Name: using a gfp-tagged tmem184a construct for confirmation of heparin receptor identity
Uploaded: 2017-02-17T13:00:00.000+00:00
Duration: 10 min 41 s
Description: Watch this Scientific Journal Video about Using a GFP-tagged TMEM184A Construct for Confirmation of Heparin Receptor Identity at JoVE.com

Research in the Lowe-Krentz lab is supported by research grant HL54269 from the National Institutes of Health to LLK.

<ol>
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D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Demystifying+heparan+sulfate-protein+interactions.">Demystifying heparan sulfate-protein interactions.</a> Annu Rev Biochem. 83, 129-157 (2014).</li><li>Chiodelli, P., Bugatti, A., Urbinati, C., Rusnati, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heparin/Heparan+sulfate+proteoglycans+glycomic+interactome+in+angiogenesis:+biological+implications+and+therapeutical+use.">Heparin/Heparan sulfate proteoglycans glycomic interactome in angiogenesis: biological implications and therapeutical use.</a> Molecules. 20, 6342-6388 (2015).</li><li>Slee, J. B., Lowe-Krentz, L. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Actin+realignment+and+cofilin+regulation+are+essential+for+barrier+integrity+during+shear+stress.">Actin realignment and cofilin regulation are essential for barrier integrity during shear stress.</a> J Cell Biochem. 114, 782-795 (2013).</li><li>Patton, W. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+a+heparin-binding+protein+using+monoclonal+antibodies+that+block+heparin+binding+to+porcine+aortic+endothelial+cells.">Identification of a heparin-binding protein using monoclonal antibodies that block heparin binding to porcine aortic endothelial cells.</a> The Biochemical journal. 311, 461-469 (1995).</li><li>Doggett, T. M., Breslin, J. 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P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Turn-on+switch+in+parathyroid+hormone+receptor+by+a+two-step+parathyroid+hormone+binding+mechanism.">Turn-on switch in parathyroid hormone receptor by a two-step parathyroid hormone binding mechanism.</a> Proc Natl Acad Sci U S A. 102, 16084-16089 (2005).</li><li>Albertazzi, L., Arosio, D., Marchetti, L., Ricci, F., Beltram, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+FRET+analysis+with+the+EGFP-mCherry+fluorescent+protein+pair.">Quantitative FRET analysis with the EGFP-mCherry fluorescent protein pair.</a> Photochem Photobiol. 85, 287-297 (2009).</li><li>Wang, 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=Domain+organization+of+the+ATP-sensitive+potassium+channel+complex+examined+by+fluorescence+resonance+energy+transfer.">Domain organization of the ATP-sensitive potassium channel complex examined by fluorescence resonance energy transfer.</a> J Biol Chem. 288, 4378-4388 (2013).</li><li>Christiansen, E., Hudson, B. D., Hansen, A. H., Milligan, G., Ulven, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+and+Characterization+of+a+Potent+Free+Fatty+Acid+Receptor+1+(FFA1)+Fluorescent+Tracer.">Development and Characterization of a Potent Free Fatty Acid Receptor 1 (FFA1) Fluorescent Tracer.</a> J Med Chem. 59, 4849-4858 (2016).</li><li>Chiang, C. F., Okou, D. T., Griffin, T. B., Verret, C. R., Green Williams, M. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=fluorescent+protein+rendered+susceptible+to+proteolysis:+positions+for+protease-sensitive+insertions.">fluorescent protein rendered susceptible to proteolysis: positions for protease-sensitive insertions.</a> Arch Biochem Biophys. 394, 229-235 (2001).</li></ol>

著者らは、開示することは何もありません。

ここで報告されたプロトコルは、血管細胞1におけるヘパリン受容体としてTMEM184Aの同定のための確証的な証拠を提供するように設計されました。ノックダウン技術は、日常的に、新規なタンパク質の同定を確認するための1つのメカニズムとして使用されます。しかし、ノックダウン後のいくつかの機能の損失は、典型的には、候補タンパク質が実際に正しい受容体（または...

