المؤلف بفضل روبرتو Kolter (كلية هارفارد الطبية) لتقديم المشورة والمساعدة له أثناء وضع هذه الشاشة coculture لا تقدر بثمن. وقالت انها أيضا وذلك بفضل ماثيو القوى لقراءة المخطوطة من أجل الوضوح، وشيا يي تشنغ للمساعدة في الحصول على الشكل 6.

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Rev. 33, 152-163 (2009).</li><li>Vlamakis, H., Aguilar, C., Losick, R., Kolter, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Control+of+cell+fate+by+the+formation+of+an+architecturally+complex+bacterial+community.">Control of cell fate by the formation of an architecturally complex bacterial community.</a> Genes Dev. 22, 945-953 (2008).</li><li>Branda, S. S., Gonzalez-Pastor, J. E., Ben-Yehuda, S., Losick, R., Kolter, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fruiting+body+formation+by+Bacillus+subtilis.">Fruiting body formation by Bacillus subtilis.</a> Proc. Natl. Acad. Sci. U.S.A. 98, 11621-11626 (2001).</li><li>Shank, E. 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=Interspecies+interactions+that+result+in+Bacillus+subtilis+forming+biofilms+are+mediated+mainly+by+members+of+its+own+genus.">Interspecies interactions that result in Bacillus subtilis forming biofilms are mediated mainly by members of its own genus.</a> Proc. Natl. Acad. Sci. U.S.A. 108, 1236-1243 (2011).</li><li>Piston, D. W., Patterson, G. H., Lippincott-Schwartz, J., Claxton, N. S., Davidson, M. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Introduction to Fluorescent Proteins. , (2013).</li><li>Chudakov, D. M., Matz, M. V., Lukyanov, S., Lukyanov, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluorescent+proteins+and+their+applications+in+imaging+living+cells+and+tissues.">Fluorescent proteins and their applications in imaging living cells and tissues.</a> Physiol. Rev. 90, 1103-1163 (2010).</li><li>Shaner, N. C., Patterson, G. H., Davidson, M. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advances+in+fluorescent+protein+technology.">Advances in fluorescent protein technology.</a> J. Cell Sci. 120, 4247-4260 (2007).</li><li>Shaner, N. C., Steinbach, P. A., Tsien, R. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+guide+to+choosing+fluorescent+proteins.">A guide to choosing fluorescent proteins.</a> Nat. Methods. 2, 905-909 (2005).</li><li>Nicolas, P., 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=Condition-dependent+transcriptome+reveals+high-level+regulatory+architecture+in+Bacillus+subtilis.">Condition-dependent transcriptome reveals high-level regulatory architecture in Bacillus subtilis.</a> Science. 335, 1103-1106 (2012).</li><li>Middleton, R., Hofmeister, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+shuttle+vectors+for+ectopic+insertion+of+genes+into+Bacillus+subtilis.">New shuttle vectors for ectopic insertion of genes into Bacillus subtilis.</a> Plasmid. 51, 238-245 (2004).</li><li>Shimotsu, H., Henner, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Construction+of+a+single-copy+integration+vector+and+its+use+in+analysis+of+regulation+of+the+trp+operon+of+Bacillus+subtilis.">Construction of a single-copy integration vector and its use in analysis of regulation of the trp operon of Bacillus subtilis.</a> Gene. 43, 85-94 (1986).</li><li>Guerout-Fleury, A. M., Frandsen, N., Stragier, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Plasmids+for+ectopic+integration+in+Bacillus+subtilis.">Plasmids for ectopic integration in Bacillus subtilis.</a> Gene. 180, 57-61 (1996).