Este trabajo fue apoyado por el NIH subvenciones RO1 DC006497, RO1 NS057289 y PO1 ES016738 (A a la Z. Zhang), Instituto de California para la Medicina Regenerativa subvenciones RS1-00331-1 y RL1-00682-1 (A a la Z. Zhang), el Parkinson estadounidense Asociación de la Enfermedad (A a la Z. Zhang y Choo YS) y la Fundación Michael J. Fox para la Investigación del Parkinson (Z. Zhang).

La detección de la ubiquitinación de proteínas en las células cultivadas <ol><li> Transfectar células cultivadas con plásmidos que expresan la proteína de interés y (epítopo de etiquetado de la versión) ubiquitina. </li><li> Hacer búfer completo lisis celular (2% SDS, 150 mM NaCl, 10 mM Tris-HCl, pH 8,0) con ortovanadato de sodio 2 mM, 50 mM de fluoruro de sodio, y los inhibidores de la proteasa. </li><li> Lisis de las células con 100 l buffer de lisis celular por placa (6 cm plato). Si un plato más grande se utiliza, ajustar el volumen en consecuencia. Agite el plato con cuidado para que el tampón de lisis cubrir toda el área de las células cultivadas. </li><li> Recoger las células con un rascador de células y la transferencia de los lisados ​​de células en un tubo eppendorf de 1,5 ml. Coloque el tubo en un plato caliente de inmediato a hervir durante 10 minutos. </li><li> Shear las células con un dispositivo de ultrasonidos. </li><li> Añadir 900ul de buffer de dilución (10 Triton mM Tris-HCl, pH 8,0, 150 mM NaCl, 2 mM EDTA, 1%). Incubar las muestras a 4 ° C durante 30-60 minutos con la rotación. </li><li> Girar las muestras diluidas a 20.000 xg durante 30 min. Transferir el sobrenadante resultante a un nuevo tubo eppendorf. Tenga cuidado de no perturbar el sedimento. </li><li> Medir la concentración de proteínas. </li><li> Prepare la proteína A o G-agarosa bolas conjugado de anticuerpos contra la proteína de interés en un buffer compatible (50% de lodo). Corte el extremo estrecho de una punta de pipeta P-200 y la transferencia de 14 a 20 l de resina de 500-1.500 mg de lisados ​​celulares preparados para inmunoprecipitación. Para las células con una eficiencia de transfección de alto, 500 mg será suficiente. Para las células con una eficiencia de transfección de baja, más proteínas puede ser necesario. </li><li> Se incuban las células lisado de perlas mezcla a 4 ° C durante la noche con la rotación. </li><li> De girar las bolas a 5000 xg durante 5 min. Aspirar el sobrenadante. Lavar la resina con la solución de lavado (10 mM Tris-HCl, pH 8,0, 1 M NaCl, 1 mM EDTA, 1% NP-40) dos veces. </li><li> Girar las cuentas por última vez a 20.000 xg durante 30 segundos. Aspirar la solución de lavado residual y hervir la resina con tampón de carga 2X SDS. </li><li> Cargar las muestras en un gel de SDS-PAGE para el análisis de inmunotransferencia. </li><li> Detectar la ubiquitina y la proteína diana con anticuerpos respectivos. Por immunoblotting, por lo general, detectar la ubiquitina en primer lugar. La membrana entonces se utiliza para detectar la proteína precipitada. </li></ol> La detección de la ubiquitinación de las proteínas diana a través de En el ensayo in vitro ubiquitinación <ol><li> Hacer buffer ubiquitinación 5X (100 mM Tris-HCl, pH 7,5, 25 mM MgCl2, 2,5 mM de DTT, 10 mM ATP). Guárdelos en pequeñas alícuotas a -20 ° C hasta por 6 meses. Algunos protocolos también añadir el fosfato de creatina y la creatina quinasa en el buffer de ATP 1,2 regeneración. </li><li> Para cada reacción, prepare una mezcla que contiene lo siguiente: <table border="1"><tbody><tr><td> L 8 </td><td> Buffer ubiquitinación 5X </td></tr><tr><td> 250 ng </td><td> ubiquitinación E1 </td></tr><tr><td> 500 ng </td><td> ubiquitinación E2 </td></tr><tr><td> 0,5 mg </td><td> ubiquitina </td></tr><tr><td> 0,5 mg </td><td> proteína de interés </td></tr><tr><td></td><td> agua a 40 l volumen total </td></tr></tbody></table> Como controles, preparar reacciones similares en la ausencia de cualquiera de E1, E2, o ubiquitina. </li><li> Incubar la mezcla a 37 ° C durante 1 hora o más. </li><li> Detener la reacción mediante la adición de SDS-PAGE muestra de amortiguación y hervir la muestra durante 10 minutos. </li><li> Cargar las muestras en gel SDS-PAGE para el análisis de inmunotransferencia. </li><li> Detectar la ubiquitina y la proteína diana con anticuerpos respectivos. </li></ol>

