Name: identification of cyclin-dependent kinase 1 specific phosphorylation sites by an in vitro kinase assay
Uploaded: 2018-05-03T15:00:00.000+00:00
Duration: 12 min 26 s
Description: Watch this Scientific Journal Video about Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay at JoVE.com

Biz Dr David King, Howard Hughes tıp Enstitüsü, University of California Berkeley kütle spektrometresi analiz ve yararlı yorumlar için teşekkür ederiz. Biz Dr Xuelian Zhu, Shanghai, Biyoloji Bilimleri enstitüleri, Çin Bilimler Akademisi, tam uzunlukta bir CENP-F yapı sağlamak için Shanghai, Çin teşekkür ederim. Son olarak, biz Dr Susan Bane, Dr Brian Callahan ve Dr Christof Grewer Binghamton Üniversitesi'nde ekipmana için teşekkür ederim. Bu araştırma State University of New York ve State University of New York Binghamton, Kimya bölümü için Araştırma Vakfı tarafından finanse edildi.

Yazarlar ifşa gerek yok.

Bizim vitro kinaz tahlil hangi hücre döngüsünün ana denetleyicisi ve birçok önemli hücresel süreçler düzenleyen kinaz Cdk1, moleküler hedefleri tanımlamak için çok güçlü bir yöntem olduğunu. Yöntem bir saf protein bir substrat Cdk1 için ve belirli fosforilasyon sitelerin kimlik sağlar Eğer belirler. Bu Cdk1 aracılığıyla fosforilasyon tarafından mekanik çalışmaları, düzenleme, hücresel süreçler için kolaylaştırır.
En kritik kütle spektrometresi...

