We thank Anne Wochele for her assistance in the laboratory and Vera Augsburger for help with the automated gel sequencer. We thank the Deutsche Forschungsgemeinschaft for funding by grants BE4038/2 and BE4038/5 within the &#8220;priority programmes&#8221; SPP1316 and SPP1617.

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The authors have nothing to disclose that would present a conflict of interest.

형광 프라이머 신장은 TSP- 또는 RNA 이차 가공 식별 어느 쪽의 RNA의 5 &#39;말단을 결정하기위한 간단하고 신속한 방법이다. 때문에 형광 프라이머의 사용, 반응이 설정 될 수 있으며, (방사성 표지 된 프라이머 경우와 달리) 추가 보안 조치없이 실행합니다. 샘플은 형광으로 검출되는 바와 같이 전기 영동 X 선 필름은 일반적으로 사용되는 방사성 방법에 비해 신속한 분석을 허용 진행되는 동안, 이들...

프라이머 신장도 1은 하나의 기본 해상도까지 특정 RNA 분자의 5 &#39;말단을 결정하기 위해 분자 방법이다. 이러한 5&#39;-RACE (cDNA의 신속한 증폭이 종료 됨) 같은 다른 방법의 장점은 빠른 처리 시간을 용이 RNA 분자의 서로 다른 길이의 혼합물을 분석 할 수있는 능력이다. 이 방법은 RNA 분자가 특정 길이의 cDNA 단편을 생성하는 특정 형광 프라이머를 사용하여 전사 반응을 반대로 실시함으로써 작동한다. 이들의 cDNA 분자 변성 폴리 아크릴 아마이드 겔에 전통적인 생거 시퀀싱 반응이 함께 실행 의한 형광 표지 된 프라이머를 사용하여 그 형광을 검출 할 수있다. 된 cDNA 단편의 길이는 5 &#39;말단 RNA의 맵핑을 허용 시퀀싱 사다리 비교에 의해 평가된다. 전통적으로, 프라이머 신장 반응을 함께 사용방사성 동위 원소와 X 선 필름에의 cDNA 분자들을 검출한다. 그들의 감도가 약간 낮다이라도 인해 건강 위험, 폐기물 처리 문제 및 취급의 용이성, 새로운 프로토콜은 자동화 된 시퀀서와 프라이머 신장의 검출을위한 형광을 이용한다. 형광 프라이머 (로모 손 년 이상) 장기간 안정적으로 형광 표지 된 프라이머를 사용하여 무선 표지 반복 절차가 생략 될 수있다. 우리는 여기에서 설명하는 방법은 자동화 겔 시퀀서를 이용하지만, 약간의 수정과, 모세관 시퀀서는 cDNA의 분리 및 검출 3에 사용될 수있다. 겔 분석 병렬 특성은 가능한 RNA 절단 또는 프로세싱 심지어 적은 양을 검출 할 수있다. 또 다른 이점은 검출 될 수 단말 절단 또는 심지어 하나의베이스 처리로서,이 방법의 고해상도이다. RNA 절단 또는 가공, t의 검출에 관련하여프라이머 확장 ypically 두 가지 종류가 구별된다. 다른 경우에, 처리가 생체 내에서 수행하고, 생성 된 RNA 정제 반면 한 경우, 효소 처리, 정제 된 RNA 정제 효소를 사용하여 시험 관내에서 수행된다. 프라이머 신장 시험 관내에서 수행에 두 경우 RNA가 RNA의 소스에 따라, 그러나, 실시되고, 상기 방법은 시험 관내 또는 생체 내 프라이머 신장이라고 하나. 여기 제시 프로토콜에서는 때문에 사용 용이성 (정제없이 필요한 단백질)과 동시에 전사 시작점 및 처리를 결정하는 가능성 단독 생체 프라이머 신장에 초점. 그러나, 시험 관내 프라이머 확장은 동일한 방법으로 설정 원칙적으로,이 프로토콜은 시작점을 제공 할 수있다. 여기에 예시 된 방법은 그것들이 높은 의무만큼 많은 세균 종에 적용될 수있다핵산의 순도 높은 수율 준비. 우리 실험실 연구 독소 항독소 (맞대기) 시스템 4,5, 프라이머 신장 방법은 광범위하게 사용되는 필드의 규정 범위에 초점을 맞춘다. TA-시스템은 안정적이고 내생 활성 독성 단백질과 독성 6,7 중화 대부분 불안정한 단백질 또는 RNA 항독소로 구성 원핵 생물의 게놈에 존재하는 작은 유전 적 요소입니다. 독소 활성은 때때로하는 RNase 활성 8,9 의해 대부분 복제, 세포벽 합성 또는 다른 메커니즘의 억제에 의해 발휘되지만. 일반적으로, RNA 분해 효소 특이성 프라이머 신장 방법 중 하나는 다른 테스트를 수행하여 결정된다. 벽개 및 전체 길이 단편의 혼합물을 동시에 그들의 5 &#39;끝나는 결정하기 위해 분석 될 수있는 프라이머 신장 반응,이 애플리케이션에 매우 적합하다. 시험 관내 및 생체 프라이머 확장에 믹스를 사용하여,특정 독소의 RNase 절단은, 예를 들어, 서열 특이성 10-13 결정될 수있다. <img alt="그림 1" fo:content-width="6in" src="/files/ftp_upload/52134/52134fig1highres.jpg" width="600" /> . 프라이머 확장 절차 1. 개요 그림 세균 배양 실험의 필요에 따라 배양 및 처리됩니다. 총 RNA는 세포의 cDNA를 수득 대상 특정 형광 DNA 프라이머를 사용하여 역전사 반응에 DNA의 흔적을 제거하기의 DNase I로 처리하고 실시로부터 추출된다. 게놈 DNA 또는 플라스미드를 추출하여 이후의 cDNA 조각과 크기 비교를 위해 형광 생거 시퀀싱 반응에 사용된다. 프라이머 신장 산물은 변성 우레아 폴리 아크릴 아미드 겔상에서 생거 시퀀싱 제품을 함께 실행하고 자동화 레이저 현미경으로 분석한다. 라 cDNA를 밴드와 함께 선까지입니다 시퀀싱베이스세인트 5 &#39;의 cDNA 끝 (파란색 화살표)의 기본. Fekete 추가 정보, 등. (3) <a href="https://www.jove.com/files/ftp_upload/52134/52134fig1highres.jpg" target="_blank">이 그림의 더 큰 버전을 보려면 여기를 클릭하십시오.</a> 전체 프라이머 신장 절차의 개요는도 1에서 발견 될 수있다. 요약하면, 박테리아 세포 수확, 배양, 세포 펠렛을 용해 및 RNA 추출. 정제 된 RNA이어서 역전사 템플릿으로 동작 할 수있다 DNA 분자의 흔적을 제거하기의 DNase I로 처리된다. 특정 형광 프라이머는 관심 영역에 교배와 이후 단일 가닥 보완 DNA (cDNA를) 결과, 전사 역, RNA에 추가됩니다. 시퀀싱 사다리 형광 프라이머를 이용하는 전통적인 생거 시퀀싱에 의해 생성 및 프라이머 신장 된 cDNA 단편의 나란히 변성 폴리 아크릴 아미드 겔상에서 분리된다. 결과겔은 관심의 5 &#39;말단의 식별을 허용 형광 밴드를 비교하여 분석된다. 전사 시작 지점 및 처리 사이트는 다음 서열 비교​​에 의해 개별적으로 평가된다.

