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、。

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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

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 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 ...

Establishment of a High-throughput Setup for Screening Small Molecules That Modulate c-di-GMP Signaling in Pseudomonas aeruginosa

Bacterial resistance to traditional antibiotics has driven research attempts to identify new drug targets in recently discovered regulatory pathways. Regulatory systems that utilize intracellular cyclic di-GMP (c-di-GMP) as a second messenger are one such class of target. c-di-GMP is a signaling molecule found in almost all bacteria that acts to regulate an extensive range of processes including antibiotic resistance, biofilm formation and virulence. The understanding of how c-di-GMP signaling controls aspects of antibiotic resistant biofilm development has suggested approaches whereby alteration of the cellular concentrations of the nucleotide or disruption of these signaling pathways may lead to reduced biofilm formation or increased susceptibility of the biofilms to antibiotics. We describe a simple high-throughput bioreporter protocol, based on green fluorescent protein (GFP), whose expression is under the control of the c-di-GMP responsive promoter cdrA, to rapidly screen for small molecules with the potential to modulate c-di-GMP cellular levels in Pseudomonas aeruginosa (P. aeruginosa). This simple protocol can screen upwards of 3,500 compounds within 48 hours and has the ability to be adapted to multiple microorganisms.

Establishment of a High-throughput Setup for Screening Small Molecules That Modulate c-di-GMP Signaling in Pseudomonas aeruginosa

This article describes the high-throughput assay that has been successfully established to screen large libraries of small molecules for their potential ability to manipulate cellular levels of cyclic di-GMP in Pseudomonas aeruginosa, providing a new powerful tool for antibacterial drug discovery and compound testing.

調節するc-ジ-GMPシグナリングで、小さな分子をスクリーニングするためのハイスループットセットアップの確立<em&gt;緑膿菌</em

Bacterial resistance to traditional antibiotics has driven research attempts to identify new drug targets in recently discovered regulatory pathways. ...

免疫・感染学

Genome-wide Analysis using ChIP to Identify Isoform-specific Gene Targets

Recruitment of transcriptional and epigenetic factors to their targets is a key step in their regulation. Prominently featured in recruitment are the protein domains that bind to specific histone modifications. One such domain is the plant homeodomain (PHD), found in several chromatin-binding proteins. The epigenetic factor RBP2 has multiple PHD domains, however, they have different functions (Figure 4). In particular, the C-terminal PHD domain, found in a RBP2 oncogenic fusion in human leukemia, binds to trimethylated lysine 4 in histone H3 (H3K4me3)1. The transcript corresponding to the RBP2 isoform containing the C-terminal PHD accumulates during differentiation of promonocytic, lymphoma-derived, U937 cells into monocytes2. Consistent with both sets of data, genome-wide analysis showed that in differentiated U937 cells, the RBP2 protein gets localized to genomic regions highly enriched for H3K4me33. Localization of RBP2 to its targets correlates with a decrease in H3K4me3 due to RBP2 histone demethylase activity and a decrease in transcriptional activity. In contrast, two other PHDs of RBP2 are unable to bind H3K4me3. Notably, the C-terminal domain PHD of RBP2 is absent in the smaller RBP2 isoform4. It is conceivable that the small isoform of RBP2, which lacks interaction with H3K4me3, differs from the larger isoform in genomic location. The difference in genomic location of RBP2 isoforms may account for the observed diversity in RBP2 function. Specifically, RBP2 is a critical player in cellular differentiation mediated by the retinoblastoma protein (pRB). Consistent with these data, previous genome-wide analysis, without distinction between isoforms, identified two distinct groups of RBP2 target genes: 1) genes bound by RBP2 in a manner that is independent of differentiation; 2) genes bound by RBP2 in a differentiation-dependent manner.
To identify differences in localization between the isoforms we performed genome-wide location analysis by ChIP-Seq. Using antibodies that detect both RBP2 isoforms we have located all RBP2 targets. Additionally we have antibodies that only bind large, and not small RBP2 isoform (Figure 4). After identifying the large isoform targets, one can then subtract them from all RBP2 targets to reveal the targets of small isoform. These data show the contribution of chromatin-interacting domain in protein recruitment to its binding sites in the genome.