Kinazlar fosfat grupları ATP yüzeyler transfer ve birçok hücresel süreçler düzenleyen enzimlerdir. Bu fosforilasyon geri alınabilir, hızlı, iki negatif ücretleri, ekler ve serbest enerji depolar ve hücreleri tarafından kullanılan en yaygın ardından değişiklikler biridir. Hücre bölünmesi döngüsü protein 2 homolog (cdc2) olarak da bilinen olan Cdk1 hücre döngüsünün bütün Ökaryotlar1,2,3,4,5ana bir denetleyicisidir ve phosphorylates bir yaklaşık 8-%13 Proteom6,7.
Bu değişiklikler için sorumlu kinaz bilinmeyen ise son proteomik çalışmalar proteinler, çoğu durumda, çok sayıda fosforilasyon site belirledik. Özellikle insan hücrelerinde bilinen Cdk1 hedeflerin sayısı düşük7var. Nasıl Cdk1 hücre döngüsü kontrol kurmak mekanik çalışmalar kullanmasına olanak tanır Cdk1 özgü fosforilasyon siteler tanımlanması önemlidir. Hücre döngüsü Yönetmeliği sadık kromozom segregasyon ve hücre bölünmesi için önemlidir ve hücresel sayısız bu önemli fizyolojik işlevi desteklemek için ortaya çıkması gereken. Bu transkripsiyon ve translasyon hücre yapısı ve organizasyon, nükleer zarf, kromozom yoğunlaşma ve Mitotik iğ Montaj Demontaj gibi dramatik bir yeniden yapılanma yanı sıra mitoz başlangıcı öncesinde durdurma içerir. Deregülasyon ve hataları bu süreçlerde kanser, doğum kusurları veya Mitotik hücre ölümüne neden olur. Cdk1 RO-3306 gibi belirli inhibitörleri fonksiyonel çalışmaları için güçlü araçlar sağlayan gelişmiş8, vardı ve bu inhibitörleri şu anda kanser tedavisi için klinik çalışmalarda bazı (9 inceleme için bakınız).
Burada, biz Cdk1 özgü fosforilasyon siteler tanımlaması sağlar bir vitro kinaz tahlil açıklayın. Bu tahlil, ticari olarak mevcut insan Cdk1/siklin B arıtılmış hedef protein vitrofazdan için kullanılır. Bir substrat fosforilasyon kütlesi artar ve iki negatif ücretleri ekler; Bu nedenle, başarılı fosforilasyon SDS-sayfa protein jel grubu yukarı doğru bir kayma tarafından onaylanır. Cdk1 özgü fosforilasyon siteleri daha sonra kütle spektrometresi fosforile vitro protein analizi tarafından tanımlanır. Deneysel tasarım ile yardımcı olmak için biz de Hesaplama araçları ve protein serisinden Cdk1 özgü fosforilasyon siteler tahmin için başvurular gözden geçirin. Ayrıca, aynı zamanda son derece saf ve homojen protein kinaz tahlil için uygun hazırlıklar verim arıtma iletişim kuralları açıklar. Son olarak, tanımlanan fosforilasyon siteleri fonksiyonel çalışmaları tarafından doğrulanması gerekir ve bir basit bağlama tahlil burada bu amaçla kullanılmıştır. Birlikte, bu Cdk1 özgü fosforilasyon siteler verimleri ve mekanik çalışmaları nasıl hücre döngüsü7,10,11Cdk1 denetler içine sağlayan çok güçlü bir yaklaşım olacaktır. Bu yöntem üzerinde saf protein dayanıyor beri herhangi bir model organizma ve verimleri güvenilir sonuçlar için uygulanabilir. Yerde, ardından değişiklikleri, etkileşim ortakları veya hücrede yerleşimi gibi ek düzenleyici mekanizmaları hücre var gibi Ancak, elde edilen fosforilasyon siteleri vitro işlevsel doğrulaması, tavsiye bu fosforilasyon siteleri erişilebilir veya Cdk1 tarafından tanınması için erişilebilir hale gelebilir.
Cdk1 (Ser/Thr-Pro-X-Lys/Arg), burada X herhangi bir kalıntı ve serin veya treonin fosforilasyonu sitedir oluşur bir fikir birliği fosforilasyon site tanır. + 1 pozisyon prolin varlığı tanıma için özellikle önemlidir. Buna ek olarak, temel kalıntıları + 2 veya 3 pozisyonlarda tercih edilmektedir, Lys veya Arg 3 içeren çoğu Cdk1 özgü fosforilasyon site ile6,12konum.
Cdk1 aktivasyonu sıkı bir şekilde düzenlenir ve mitoz1,2,3,4,5başlangıcı için yol açar. Siklin bağımlı kinaz aktivitesinin genel olarak onların dernek ile farklı siklinlere (siklin A, B, C, D ve E insanlarda), hücre döngüsü13boyunca düzeyleri salınan ifade edilir bağlıdır. Cdk1 ifade hücre döngüsü boyunca sabittir ve siklin A ve B5,13,14,15, olarak siklin düzenleyici alt birimleri ile dernek, düzenleme, faaliyete dayanan de translasyon modifikasyon. Cdk1/siklin B kompleks oluşumu kinaz harekete geçirmek5,14,15,16,17,18için gereklidir. G2 evresinde, siklin B sitozol tercüme ve nerede Cdk15,14,15,16,17,-18bağlar çekirdeği'a içe aktarılan; Ancak, B Cdk1/siklin fosforilasyon (membran ilişkili tirozin ve treonin özel cdc2 inhibitör kinaz) artıkları Thr14 ve Tyr15 insan Cdk1 inhibitör kinaz Myt1 tarafından ve Wee1, sırasıyla19tarafından Inaktif tutulur, 20,21. Geç G2 aşamasında, hücre bölünmesi döngüsü 25 fosfataz (cdc25) tarafından Thr14 ve Tyr15 dephosphorylation Cdk1/siklin B kompleks kinaz aktivitesinin etkinleştirir ve mitoz12,14, inisiyasyon tetikler 18 , 20 , 22 , 23. Thr161 fosforilasyon da Cdk1/siklin B harekete geçirmek için gereklidir ve Cdk7, Cdk aktive kinaz (CAK)18aracılık ettiği. Siklin B anafaz bozulma Cdk1, mitoz24,25dan çıkış sağlayan inaktive. B Cdk1/siklin aktivasyonu bu nedenle karmaşık bir süreçtir. Burada sunulan Protokolü piyasada bulunan Cdk1/siklin b ile gerçekleştirilir Böcek hücrelerinde rekombinant ifade bu kompleksin sırasında bu harekete geçirmek içinde vivo endojen kinaz14,20 ve arıtılmış durumda etkin kalır. Elde edilen aktif, rekombinant insan Cdk1/siklin B vitro kinaz deneyleri için uygundur.
Burada, biz Cdk1 özgü fosforilasyon siteler insan şeması protein F (CENP-F)10tanımlaması için bir iletişim kuralı tanımlamak. CENP-F, interfaz (G1 ve S-fazlı) en sırasında çekirdeğinde bulunan ve Cdk1 bağımlı bir şekilde10, G2 aşama26,27,28 sitozol verilir bir kinetochore protein 11. nükleer yerelleştirme önerebilirim cNLS26tarafından haiz. kolaylaştırır, birlikte karyopherin β ve RanGDP, cNLS-yük alma çekirdeği29içine nükleer taşıma faktörü karyopherin α cNLSs algılanır. G2 aşamasında nükleer verme yolu ile an bilinmeyen verme yolu10kolaylaştırılmıştır. CENP-F sitozol içinde bulunduğu nükleer zarf oluşturulmuştur ve sırayla motor protein kompleksi dinein30,31acemi. Bu yol için centrosome ilgili çekirdek Mitotik Milli Meclisi ilk aşamalarında Mitotik girdinin doğru zamanlama ve beyin temel bir işlemde önemlidir dinein bağımlı bir şekilde konumlandırmak önemlidir geliştirme30,31,32. G2 aşamasında başlayan, CENP-F de kinetochore sadık kromozom segregasyon27,28,33,34,35 için önemli roller bulunduğu monte edilir . Bir anahtar düzenleyici bu yollar CENP-F nükleer ihracat Cdk110,11tarihinde bağlıdır G2 aşamasında adımdır. Biz burada bir protokol Cdk1 özgü fosforilasyon siteler CENP-F. cNLS içinde tanımlanması için tarif Phosphomimetic mutasyonlar bu sitelerin CENP-F B Cdk1/siklin doğrudan CENP-F Hücrede yerleşimi onun cNLS10fosforilasyon tarafından düzenleyen düşündüren, nükleer alınmasıyla yavaşlatacak.
Kinaz Cdk1. saf hedef proteinler fosforile vitro piyasada bulunan Cdk1/siklin B kompleks ve fosforilasyon siteler için genel olarak, bu vitro kinaz tahlil belirli yüzeylerde tanımlaması sağlar daha sonra kütle spektrometresi tarafından tanımlanır. Cdk1 özgü fosforilasyon siteler tanımlaması nasıl Cdk1 hücre döngüsü kontrol ortaya mekanik çalışmaları destekler.