新規な機能のための候補タンパク質の同定は、多くの場合、部分配列決意が続く親和性に基づく分離プロトコルに依存します。新たに同定されたタンパク質の最近の例は、膜貫通タンパク質184A（TMEM184A）、ヘパリン親和性相互作用1後に同定ヘパリン受容体、およびTgPH1、ホスホイノシチドPI（3,5）P 2 2を特異的に結合するプレクストリン相同ドメインタンパク質が含まれます。その他の新規タンパク質の同定は、このような、 らビタミンによって、そのようなペプチドの直接配列分析を必要とします。人は、以前に特徴付けられていない遺伝子3からタンパク質産物を識別するために、膜貫通ペプチドを使用していました。同様に、新規のタンパク質配列の同定は、このような新しい4TMタンパク質4の識別として以前に特徴付けられるタンパク質ファミリーの探索バイオインフォマティクスを用いて達成することができます。アクアポリンファミリー遺伝子配列の検査は、Alを有しますそのように新しい機能5と新メンバーの同定をもたらしました。識別後、タンパク質機能の解析は、しばしば、このようなアクアポリンの場合のように、タンパク質機能の特異的なアッセイを用いて試験することができる次のステップは、典型的には。 可能な場合は、新たに同定されたタンパク質の機能は、特定の酵素または類似のインビトロ機能アッセイを用いて調べることができます。新規タンパク質の多くの機能が唯一無傷の細胞または生物で発生する複雑な相互作用に依存しているため、in vitroアッセイは、必ずしも有効ではありません。しかし、 インビボアッセイは、それらが遺伝子配列に依存するように設計されなければなりません。細胞培養、および/または単純なモデル生物では、ノックダウンは、タンパク質/機能同定6のための証拠を提供することができます。上記のように同定された新規のタンパク質と、単に機能を確認するために、タンパク質をノックダウンすることがしばしば不十分です、D遺伝子配列に依存してin vivoでの機能アッセイの設計は、新規タンパク質の特徴付けのために重要になります。 ノックダウンは、識別と一致する結果が得られた後、ヘパリンレセプターとしてTMEM184Aの最近の同定は、アフィニティークロマトグラフィーおよびMALDI MS 1を使用して（すなわち、血管平滑筋および内皮細胞における炎症応答において増殖を調節する）、7は、アッセイのコレクションを開発する機会を提供し。最近のレビューは、ヘパリンは、多くの増殖因子、それらの受容体、細胞外マトリックス成分、細胞接着受容体、および他のタンパク質8と特異的に相互作用することが確認されました。血管系では、ヘパリンおよびヘパラン硫酸プロテオグリカン（ヘパリンと同様の構造でヘパラン硫酸鎖を含む）は、数百のタンパク質9と相互作用します。機能的に股関節を確認するために、トンTMEM184Aはヘパリンの取り込みと結合に関与していた、TMEM184Aための遺伝子構築物を使用される技術が開発されました。本レポートでは、GFP-TMEM184Aに基づくアッセイのコレクションはヘパリン受容体としてTMEM184Aの身元を確認するのに使用するための構築物が含まれます。