Here we are presenting a chromatin immunoprecipitation (ChIP) procedure for genome-wide location analysis of protein isoforms that differ in a histone-binding domain. We are applying it to ChIP-Seq analysis to identify the targets of the KDM5A/JARID1A/RBP2 histone demethylase.

アイソフォーム特異的遺伝子標的を同定するためのチップを使用してゲノムワイド解析

Recruitment of transcriptional and epigenetic factors to their targets is a key step in their regulation. Prominently featured in recruitment are the ...

生物学

Mapping Bacterial Functional Networks and Pathways in Escherichia Coli using Synthetic Genetic Arrays

Phenotypes are determined by a complex series of physical (e.g. protein-protein) and functional (e.g. gene-gene or genetic) interactions (GI)1. While physical interactions can indicate which bacterial proteins are associated as complexes, they do not necessarily reveal pathway-level functional relationships1. GI screens, in which the growth of double mutants bearing two deleted or inactivated genes is measured and compared to the corresponding single mutants, can illuminate epistatic dependencies between loci and hence provide a means to query and discover novel functional relationships2. Large-scale GI maps have been reported for eukaryotic organisms like yeast3-7, but GI information remains sparse for prokaryotes8, which hinders the functional annotation of bacterial genomes. To this end, we and others have developed high-throughput quantitative bacterial GI screening methods9, 10.
Here, we present the key steps required to perform quantitative E. coli Synthetic Genetic Array (eSGA) screening procedure on a genome-scale9, using natural bacterial conjugation and homologous recombination to systemically generate and measure the fitness of large numbers of double mutants in a colony array format. Briefly, a robot is used to transfer, through conjugation, chloramphenicol (Cm) - marked mutant alleles from engineered Hfr (High frequency of recombination) 'donor strains' into an ordered array of kanamycin (Kan) - marked F- recipient strains. Typically, we use loss-of-function single mutants bearing non-essential gene deletions (e.g. the 'Keio' collection11) and essential gene hypomorphic mutations (i.e. alleles conferring reduced protein expression, stability, or activity9, 12, 13) to query the functional associations of non-essential and essential genes, respectively. After conjugation and ensuing genetic exchange mediated by homologous recombination, the resulting double mutants are selected on solid medium containing both antibiotics. After outgrowth, the plates are digitally imaged and colony sizes are quantitatively scored using an in-house automated image processing system14. GIs are revealed when the growth rate of a double mutant is either significantly better or worse than expected9. Aggravating (or negative) GIs often result between loss-of-function mutations in pairs of genes from compensatory pathways that impinge on the same essential process2. Here, the loss of a single gene is buffered, such that either single mutant is viable. However, the loss of both pathways is deleterious and results in synthetic lethality or sickness (i.e. slow growth). Conversely, alleviating (or positive) interactions can occur between genes in the same pathway or protein complex2 as the deletion of either gene alone is often sufficient to perturb the normal function of the pathway or complex such that additional perturbations do not reduce activity, and hence growth, further. Overall, systematically identifying and analyzing GI networks can provide unbiased, global maps of the functional relationships between large numbers of genes, from which pathway-level information missed by other approaches can be inferred9.

Mapping Bacterial Functional Networks and Pathways in Escherichia Coli using Synthetic Genetic Arrays

Systematic, large-scale synthetic genetic (gene-gene or epistasis) interaction screens can be used to explore genetic redundancy and pathway cross-talk. Here, we describe a high-throughput quantitative synthetic genetic array screening technology, termed eSGA that we developed for elucidating epistatic relationships and exploring genetic interaction networks in Escherichia coli.

細菌機能ネットワークとPathwaysでのマッピング<em&gt;大腸菌</em&gt;合成遺伝子配列を用いて

Phenotypes  are determined by a complex series of physical (e.g. protein-protein) and  functional (e.g. gene-gene or genetic) interactions (GI)1. While ...