<ol>
	<li>Xiong, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=PINK1,+and+DJ-1+form+a+ubiquitin+E3+ligase+complex+promoting+unfolded+protein+degradation.">PINK1, and DJ-1 form a ubiquitin E3 ligase complex promoting unfolded protein degradation.</a> J Clin Invest. 119, 650-660 (2009).</li><li>Xirodimas, D. P., Saville, M. K., Bourdon, J. C., Hay, R. T., Lane, D. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mdm2-mediated+NEDD8+conjugation+of+p53+inhibits+its+transcriptional+activity.">Mdm2-mediated NEDD8 conjugation of p53 inhibits its transcriptional activity.</a> Cell. 118, 83-97 (2004).</li><li>Didier, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=RNF5,+a+RING+finger+protein+that+regulates+cell+motility+by+targeting+paxillin+ubiquitination+and+altered+localization.">RNF5, a RING finger protein that regulates cell motility by targeting paxillin ubiquitination and altered localization.</a> Mol Cell Biol. 23, 5331-5345 (2003).</li><li>Laney, J. D., Hochsetrasser, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Unit+14.5+Analysis+of+Protein+Ubiquitination.">Unit 14.5 Analysis of Protein Ubiquitination.</a> Current Protocols in Protein Science. , 14.5.1-14.5.11 (2002).</li></ol>

The authors have nothing to disclose.

En esta presentación, lo primero que describió las medidas que permitan detectar modificaciones ubiquitina a una proteína de interés en los cultivos de células de mamíferos. Con el fin de detectar la ubiquitinación específicamente en la proteína de interés, no en las proteínas que interactúan de forma no covalente, se utilizó una condición estricta para la lisis celular, inmunoprecipitación y el lavado de 1,3. Ubiquitinación, detectado por inmunoprecipitación de la proteína diana en un estad...

detection of protein ubiquitination

Ubiquitinación, la unión covalente de la ubiquitina polipéptido que se dirigen a proteínas, es una modificación postraduccional clave llevadas a cabo por un conjunto de tres enzimas. Estos incluyen la activación de la enzima ubiquitina E1, E2 ubiquitina-conjugación enzima, y ​​E3 ubiquitina ligasa. A diferencia de E1 y E2, E3 ubiquitina ligasas pantalla especificidad de sustrato. Por otro lado, numerosas enzimas deubiquitylating tienen un papel en el procesamiento de las proteínas polyubiquitinated. Ubiquitinación puede resultar en un cambio de la estabilidad de las proteínas, localización celular y la actividad biológica. Las mutaciones de los genes implicados en la vía de ubiquitinación / deubiquitination o alteración de la función del sistema ubiquitina están asociados con muchas enfermedades diferentes humanos, tales como varios tipos de cáncer, neurodegeneración, y trastornos metabólicos. La detección de ubiquitination alterado o normal de las proteínas diana pueden proporcionar una mejor comprensión de la patogénesis de estas enfermedades. Aquí se describen los protocolos para detectar la ubiquitinación de proteínas en las células cultivadas<em&gt; In vivo</em&gt; Y tubos de ensayo<em&gt; In vitro</em&gt;. Estos protocolos son también útiles para detectar otras ubiquitina-como la modificación de moléculas pequeñas como sumolyation y neddylation.

Watch this Scientific Journal Video about Detection of Protein Ubiquitination at JoVE.com

Detection of Protein Ubiquitination

Ubiquitinación es una modificación postraduccional clave llevadas a cabo por un conjunto de tres enzimas. Las mutaciones de los genes implicados en esta modificación se asocian con muchas enfermedades humanas diferentes. Aquí se describen los protocolos para detectar la ubiquitinación de proteínas en las células cultivadas<em&gt; In vivo</em&gt; Y tubos de ensayo<em&gt; In vitro</em&gt;.

La detección de ubiquitinación de proteínas

Ubiquitination, the covalent attachment of the polypeptide ubiquitin to target proteins, is a key posttranslational modification carried out by a set of ...