<table><tbody><tr><td>GFP-TMEM184A construct</td><td>OriGene</td><td>RG213192</td><td></td></tr><tr><td>Rhodamine-Heparin</td><td>Creative PEGWorks</td><td>HP-204</td><td>Light Sensitive</td></tr><tr><td>Fluorescein-Heparin</td><td>Creative PEGWorks</td><td>HP-201</td><td>Light Sensitive</td></tr><tr><td>Mowiol</td><td>EMD Millipore</td><td>475904-100GM</td><td></td></tr><tr><td>Paraformaldehyde (PFA, methanol free)</td><td>Thermo Sci Pierce Biotech, available through Fisher Scientific</td><td>PI28908 at Fisher</td><td>Use in Fume Hood</td></tr><tr><td>Reacti-bind neutravidin plates (Avidin coated black 96-well dishes)</td><td>Thermo Sci Pierce Biotech, through Fisher Scientific</td><td>PI15510 at Fisher</td><td>Pay attention to shelf-life</td></tr><tr><td>Black 96-well plates</td><td>Corning Life Sciences Plastic, purchased through Fisher Scientific</td><td>064432 at Fisher</td><td></td></tr><tr><td>A7r5 vascular smooth muscle cell line</td><td>ATCC</td><td>CRL 1444</td><td>Can be exchanged into MEM medium&lt;sup&gt;1&lt;/sup&gt;</td></tr><tr><td>BAOEC bovine aortic endothelial cells</td><td>Cell Applications, Inc.</td><td>B304-05</td><td>Culture as recommended initially, can be exchanged into MEM medium for continuing culture&lt;sup&gt;1,7&lt;/sup&gt;</td></tr><tr><td>BAOSMC bovine aortic smooth muscle cells</td><td>Cell Applications, Inc.</td><td>B354-05</td><td>Culture as recommended initially, can be exchanged into MEM medium for continuing culture&lt;sup&gt;1&lt;/sup&gt;</td></tr><tr><td>RAOEC rat aortic endothelial cells</td><td>Cell Applications, Inc.</td><td>R304-05a</td><td>Culture as recommended initially, can be exchanged into MEM medium for continuing culture&lt;sup&gt;7&lt;/sup&gt;</td></tr><tr><td>Biotinylated anti-GFP</td><td>Thermo Sci Pierce Biotech, through Fisher Scientific</td><td>MA5-15256-BTIN</td><td></td></tr><tr><td>Streptavidin-coated beads</td><td>Sigma</td><td>S1638</td><td></td></tr><tr><td>HeBS</td><td>Available from Bio-Rad</td><td></td><td>Can be prepared in the lab. The pH is 6.8</td></tr><tr><td>TMEM184A antibody to the N-terminus</td><td>Santa Cruz Biotechnology</td><td>sc292006</td><td>Only known TMEM184A antibody to N-terminal region.</td></tr><tr><td>TMEM184A antibody to the C-terminus</td><td>Obtained from ProSci Inc, Poway, CA&amp;nbsp;</td><td>Pro Sci 5681</td><td>ProSci used in &lt;strong&gt;Figure 1&lt;/strong&gt;</td></tr><tr><td>GFP antibodies</td><td>Santa Cruz Biotechnology</td><td>sc9996</td><td>Used in &lt;strong&gt;Figure 5&lt;/strong&gt;</td></tr><tr><td>Secondary antibodies, labeled with TRITC or Cy3</td><td>Jackson ImmunoResearch Laboratories, Inc, West Grove, PA</td><td>711 025 152 (donkey anti-rabbit, TRITC)&lt;br/&gt; 715 165 150 (donkey anti-mouse, Cy3)</td><td>Minimal cross-reactivity to minimize any nonspecific staining.</td></tr><tr><td>CHAPS</td><td>Purchased from Sigma</td><td>C5849</td><td>Note that this specific catalog number has been discontinued.&amp;nbsp; Supplier will provide information regarding replacement.</td></tr><tr><td>Live imaging 35-mm dishes</td><td>MatTek (Ashland MA)</td><td>P35G-1.0 &amp;ndash; 20 mm - C</td><td></td></tr><tr><td>Confocal Microscope</td><td>Zeiss</td><td>LSM 510 Meta with a 63X oil-immersion lens</td><td>Used for images and live-imaging in &lt;strong&gt;Figures 1, 2 and 3&lt;/strong&gt;</td></tr><tr><td>Confocal Microscope</td><td>Nikon</td><td>C2+ confocal with a 60X oil-immersion lens</td><td>Used for images in &lt;strong&gt;Figure 5&lt;/strong&gt;</td></tr><tr><td>Confocal Microscope</td><td>Zeiss</td><td>Zeiss LSM 880 with a 63X oil-immersion lens</td><td>Used for images in &lt;strong&gt;Figure 2C&lt;/strong&gt;</td></tr><tr><td>Electroporation equipment</td><td>Bio-Rad</td><td>Gene Pulser X-Cell System</td><td></td></tr><tr><td>Electroporation cuvettes</td><td>Available from MidSci</td><td>EC2L</td><td>Can also be obtained from equipment supplier</td></tr><tr><td>Plate reader</td><td>TECAN</td><td>TECAN Infinite&amp;reg; m200 Pro plate reader</td><td>Readings in the middle of the wells rather than at the surface.</td></tr><tr><td>Computer program for measuring staining intensity</td><td>Image J</td><td>https://imagej.nih.gov/ij/&lt;br/&gt; Program and information available on-line</td><td>Any appropriate program can be used. See https://theolb.readthedocs.io/en/latest/imaging/measuring-cell-fluorescence-using-imagej.html for additional detail&amp;nbsp;&amp;nbsp;</td></tr><tr><td>Cell Culture trypsin solution</td><td>Sigma</td><td>T4174</td><td>purchased as a 10x solution</td></tr></tbody></table>

using a gfp-tagged tmem184a construct for confirmation of heparin receptor identity

