genes. Its major limitation is the difficulty to employ ChIP in large-scale assays analyzing the target genes of multiple transcription factors in intact organisms.

Chronic lymphocytic leukemia (CLL) is the most common leukemia in the western world. NFAT transcription factors are important regulators of development and activation in numerous cell types. Here, we present a protocol for the use of chromatin immunoprecipitation (ChIP) in human CLL cells to identify novel target genes of NFAT2.

慢性リンパ性白血病の新規 NFAT2 ターゲット遺伝子を識別するクロマチン免疫沈降法

Chronic lymphocytic leukemia (CLL) is characterized by the expansion of malignant B cell clones and represents the most common leukemia in western ...

がん研究

A Fluorescence-based Method to Study Bacterial Gene Regulation in Infected Tissues

Bacterial virulence genes are often regulated at the transcriptional level by multiple factors that respond to different environmental signals. Some factors act directly on virulence genes; others control pathogenesis by adjusting the expression of downstream regulators or the accumulation of signals that affect regulator activity. While regulation has been studied extensively during in vitro growth, relatively little is known about how gene expression is adjusted during infection. Such information is important when a particular gene product is a candidate for therapeutic intervention. Transcriptional approaches like quantitative, real-time RT-PCR and RNA-Seq are powerful ways to examine gene expression on a global level but suffer from many technical challenges including low abundance of bacterial RNA compared to host RNA, and sample degradation by RNases. Evaluating regulation using fluorescent reporters is relatively easy and can be multiplexed with fluorescent proteins with unique spectral properties. The method allows for single-cell, spatiotemporal analysis of gene expression in tissues that exhibit complex three-dimensional architecture and physiochemical gradients that affect bacterial regulatory networks. Such information is lost when data are averaged over the bulk population. Herein, we describe a method for quantifying gene expression in bacterial pathogens in situ. The method is based on simple tissue processing and direct observation of fluorescence from reporter proteins. We demonstrate the utility of this system by examining the expression of Staphylococcus aureus thermonuclease (nuc), whose gene product is required for immune evasion and full virulence ex vivo and in vivo. We show that nuc-gfp is strongly expressed in renal abscesses and reveal heterogeneous gene expression due in part to apparent spatial regulation of nuc promoter activity in abscesses fully engaged with the immune response. The method can be applied to any bacterium with a manipulatable genetic system and any infection model, providing valuable information for preclinical studies and drug development.

Described here is a method for analyzing bacterial gene expression in animal tissues at a cellular level. This method provides a resource for studying the phenotypic diversity occurring within a bacterial population in response to the tissue environment during an infection.

感染した組織の細菌の遺伝子の規則を勉強する蛍光ベースのメソッド

Bacterial virulence genes are often regulated at the transcriptional level by multiple factors that respond to different environmental signals. Some ...

遺伝学

Stress-induced Antibiotic Susceptibility Testing on a Chip

We have developed a rapid microfluidic method for antibiotic susceptibility testing in a stress-based environment. Fluid is passed at high speeds over bacteria immobilized on the bottom of a microfluidic channel. In the presence of stress and antibiotic, susceptible strains of bacteria die rapidly. However, resistant bacteria survive these stressful conditions. The hypothesis behind this method is new: stress activation of biochemical pathways, which are targets of antibiotics, can accelerate antibiotic susceptibility testing. As compared to standard antibiotic susceptibility testing methods, the rate-limiting step -&#160;bacterial growth -&#160;is omitted during antibiotic application. The technical implementation of the method is in a combination of standard techniques and innovative approaches. The standard parts of the method include bacterial culture protocols, defining microfluidic channels in polydimethylsiloxane&#160;(PDMS), cell viability monitoring with fluorescence, and batch image processing for bacteria counting. Innovative parts of the method are in the use of culture media flow for mechanical stress application, use of enzymes to damage but not kill the bacteria, and use of microarray substrates for bacterial attachment. The developed platform can be used in antibiotic and nonantibiotic related drug development and testing. As compared to the standard bacterial suspension experiments, the effect of the drug can be turned on and off repeatedly over controlled time periods. Repetitive observation of the same bacterial population is possible over the course of the same experiment.

We have developed a microfluidic platform for rapid antibiotic susceptibility testing. Fluid is passed at high speeds over bacteria immobilized on the bottom of a microfluidic channel. In the presence of stress and antibiotic, susceptible strains of bacteria die rapidly. However, resistant bacteria can survive these stressful conditions.

チップ上でのストレス誘発抗生物質感受性試験

We have developed a rapid microfluidic method for antibiotic susceptibility testing in a stress-based environment. Fluid is passed at high speeds over ...