<table><tbody><tr><td>2800 mL baffled Fernbach flask</td><td>Corning</td><td>44232XL</td><td></td></tr><tr><td>ampicillin</td><td>Gold Biotechnology</td><td>A-301-25</td><td></td></tr><tr><td>ATP</td><td>Fisher Scientfiic</td><td>BP413-25</td><td></td></tr><tr><td>benzamidine hydrochloride</td><td>Millipore Sigma</td><td>B6506-25</td><td></td></tr><tr><td>bottletop filter</td><td>Corning</td><td>431161</td><td></td></tr><tr><td>Cdk1/cyclin B recombinant, human 20,000 U/mL</td><td>New England Biolabs</td><td>P6020</td><td></td></tr><tr><td>Cdk1/cyclin B (alternate source)</td><td>EMD Millipore</td><td>14-450</td><td></td></tr><tr><td>Cdk1/cyclin B (alternate source)</td><td>Invitrogen</td><td>PV3292</td><td></td></tr><tr><td>Cdk1/cyclin B + 10x PK buffer</td><td>New England Biolabs</td><td>P6020</td><td></td></tr><tr><td>CENP-F (residues 2987 &amp;ndash; 3065) pGEX6P1 plasmid</td><td>Available upon request.</td><td></td><td></td></tr><tr><td>centrifuge: Heraeus Multifuge X3R, cooled, with TX-1000 swing-out rotor</td><td>Thermo Scientific</td><td>10033-778</td><td></td></tr><tr><td>centrifugal filter units: Amicon Ultra-15 centrifugal filter units, 3 kDa cutoff, Ultracel-PL membranes</td><td>EMD Millipore</td><td>UFC900324</td><td></td></tr><tr><td>chlorampenicol</td><td>Gold Biotechnology</td><td>C-105-100</td><td></td></tr><tr><td>D/L methionine</td><td>Agros Organics / Fisher</td><td>125650010</td><td></td></tr><tr><td>desalting pipet tips: Zip tips</td><td>Millipore Sigma</td><td>ZTC18S008</td><td></td></tr><tr><td>disposable chromatography columns, Econo-Pac 1.5 x 12 cm</td><td>Biorad</td><td>7321010</td><td></td></tr><tr><td>dithiothreitol</td><td>Gold Biotechnology</td><td>DTT50</td><td></td></tr><tr><td>&lt;em&gt;E. coli&lt;/em&gt; Rosetta 2(DE3)pLysS strain</td><td>EMD Millipore</td><td>71403</td><td></td></tr><tr><td>electrospray ionization Fourier transform ion</td><td>Bruker Amazon</td><td>Apex III</td><td></td></tr><tr><td>cyclotron resonance mass spectrometer</td><td></td><td></td><td></td></tr><tr><td>electrospray ionization ion trap mass spectrometer</td><td>Bruker Amazon</td><td>custom</td><td></td></tr><tr><td>fixed angle rotor: Fiberlite F15-8x-50cy</td><td>Thermo Scientific</td><td>97040-276</td><td></td></tr><tr><td>FPLC system: &amp;Auml;kta Pure FPLC</td><td>GE Healthcare</td><td>29032697</td><td></td></tr><tr><td>Gel filtration column: Superdex 200 Increase 10/300 GL</td><td>GE Healthcare</td><td>28990944</td><td></td></tr><tr><td>glutathione agarose</td><td>Pierce</td><td>16101</td><td></td></tr><tr><td>glutathione, reduced</td><td>Millipore Sigma</td><td>G4251-50g</td><td></td></tr><tr><td>incubation shaker: multitron shaker</td><td>Infors</td><td>I10102</td><td></td></tr><tr><td>isopropyl &amp;beta;-D-1-thiogalactopyranoside</td><td>Gold Biotechnology</td><td>I2481C50</td><td></td></tr><tr><td>kanamycin</td><td>Gold Biotechnology</td><td>K-120-25</td><td></td></tr><tr><td>karyopherin &amp;alpha; pet-28a pres plasmid</td><td>Available upon request.</td><td></td><td></td></tr><tr><td>Luria Bertani medium</td><td>Fisher Scientfiic</td><td>BP1426-2</td><td></td></tr><tr><td>microcentrifuge 5418R, refrigerated</td><td>Eppendorf</td><td>5401000013</td><td></td></tr><tr><td>microtubes (0.5 mL)</td><td>Eppendorf</td><td>30121023</td><td></td></tr><tr><td>microtubes (1.5 mL)</td><td>Eppendorf</td><td>30120086</td><td></td></tr><tr><td>Nickel affinity gel: His-Select Nickel affinity gel</td><td>Millipore Sigma</td><td>P6611-100ml</td><td></td></tr><tr><td>pGEX-6P-1 plasmid</td><td>Millipore Sigma</td><td>GE28-9546-48</td><td></td></tr><tr><td>phenylmethylsulfonyl fluoride</td><td>Gold Biotechnology</td><td>P470-10</td><td></td></tr><tr><td>PS protease: PreScission protease</td><td>GE Healthcare</td><td>27084301</td><td></td></tr><tr><td>Phos-tag acrylamide</td><td>Wako Pure Chem. Ind.</td><td>304-93521</td><td></td></tr><tr><td>reduced gluthathione</td><td>Millipore Sigma</td><td>G4251-50g</td><td></td></tr><tr><td>roundbottom centrifuge tubes (Oakridge tubes)</td><td>Fisher Scientfiic</td><td>055291D</td><td></td></tr><tr><td>site-directed mutagenesis kit: QuikChange Lightning</td><td>Agilent</td><td>210518</td><td></td></tr><tr><td>Site-Directed Mutagenesis Kit</td><td></td><td></td><td></td></tr><tr><td>sonifier: Branson S-250D sonifier</td><td>Branson</td><td>15 338 125</td><td></td></tr><tr><td>Spectra/Por 1RC dialysis membrane (6-8 kDa cutoff)</td><td>Spectrum Labs</td><td>08 670B</td><td></td></tr><tr><td>swing out rotor TX-1000</td><td>Thermo Scientific</td><td>10033-778</td><td></td></tr></tbody></table>