新規タンパク質は、親和性に基づく分離やバイオインフォマティクス解析によって識別されると、彼らはしばしば、主に特徴付けられていないです。予測される配列内の特定のペプチドに対する抗体は、いくつかのローカライズ実験を可能にします。しかし、抗体と他の可能な相互作用は、多くの場合、除外することはできません。この状況は、タンパク質配列に依存するアッセイのセットを開発する機会を提供しました。具体的には、タンパク質のC末端にGFPコード配列に連結された遺伝子配列を含む構築物が得られ、これらの目的のために使用しました。局在化、リガンド親和性、および機能の利得を特徴付けるための実験は、最初に設計し、ヘパリン受容体1としてTMEM184Aの同定を確認するために行きました。さらに、構築物は膜トポロジーの問題に取り組む研究および詳細なタンパク質 - リガンド相互作用のために使用することができます。本報告書は、ARを提示します簡単に他の新規タンパク質のために適合させることができる血管細胞で発現したGFP-TMEM184A構築に基づいて実験プロトコルのアンジュ。

、理論的には、任意のDNAのトランスフェクション細胞への構築物は、親油性のトランスフェクション試薬を用いて達成することができるが、これまでの報告は、GFPのより効果的なトランスフェクションはエレクトロポレーション12を使用して、内皮細胞への構築物を示します。ここに提供されたプロトコルは、一般的に使用される主要由来内皮細胞?...

Watch this Scientific Journal Video about Using a GFP-tagged TMEM184A Construct for Confirmation of Heparin Receptor Identity at JoVE.com

Using a GFP-tagged TMEM184A Construct for Confirmation of Heparin Receptor Identity

真核生物の発現のために設計されたカルボキシ末端にGFPタグを有する構築物をコードするTMEM184Aは、血管細胞中のヘパリン受容体としてTMEM184Aの同定を確認するために設計されたアッセイに使用しました。

GFPタグTMEM184Aを使用すると、ヘパリン受容体のアイデンティティの確認のために構築します

When novel proteins are identified through affinity-based isolation and bioinformatics analysis, they are often largely uncharacterized. Antibodies ...

using-gfp-tagged-tmem184a-construct-for-confirmation-heparin-receptor

Universidad San Sebastian

Research

JoVE Journal

Genetics

7.9K ビュー.  Lehigh University. 真核生物の発現のために設計されたカルボキシ末端にGFPタグを有する構築物をコードするTMEM184Aは、血管細胞中のヘパリン受容体としてTMEM184Aの同定を確認するために設計されたアッセイに使用しました。 

ビデオ: Using a GFP-tagged TMEM184A Construct for Confirmation of Heparin Receptor Identity

Expression and Purification of the Human Lipid-sensitive Cation Channel TRPC3 for Structural Determination by Single-particle Cryo-electron Microscopy

Transient receptor potential channels (TRPCs) of the canonical TRP subfamily are nonselective cation channels that play an essential role in calcium homeostasis, particularly store-operated calcium entry, which is critical to maintaining proper function of synaptic vesicle release and intracellular signaling pathways. Accordingly, TRPC channels have been implicated in a variety of human diseases including cardiovascular disorders such as cardiac hypertrophy, neurodegenerative disorders such as Parkinson&#39;s disease, and neurologic disorders such as spinocerebellar ataxia. Therefore, TRPC channels represent a potential pharmacologic target in human diseases. However, the molecular mechanisms of gating in these channels are still unclear. The difficulty in obtaining large quantities of stable, homogeneous, and purified protein has been a limiting factor in structure determination studies, particularly for mammalian membrane proteins such as the TRPC ion channels. Here, we present a protocol for the large-scale expression of mammalian ion channel membrane proteins using a modified baculovirus gene transfer system and the purification of these proteins by affinity and size-exclusion chromatography. We further present a protocol to collect single-particle cryo-electron microscopy images from purified protein and to use these images to determine the protein structure. Structure determination is a powerful method for understanding the mechanisms of gating and function in ion channels.