</li><li>Semsey, S., Blaha, B., Koles, K., Orosz, L., Papp, P. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Site-specific+integrative+elements+of+rhizobiophage+16-3+can+integrate+into+proline+tRNA+(CGG)+genes+in+different+bacterial+genera.">Site-specific integrative elements of rhizobiophage 16-3 can integrate into proline tRNA (CGG) genes in different bacterial genera.</a> J. Bacteriol. 184, 177-182 (2002).</li><li>Charpentier, E., 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=Novel+cassette-based+shuttle+vector+system+for+gram-positive+bacteria.">Novel cassette-based shuttle vector system for gram-positive bacteria.</a> Appl. Environ. Microbiol. 70, 6076-6085 (2004).</li><li>Yang, H. Y., Kim, Y. W., Chang, H. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Construction+of+an+integration-proficient+vector+based+on+the+site-specific+recombination+mechanism+of+enterococcal+temperate+phage+phiFC1.">Construction of an integration-proficient vector based on the site-specific recombination mechanism of enterococcal temperate phage phiFC1.</a> J. Bacteriol. 184, 1859-1864 (2002).</li><li>Choi, K. H., Schweizer, H. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=mini-Tn7+insertion+in+bacteria+with+single+attTn7+sites:+example+Pseudomonas+aeruginosa.">mini-Tn7 insertion in bacteria with single attTn7 sites: example Pseudomonas aeruginosa.</a> Nat. Protoc. 1, 153-161 (2006).</li><li>Craig, N. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tn7:+a+target+site-specific+transposon.">Tn7: a target site-specific transposon.</a> Mol. Microbiol. 5, 2569-2573 (1991).</li><li>Garcia-Betancur, J. C., Yepes, A., Schneider, J., Lopez, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-cell+analysis+of+Bacillus+subtilis+biofilms+using+fluorescence+microscopy+and+flow+cytometry.">Single-cell analysis of Bacillus subtilis biofilms using fluorescence microscopy and flow cytometry.</a> J. Vis. Exp. (60), e3796 (2012).</li><li>Lopez, D., Fischbach, M. A., Chu, F., Losick, R., Kolter, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structurally+diverse+natural+products+that+cause+potassium+leakage+trigger+multicellularity+in+Bacillus+subtilis.">Structurally diverse natural products that cause potassium leakage trigger multicellularity in Bacillus subtilis.</a> Proc. Natl. Acad. Sci. U.S.A. 106, 280-285 (2009).</li><li>Vartoukian, S. R., Palmer, R. M., Wade, W. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Strategies+for+culture+of+'unculturable'+bacteria.">Strategies for culture of 'unculturable' bacteria.</a> FEMS Microbiol. Lett. 309, 1-7 (2010).</li><li>Romano, J. D., Kolter, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pseudomonas-Saccharomyces+interactions:+influence+of+fungal+metabolism+on+bacterial+physiology+and+survival.">Pseudomonas-Saccharomyces interactions: influence of fungal metabolism on bacterial physiology and survival.</a> J. Bacteriol. 187, 940-948 (2005).</li><li>Branda, S. S., Chu, F., Kearns, D. B., Losick, R., Kolter, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+major+protein+component+of+the+Bacillus+subtilis+biofilm+matrix.">A major protein component of the Bacillus subtilis biofilm matrix.</a> Mol. Microbiol. 59, 1229-1238 (2006).</li><li>Zengler, K., 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=Cultivating+the+uncultured.">Cultivating the uncultured.</a> Proc. Natl. Acad. Sci. U.S.A. 99, 15681-15686 (2002).</li></ol>