Research

JoVE Journal

Biology

42.6K vistas.  The Sanford Burnham Institute for Medical Research. Ubiquitinación es una modificación postraduccional clave llevadas a cabo por un conjunto de tres enzimas. Las mutaciones de los genes implicados en esta modificación se asocian con muchas enfermedades humanas diferentes. Aquí se describen los protocolos para detectar la ubiquitinación de proteínas en las células cultivadas In vivo Y tubos de ensayo In vitro.

Video: Detection of Protein Ubiquitination

Batch Immunostaining for Large-Scale Protein Detection in the Whole Monkey Brain

Immunohistochemistry (IHC) is one of the most widely used laboratory techniques for the detection of target proteins in situ. Questions concerning the expression pattern of a target protein across the entire brain are relatively easy to answer when using IHC in small brains, such as those of rodents. However, answering the same questions in large and convoluted brains, such as those of primates presents a number of challenges. Here we present a systematic approach for immunodetection of target proteins in an adult monkey brain. This approach relies on the tissue embedding and sectioning methodology of NeuroScience Associates (NSA) as well as tools developed specifically for batch-staining of free-floating sections. It results in uniform staining of a set of sections which, at a particular interval, represents the entire brain. The resulting stained sections can be subjected to a wide variety of analytical procedures in order to measure protein levels, the population of neurons expressing a certain protein.

Large-scale immunodetection of target proteins across the entire primate brain is possible by employing novel tissue embedding and sectioning methods combined with the use of creative apparatus for batch staining of multiple free-floating sections at a given time.

Lote de inmunotinción para la detección de proteínas a gran escala en el cerebro del mono entero

Immunohistochemistry (IHC) is one of the most widely used laboratory techniques for the detection of target proteins in situ. Questions concerning the ...

Investigación

Biología

Staining of Proteins in Gels with Coomassie G-250 without Organic Solvent and Acetic Acid

In classical protein staining protocols using Coomassie Brilliant Blue (CBB), solutions with high contents of toxic and flammable organic solvents (Methanol, Ethanol or 2-Propanol) and acetic acid are used for fixation, staining and destaining of proteins in a gel after SDS-PAGE. To speed up the procedure, heating the staining solution in the microwave oven for a short time is frequently used. This usually results in evaporation of toxic or hazardous Methanol, Ethanol or 2-Propanol and a strong smell of acetic acid in the lab which should be avoided due to safety considerations. In a protocol originally published in two patent applications by E.M. Wondrak (US2001046709 (A1), US6319720 (B1)), an alternative composition of the staining solution is described in which no organic solvent or acid is used. The CBB is dissolved in bidistilled water (60-80mg of CBB G-250 per liter) and 35 mM HCl is added as the only other compound in the staining solution. The CBB staning of the gel is done after SDS-PAGE and thorough washing of the gel in bidistilled water. By heating the gel during the washing and staining steps, the process can be finished faster and no toxic or hazardous compunds are evaporating. The staining of proteins occurs already within 1 minute after heating the gel in staining solution and is fully developed after 15-30 min with a slightly blue background that is destained completely by prolonged washing of the stained gel in bidistilled water, without affecting the stained protein bands.

A short protocol for protein staining with Coomassie Brilliant Blue (CBB) G-250 in polyacrylamide gels is described without using organic solvents or acetic acid as in the classical staining procedures with CBB.

Tinción de las proteínas en geles con Coomassie G-250, sin ácido disolvente orgánico y el acético

In classical protein staining protocols using Coomassie Brilliant Blue (CBB), solutions with high contents of toxic and flammable organic solvents ...

Using the GELFREE 8100 Fractionation System for Molecular Weight-Based Fractionation with Liquid Phase Recovery

The GELFREE 8100 Fractionation System is a novel protein fractionation system designed to maximize protein recovery during molecular weight based fractionation. The system is comprised of single-use, 8-sample capacity cartridges and a benchtop GELFREE Fractionation Instrument. During separation, a constant voltage is applied between the anode and cathode reservoirs, and each protein mixture is electrophoretically driven from a loading chamber into a specially designed gel column gel. Proteins are concentrated into a tight band in a stacking gel, and separated based on their respective electrophoretic mobilities in a resolving gel. As proteins elute from the column, they are trapped and concentrated in liquid phase in the collection chamber, free of the gel. The instrument is then paused at specific time intervals, and fractions are collected using a pipette. This process is repeated until all desired fractions have been collected. If fewer than 8 samples are run on a cartridge, any unused chambers can be used in subsequent separations.
This novel technology facilitates the quick and simple separation of up to 8 complex protein mixtures simultaneously, and offers several advantages when compared to previously available fractionation methods. This system is capable of fractionating up to 1mg of total protein per channel, for a total of 8mg per cartridge. Intact proteins over a broad mass range are separated on the basis of molecular weight, retaining important physiochemical properties of the analyte. The liquid phase entrapment provides for high recovery while eliminating the need for band or spot cutting, making the fractionation process highly reproducible1.