生物工学

An Assay for Quantifying Protein-RNA Binding in Bacteria

In the initiation step of protein translation, the ribosome binds to the initiation region of the mRNA. Translation initiation can be blocked by binding of an RNA binding protein (RBP) to the initiation region of the mRNA, which interferes with ribosome binding. In the presented method, we utilize this blocking phenomenon to quantify the binding affinity of RBPs to their cognate and non-cognate binding sites. To do this, we insert a test binding site in the initiation region of a reporter mRNA and induce the expression of the test RBP. In the case of RBP-RNA binding, we observed a sigmoidal repression of the reporter expression as a function of RBP concentration. In the case of no-affinity or very low affinity between binding site and RBP, no significant repression was observed. The method is carried out in live bacterial cells, and does not require expensive or sophisticated machinery. It is useful for quantifying and comparing between the binding affinities of different RBPs that are functional in bacteria to a set of designed binding sites. This method may be inappropriate for binding sites with high structural complexity. This is due to the possibility of repression of ribosomal initiation by complex mRNA structure in the absence of RBP, which would result in lower basal reporter gene expression, and thus less-observable reporter repression upon RBP binding.

In this method, we quantify the binding affinity of RNA binding proteins (RBPs) to cognate and non-cognate binding sites using a simple, live, reporter assay in bacterial cells. The assay is based on repression of a reporter gene.

細菌におけるタンパク質-RNA結合を定量するためのアッセイ

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

Discovering CsgD Regulatory Targets in Salmonella Biofilm Using Chromatin Immunoprecipitation and High-Throughput Sequencing (ChIP-seq)

Chromatin immunoprecipitation followed by sequencing (ChIP-seq) is a technique that can be used to discover the regulatory targets of transcription factors, histone modifications, and other DNA-associated proteins. ChIP-seq data can also be used to find differential binding of transcription factors in different environmental conditions or cell types. Initially, ChIP was performed through hybridization on a microarray (ChIP-chip); however, ChIP-seq has become the preferred method through technological advancements, decreasing financial barriers to sequencing, and massive amounts of high-quality data output. Techniques of performing ChIP-seq with bacterial biofilms, a major source of persistent and chronic infections, are described in this protocol. ChIP-seq is performed on Salmonella enterica serovar Typhimurium biofilm and planktonic cells, targeting the master biofilm regulator, CsgD, to determine differential binding in the two cell types. Here, we demonstrate the appropriate amount of biofilm to harvest, normalizing to a planktonic control sample, homogenizing biofilm for cross-linker access, and performing routine ChIP-seq steps to obtain high quality sequencing results.

Discovering CsgD Regulatory Targets in Salmonella Biofilm Using Chromatin Immunoprecipitation and High-Throughput Sequencing ChIP-seq

Chromatin immunoprecipitation coupled with next-generation sequencing (ChIP-seq) is a method used to establish interactions between transcription factors and the genomic sequences they control. This protocol outlines techniques for performing ChIP-seq with bacterial biofilms, using Salmonella enterica serovar Typhimurium bacterial biofilm as an example.

クロマチン免疫沈降とハイスループットシーケンシング(ChIP-seq)を用いたサルモネラバイオフィルムにおけるCsgD調節標的の発見

Chromatin immunoprecipitation followed by sequencing (ChIP-seq) is a technique that can be used to discover the regulatory targets of transcription ...

Gene Expression Profiling of Infecting Microbes Using a Digital Bar-coding Platform

For most mammalian pathogens, gene expression profiling studies have been limited by technical difficulties to accurately quantify pathogen gene transcripts from infected tissues. Pathogen RNA constitutes a tiny portion of the total RNA isolated from infected tissue samples. Both microarray and RNAseq technologies have difficulties in generating reliable reads for weakly expressed pathogen genes. Mutant pathogen strains with reduced in vivo proliferation pose an even bigger challenge. Here we describe an in vivo gene expression profiling protocol that is very fast, extremely sensitive and highly reproducible. We developed this protocol during our investigation of the fungal pathogen Candida albicans in a murine model of hematogenously disseminated candidiasis. Using this protocol, we have documented time courses of dynamically regulated C. albicans gene expression during kidney infection, and discovered unexpected features of gene expression responses to antifungal drug treatment in vivo.

We developed a protocol that is fast, sensitive and reproducible for pathogen gene expression profiling during an infection.

デジタルバーコードプラットフォームを使用して感染する微生物の遺伝子発現プロファイリング

For most mammalian pathogens, gene expression profiling studies have been limited by technical difficulties to accurately quantify pathogen gene ...

免疫・感染学

Pulldown Assay Coupled with Co-Expression in Bacteria Cells as a Time-Efficient Tool for Testing Challenging Protein-Protein Interactions

Pulldown is an easy and widely used protein-protein interaction assay. However, it has limitations in studying protein complexes that do not assemble effectively in vitro. Such complexes may require co-translational assembly and the presence of molecular chaperones; either they form stable oligomers which cannot dissociate and re-associate in vitro or are unstable without a binding partner. To overcome these problems, it is possible to use a method based on the bacterial co-expression of differentially tagged proteins using a set of compatible vectors followed by the conventional pulldown techniques. The workflow is more time-efficient compared to traditional pulldown because it lacks the time-consuming steps of separate purification of interacting proteins and their following incubation. Another advantage is a higher reproducibility due to a significantly smaller number of steps and a shorter period of time in which proteins that exist within the in vitro environment are exposed to proteolysis and oxidation. The method was successfully applied for studying a number of protein-protein interactions when other in vitro techniques were found to be unsuitable. The method can be used for batch testing protein-protein interactions. Representative results are shown for studies of interactions between BTB domain and intrinsically disordered proteins, and of heterodimers of zinc-finger-associated domains.