يعلن الكتاب أنه ليس لديهم مصالح مالية المتنافسة.

واحدة من القيود المتأصلة في هذا البروتوكول هو أنه يعتمد على cultivability الكائنات الميكروبية. كما تم توثيقه جيدا 24، معظم الحياة الميكروبية على هذا الكوكب لا يمكن (حتى الآن) يمكن زراعتها تحت ظروف زراعة استكشافها حتى الآن. وبالتالي، فإن عددا كبيرا من التفاعلات بين الأ?...

<table border="1">
	<tbody>
		<tr>
			<td>Name of Reagent/ Equipment</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments/Description</td>
		</tr>
		<tr>
			<td>Spectrophotometer</td>
			<td></td>
			<td></td>
			<td>Any spectrophotomer capable of measuing OD600 absorbance values.</td>
		</tr>
		<tr>
			<td>Luria broth, Lennox</td>
			<td>VWR</td>
			<td>80017-484</td>
			<td>Alternative media sources may be necessary.</td>
		</tr>
		<tr>
			<td>Glass beads, 3 mm</td>
			<td>VWR</td>
			<td>26396-508</td>
			<td></td>
		</tr>
		<tr>
			<td>Gel loading tips, round</td>
			<td>VWR</td>
			<td>29442-666</td>
			<td></td>
		</tr>
		<tr>
			<td>Glass rods</td>
			<td>VWR</td>
			<td>59060-069</td>
			<td></td>
		</tr>
		<tr>
			<td>Fluorescence dissecting stereoscope</td>
			<td>Zeiss</td>
			<td>N/A</td>
			<td>The author used a Zeiss Stemi SV6 dissection stereoscope with an EXFO X-cite 120 fluorescent light source, a long-pass YFP filter cube, an achromat 0.63X objective, 10X eyepieces, and an Axio HRC HR digital camera. Most screening was done with the focusing mount at 2.0-3.2X. Any dissecting stereoscope with fluorescence capabilities is fine, provided you have the correct filters for the FP you are using. It is best if there is a shutter that allows you to easily switch between brightfield and fluorescense, as well as a stage that allows illumination from above and below. If you want to capture images, an attached camera is also necessary.</td>
		</tr>
	</tbody>
</table>

using coculture to detect chemically mediated interspecies interactions

في الطبيعة، ونادرا ما توجد البكتيريا في عزلة، بل هي بدلا محاطة مجموعة متنوعة من الكائنات الحية الدقيقة الأخرى التي تغير البيئة المحلية عن طريق إفراز نواتج الأيض. هذه المركبات لديها القدرة لتعديل وظائف الأعضاء والتفريق بين جيرانهم والميكروبية من العوامل الهامة المحتملة في إنشاء وصيانة للمجتمعات الميكروبية المعقدة. قمنا بتطوير شاشة القائم على مضان coculture لتحديد مثل هذه التفاعلات الميكروبية بوساطة كيميائيا. ينطوي على الشاشة الجمع بين النسخي فلوري مراسل سلالة بالميكروبات البيئية على وسائل الاعلام الصلبة والسماح للمستعمرات أن ينمو في coculture. تم تصميم مراسل النسخي الفلورسنت بحيث السلالة البكتيرية اختيار تتفلور عندما يتم التعبير عن النمط الظاهري معينة من الفائدة (أي تشكيل بيوفيلم، تبوغ والإنتاج عامل الفوعة، الخ.) يتم تنفيذ فحص في ظل ظروف النمو عرجإعادة هذا النمط الظاهري لا يتم التعبير (وبالتالي سلالة المراسل هو عادة nonfluorescent). عندما يفرز الميكروب والبيئية المستقلب الذي ينشط هذا النمط الظاهري، فإنه ينشر من خلال أجار وينشط مراسل بناء الفلورسنت. وهذا يسمح للتحريض-المنتجة للميكروب المستقلب ليتم الكشف عن: هم المستعمرات nonfluorescent معظم الأقرب إلى المستعمرات الفلورسنت. وبالتالي، هذه الشاشة يسمح تحديد الميكروبات البيئية التي تنتج نواتج إنتشاري التي تنشط استجابة فسيولوجية معينة في سلالة المراسل. يناقش هذا المنشور كيفية: أ) تحديد شروط الفحص coculture المناسبة، ب) إعداد المراسل والميكروبات البيئية للفحص، ج) أداء الشاشة coculture، د) عزل المفترضة حمل الكائنات الحية، وه) تأكيد نشاطهم في الشاشة الثانوية. قمنا بتطوير هذه الطريقة للكشف عن الكائنات الحية في التربة التي تنشط بيوفيلم مصفوفة الإنتاج في العصوية الرقيقة </م&gt;، ولكن نحن أيضا مناقشة الاعتبارات لتطبيق هذا النهج لغيرها من البكتيريا وراثيا لين العريكة.

تم استخدام هذه الشاشة لتحديد الكائنات الحية في التربة إفراز مركبات التي تغير فسيولوجيا B. الرقيقة. نتائج وصفها هنا التركيز على نوع من الخلايا المنتجة للمصفوفة B. الرقيقة، التي تنتج البروتين وexopolysaccharide التي مطلوبة من أجل تشكيل بيوفيلم قوية في هذه البكتيريا. ا...