<table border="0" cellpadding="0" cellspacing="0" width="1200">
	<tbody>
		<tr height="20">
			<td height="20" style="height:20px;width:399px;"><a name="RANGE!A1:D16">Name</a></td>
			<td style="width:196px;">Supplier</td>
			<td style="width:244px;">Catalog Number(s)</td>
			<td style="width:363px;">Comment</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:399px;">AMV Reverse Transcriptase (20-25 U/&#181;l)</td>
			<td style="width:196px;">NEB / Roche</td>
			<td style="width:244px;">NEB: M0277-T / Roche: 10109118001</td>
			<td style="width:363px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:21px;width:399px;">DNase I (RNase free)</td>
			<td style="width:196px;">Ambion (life technologies)</td>
			<td style="width:244px;">AM2222</td>
			<td style="width:363px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:399px;">FastPrep-24 Instrument&#160;</td>
			<td style="width:196px;">MPBio</td>
			<td align="right">116004500</td>
			<td style="width:363px;"></td>
		</tr>
		<tr height="80">
			<td height="80" style="height:80px;width:399px;">Fluorescently labeled primers</td>
			<td style="width:196px;">Biomers</td>
			<td style="width:244px;">n/a</td>
			<td style="width:363px;">5&#8217; DY-681 modification of &#8220;ordinary&#8221; DNA oligonucleotides. Compatible dyes such as the LICOR IRDye 700/800 are also available from other suppliers such as IDTdna.</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:399px;">Li-Cor 4200 Sequencer incl. ImagIR Data collection software</td>
			<td style="width:196px;">Li-Cor</td>
			<td style="width:244px;"></td>
			<td style="width:363px;">Product discontinued</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:399px;">NanoDrop 2000</td>
			<td style="width:196px;">Thermo Scientific</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:399px;">Nuclease free water</td>
			<td style="width:196px;">Ambion (life technologies)</td>
			<td style="width:244px;">AM9915G</td>
			<td style="width:363px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:399px;">Plasmid mini preparation kit</td>
			<td style="width:196px;">QIAGEN</td>
			<td align="right">12125</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:399px;">RapidGel-XL-40% Concentrate</td>
			<td style="width:196px;">USB</td>
			<td style="width:244px;">US75863</td>
			<td style="width:363px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:399px;">RNA STORAGE BUFFER</td>
			<td style="width:196px;">Ambion (life technologies)</td>
			<td>AM7000</td>
			<td style="width:363px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:399px;">Roti-Aqua-P/C/I</td>
			<td style="width:196px;">Carl Roth</td>
			<td style="width:244px;">X985.3</td>
			<td style="width:363px;">Alternative: &#8220;Acid-Phenol:Chloroform, pH 4.5 (with IAA, 125:24:1)&#8221; from Ambion (AM9720)</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:399px;">SUPERase&#8226;In RNase Inhibitor</td>
			<td style="width:196px;">Ambion (life technologies)</td>
			<td style="width:244px;">AM2696</td>
			<td style="width:363px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:399px;">Thermo Sequenase fluorescently labelled primer cycle sequencing kit with 7-deaza-dGTP</td>
			<td style="width:196px;">GE Healthcare</td>
			<td style="width:244px;">RPN2538</td>
			<td style="width:363px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:399px;">TRIzol reagent</td>
			<td style="width:196px;">life technologies</td>
			<td style="width:244px;">15596-026</td>
			<td style="width:363px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:399px;">Zirconia/Silica Beads 0.1 mm</td>
			<td style="width:196px;">BioSpec</td>
			<td style="width:244px;">11079101z</td>
			<td style="width:363px;"></td>
		</tr>
	</tbody>
</table>