This protocol describes techniques used to determine ion channel structures by cryo-electron microscopy, including a baculovirus system used to efficiently express genes in mammalian cells with minimum effort and toxicity, protein extraction, purification, and quality checking, sample grid preparation and screening, as well as data collection and processing.

式と単一粒子の低温電子顕微鏡による構造決定のための人間脂質感受性陽イオン チャネル TRPC3 の精製

Transient receptor potential channels (TRPCs) of the canonical TRP subfamily are nonselective cation channels that play an essential role in calcium ...

生化学

Optimizing the Genetic Incorporation of Chemical Probes into GPCRs for Photo-crosslinking Mapping and Bioorthogonal Chemistry in Live Mammalian Cells

The genetic incorporation of non-canonical amino acids (ncAAs) via amber stop codon suppression is a powerful technique to install artificial probes and reactive moieties onto proteins directly in the live cell. Each ncAA is incorporated by a dedicated orthogonal suppressor-tRNA/amino-acyl-tRNA-synthetase (AARS) pair that is imported into the host organism. The incorporation efficiency of different ncAAs can greatly differ, and be unsatisfactory in some cases. Orthogonal pairs can be improved by manipulating either the AARS or the tRNA. However, directed evolution of tRNA or AARS using large libraries and dead/alive selection methods are not feasible in mammalian cells. Here, a facile and robust fluorescence-based assay to evaluate the efficiency of orthogonal pairs in mammalian cells is presented. The assay allows screening tens to hundreds of AARS/tRNA variants with a moderate effort and within a reasonable time. Use of this assay to generate new tRNAs that significantly improve the efficiency of the pyrrolysine orthogonal system is described, along with the application of ncAAs to the study of G-protein coupled receptors (GPCRs), which are challenging objects for ncAA mutagenesis. First, by systematically incorporating a photo-crosslinking ncAA throughout the extracellular surface of a receptor, binding sites of different ligands on the intact receptor are mapped directly in the live cell. Second, by incorporating last-generation ncAAs into a GPCR, ultrafast catalyst-free receptor labeling with a fluorescent dye is demonstrated, which exploits bioorthogonal strain-promoted inverse Diels Alder cycloaddition (SPIEDAC) on the live cell. As ncAAs can be generally applied to any protein independently on its size, the method is of general interest for a number of applications. In addition, ncAA incorporation does not require any special equipment and is easily performed in standard biochemistry labs.

A facile fluorescence assay is presented to evaluate the efficiency of amino-acyl-tRNA-synthetase/tRNA pairs incorporating non-canonical amino-acids (ncAAs) into proteins expressed in mammalian cells. The application of ncAAs to study G-protein coupled receptors (GPCRs) is described, including photo-crosslinking mapping of binding sites and bioorthogonal GPCR labeling on live cells.

光橋マッピングおよび生きている哺乳類細胞における Bioorthogonal 化学の Gpcr にプローブを化学物質の遺伝的結合の最適化

The genetic incorporation of non-canonical amino acids (ncAAs) via amber stop codon suppression is a powerful technique to install artificial probes and ...

化学

Measuring TCR-pMHC Binding In Situ using a FRET-based Microscopy Assay

T-cells are remarkably specific and effective when recognizing antigens in the form of peptides embedded in MHC molecules (pMHC) on the surface of Antigen Presenting Cells (APCs). This is despite T-cell antigen receptors (TCRs) exerting usually a moderate affinity (&#181;M range) to antigen when binding is measured in vitro1. In view of the molecular and cellular parameters contributing to T-cell antigen sensitivity, a microscopy-based methodology has been developed as a means to monitor TCR-pMHC binding in situ, as it occurs within the synapse of a live T-cell and an artificial and functionalized glass-supported planar lipid bilayer (SLB), which mimics the cell membrane of an Antigen presenting Cell (APC) 2. Measurements are based on F&#246;rster Resonance Energy Transfer (FRET) between a blue- and red-shifted fluorescent dye attached to the TCR and the pMHC. Because the efficiency of FRET is inversely proportional to the sixth power of the inter-dye distance, one can employ FRET signals to visualize synaptic TCR-pMHC binding. The sensitive of the microscopy approach supports detection of single molecule FRET events. This allows to determine the affinity and off-rate of synaptic TCR-pMHC interactions and in turn to interpolate the on-rate of binding. Analogous assays could be applied to measure other receptor-ligand interactions in their native environment.