Watch this Scientific Journal Video about Using Coculture to Detect Chemically Mediated Interspecies Interactions at JoVE.com

Using Coculture to Detect Chemically Mediated Interspecies Interactions

البكتيريا تنتج مركبات يفرز التي لديها القدرة على التأثير في علم وظائف الأعضاء من جيرانهم الميكروبية. نحن هنا وصف شاشة coculture التي تسمح الكشف عن مثل هذه التفاعلات بين الأنواع بوساطة كيميائيا عن طريق خلط التربة مع سلالات الميكروبات مراسل النسخي الفلورسنت من العصوية الرقيقة على وسائل الاعلام الصلبة.

باستخدام Coculture لكشف كيميائيا وساطة بين الأنواع التفاعلات

In nature, bacteria rarely exist in isolation; they are instead surrounded by a diverse array of other microorganisms that alter the local environment by ...

using-coculture-to-detect-chemically-mediated-interspecies

Research

JoVE Journal

Biology

13.5K Views.  University of North Carolina at Chapel Hill.  البكتيريا تنتج مركبات يفرز التي لديها القدرة على التأثير في علم وظائف الأعضاء من جيرانهم الميكروبية. نحن هنا وصف شاشة coculture التي تسمح الكشف عن مثل هذه التفاعلات بين الأنواع بوساطة كيميائيا عن طريق خلط التربة مع سلالات الميكروبات مراسل الن?...

Video: Using Coculture to Detect Chemically Mediated Interspecies Interactions

Microfluidic Co-culture of Epithelial Cells and Bacteria for Investigating Soluble Signal-mediated Interactions

The human gastrointestinal (GI) tract is a unique environment in which intestinal epithelial cells and non-pathogenic (commensal) bacteria coexist. It has been proposed that the microenvironment that the pathogen encounters in the commensal layer is important in determining the extent of colonization. Current culture methods for investigating pathogen colonization are not well suited for investigating this hypothesis as they do not enable co-culture of bacteria and epithelial cells in a manner that mimics the GI tract microenvironment. Here we describe a microfluidic co-culture model that enables independent culture of eukaryotic cells and bacteria, and testing the effect of the commensal microenvironment on pathogen colonization. The co-culture model is demonstrated by developing a commensal Escherichia coli biofilm among HeLa cells, followed by introduction of enterohemorrhagic E. coli (EHEC) into the commensal island, in a sequence that mimics the sequence of events in GI tract infection.

This protocol describes a microfluidic co-culture model for simultaneous and localized culture of epithelial cells and bacteria. This model can be used for investigating the role of different soluble molecular signals on pathogenesis as well as screen the effectiveness of putative probiotic bacterial strains.

ميكروفلويديك المشارك ثقافة الخلايا الظهارية والبكتيريا للتحقيق في ذوبان الإشارات بوساطة التفاعلات

The human gastrointestinal (GI) tract is a unique environment in which intestinal epithelial cells and non-pathogenic (commensal) bacteria coexist. It has ...

Analysis of Schwann-astrocyte Interactions Using In Vitro Assays

Schwann cells are one of the commonly used cells in repair strategies following spinal cord injuries. Schwann cells are capable of supporting axonal regeneration and sprouting by secreting growth factors 1,2 and providing growth promoting adhesion molecules 3 and extracellular matrix molecules 4. In addition they myelinate the demyelinated axons at the site of injury 5.
However following transplantation, Schwann cells do not migrate from the site of implant and do not intermingle with the host astrocytes 6,7. This results in formation of a sharp boundary between the Schwann cells and astrocytes, creating an obstacle for growing axons trying to exit the graft back into the host tissue proximally and distally. Astrocytes in contact with Schwann cells also undergo hypertrophy and up-regulate the inhibitory molecules 8-13.
In vitro assays have been used to model Schwann cell-astrocyte interactions and have been important in understanding the mechanism underlying the cellular behaviour.
These in vitro assays include boundary assay, where a co-culture is made using two different cells with each cell type occupying different territories with only a small gap separating the two cell fronts. As the cells divide and migrate, the two cellular fronts get closer to each other and finally collide. This allows the behaviour of the two cellular populations to be analyzed at the boundary. Another variation of the same technique is to mix the two cellular populations in culture and over time the two cell types segregate with Schwann cells clumped together as islands in between astrocytes together creating multiple Schwann-astrocyte boundaries.
The second assay used in studying the interaction of two cell types is the migration assay where cellular movement can be tracked on the surface of the other cell type monolayer 14,15. This assay is commonly known as inverted coverslip assay. Schwann cells are cultured on small glass fragments and they are inverted face down onto the surface of astrocyte monolayers and migration is assessed from the edge of coverslip.
Both assays have been instrumental in studying the underlying mechanisms involved in the cellular exclusion and boundary formation. Some of the molecules identified using these techniques include N-Cadherins 15, Chondroitin Sulphate proteoglycans(CSPGs) 16,17, FGF/Heparin 18, Eph/Ephrins19.
This article intends to describe boundary assay and migration assay in stepwise fashion and elucidate the possible technical problems that might occur.