fluorescence based primer extension technique to determine transcriptional starting points and cleavage sites of rnases in vivo

형광 계 프라이머 신장 (FPE)는 전사 시작점 또는 RNA 분자의 프로세싱 사이트를 결정하기 위해 분자 방법이다. 이것은 특정 형광 표지 된 프라이머 및 폴리 아크릴 아미드 겔 전기 영동을 변성하여 수득 된 cDNA 단편의 후속 분석을 이용하여 관심있는 RNA의 역전사에 의해 달성된다. 동시에, 전통적인 생거 시퀀싱 반응은 자신의 정확한 해당 기지의 cDNA 단편의 단부를 매핑 겔상에서 실행된다. 제품은 복제되어야 복수 후보 서열 5&#39;-RACE (cDNA를 엔드 신속한 증폭), 대조적으로, 프라이머 신장에 의해 생성 된 cDNA 단편의 대부분은 동시에 하나 겔 실행에서 검출 할 수있다. 또한, (결과를 최종 분석에 역전사에서) 모든 절차는 하나의 작업 일에 완료 할 수 있습니다. 형광 표지 된 프라이머를 사용함으로써, 유해 방사성 동위 원소의 사용은 표지 된 시약을회피 할 수 있고, 제품은 전기 영동 과정에서 검출 될 수 있기 때문에 처리 시간이 감소된다. 다음의 프로토콜에서는 확실하고 신속 S.에서 (예를 들어, 독소 항독소 시스템 구성 요소) 시작점 및 RNA 프로세싱 사이트 전사을 추론의 RNA의 5 &#39;말단을 검출하는 생체 내 형광 프라이머 신장 방법을 서술 구균, E. 대장균 및 기타 세균.