identification of cyclin-dependent kinase 1 specific phosphorylation sites by an in vitro kinase assay

Siklin bağımlı kinaz 1 (Cdk1) hücre döngüsünün bütün Ökaryotlarda bir ana denetleyicisidir ve Proteom yaklaşık 8-%13 phosphorylates; Ancak, özellikle insan hücrelerinde Cdk1 için belirlenen hedeflerin sayısı hala düşük. Nasıl Cdk1 hücre döngüsü kontrol içine mekanik anlayışlar sağladıkları gibi Cdk1 özgü fosforilasyon siteler tanımlanması önemlidir. Hücre döngüsü Yönetmeliği sadık kromozom ayrımı için önemlidir ve bu karmaşık bir süreç içinde kusurları kromozom anomalileri ve kanser neden.
Burada, biz Cdk1 özgü fosforilasyon siteleri tanımlamak için kullanılan bir vitro kinaz tahlil açıklayın. Bu tahlil fosforile vitro arıtılmış bir proteindir ticari olarak mevcut insan Cdk1/siklin B. başarılı tarafından fosforilasyon SDS-PAGE tarafından onaylandıktan ve fosforilasyon siteleri daha sonra kütle spektrometresi tarafından tanımlanır. Ayrıca son derece saf ve homojen protein kinaz tahlil ve bağlama tahlil için uygun hazırlıklar arasındaki etkileşimi probları tanımlanan fosforilasyon siteleri fonksiyonel doğrulanması için verim arıtma iletişim kurallarını açıklar bir klasik nükleer yerelleştirme sinyal (cNLS) ve onun nükleer taşıma reseptör karyopherin α. Deneysel tasarım ile yardımcı olmak için protein dizilerinden Cdk1 özgü fosforilasyon siteler tahmin için yaklaşımlar gözden geçirin. Birlikte bu protokollerin Cdk1 özgü fosforilasyon siteler verimleri ve mekanik çalışmaları nasıl Cdk1 hücre döngüsü kontrol eder içine sağlayan çok güçlü bir yaklaşım sunuyoruz. Bu yöntem üzerinde saf protein dayanıyor beri bu herhangi bir model organizma ve verimleri güvenilir sonuçlar için özellikle hücre fonksiyonel çalışmalar ile birlikte uygulanabilir.