Analysis of Schwann-astrocyte Interactions Using In Vitro Assays

This article intends to describe in stepwise fashion the commonly used in vitro assays used in studying Schwann cell-asrtocyte interactions.

تحليل شفان نجمية طريق التفاعلات في المختبر فحوصات

Schwann cells are one of the commonly used cells in repair strategies following spinal cord injuries. Schwann cells are capable of supporting axonal ...

The MultiBac Protein Complex Production Platform at the EMBL

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

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

على البروتين MultiBac مجمع منصة الإنتاج في EMBL

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

Rapid Synthesis and Screening of Chemically Activated Transcription Factors with GFP-based Reporters

Synthetic biology aims to rationally design and build synthetic circuits with desired quantitative properties, as well as provide tools to interrogate the structure of native control circuits. In both cases, the ability to program gene expression in a rapid and tunable fashion, with no off-target effects, can be useful. We have constructed yeast strains containing the ACT1 promoter upstream of a URA3 cassette followed by the ligand-binding domain of the human estrogen receptor and VP16. By transforming this strain with a linear PCR product containing a DNA binding domain and selecting against the presence of URA3, a constitutively expressed artificial transcription factor (ATF) can be generated by homologous recombination. ATFs engineered in this fashion can activate a unique target gene in the presence of inducer, thereby eliminating both the off-target activation and nonphysiological growth conditions found with commonly used conditional gene expression systems. A simple method for the rapid construction of GFP reporter plasmids that respond specifically to a native or artificial transcription factor of interest is also provided.

This protocol describes an experimental procedure for the rapid construction of artificial transcription factors (ATFs) with cognate GFP reporters&#160;and quantification of the ATFs ability to stimulate GFP expression via flow cytometry.

التجميعي السريع وفحص عوامل النسخ المنشط كيميائيا مع مراسلون القائم GFP

Synthetic biology aims to rationally design and build synthetic circuits with desired quantitative properties, as well as provide tools to interrogate the ...

Determination of Protein-ligand Interactions Using Differential Scanning Fluorimetry

A wide range of methods are currently available for determining the dissociation constant between a protein and interacting small molecules. However, most of these require access to specialist equipment, and often require a degree of expertise to effectively establish reliable experiments and analyze data. Differential scanning fluorimetry (DSF) is being increasingly used as a robust method for initial screening of proteins for interacting small molecules, either for identifying physiological partners or for hit discovery. This technique has the advantage that it requires only a PCR machine suitable for quantitative PCR, and so suitable instrumentation is available in most institutions; an excellent range of protocols are already available; and there are strong precedents in the literature for multiple uses of the method. Past work has proposed several means of calculating dissociation constants from DSF data, but these are mathematically demanding. Here, we demonstrate a method for estimating dissociation constants from a moderate amount of DSF experimental data. These data can typically be collected and analyzed within a single day. We demonstrate how different models can be used to fit data collected from simple binding events, and where cooperative binding or independent binding sites are present. Finally, we present an example of data analysis in a case where standard models do not apply. These methods are illustrated with data collected on commercially available control proteins, and two proteins from our research program. Overall, our method provides a straightforward way for researchers to rapidly gain further insight into protein-ligand interactions using DSF.