도 6에 도시 된 바와 같이, 프라이머 신장 반응 관심 사체의 전사 시작 포인트를 결정하는데 사용될 수 있고 (통상적으로 -10 -35 원소로 식별 됨) 프로모터 영역을 추론 할 수 있습니다. 최상위 (가장 긴)의 cDNA 단편의 mRNA의 5 &#39;말단을 나타내며, 따라서 시퀀싱 사다리에 비해 용이하게 매핑 될 수있다. <img alt="그림 6" src="/files/ftp_upload/52134/52134fig6highres.jpg" /> <st...

Watch this Scientific Journal Video about Fluorescence Based Primer Extension Technique to Determine Transcriptional Starting Points and Cleavage Sites of RNases In Vivo at JoVE.com

Fluorescence Based Primer Extension Technique to Determine Transcriptional Starting Points and Cleavage Sites of RNases In Vivo

We here describe a fluorescence based primer extension method to determine transcriptional starting points from bacterial transcripts and RNA processing in vivo using an automated gel sequencer.

형광 기반 프라이머 확장 기술은 전사 시작 포인트 및 RNases의 쪼개짐 사이트를 확인하는<em&gt; 생체</em

Fluorescence based primer extension (FPE) is a molecular method to determine transcriptional starting points or processing sites of RNA molecules. This is ...

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Research

JoVE Journal

Biology

Fluorescence Based Primer Extension Technique to Determine Transcriptional Starting Points and Cleavage Sites of RNases In Vivo

26.8K 조회수.  University of Tübingen. We here describe a fluorescence based primer extension method to determine transcriptional starting points from bacterial transcripts and RNA processing in vivo using an automated gel sequencer.

비디오: Fluorescence Based Primer Extension Technique to Determine Transcriptional Starting Points and Cleavage Sites of RNases In Vivo

Proboscis Extension Response (PER) Assay in Drosophila

Proboscis extension response (PER) is a taste behavior assay that has been used in flies as well as in honeybees.
On the surface of the fly's mouth (labellum), there are hair-like structures called sensilla which houses taste neurons. When an attractive substance makes contact to the labellum, the fly extends its proboscis to consume the material. Proboscis Extension Response (PER) assay measures this taste behavior response, and it is a useful method to learn about food preferences in a single fly. Solutions of various sugars, such as sucrose, glucose and fructose, are very attractive to the fly. The effect of aversive substances can also be tested as reduction of PER when mixed in a sweet solution.Despite the simplicity of the basic procedure, there are many things that can prevent it from working. One of the factors that requires attention is the fly's responsive state. The required starvation time to bring the fly to the proper responsive state varies drastically from 36 to 72 hours. We established a series of controls to evaluate the fly's state and which allows screening out of non-responsive or hyper-responsive individual animals. Another important factor is the impact level and the position of the contact to the labellum, which would be difficult to describe by words. This video presentation demonstrates all these together with several other improvements that would increase the reproducibility of this method.

Proboscis Extension Response PER Assay in Drosophila

Proboscis extension response or PER is a taste behavior assay that has been used in flies as well as in honeybees. When the proboscis makes contact with an attractive substance, the fly extends its proboscis to consume the substance. Solutions of various sugars are very attractive to the fly.

Drosophila의 코 확장 응답 (당) 어세이

Proboscis extension response (PER) is a taste behavior assay that has been used in flies as well as in honeybees.
On the surface of the fly's mouth ...