Measuring TCR-pMHC Binding In Situ using a FRET-based Microscopy Assay

This manuscript describes how to conduct (single molecule) F&#246;rster Resonance Energy Transfer (FRET)- based assays to measure the binding dynamics between T-cell antigen receptor (TCR) and antigenic peptide-loaded MHC molecules as they occur within the immunological synapse of a T-cell in contact with a functionalized planar supported lipid bilayer.

TCR-のpMHCが結合を測定します<em&gt;その場で</em&gt; FRETベースの顕微鏡アッセイを使用して

T-cells are remarkably specific and effective when recognizing antigens in the form of peptides embedded in MHC molecules (pMHC) on the surface of Antigen ...

生物工学

<meta charset="utf8"></head><body>CRISPR/Cas9ノックインを用いたゼブラフィッシュ幼生の蛍光タンパク質標識

Fluorescence Labeling to Visualize Low-Expressed Proteins in Zebrafish

CRISPR/Cas9-mediated knock-in (KI) technology allows for easier fluorescent-protein tagging in zebrafish (Danio rerio), a preferred model organism for in vivo imaging due to its transparency during the early developmental stage. Here, we provide a detailed protocol for performing high-efficiency fluorescence gene KI, rapid screening for KI founders, and low-abundance protein tracing in zebrafish larvae, which will lay a critical foundation for subsequent physio-pathological studies in zebrafish. The current protocol includes complete steps for the sgRNA design for the gene of interest, sgRNA in vitro transcription, Cas9 mRNA in vitro transcription, in vivo sgRNA screen for the one with the highest efficiency, donor plasmid design and construction, microinjection in zebrafish larvae, KI founder screen and zebrafish live imaging. Critical steps, troubleshooting tips, quality control methods, and advantages and applications of this protocol are included and discussed. This protocol assures quick and accurate results at a low cost and has been validated by multiple trials.

<meta charset="utf8"></head><body>ゼブラフィッシュの低発現タンパク質を可視化するための蛍光標識

Here, we present a protocol to label proteins with a fluorescence protein tag in zebrafish larvae, a newly developed and modified in vivo system especially useful for visualizing low-abundance proteins in zebrafish.

ゼブラフィッシュの低発現タンパク質を可視化するための蛍光標識

CRISPR/Cas9-mediated knock-in (KI) technology allows for easier fluorescent-protein tagging in zebrafish (Danio rerio), a preferred model organism for in ...

遺伝学

Using an &#945;-Bungarotoxin Binding Site Tag to Study GABA A Receptor Membrane Localization and Trafficking

It is increasingly evident that neurotransmitter receptors, including ionotropic GABA A receptors (GABAAR), exhibit highly dynamic trafficking and cell surface mobility1-7. To study receptor cell surface localization and endocytosis, the technique described here combines the use of fluorescent &#945;-bungarotoxin with cells expressing constructs containing an &#945;-bungarotoxin (Bgt) binding site (BBS). The BBS (WRYYESSLEPYPD) is based on the &#945; subunit of the muscle nicotinic acetylcholine receptor, which binds Bgt with high affinity8,9. Incorporation of the BBS site allows surface localization and measurements of receptor insertion or removal with application of exogenous fluorescent Bgt, as previously described in the tracking of GABAA and metabotropic GABAB receptors2,10. In addition to the BBS site, we inserted a pH-sensitive GFP (pHGFP11) between amino acids 4 and 5 of the mature GABAAR subunit by standard molecular biology and PCR cloning strategies (see Figure 1)12. The BBS is 3&#39; of the pH-sensitive GFP reporter, separated by a 13-amino acid alanine/proline linker. For trafficking studies described in this publication that are based on fixed samples, the pHGFP serves as a reporter of total tagged GABAAR subunit protein levels, allowing normalization of the Bgt labeled receptor population to total receptor population. This minimizes cell to cell Bgt staining signal variability resulting from higher or lower baseline expression of the tagged GABAAR subunits. Furthermore the pHGFP tag enables easy identification of construct expressing cells for live or fixed imaging experiments.