Differential scanning fluorimetry is a widely used method for screening libraries of small molecules for interactions with proteins. Here, we present a straightforward method to extend these analyses to provide an estimate of the dissociation constant between a small molecule and its protein partner.

تحديد تفاعلات البروتين يجند عن طريق المسح الضوئي التفاضلية Fluorimetry

A wide range of methods are currently available for determining the dissociation constant between a protein and interacting small molecules. However, most ...

Probing High-density Functional Protein Microarrays to Detect Protein-protein Interactions

High-density functional protein microarrays containing ~4,200 recombinant yeast proteins are examined for kinase protein-protein interactions using an affinity purified yeast kinase fusion protein containing a V5-epitope tag for read-out. Purified kinase is obtained through culture of a yeast strain optimized for high copy protein production harboring a plasmid containing a Kinase-V5 fusion construct under a GAL inducible promoter. The yeast is grown in restrictive media with a neutral carbon source for 6 hr followed by induction with 2% galactose. Next, the culture is harvested and kinase is purified using standard affinity chromatographic techniques to obtain a highly purified protein kinase for use in the assay. The purified kinase is diluted with kinase buffer to an appropriate range for the assay and the protein microarrays are blocked prior to hybridization with the protein microarray. After the hybridization, the arrays are probed with monoclonal V5 antibody to identify proteins bound by the kinase-V5 protein. Finally, the arrays are scanned using a standard microarray scanner, and data is extracted for downstream informatics analysis1,2 to determine a high confidence set of protein interactions for downstream validation in vivo.

Using protein microarrays containing nearly the entire S. cerevisiae proteome is probed for rapid unbiased interrogation of thousands of protein-protein interactions in parallel. This method can be utilized for protein-small molecule, posttranslational modification, and other assays in high-throughput.

التحقيق عالية الكثافة ميكروأرس البروتين وظيفية لكشف البروتين البروتين التفاعلات

High-density functional protein microarrays containing ~4,200 recombinant yeast proteins are examined for kinase protein-protein interactions using an ...

Using Caenorhabditis elegans to Screen for Tissue-Specific Chaperone Interactions

Correct folding and assembly of proteins and protein complexes are essential for cellular function. Cells employ quality control pathways that correct, sequester or eliminate damaged proteins to maintain a healthy proteome, thus ensuring cellular proteostasis and preventing further protein damage. Because of redundant functions within the proteostasis network, screening for detectable phenotypes using knockdown or mutations in chaperone-encoding genes in the multicellular organism Caenorhabditis elegans results in the detection of minor or no phenotypes in most cases. We have developed a targeted screening strategy to identify chaperones required for a specific function and thus bridge the gap between phenotype and function. Specifically, we monitor novel chaperone interactions using RNAi synthetic interaction screens, knocking-down chaperone expression, one chaperone at a time, in animals carrying a mutation in a chaperone-encoding gene or over-expressing a chaperone of interest. By disrupting two chaperones that individually present no gross phenotype, we can identify chaperones that aggravate or expose a specific phenotype when both perturbed. We demonstrate that this approach can identify specific sets of chaperones that function together to modulate the folding of a protein or protein complexes associated with a given phenotype.

Using Caenorhabditis elegans to Screen for Tissue-Specific Chaperone Interactions

To study chaperone-chaperone and chaperone-substrate interactions, we perform synthetic interaction screens in Caenorhabditis elegans using RNA interference in combination with mild mutations or over-expression of chaperones and monitor tissue-specific protein dysfunction at the organismal level.

استخدام Elegans Caenorhabditis إلى الشاشة لتفاعلات Chaperone الأنسجة محددة

Correct folding and assembly of proteins and protein complexes are essential for cellular function. Cells employ quality control pathways that correct, ...