The accompanying video describes the use of the GELFREE 8100 Fractionation System, which partitions complex protein samples on the basis of molecular weight and recovers the fractions in liquid phase. The video describes how the technology works, how it is used, and provides resultant data, with polyacrylamide gel electrophoresis analysis of fractionated bovine liver homogenate.

Utilizando el sistema de fraccionamiento GELFREE 8100 de peso molecular basado en Fraccionamiento con la recuperación de la fase líquida

The GELFREE 8100 Fractionation System is a novel protein fractionation system designed to maximize protein recovery during molecular weight based ...

In-vivo Detection of Protein-protein Interactions on Micro-patterned Surfaces

Unraveling the interaction network of molecules in-vivo is key to understanding the mechanisms that regulate cell function and metabolism. A multitude of methodological options for addressing molecular interactions in cells have been developed, but most of these methods suffer from being rather indirect and therefore hardly quantitative. On the contrary, a few high-end quantitative approaches were introduced, which however are difficult to extend to high throughput. To combine high throughput capabilities with the possibility to extract quantitative information, we recently developed a new concept for identifying protein-protein interactions (Schwarzenbacher et al., 2008). Here, we describe a detailed protocol for the design and the construction of this system which allows for analyzing interactions between a fluorophore-labeled protein ("prey") and a membrane protein ("bait") in-vivo. Cells are plated on micropatterned surfaces functionalized with antibodies against the bait exoplasmic domain. Bait-prey interactions are assayed via the redistribution of the fluorescent prey. The method is characterized by high sensitivity down to the level of single molecules, the capability to detect weak interactions, and high throughput capability, making it applicable as screening tool.

In-vivo Detection of Protein-protein Interactions on Micro-patterned Surfaces

This video shows experiments with subsequent analysis of protein-protein interactions by the use of micro-patterned surfaces. The approach offers the possibility to detect protein interactions in living cells and combines high throughput capabilities with the possibility to extract quantitative information.

En vivo-La detección de interacciones proteína-proteína en la Micro-patrón superficies

Unraveling the interaction network of molecules in-vivo is key to understanding the mechanisms that regulate cell function and metabolism. A multitude of ...

Detection of Protein Interactions in Plant using a Gateway Compatible Bimolecular Fluorescence Complementation (BiFC) System

We have developed a BiFC technique to test the interaction between two proteins in vivo. This is accomplished by splitting a yellow fluorescent protein (YFP) into two non-overlapping fragments. Each fragment is cloned in-frame to a gene of interest. These constructs can then be co-transformed into Nicotiana benthamiana via Agrobacterium mediated transformation, allowing the transit expression of fusion proteins. The reconstitution of YFP signal only occurs when the inquest proteins interact 1-7. To test and validate the protein-protein interactions, BiFC can be used together with yeast two hybrid (Y2H) assay. This may detect indirect interactions which can be overlooked in the Y2H. Gateway technology is a universal platform that enables researchers to shuttle the gene of interest (GOI) into as many expression and functional analysis systems as possible8,9. Both the orientation and reading frame can be maintained without using restriction enzymes or ligation to make expression-ready clones. As a result, one can eliminate all the re-sequencing steps to ensure consistent results throughout the experiments. We have created a series of Gateway compatible BiFC and Y2H vectors which provide researchers with easy-to-use tools to perform both BiFC and Y2H assays10. Here, we demonstrate the ease of using our BiFC system to test protein-protein interactions in N. benthamiana plants.

Detection of Protein Interactions in Plant using a Gateway Compatible Bimolecular Fluorescence Complementation BiFC System

We have developed a technique to test protein-protein interactions in plant. A yellow fluorescent protein (YFP) is split into two non-overlapping fragments. Each fragment is cloned in-frame to a gene of interest via Gateway system, enabling expression of fusion proteins. Reconstitution of YFP signal only occurs when the inquest proteins interact.