연구

생물학

Mesoscopic Fluorescence Tomography for In-vivo Imaging of Developing Drosophila

Visualizing developing organ formation as well as progession and treatment of disease often heavily relies on the ability to optically interrogate molecular and functional changes in intact living organisms. Most existing optical imaging methods are inadequate for imaging at dimensions that lie between the penetration limits of modern optical microscopy (0.5-1mm) and the diffusion-imposed limits of optical macroscopy (&gt;1cm) [1]. Thus, many important model organisms, e.g. insects, animal embryos or small animal extremities, remain inaccessible for in-vivo optical imaging. 
Although there is increasing interest towards the development of nanometer-resolution optical imaging methods, there have not been many successful efforts in improving the imaging penetration depth. The ability to perform in-vivo imaging beyond microscopy limits is in fact met with the difficulties associated with photon scattering present in tissues. Recent efforts to image entire embryos for example [2,3] require special chemical treatment of the specimen, to clear them from scattering, a procedure that makes them suitable only for post-mortem imaging. These methods however evidence the need for imaging larger specimens than the ones usually allowed by two-photon or confocal microscopy, especially in developmental biology and in drug discovery.
We have developed a new optical imaging technique named Mesoscopic Fluorescence Tomography [4], which appropriate for non-invasive in-vivo imaging at dimensions of 1mm-5mm. The method exchanges resolution for penetration depth, but offers unprecedented tomographic imaging performance and it has been developed to add time as a new dimension in developmental biology observations (and possibly other areas of biological research) by imparting the ability to image the evolution of fluorescence-tagged responses over time. As such it can accelerate studies of morphological or functional dependencies on gene mutations or external stimuli, and can importantly, capture the complete picture of development or tissue function by allowing longitudinal time-lapse visualization of the same, developing organism.
The technique utilizes a modified laboratory microscope and multi-projection illumination to collect data at 360-degree projections. It applies the Fermi simplification to Fokker-Plank solution of the photon transport equation, combined with geometrical optics principles in order to build a realistic inversion scheme suitable for mesoscopic range. This allows in-vivo whole-body visualization of non-transparent three-dimensional structures in samples up to several millimeters in size.
We have demonstrated the in-vivo performance of the technique by imaging three-dimensional structures of developing Drosophila tissues in-vivo and by following the morphogenesis of the wings in the opaque Drosophila pupae in real time over six consecutive hours.

Mesoscopic Fluorescence Tomography for In-vivo Imaging of Developing Drosophila

Mesoscopic fluorescence tomography operates beyond the penetration limits of tissue-sectioning fluorescence microscopy. The technique is based on multi-projection illumination and a photon transport description. We demonstrate in-vivo whole-body 3D visualization of the morphogenesis of GFP-expressing wing imaginal discs in Drosophila melanogaster.

에 대한 Mesoscopic 형광 Tomography 인 - 생체내</em개발> 이미징 Drosophila</em

Visualizing  developing organ formation as well as progession and treatment of disease often  heavily relies on the ability to optically interrogate ...

Primer Extension Capture: Targeted Sequence Retrieval from Heavily Degraded DNA Sources

We present a method of targeted DNA sequence retrieval from DNA sources which are heavily degraded and contaminated with microbial DNA, as is typical of ancient bones. The method greatly reduces sample destruction and sequencing demands relative to direct PCR or shotgun sequencing approaches. We used this method to reconstruct the complete mitochondrial DNA (mtDNA) genomes of five Neandertals from across their geographic range. The mtDNA genetic diversity of the late Neandertals was approximately three times lower than that of contemporary modern humans. Together with analyses of mtDNA protein evolution, these data suggest that the long-term effective population size of Neandertals was smaller than that of modern humans and extant great apes.

We present a method of targeted ancient DNA sequence retrieval, which we used to reconstruct the complete mitochondrial genomes of five Neandertal individuals. Comparison of these sequences with present day humans suggests that Neandertals had a long term low effective population size.

프라이머 확장 캡처 : 경비 저하 DNA 소스에서 타겟 시퀀스 불러오기

We present a method of targeted DNA sequence retrieval from DNA sources which are heavily degraded and contaminated with microbial DNA, as is typical of ...

Isolation of Ribosome Bound Nascent Polypeptides in vitro to Identify Translational Pause Sites Along mRNA