Graphene Enclosure of Chemically Fixed Mammalian Cells for Liquid-Phase Electron Microscopy

A protocol is described for investigating the human epidermal growth factor receptor 2 (HER2) in the intact plasma membrane of breast cancer cells using scanning transmission electron microscopy (STEM). Cells of the mammalian breast cancer cell line SKBR3 were grown on silicon microchips with silicon nitride (SiN) windows. Cells were chemically fixed, and HER2 proteins were labeled with quantum dot nanoparticles (QDs), using a two-step biotin-streptavidin binding protocol. The cells were coated with multilayer graphene to maintain a hydrated state, and to protect them from electron beam damage during STEM. To examine the stability of the samples under electron beam irradiation, a dose series experiment was performed. Graphene-coated and non-coated samples were compared. Beam induced damage, in the form of bright artifacts, appeared for some non-coated samples at increased electron dose D, while no artifacts appeared on coated samples.

Presented here is a protocol for labeling membrane proteins in mammalian cells and coating the sample with graphene for liquid-phase scanning transmission electron microscopy. The stability of the samples against the damage caused by radiation can also studied with this protocol.

حاوية الجرافين من خلايا الثدييات الثابتة كيميائياً للمجهر الإلكتروني للمرحلة السائلة

A protocol is described for investigating the human epidermal growth factor receptor 2 (HER2) in the intact plasma membrane of breast cancer cells using ...

Culture Methods to Study Apical-Specific Interactions using Intestinal Organoid Models

The lining of the gut epithelium is made up of a simple layer of specialized epithelial cells that expose their apical side to the lumen and respond to external cues. Recent optimization of in vitro culture conditions allows for the re-creation of the intestinal stem cell niche and the development of advanced 3-dimensional (3D) culture systems that recapitulate the cell composition and the organization of the epithelium. Intestinal organoids embedded in an extracellular matrix (ECM) can be maintained for long-term and self-organize to generate a well-defined, polarized epithelium that encompasses an internal lumen and an external exposed basal side. This restrictive nature of the intestinal organoids presents challenges in accessing the apical surface of the epithelium in vitro and limits the investigation of biological mechanisms such as nutrient uptake and host-microbiota/host-pathogen interactions. Here, we describe two methods that facilitate access to the apical side of the organoid epithelium and support the differentiation of specific intestinal cell types. First, we show how ECM removal induces an inversion of the epithelial cell polarity and allows for the generation of apical-out 3D organoids. Second, we describe how to generate 2-dimensional (2D) monolayers from single cell suspensions derived from intestinal organoids, comprised of&#160;mature and differentiated cell types. These techniques provide novel tools to study apical-specific interactions of the epithelium with external cues in vitro and promote the use of organoids as a platform to facilitate precision medicine.

Here we present two protocols that allow the modeling of intestinal apical-specific interactions. Organoid-derived intestinal monolayers and Air-Liquid Interface (ALI) cultures facilitate the generation of well-differentiated epithelia accessible from both luminal and basolateral sides, whereas polarity-inverted intestinal organoids expose their apical side and are amenable to high throughput assays.

أساليب الثقافة لدراسة التفاعلات Apical محددة باستخدام نماذج الجهاز المعوي

The lining of the gut epithelium is made up of a simple layer of specialized epithelial cells that expose their apical side to the lumen and respond to ...

Bioinformatics Resources for the Study of Glycan-Mediated Protein Interactions

The Glyco@Expasy initiative was launched as a collection of interdependent databases and tools spanning several aspects of knowledge in glycobiology. In particular, it aims at highlighting interactions between glycoproteins (such as cell surface receptors) and carbohydrate-binding proteins mediated by glycans. Here, major resources of the collection are introduced through two illustrative examples centered on the N-glycome of the human Prostate Specific Antigen (PSA) and the O-glycome of human serum proteins. Through different database queries and with the help of visualization tools, this article shows how to explore and compare content in a continuum to gather and correlate otherwise scattered pieces of information. Collected data are destined to feed more elaborate scenarios of glycan function. Glycoinformatics introduced here is, therefore, proposed as a means to either strengthen, shape, or refute assumptions on the specificity of a protein glycome in a given context.

This protocol illustrates how to explore, compare, and interpret human protein glycomes with online resources.

موارد المعلوماتية الحيوية لدراسة تفاعلات البروتين بوساطة الجليكان

The Glyco@Expasy initiative was launched as a collection of interdependent databases and tools spanning several aspects of knowledge in glycobiology. In ...