Here, we describe a method for the bacterial co-expression of differentially tagged proteins using a set of compatible vectors, followed by the conventional pulldown techniques to study protein complexes that cannot assemble in vitro.

細菌細胞での共発現と組み合わせたプルダウンアッセイは、困難なタンパク質間相互作用をテストするための時間効率の良いツールとして

Pulldown is an easy and widely used protein-protein interaction assay. However, it has limitations in studying protein complexes that do not assemble ...

生化学

<meta charset="utf8"></head><body>Precision DNAzyme ナノマシンによる識別型RNAおよびDNA分析

DNAzyme 10-23 - Based Nanomachines for Nucleic Acid Recognition

DNAzyme-based nanomachines (DNM) for the detection of DNA and RNA sequences (analytes) are multifunctional structures made of oligonucleotides. Their functions include tight analyte binding, highly selective analyte recognition, fluorescent signal amplification by multiple catalytic cleavages of a fluorogenic reporter substrate, and fluorogenic substrate attraction for an increase in sensor response. Functional units are attached to a common DNA scaffold for their cooperative action. The RNA-cleaving 10-23 DNMs feature&#160;improved sensitivity in comparison with non-catalytic hybridization probes. The stability of the DNM and the increased chances of substrate recognition are provided&#160;by a double-stranded DNA fragment,&#160;a tile. DNM can differentiate two analytes with a single nucleotide difference in a folded RNA and a double-stranded DNA and detect analytes at concentrations ~1000 times lower than other protein-free hybridization probes. This article presents the concept behind the diagnostic potential of DNA-nanomachine activity and overviews DNM design, assembly, and application&#160;in nucleic acid detection assays.

<meta charset="utf8"></head><body>著者スポットライト:DNAナノセンサーの進歩 – 分子検出における感度と選択性の課題への対処

The DNAzyme-based nanomachines can be used for highly selective and sensitive detection of nucleic acids. This article describes a detailed protocol for the design of DNAzyme-based nanomachines with a 10-23 core using free software and their application in the detection of an Epstein-Barr virus fragment as an example.

DNAzyme 10-23 - 核酸認識用ナノマシン

DNAzyme-based nanomachines (DNM) for the detection of DNA and RNA sequences (analytes) are multifunctional structures made of oligonucleotides. Their ...

細菌のための2つの成分規制システムを遺伝子標的を決定するために、DNA親和性精製チップ（DAP-チップ）方法

要約

さらに動画を探す

この動画の章

慢性リンパ性白血病の新規 NFAT2 ターゲット遺伝子を識別するクロマチン免疫沈降法

感染した組織の細菌の遺伝子の規則を勉強する蛍光ベースのメソッド

チップ上でのストレス誘発抗生物質感受性試験

細菌におけるタンパク質-RNA結合を定量するためのアッセイ

クロマチン免疫沈降とハイスループットシーケンシング(ChIP-seq)を用いたサルモネラバイオフィルムにおけるCsgD調節標的の発見

デジタルバーコードプラットフォームを使用して感染する微生物の遺伝子発現プロファイリング

細菌細胞での共発現と組み合わせたプルダウンアッセイは、困難なタンパク質間相互作用をテストするための時間効率の良いツールとして

DNAzyme 10-23 - 核酸認識用ナノマシン

DNAzyme 10-23 - 核酸認識用ナノマシン

DNAzyme 10-23 - 核酸認識用ナノマシン

細菌のための2つの成分​​規制システムを遺伝子標的を決定するために、DNA親和性精製チップ（DAP-チップ）方法

要約

さらに動画を探す

この動画の章

慢性リンパ性白血病の新規 NFAT2 ターゲット遺伝子を識別するクロマチン免疫沈降法

感染した組織の細菌の遺伝子の規則を勉強する蛍光ベースのメソッド

チップ上でのストレス誘発抗生物質感受性試験

細菌におけるタンパク質-RNA結合を定量するためのアッセイ

クロマチン免疫沈降とハイスループットシーケンシング(ChIP-seq)を用いたサルモネラバイオフィルムにおけるCsgD調節標的の発見

デジタルバーコードプラットフォームを使用して感染する微生物の遺伝子発現プロファイリング

細菌細胞での共発現と組み合わせたプルダウンアッセイは、困難なタンパク質間相互作用をテストするための時間効率の良いツールとして

DNAzyme 10-23 - 核酸認識用ナノマシン

DNAzyme 10-23 - 核酸認識用ナノマシン

DNAzyme 10-23 - 核酸認識用ナノマシン

細菌のための2つの成分規制システムを遺伝子標的を決定するために、DNA親和性精製チップ（DAP-チップ）方法