A Fast and Reliable Pipeline for Bacterial Transcriptome Analysis Case study: Serine-dependent Gene Regulation in Streptococcus pneumoniae

Gene expression and its regulation are very important to understand the behavior of cells under different conditions. Various techniques are used nowadays to study gene expression, but most are limited in terms of providing an overall picture of the expression of the whole transcriptome. DNA microarrays offer a fast and economic research technology, which gives a full overview of global gene expression and have a vast number of applications including identification of novel genes and transcription factor binding sites, characterization of transcriptional activity of the cells and also help in analyzing thousands of genes (in a single experiment). In the present study, the conditions for bacterial transcriptome analysis from cell harvest to DNA microarray analysis have been optimized. Taking into account the time, costs and accuracy of the experiments, this technology platform proves to be very useful and universally applicabale for studying bacterial transcriptomes. Here, we perform DNA microarray analysis with Streptococcus pneumoniae as a case-study by comparing the transcriptional responses of S. pneumoniae grown in the presence of varying L-serine concentrations in the medium. Total RNA was isolated by using a Macaloid method using an RNA isolation kit and the quality of RNA was checked by using an RNA quality check kit. cDNA was prepared using reverse transcriptase and the cDNA samples were labelled using one of two amine-reactive fluorescent dyes. Homemade DNA microarray slides were used for hybridization of the labelled cDNA samples and microarray data were analyzed by using a cDNA microarray data pre-processing framework (Microprep). Finally, Cyber-T was used to analyze the data generated using Microprep for the identification of statistically significant differentially expressed genes. Furthermore, in-house built software packages (PePPER, FIVA, DISCLOSE, PROSECUTOR, Genome2D) were used to analyze data.

A Fast and Reliable Pipeline for Bacterial Transcriptome Analysis Case study: Serine-dependent Gene Regulation in Streptococcus pneumoniae

This manuscript describes the use of state-of-the-art technology provided by DNA-microarrays. Microarrays provide an overview of the transcriptomic changes in bacteria incurred under a specific condition. Moreover, we highlight the ease by which large amounts of data can be analyzed by using convenient in-house developed software packages.

細菌のトランスクリプトーム解析ケーススタディのための高速かつ信頼性の高いパイプライン：セリン依存の遺伝子調節に<em&gt;肺炎球菌</em

Gene expression and its regulation are very important to understand the behavior of cells under different conditions. Various techniques are used nowadays ...

Functional Complementation Analysis (FCA): A Laboratory Exercise Designed and Implemented to Supplement the Teaching of Biochemical Pathways

Functional complementation assay (FCA) is an in vivo assay that is widely used to elucidate the function/role of genes/enzymes. This technique is very common in biochemistry, genetics and many other disciplines. A comprehensive overview of the technique to supplement the teaching of biochemical pathways pertaining to amino acids, peptidoglycan and the bacterial stringent response is reported in this manuscript. Two cDNAs from the model plant organism Arabidopsis thaliana that are involved in the metabolism of lysine (L,L-diaminopimelate aminotransferase (dapL) and tyrosine aminotransferase (tyrB) involved in the metabolism of tyrosine and phenylalanine are highlighted. In addition, the bacterial peptidoglycan anabolic pathway is highlighted through the analysis of the UDP-N-acetylmuramoyl-L-alanyl-D-glutamate-meso-2,6-diaminopimelate ligase (murE) gene from the bacterium Verrucomicrobium spinosum involved in the cross-linking of peptidoglycan. The bacterial stringent response is also reported through the analysis of the rsh (relA/spoT homolog) bifunctional gene responsible for a hyper-mucoid phenotype in the bacterium Novosphingobium sp. Four examples of FCA are presented. The video will focus on three of them, namely lysine, peptidoglycan and the stringent response.