Son zamanlarda bir cNLS10bulunan bir CENP-F parçadaki Cdk1 özgü fosforilasyon siteleri tanımlamak için bir vitro kinaz tahlil (şekil 1) kullandık. Bu sinyal CENP-F nükleer yerelleştirme Interphase lerin confers. G2 evresinde, CENP-F sitozol Cdk1 bağlı şekilde çekirdek verilir. Nasıl CENP-f Hücrede yerleşimi Cdk1 düzenleyen üzerinde mekanik anlayışlar elde etmek için biz üreticisinin sunucu<sup class="xref...

Watch this Scientific Journal Video about Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay at JoVE.com

Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay

Siklin bağımlı kinaz 1 (Cdk1) hücre döngüsünün G2 aşamasında aktif ve birçok hücresel yolları düzenler. Burada, bir vitro kinaz tahlil için bir protokol ile bu önemli kinaz hücresel hedefleri oluşturmak üzere Cdk1 özgü fosforilasyon siteler tanımlaması sağlar Cdk1 mevcut.

Siklin bağımlı kinaz 1 tanımlaması belirli fosforilasyon siteleri bir Vitro kinaz tarafından tahlil

Cyclin-dependent kinase 1 (Cdk1) is a master controller for the cell cycle in all eukaryotes and phosphorylates an estimated 8 - 13% of the proteome; ...

identification-cyclin-dependent-kinase-1-specific-phosphorylation

Universidad de Cartagena UDEC

Research

JoVE Journal

Biochemistry

Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay

18.5K Görüntüleme.  State University of New York at Binghamton. Siklin bağımlı kinaz 1 (Cdk1) hücre döngüsünün G2 aşamasında aktif ve birçok hücresel yolları düzenler. Burada, bir vitro kinaz tahlil için bir protokol ile bu önemli kinaz hücresel hedefleri oluşturmak üzere Cdk1 özgü fosforilasyon siteler tanımlaması sağlar Cdk1 mevcut.

Video: Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay

Assaying Protein Kinase Activity with Radiolabeled ATP

Protein kinases are able to govern large-scale cellular changes in response to complex arrays of stimuli, and much effort has been directed at uncovering allosteric details of their regulation. Kinases comprise signaling networks whose defects are often hallmarks of multiple forms of cancer and related diseases, making an assay platform amenable to manipulation of upstream regulatory factors and validation of reaction requirements critical in the search for improved therapeutics. Here, we describe a basic kinase assay that can be easily adapted to suit specific experimental questions including but not limited to testing the effects of biochemical and pharmacological agents, genetic manipulations such as mutation and deletion, as well as cell culture conditions and treatments to probe cell signaling mechanisms. This assay utilizes radiolabeled [&#947;-32P] ATP, which allows for quantitative comparisons and clear visualization of results, and can be modified for use with immunoprecipitated or recombinant kinase, specific or typified substrates, all over a wide range of reaction conditions.

Protein kinases are highly evolved signaling enzymes and scaffolds that are critical for inter- and intracellular signal transduction. We present a protocol for measuring kinase activity through the use of radiolabeled adenosine triphosphate ([&#947;-32P] ATP), a reliable method to aid in elucidation of cellular signaling regulation.

Protein Kinaz Aktivitesini Radyoaktif Etiketli ATP ile Tahlil

Protein kinases are able to govern large-scale cellular changes in response to complex arrays of stimuli, and much effort has been directed at uncovering ...