The rate of translational elongation is non-uniform. mRNA secondary structure, codon usage and mRNA associated proteins may alter ribosome movement on the messagefor review see 1. However, it's now widely accepted that synonymous codon usage is the primary cause of non-uniform translational elongation rates1. Synonymous codons are not used with identical frequency. A bias exists in the use of synonymous codons with some codons used more frequently than others2. Codon bias is organism as well as tissue specific2,3. Moreover, frequency of codon usage is directly proportional to the concentrations of cognate tRNAs4. Thus, a frequently used codon will have higher multitude of corresponding tRNAs, which further implies that a frequent codon will be translated faster than an infrequent one. Thus, regions on mRNA enriched in rare codons (potential pause sites) will as a rule slow down ribosome movement on the message and cause accumulation of nascent peptides of the respective sizes5-8. These pause sites can have functional impact on the protein expression, mRNA stability and protein foldingfor review see 9. Indeed, it was shown that alleviation of such pause sites can alter ribosome movement on mRNA and subsequently may affect the efficiency of co-translational (in vivo) protein folding1,7,10,11. To understand the process of protein folding in vivo, in the cell, that is ultimately coupled to the process of protein synthesis it is essential to gain comprehensive insights into the impact of codon usage/tRNA content on the movement of ribosomes along mRNA during translational elongation.
Here we describe a simple technique that can be used to locate major translation pause sites for a given mRNA translated in various cell-free systems6-8. This procedure is based on isolation of nascent polypeptides accumulating on ribosomes during in vitro translation of a target mRNA. The rationale is that at low-frequency codons, the increase in the residence time of the ribosomes results in increased amounts of nascent peptides of the corresponding sizes. In vitro transcribed mRNA is used for in vitro translational reactions in the presence of radioactively labeled amino acids to allow the detection of the nascent chains. In order to isolate ribosome bound nascent polypeptide complexes the translation reaction is layered on top of 30% glycerol solution followed by centrifugation. Nascent polypeptides in polysomal pellet are further treated with ribonuclease A and resolved by SDS PAGE. This technique can be potentially used for any protein and allows analysis of ribosome movement along mRNA and the detection of the major pause sites. Additionally, this protocol can be adapted to study factors and conditions that can alter ribosome movement and thus potentially can also alter the function/conformation of the protein.

Isolation of Ribosome Bound Nascent Polypeptides in vitro to Identify Translational Pause Sites Along mRNA

A technique to identify translational pause sites on mRNA is described. This procedure is based on isolation of nascent polypeptides accumulating on ribosomes during in vitro translation of a target mRNA, followed by the size analysis of the nascent chains using a denaturing gel electrophoresis.

Ribosome 바운드 초기 Polypeptides의 분리<em&gt; 체외에서</em&gt; mRNA 함께 Translational 일시 중지 사이트를 식별하려면

The rate of translational elongation is non-uniform. mRNA secondary structure, codon usage and mRNA associated proteins may alter ribosome movement on the ...

Single-molecule Imaging of Gene Regulation In vivo Using Cotranslational Activation by Cleavage (CoTrAC)

We describe a fluorescence microscopy method, Co-Translational Activation by Cleavage (CoTrAC) to image the production of protein molecules in live cells with single-molecule precision without perturbing the protein's functionality. This method makes it possible to count the numbers of protein molecules produced in one cell during sequential, five-minute time windows. It requires a fluorescence microscope with laser excitation power density of ~0.5 to 1 kW/cm2, which is sufficiently sensitive to detect single fluorescent protein molecules in live cells. The fluorescent reporter used in this method consists of three parts: a membrane targeting sequence, a fast-maturing, yellow fluorescent protein and a protease recognition sequence. The reporter is translationally fused to the N-terminus of a protein of interest. Cells are grown on a temperature-controlled microscope stage. Every five minutes, fluorescent molecules within cells are imaged (and later counted by analyzing fluorescence images) and subsequently photobleached so that only newly translated proteins are counted in the next measurement.
Fluorescence images resulting from this method can be analyzed by detecting fluorescent spots in each image, assigning them to individual cells and then assigning cells to cell lineages. The number of proteins produced within a time window in a given cell is calculated by dividing the integrated fluorescence intensity of spots by the average intensity of single fluorescent molecules. We used this method to measure expression levels in the range of 0-45 molecules in single 5 min time windows. This method enabled us to measure noise in the expression of the &lambda; repressor CI, and has many other potential applications in systems biology.

Single-molecule Imaging of Gene Regulation In vivo Using Cotranslational Activation by Cleavage CoTrAC

We describe a fluorescence microscopy method, Co-Translational Activation by Cleavage (CoTrAC), to image the production of protein molecules in live cells with single-molecule precision without perturbing the protein's functionality. This method has been used to follow the stochastic expression dynamics of a transcription factor, the &lambda; repressor CI 1.

유전자 규정의 단일 분자 이미징<em&gt; 생체에</em&gt; 절단하여 Cotranslational 인증 (CoTrAC)를 사용

We describe a fluorescence microscopy method, Co-Translational Activation by Cleavage (CoTrAC) to image the production of protein molecules in live cells ...