Functional Complementation Analysis FCA: A Laboratory Exercise Designed and Implemented to Supplement the Teaching of Biochemical Pathways

The validation of enzymatic activities involved in biochemical pathways can be elucidated using functional complementation analysis (FCA). Described in this manuscript is the FCA assay demonstrating the enzymatic activity of enzymes involved in the metabolism of amino acids, bacterial stringent response and bacterial peptidoglycan biosynthesis.

機能的相補性分析（FCA）：生化学的経路の授業を補足するように設計および実装実験演習

Functional complementation assay (FCA) is an in vivo assay that is widely used to elucidate the function/role of genes/enzymes. This technique is very ...

Using Microtiter Dish Radiolabeling for Multiple In Vivo Measurements Of Escherichia coli (p)ppGpp Followed by Thin Layer Chromatography

The (p)ppGpp nucleotide functions as a global regulator in bacteria in response to a variety of physical and nutritional stress. It has a rapid onset, in seconds, which leads to accumulation of levels that approach or exceed those of GTP pools. Stress reversal occasions a rapid disappearance of (p)ppGpp, often with a half-life of less than a minute. The presence of (p)ppGpp results in alterations of cellular gene expression and metabolism that counter the damaging effects of stress. Gram-negative and Gram-positive bacteria have different response mechanisms, but both depend on (p)ppGpp concentration. In any event, there is a need to simultaneously monitor many radiolabeled bacterial cultures at time intervals that may vary from 10 seconds to hours during critical stress transition periods. This protocol addresses this technical challenge. The method takes advantage of temperature- and shaker-controlled microtiter dish incubators that allow parallel monitoring of growth (absorbance) and rapid sampling of uniformly phosphate-radiolabeled cultures to resolve and quantitate nucleotide pools by thin-layer chromatography on PEI-cellulose. Small amounts of sample are needed for multiple technical and biological replicates of analyses. Complex growth transitions, such as diauxic growth and rapid (p)ppGpp turnover rates can be quantitatively assessed by this method.

Using Microtiter Dish Radiolabeling for Multiple In Vivo Measurements Of Escherichia coli pppGpp Followed by Thin Layer Chromatography

The growth of radiolabeled bacterial cultures in microtiter dishes facilitates high throughput sampling that allows multiple technical and biological replicate assays of nucleotide pool abundance, including that of (p)ppGpp. The effects of growth transitions provoked by sources of physiological stress as well as recovery from stress can be monitored.

大腸菌(p)ppGppの複数の生体内測定に対するマイクロチター皿放射ラベリングの使用、その後に薄層クロマトグラフィー

The (p)ppGpp nucleotide functions as a global regulator in bacteria in response to a variety of physical and nutritional stress. It has a rapid onset, in ...

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

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

調節するc-ジ-GMPシグナリングで、小さな分子をスクリーニングするためのハイスループットセットアップの確立

アイソフォーム特異的遺伝子標的を同定するためのチップを使用してゲノムワイド解析

細菌機能ネットワークとPathwaysでのマッピング

細菌のトランスクリプトーム解析ケーススタディのための高速かつ信頼性の高いパイプライン：セリン依存の遺伝子調節に

機能的相補性分析（FCA）：生化学的経路の授業を補足するように設計および実装実験演習

大腸菌(p)ppGppの複数の生体内測定に対するマイクロチター皿放射ラベリングの使用、その後に薄層クロマトグラフィー

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

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

調節するc-ジ-GMPシグナリングで、小さな分子をスクリーニングするためのハイスループットセットアップの確立

アイソフォーム特異的遺伝子標的を同定するためのチップを使用してゲノムワイド解析

細菌機能ネットワークとPathwaysでのマッピング

細菌のトランスクリプトーム解析ケーススタディのための高速かつ信頼性の高いパイプライン：セリン依存の遺伝子調節に

機能的相補性分析（FCA）：生化学的経路の授業を補足するように設計および実装実験演習

大腸菌(p)ppGppの複数の生体内測定に対するマイクロチター皿放射ラベリングの使用、その後に薄層クロマトグラフィー

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