Biyokimya

Oligopeptide Competition Assay for Phosphorylation Site Determination

Protein phosphorylation at specific sites determines its conformation and interaction with other molecules. Thus, protein phosphorylation affects biological functions and characteristics of the cell. Currently, the most common method for discovering phosphorylation sites is by liquid chromatography/mass spectrometry (LC/MS) analysis, a rapid and sensitive method. However, relatively labile phosphate moieties are often released from phosphopeptides during the fragmentation step, which often yields false-negative signals. In such cases, a traditional in vitro kinase assay using site-directed mutants would be more accurate, but this method is laborious and time-consuming. Therefore, an alternative method using peptide competition may be advantageous. The consensus recognition motif of 5&#39; adenosine monophosphate-activated protein kinase (AMPK) has been established1 and was validated using a positional scanning peptide library assay2. Thus, AMPK phosphorylation sites for a novel substrate could be predicted and confirmed by the peptide competition assays. In this report, we describe the detailed steps and procedures for the in vitro oligopeptide-competing kinase assay by illustrating AMPK-mediated nuclear factor erythroid 2-related factor 2 (Nrf2) phosphorylation. To authenticate the phosphorylation site, we carried out a sequential in vitro kinase assay using a site-specific mutant. Overall, the peptide competition assay provides a method to screen multiple potential phosphorylation sites and to identify sites for validation by the phosphorylation site mutants.

Peptide competition assays are widely used in a variety of molecular and immunological experiments. This paper describes a detailed method for an in vitro oligopeptide-competing kinase assay and the associated validation procedures, which may be useful to find specific phosphorylation sites.

Fosforilasyon Saha Tespiti İçin Oligopeptide Rekabet Testi

Protein phosphorylation at specific sites determines its conformation and interaction with other molecules. Thus, protein phosphorylation affects ...

Identification of Novel CK2 Kinase Substrates Using a Versatile Biochemical Approach

The study of kinase-substrate relationships is essential to gain a complete understanding of the functions of these enzymes and their downstream targets in both physiological and pathological states. CK2 is an evolutionarily conserved serine/threonine kinase with a growing list of hundreds of substrates involved in multiple cellular processes. Due to its pleiotropic properties, identifying and characterizing a comprehensive set of CK2 substrates has been particularly challenging and remains a hurdle in the study of this important enzyme. To address this challenge, we have devised a versatile experimental strategy that enables the targeted enrichment and identification of putative CK2 substrates. This protocol takes advantage of the unique dual co-substrate specificity of CK2 allowing for specific thiophosphorylation of its substrates in a cell or tissue lysate. These substrate proteins are subsequently alkylated, immunoprecipitated, and identified by liquid chromatography/tandem mass spectrometry (LC-MS/MS). We have previously used this approach to successfully identify CK2 substrates from Drosophila ovaries and here we extend the application of this protocol to human glioblastoma cells, illustrating the adaptability of this method to investigate the biological roles of this kinase in various model organisms and experimental systems.

The objective of this protocol is to label, enrich, and identify substrates of protein kinase CK2 from a complex biological sample such as a cell lysate or tissue homogenate. This method leverages unique aspects of CK2 biology for this purpose.

Kimliği roman CK2 kinaz yüzeylerde çok yönlü bir biyokimyasal yaklaşım kullanarak

The study of kinase-substrate relationships is essential to gain a complete understanding of the functions of these enzymes and their downstream targets ...

Characterization at the Molecular Level using Robust Biochemical Approaches of a New Kinase Protein

Extensive whole genome sequencing has identified many Open Reading Frames (ORFs) providing many potential proteins. These proteins may have important roles for the cell and may unravel new cellular processes. Among proteins, kinases are major actors as they belong to cell signaling pathways and have the ability to switch on or off many processes crucial to the fate of the cell, such as cell growth, division, differentiation, motility, and death.
In this study, we focused on a new potential kinase protein, LIMK2-1. We demonstrated its existence by Western Blot using a specific antibody. We evaluated its interaction with an upstream regulating protein using coimmunoprecipitation experiments. Coimmunoprecipitation is a very powerful technique able to detect the interaction between two target proteins. It may also be used to detect new partners of a bait protein. The bait protein may be purified either via a tag engineered to its sequence or via an antibody specifically targeting it. These protein complexes may then be separated by SDS-PAGE (Sodium Dodecyl Sulfate PolyAcrylamide Gel) and identified using mass spectrometry. Immunoprecipitated LIMK2-1 was also used to test its kinase activity in vitro by &#947;[32P] ATP labeling. This well-established assay may use many different substrates, and mutated versions of the bait may be used to assess the role of specific residues. The effects of pharmacological agents may also be evaluated since this technique is both highly sensitive and quantitative. Nonetheless, radioactivity handling requires particular caution. Kinase activity may also be assessed with specific antibodies targeting the phospho group of the modified amino acid. These kinds of antibodies are not commercially available for all the phospho modified residues.