A Quantitative Assay to Study Protein:DNA Interactions, Discover Transcriptional Regulators of Gene Expression, and Identify Novel Anti-tumor Agents

Many DNA-binding assays such as electrophoretic mobility shift assays (EMSA), chemiluminescent assays, chromatin immunoprecipitation (ChIP)-based assays, and multiwell-based assays are used to measure transcription factor activity. However, these assays are nonquantitative, lack specificity, may involve the use of radiolabeled oligonucleotides, and may not be adaptable for the screening of inhibitors of DNA binding. On the other hand, using a quantitative DNA-binding enzyme-linked immunosorbent assay (D-ELISA) assay, we demonstrate nuclear protein interactions with DNA using the RUNX2 transcription factor that depend on specific association with consensus DNA-binding sequences present on biotin-labeled oligonucleotides. Preparation of cells, extraction of nuclear protein, and design of double stranded oligonucleotides are described. Avidin-coated 96-well plates are fixed with alkaline buffer and incubated with nuclear proteins in nucleotide blocking buffer. Following extensive washing of the plates, specific primary antibody and secondary antibody incubations are followed by the addition of horseradish peroxidase substrate and development of the colorimetric reaction. Stop reaction mode or continuous kinetic monitoring were used to quantitatively measure protein interaction with DNA. We discuss appropriate specificity controls, including treatment with non-specific IgG or without protein or primary antibody. Applications of the assay are described including its utility in drug screening and representative positive and negative results are discussed.

We developed a quantitative DNA-binding, ELISA-based assay to measure transcription factor interactions with DNA. High specificity for the RUNX2 protein was achieved with a consensus DNA-recognition oligonucleotide and specific monoclonal antibody. Colorimetric detection with an enzyme-coupled antibody substrate reaction was monitored in real time.

유전자 발현의 DNA 상호 작용, 디스 전사 레귤레이터, 그리고 소설 안티 종양 에이전트를 식별 : 단백질을 연구하는 정량 분석

Many DNA-binding assays such as electrophoretic mobility shift assays (EMSA), chemiluminescent assays, chromatin immunoprecipitation (ChIP)-based assays, ...

A Proteoliposome-Based Efflux Assay to Determine Single-molecule Properties of Cl- Channels and Transporters

The last 15 years have been characterized by an explosion in the ability to overexpress and purify membrane proteins from prokaryotic organisms as well as from eukaryotes. This increase has been largely driven by the successful push to obtain structural information on membrane proteins. However, the ability to functionally interrogate these proteins has not advanced at the same rate and is often limited to qualitative assays of limited quantitative value, thereby limiting the mechanistic insights that they can provide. An assay to quantitatively investigate the transport activity of reconstituted Cl- channels or transporters is described. The assay is based on the measure of the efflux rate of Cl- from proteoliposomes following the addition of the K+ ionophore valinomycin to shunt the membrane potential. An ion sensitive electrode is used to follow the time-course of ion efflux from proteoliposomes reconstituted with the desired protein. The method is highly suited for mechanistic studies, as it allows for the quantitative determination of key properties of the reconstituted protein, such as its unitary transport rate, the fraction of active protein and the molecular mass of the functional unit. The assay can also be utilized to determine the effect of small molecule compounds that directly inhibit/activate the reconstituted protein, as well as to test the modulatory effects of the membrane composition or lipid-modifying reagents. Where possible, direct comparison between results obtained using this method were found to be in good agreement with those obtained using electrophysiological approaches. The technique is illustrated using CLC-ec1, a CLC-type H+/Cl- exchanger, as a model system. The efflux assay can be utilized to study any Cl- conducting channel/transporter and, with minimal changes, can be adapted to study any ion-transporting protein.

A Proteoliposome-Based Efflux Assay to Determine Single-molecule Properties of Cl- Channels and Transporters

Proteoliposomes are used to study purified channels and transporters reconstituted in a well-defined biochemical environment. An experimental procedure to measure efflux mediated by these proteins is illustrated. The steps to prepare proteoliposomes, perform the recordings, and analyze data to quantitatively determine the functional properties of the reconstituted protein are described.