Here we demonstrate the use of fluorescent Alexa dye coupled to &#945;-bungarotoxin to measure GABA A receptor surface localization and endocytosis in hippocampal neurons. Through the use of constructs bearing a short extracellular tag that binds &#945;-bungarotoxin, analysis of plasma membrane protein endocytic trafficking can be achieved.

GABA A受容体の膜局在化および輸送を研究するために、α-ブンガロトキシン結合部位タグを使用して

It is increasingly evident that neurotransmitter receptors, including ionotropic GABA A receptors (GABAAR), exhibit highly dynamic trafficking and cell ...

神経科学

Imaging Protein-protein Interactions in vivo

Protein-protein interactions are a hallmark of all essential cellular processes. However, many of these interactions are transient, or energetically weak, preventing their identification and analysis through traditional biochemical methods such as co-immunoprecipitation. In this regard, the genetically encodable fluorescent proteins (GFP, RFP, etc.) and their associated overlapping fluorescence spectrum have revolutionized our ability to monitor weak interactions in vivo using F&ouml;rster resonance energy transfer (FRET)1-3. Here, we detail our use of a FRET-based proximity assay for monitoring receptor-receptor interactions on the endothelial cell surface.

Imaging Protein-protein Interactions in vivo

This protocol describes how to image protein-protein interactions using a FRET-based proximity assay.

イメージングタンパク質間相互作用 in vivoで</em

Protein-protein interactions are a hallmark of all essential cellular processes. However, many of these interactions are transient, or energetically weak, ...

生物学

Genetically-encoded Molecular Probes to Study G Protein-coupled Receptors

To facilitate structural and dynamic studies of G protein-coupled receptor (GPCR) signaling complexes, new approaches are required to introduce informative probes or labels into expressed receptors that do not perturb receptor function. We used amber codon suppression technology to genetically-encode the unnatural amino acid, p-azido-L-phenylalanine (azF) at various targeted positions in GPCRs heterologously expressed in mammalian cells. The versatility of the azido group is illustrated here in different applications to study GPCRs in their native cellular environment or under detergent solubilized conditions. First, we demonstrate a cell-based targeted photocrosslinking technology to identify the residues in the ligand-binding pocket of GPCR where a tritium-labeled small-molecule ligand is crosslinked to a genetically-encoded azido amino acid. We then demonstrate site-specific modification of GPCRs by the bioorthogonal Staudinger-Bertozzi ligation reaction that targets the azido group using phosphine derivatives. We discuss a general strategy for targeted peptide-epitope tagging of expressed membrane proteins in-culture and its detection using a whole-cell-based ELISA approach. Finally, we show that azF-GPCRs can be selectively tagged with fluorescent probes. The methodologies discussed are general, in that they can in principle be applied to any amino acid position in any expressed GPCR to interrogate active signaling complexes.

We genetically-encode the unnatural amino acid, p-azido-L-phenylalanine at various targeted positions in GPCRs and show the versatility of the azido group in different applications. These include a targeted photocrosslinking technology to identify residues in the ligand-binding pocket of a GPCR, and site-specific bioorthogonal modification of GPCRs with a peptide-epitope tag or fluorescent probe.

遺伝的にコードされた分子プローブは、Gタンパク質共役受容体を研究する

To facilitate structural and dynamic studies of G protein-coupled receptor (GPCR) signaling complexes, new approaches are required to introduce ...