We characterized a new kinase protein using robust biochemical approaches: Western Blot analysis with a dedicated specific antibody on different cell lines and tissues, interactions by coimmunoprecipitation experiments, kinase activity detected by Western Blot using a phospho-specific antibody and by &#947;[32P] ATP labeling.

Yeni kinaz proteinin sağlam biyokimyasal yaklaşımlar kullanılarak moleküler düzeyde karakterize edilmesi

Extensive whole genome sequencing has identified many Open Reading Frames (ORFs) providing many potential proteins. These proteins may have important ...

Non-Radioactive In Vitro Cardiac Myosin Light Chain Kinase Assays

Cardiac-specific myosin regulatory light chain kinase (cMLCK) regulates cardiac sarcomere structure and contractility by phosphorylating the ventricular isoform of the myosin regulatory light chain (MLC2v). MLC2v phosphorylation levels are significantly reduced in failing hearts, indicating the clinical importance of assessing the activity of cMLCK and the phosphorylation level of MLC2v to elucidate the pathogenesis of heart failure. This paper describes nonradioactive methods to assess both the activity of cMLCK and MLC2v phosphorylation levels. In vitro kinase reactions are performed using recombinant cMLCK with recombinant calmodulin and MLC2v in the presence of ATP and calcium at 25 &#176;C, which are followed by either a bioluminescent ADP detection assay or a phosphate-affinity SDS-PAGE. In the representative study, the bioluminescent ADP detection assay showed a strict linear increase of the signal at cMLCK concentrations between 1.25 nM to 25 nM. Phosphate-affinity SDS-PAGE also showed a linear increase of phosphorylated MLC2v in the same cMLCK concentration range. Next, the time-dependency of the reactions was examined at the concentration of 5 nM cMLCK. A bioluminescent ADP detection assay showed a linear increase in the signal during 90 min of the reaction. Similarly, phosphate-affinity SDS-PAGE showed a time-dependent increase of phosphorylated MLC2v. The biochemical parameters of cMLCK for MLC2v were determined by a Michaelis-Menten plot using the bioluminescent ADP detection assay. The Vmax was 1.65 &#177; 0.10 mol/min/mol kinase and the average Km was around 0.5 USA &#181;M at 25 &#176;C. Next, the activity of wild type and the dilated cardiomyopathy-associated p.Pro639Valfs*15 mutant cMLCK were measured. The bioluminescent ADP detection assay and phosphate-affinity SDS-PAGE correctly detected defects in cMLCK activity and MLC2v phosphorylation, respectively. In conclusion, a combination of the bioluminescent ADP detection assay and the phosphate-affinity SDS-PAGE is a simple, accurate, safe, low-cost, and flexible method to measure cMLCK activity and the phosphorylation level of MLC2v.

This study describes protocols for nonradiometric methods, a bioluminescent ADP detection assay and a phosphate-affinity SDS-PAGE, to determine the kinase activity of cardiac myosin light chain kinase (cMLCK) and the phosphorylation level of its substrate, myosin regulatory light chain (MLC2v).

Cardiac-specific myosin regulatory light chain kinase (cMLCK) regulates cardiac sarcomere structure and contractility by phosphorylating the ventricular ...

Monitoring Kinase and Phosphatase Activities Through the Cell Cycle by Ratiometric FRET

F&ouml;rster resonance energy transfer (FRET)-based reporters1 allow the assessment of endogenous kinase and phosphatase activities in living cells. Such probes typically consist of variants of CFP and YFP, intervened by a phosphorylatable sequence and a phospho-binding domain. Upon phosphorylation, the probe changes conformation, which results in a change of the distance or orientation between CFP and YFP, leading to a change in FRET efficiency (Fig 1). Several probes have been published during the last decade, monitoring the activity balance of multiple kinases and phosphatases, including reporters of PKA2, PKB3, PKC4, PKD5, ERK6, JNK7, Cdk18, Aurora B9 and Plk19. Given the modular design, additional probes are likely to emerge in the near future10. 
Progression through the cell cycle is affected by stress signaling pathways 11. Notably, the cell cycle is regulated differently during unperturbed growth compared to when cells are recovering from stress12.Time-lapse imaging of cells through the cell cycle therefore requires particular caution. This becomes a problem particularly when employing ratiometric imaging, since two images with a high signal to noise ratio are required to correctly interpret the results. Ratiometric FRET imaging of cell cycle dependent changes in kinase and phosphatase activities has predominately been restricted to sub-sections of the cell cycle8,9,13,14.
Here, we discuss a method to monitor FRET-based probes using ratiometric imaging throughout the human cell cycle. The method relies on equipment that is available to many researchers in life sciences and does not require expert knowledge of microscopy or image processing.