Proteoliposome 기반 유출 분석은 CL의 단일 분자의 속성을 확인하는<sup&gt; -</sup&gt; 채널 및 전송기

The last 15 years have been characterized by an explosion in the ability to overexpress and purify membrane proteins from prokaryotic organisms as well as ...

Methods to Discover Alternative Promoter Usage and Transcriptional Regulation of Murine Bcrp1

Gene expression in different tissues is often controlled by alternative promoters that result in the synthesis of mRNA with unique &#8212; usually untranslated &#8212; first exons. Bcrp1 (Abcg2), the murine orthologue of the ABC transporter Breast Cancer Resistance Protein (BCRP, ABCG2), has at least four alternative promoters that are designated by the corresponding four alternative first exons produced: E1U, E1A, E1B, and E1C. Herein, in-silico protocols are presented to predict alternative promoter usage for Bcrp1. Furthermore, reporter assay methods are described to produce reporter constructs for alternative promoters and to determine the functionality of putative promoters upstream of the alternative first exons that are identified.

With the murine ABC transporter Bcrp1 (Abcg2) as an example, in-silico protocols are presented to detect alternative promoter usage in genes expressed in mouse tissues, and to evaluate the functionality of the alternative promoters identified using reporter assays.

방법은 쥐 Bcrp1의 대체 발기인 사용 및 전사 규정을 발견 할 수

Gene expression in different tissues is often controlled by alternative promoters that result in the synthesis of mRNA with unique &#8212; usually ...

In Vitro and In Vivo Approaches to Determine Intestinal Epithelial Cell Permeability

The intestinal barrier defends against pathogenic microorganism and microbial toxin. Its function is regulated by tight junction permeability and epithelial cell integrity, and disruption of the intestinal barrier function contributes to progression of gastrointestinal and systemic disease. Two simple methods are described here to measure the permeability of intestinal epithelium. In vitro, Caco-2BBe cells are plated in tissue culture wells as a monolayer and transepithelial electrical resistance (TER) can be measured by an epithelial (volt/ohm) meter. This method is convincing because of its user-friendly operation and repeatability. In vivo, mice are gavaged with 4 kDa fluorescein isothiocyanate (FITC)-dextran, and the FITC-dextran concentrations are measured in collected serum samples from mice to determine the epithelial permeability. Oral gavage provides an accurate dose, and therefore is the preferred method to measure the intestinal permeability in vivo. Taken together, these two methods can measure the permeability of the intestinal epithelium in vitro and in vivo, and hence be used to study the connection between diseases and barrier function.

In Vitro and In Vivo Approaches to Determine Intestinal Epithelial Cell Permeability

Two methods are presented here to determine intestinal barrier function. An epithelial meter (volt/ohm) is used for measurements of transepithelial electrical resistance of cultured epithelia directly in tissue culture wells. In mice, the FITC-dextran gavage method is used to determine the intestinal permeability in vivo.

생체 외에서 그리고 Vivo에서 접근 장 상피 세포 침투성을 결정 하

The intestinal barrier defends against pathogenic microorganism and microbial toxin. Its function is regulated by tight junction permeability and ...

Profiling of H3K4me3 Modification in Plants using Cleavage under Targets and Tagmentation

Epigenomic regulation at the chromatic level, including DNA and histone modifications, behaviors of transcription factors, and non-coding RNAs with their recruited proteins, lead to temporal and spatial control of gene expression. Cleavage under targets and tagmentation (CUT&#38;Tag) is an enzyme-tethering method in which the specific chromatin protein is firstly recognized by its specific antibody, and then the antibody tethers a protein A-transposase (pA-Tn5) fusion protein, which cleaves the targeted chromatin in situ by the activation of magnesium ions. Here, we provide our previously published CUT&#38;Tag protocol using intact nuclei isolated from allortetraploid cotton leaves with modification. This step-by-step protocol can be used for epigenomic research in plants. In addition, substantial modifications for plant nuclei isolation are provided with critical comments.

Cleavage under targets and tagmentation (CUT&amp;Tag) is an efficient chromatin epigenomic profiling strategy. This protocol presents a refined CUT&amp;Tag strategy for the profiling of histone modifications in plants.

표적 및 태비네이션 하에서 절단을 사용하는 식물에서의 H3K4me3 수정 프로파일링

Epigenomic regulation at the chromatic level, including DNA and histone modifications, behaviors of transcription factors, and non-coding RNAs with their ...