Detección de interacciones de proteínas en la planta mediante un Gateway Compatible Complementación fluorescencia bimoleculares (BiFC) del sistema

We have developed a BiFC technique to test the interaction between two proteins in vivo. This is accomplished by splitting a yellow fluorescent protein ...

Green Fluorescent Protein-based Expression Screening of Membrane Proteins in Escherichia coli

The production of recombinant membrane proteins for structural and functional studies remains technically challenging due to low levels of expression and the inherent instability of many membrane proteins once solubilized in detergents. A protocol is described that combines ligation independent cloning of membrane proteins as GFP fusions with expression in Escherichia coli detected by GFP fluorescence. This enables the construction and expression screening of multiple membrane protein/variants to identify candidates suitable for further investment of time and effort. The GFP reporter is used in a primary screen of expression by visualizing GFP fluorescence following SDS polyacrylamide gel electrophoresis (SDS-PAGE). Membrane proteins that show both a high expression level with minimum degradation as indicated by the absence of free GFP, are selected for a secondary screen. These constructs are scaled and a total membrane fraction prepared and solubilized in four different detergents. Following ultracentrifugation to remove detergent-insoluble material, lysates are analyzed by fluorescence detection size exclusion chromatography (FSEC). Monitoring the size exclusion profile by GFP fluorescence provides information about the mono-dispersity and integrity of the membrane proteins in different detergents. Protein: detergent combinations that elute with a symmetrical peak with little or no free GFP and minimum aggregation are candidates for subsequent purification. Using the above methodology, the heterologous expression in E. coli of SED (shape, elongation, division, and sporulation) proteins from 47 different species of bacteria was analyzed. These proteins typically have ten transmembrane domains and are essential for cell division. The results show that the production of the SEDs orthologues in E. coli was highly variable with respect to the expression levels and integrity of the GFP fusion proteins. The experiment identified a subset for further investigation.

Green Fluorescent Protein-based Expression Screening of Membrane Proteins in Escherichia coli

A streamlined approach to screening for the expression of recombinant membrane proteins in Escherichia coli based on fusion to green fluorescent protein is presented.

Fluorescente verde a base de proteína Expresión Proyección de proteínas de membrana en<em&gt; Escherichia coli</em

The production of recombinant membrane proteins for structural and functional studies remains technically challenging due to low levels of expression and ...

Protein Purification Technique that Allows Detection of Sumoylation and Ubiquitination of Budding Yeast Kinetochore Proteins Ndc10 and Ndc80

Post-translational Modifications (PTMs), such as phosphorylation, methylation, acetylation, ubiquitination, and sumoylation, regulate the cellular function of many proteins. PTMs of kinetochore proteins that associate with centromeric DNA mediate faithful chromosome segregation to maintain genome stability. Biochemical approaches such as mass spectrometry and western blot analysis are most commonly used for identification of PTMs. Here, a protein purification method is described that allows the detection of both sumoylation and ubiquitination of the kinetochore proteins, Ndc10 and Ndc80, in Saccharomyces cerevisiae. A strain that expresses polyhistidine-Flag-tagged Smt3 (HF-Smt3) and Myc-tagged Ndc10 or Ndc80 was constructed and used for our studies. For detection of sumoylation, we devised a protocol to affinity purify His-tagged sumoylated proteins by using nickel beads and used western blot analysis with anti-Myc antibody to detect sumoylated Ndc10 and Ndc80. For detection of ubiquitination, we devised a protocol for immunoprecipitation of Myc-tagged proteins and used western blot analysis with anti-Ub antibody to show that Ndc10 and Ndc80 are ubiquitinated. Our results show that epitope tagged-protein of interest in the His-Flag tagged Smt3 strain facilitates the detection of multiple PTMs. Future studies should allow exploitation of this technique to identify and characterize protein interactions that are dependent on a specific PTM.

This manuscript describes the detection of sumoylation and ubiquitination of kinetochore proteins, Ndc10 and Ndc80, in the budding yeast Saccharomyces cerevisiae.

Proteína técnica de purificación que permite la detección de Sumoylation y Ubiquitination de levadura en ciernes cinetocoro Proteínas Ndc10 y Ndc80

Post-translational Modifications (PTMs), such as phosphorylation, methylation, acetylation, ubiquitination, and sumoylation, regulate the cellular ...