Determination of the Relative Cell Surface and Total Expression of Recombinant Ion Channels Using Flow Cytometry

Inherited or de novo mutations in cation-selective channels may lead to sudden cardiac death. Alteration in the plasma membrane trafficking of these multi-spanning transmembrane proteins, with or without change in channel gating, is often postulated to contribute significantly in this process. It has thus become critical to develop a method to quantify the change of the relative cell surface expression of cardiac ion channels on a large scale. Herein, a detailed protocol is provided to determine the relative total and cell surface expression of cardiac L-type calcium channels CaV1.2 and membrane-associated subunits in tsA-201 cells using two-color fluorescent cytometry assays. Compared with other microscopy-based or immunoblotting-based qualitative methods, flow cytometry experiments are fast, reproducible, and large-volume assays that deliver quantifiable end-points on large samples of live cells (ranging from 104 to 106 cells) with similar cellular characteristics in a single flow. Constructs were designed to constitutively express mCherry at the intracellular C-terminus (thus allowing a rapid assessment of the total protein expression) and express an extracellular-facing hemagglutinin (HA) epitope to estimate the cell surface expression of membrane proteins using an anti-HA fluorescence conjugated antibody. To avoid false negative, experiments were also conducted in permeabilized cells to confirm the accessibility and proper expression of the HA epitope. The detailed procedure provides: (1) design of tagged DNA (deoxyribonucleic acid) constructs, (2) lipid-mediated transfection of constructs in tsA-201 cells, (3) culture, harvest, and staining of non-permeabilized and permeabilized cells, and (4) acquisition and analysis of fluorescent signals. Additionally, the basic principles of flow cytometry are explained and the experimental design, including the choice of fluorophores, titration of the HA antibody and control experiments, is thoroughly discussed. This specific approach offers objective relative quantification of the total and cell surface expression of ion channels that can be extended to study ion pumps and plasma membrane transporters.

Inherited cardiac arrhythmias are often caused by mutations that alter the surface delivery of one or more ion channels. Here, we adapt flow cytometry assays to provide a quantification of the relative total and cell surface protein expression of recombinant ion channels expressed in tsA-201 cells.

フローサイトメトリーを用いた組換えイオンチャネルの相対的な細胞表面および合計式の決意

Inherited or de novo mutations in cation-selective channels may lead to sudden cardiac death. Alteration in the plasma membrane trafficking of these ...

GFPタグTMEM184Aを使用すると、ヘパリン受容体のアイデンティティの確認のために構築します

要約

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式と単一粒子の低温電子顕微鏡による構造決定のための人間脂質感受性陽イオンチャネル TRPC3 の精製

光橋マッピングおよび生きている哺乳類細胞における Bioorthogonal 化学の Gpcr にプローブを化学物質の遺伝的結合の最適化

TCR-のpMHCが結合を測定します

ゼブラフィッシュの低発現タンパク質を可視化するための蛍光標識

ゼブラフィッシュの低発現タンパク質を可視化するための蛍光標識

ゼブラフィッシュの低発現タンパク質を可視化するための蛍光標識

GABA A受容体の膜局在化および輸送を研究するために、α-ブンガロトキシン結合部位タグを使用して

イメージングタンパク質間相互作用 in vivoで

遺伝的にコードされた分子プローブは、Gタンパク質共役受容体を研究する

フローサイトメトリーを用いた組換えイオンチャネルの相対的な細胞表面および合計式の決意

GFPタグTMEM184Aを使用すると、ヘパリン受容体のアイデンティティの確認のために構築します

要約

さらに動画を探す

この動画の章

式と単一粒子の低温電子顕微鏡による構造決定のための人間脂質感受性陽イオン チャネル TRPC3 の精製

光橋マッピングおよび生きている哺乳類細胞における Bioorthogonal 化学の Gpcr にプローブを化学物質の遺伝的結合の最適化

TCR-のpMHCが結合を測定します

ゼブラフィッシュの低発現タンパク質を可視化するための蛍光標識

ゼブラフィッシュの低発現タンパク質を可視化するための蛍光標識

ゼブラフィッシュの低発現タンパク質を可視化するための蛍光標識

GABA A受容体の膜局在化および輸送を研究するために、α-ブンガロトキシン結合部位タグを使用して

イメージングタンパク質間相互作用 in vivoで

遺伝的にコードされた分子プローブは、Gタンパク質共役受容体を研究する

フローサイトメトリーを用いた組換えイオンチャネルの相対的な細胞表面および合計式の決意

式と単一粒子の低温電子顕微鏡による構造決定のための人間脂質感受性陽イオンチャネル TRPC3 の精製