Detection of Ligand-activated G Protein-coupled Receptor Internalization by Confocal Microscopy

Confocal laser scanning microscopy (CLSM) is an optical imaging technique for high-contrast imaging. It is a powerful approach to visualize fluorescent fusion proteins, such as green fluorescent protein (GFP), to determine their expression, localization, and function. The subcellular localization of target proteins is important for identification, characterization, and functional analyses. Internalization is one of the predominant mechanisms controlling G protein-coupled receptor (GPCR) signaling to ensure the appropriate cellular responses to stimuli. Here, we describe an experimental method to detect the subcellular localization and internalization of GPCR in HEK293 cells with confocal microscopy. In addition, this experiment provides some details about cell culture and transfection. This protocol is compatible with a variety of widely available fluorescent markers and is applicable to the visualization of the subcellular localization of a majority of proteins, as well as of the internalization of GPCR. This technique should enable researchers to efficiently manipulate GPCR gene expression in mammalian cell lines and should facilitate studies on GPCR subcellular localization and internalization.

This protocol describes confocal microscopy detection of G protein-coupled receptor (GPCR) internalization in mammalian cells. It includes the basic cell culture, transfection, and confocal microscopy procedure and provides an efficient and easily interpretable method to detect the subcellular localization and internalization of fusion-expressed GPCR.

La detección de activados por ligando G receptor acoplado a proteína internalización por microscopía confocal

Confocal laser scanning microscopy (CLSM) is an optical imaging technique for high-contrast imaging. It is a powerful approach to visualize fluorescent ...

In Vivo Detection and Analysis of Rb Protein SUMOylation in Human Cells

The post-translational modifications of proteins are critical for the proper regulation of intracellular signal transduction. Among these modifications, small ubiquitin-related modifier (SUMO) is a ubiquitin-like protein that is covalently attached to the lysine residues of a variety of target proteins to regulate cellular processes, such as gene transcription, DNA repair, protein interaction and degradation, subcellular transport, and signal transduction. The most common approach to detecting protein SUMOylation is based on the expression and purification of recombinant tagged proteins in bacteria, allowing for an in vitro biochemical reaction which is simple and suitable for addressing mechanistic questions. However, due to the complexity of the process of SUMOylation in vivo, it is more challenging to detect and analyze protein SUMOylation in cells, especially when under endogenous conditions. A recent study by the authors of this paper revealed that endogenous retinoblastoma (Rb) protein, a tumor suppressor that is vital to the negative regulation of the cell cycle progression, is specifically SUMOylated at the early G1 phase. This paper describes a protocol for the detection and analysis of Rb SUMOylation under both endogenous and exogenous conditions in human cells. This protocol is appropriate for the phenotypical and functional investigation of the SUMO-modification of Rb, as well as many other SUMO-targeted proteins, in human cells.

In Vivo Detection and Analysis of Rb Protein SUMOylation in Human Cells

Small ubiquitin-related modifier (SUMO) family proteins are conjugated to the lysine residues of target proteins to regulate various cellular processes. This paper describes a protocol for the detection of retinoblastoma (Rb) protein SUMOylation under endogenous and exogenous conditions in human cells.

En Vivo Detección y análisis de la sumoilación de la proteína Rb en células humanas

The post-translational modifications of proteins are critical for the proper regulation of intracellular signal transduction. Among these modifications, ...

Automated Detection and Analysis of Exocytosis

Timelapse TIRF microscopy of pH-sensitive GFP (pHluorin) attached to vesicle SNARE proteins is an effective method to visualize single vesicle exocytic events in cell culture. To perform an unbiased, efficient identification and analysis of such events, a computer-vision based approach was developed and implemented in MATLAB. The analysis pipeline consists of a cell segmentation and exocytic-event identification algorithm. The computer-vision approach includes tools for investigating multiple parameters of single events, including the half-life of fluorescence decay and peak &#916;F/F, as well as whole-cell analysis of the frequency of exocytosis. These and other parameters of fusion are used in a classification approach to distinguish distinct fusion modes. Here a newly built GUI performs the analysis pipeline from start to finish. Further adaptation of Ripley&#39;s K function in R Studio is used to distinguish between clustered, dispersed, or random occurrence of fusion events in both space and time.

We developed automated computer vision software to detect exocytic events marked by pH-sensitive fluorescent probes. Here, we demonstrate the use of a graphical user interface and RStudio to detect fusion events, analyze and display spatiotemporal parameters of fusion, and classify events into distinct fusion modes.

Detección y análisis automatizados de exocitosis

Timelapse TIRF microscopy of pH-sensitive GFP (pHluorin) attached to vesicle SNARE proteins is an effective method to visualize single vesicle exocytic ...