FRET-based reporters are increasingly used to monitor kinase and phosphatase activities in live cells. Here we describe a method on how to use FRET-based reporters to assess cell cycle-dependent changes in target phosphorylation.

Hücre Döngüsü FRET oranlı metrik sayesinde Kinaz ve Fosfataz Aktiviteleri İzleme

F&ouml;rster resonance energy transfer (FRET)-based reporters1 allow the assessment of endogenous kinase and phosphatase activities in living cells. Such ...

Biyoloji

Assaying the Kinase Activity of LRRK2 in vitro

Leucine Rich Repeat Kinase 2 (LRRK2) is a 2527 amino acid member of the ROCO family of proteins, possessing a complex, multidomain structure including a GTPase domain (termed ROC, for Ras of Complex proteins) and a kinase domain1. The discovery in 2004 of mutations in LRRK2 that cause Parkinson's disease (PD) resulted in LRRK2 being the focus of a huge volume of research into its normal function and how the protein goes awry in the disease state2,3. Initial investigations into the function of LRRK2 focused on its enzymatic activities4-6. Although a clear picture has yet to emerge of a consistent alteration in these due to mutations, data from a number of groups has highlighted the importance of the kinase activity of LRRK2 in cell death linked to mutations7,8. Recent publications have reported inhibitors targeting the kinase activity of LRRK2, providing a key experimental tool9-11. In light of these data, it is likely that the enzymatic properties of LRRK2 afford us an important window into the biology of this protein, although whether they are potential drug targets for Parkinson's is open to debate.
A number of different approaches have been used to assay the kinase activity of LRRK2. Initially, assays were carried out using epitope tagged protein overexpressed in mammalian cell lines and immunoprecipitated, with the assays carried out using this protein immobilised on agarose beads4,5,7. Subsequently, purified recombinant fragments of LRRK2 in solution have also been used, for example a GST tagged fragment purified from insect cells containing residues 970 to 2527 of LRRK212. Recently, Dani&euml;ls et al. reported the isolation of full length LRRK2 in solution from human embryonic kidney cells, however this protein is not widely available13. In contrast, the GST fusion truncated form of LRRK2 is commercially available (from Invitrogen, see table 1 for details), and provides a convenient tool for demonstrating an assay for LRRK2 kinase activity. Several different outputs for LRRK2 kinase activity have been reported. Autophosphorylation of LRRK2 itself, phosphorylation of Myelin Basic Protein (MBP) as a generic kinase substrate and phosphorylation of an artificial substrate - dubbed LRRKtide, based upon phosphorylation of threonine 558 in Moesin - have all been used, as have a series of putative physiological substrates including &alpha;-synuclein, Moesin and 4-EBP14-17. The status of these proteins as substrates for LRRK2 remains unclear, and as such the protocol described below will focus on using MBP as a generic substrate, noting the utility of this system to assay LRRK2 kinase activity directed against a range of potential substrates.

Assaying the Kinase Activity of LRRK2 in vitro

Leucine Rich Repeat Kinase 2 is a large multidomain kinase, mutations in which are the most common genetic cause of Parkinson's disease. Analysis of the kinase activity of this protein has proven to be a crucial tool in understanding the biology and dysfunction of this protein. In this paper, in vitro assaying of the kinase activity of LRRK2 and a selection of its mutants is described, providing an experimental system to examine phosphorylation of putative substrates and potential dysfunction of LRRK2 in disease.

LRRK2 Kinaz Aktivitesi Assaying In vitro</em

Leucine Rich Repeat Kinase 2 (LRRK2) is a 2527 amino acid member of the ROCO family of proteins, possessing a complex, multidomain structure including a ...

Identification of Post-translational Modifications of Plant Protein Complexes

Plants adapt quickly to changing environments due to elaborate perception and signaling systems. During pathogen attack, plants rapidly respond to infection via the recruitment and activation of immune complexes. Activation of immune complexes is associated with post-translational modifications (PTMs) of proteins, such as phosphorylation, glycosylation, or ubiquitination. Understanding how these PTMs are choreographed will lead to a better understanding of how resistance is achieved.
Here we describe a protein purification method for nucleotide-binding leucine-rich repeat (NB-LRR)-interacting proteins and the subsequent identification of their post-translational modifications (PTMs). With small modifications, the protocol can be applied for the purification of other plant protein complexes. The method is based on the expression of an epitope-tagged version of the protein of interest, which is subsequently partially purified by immunoprecipitation and subjected to mass spectrometry for identification of interacting proteins and PTMs.
This protocol demonstrates that: i). Dynamic changes in PTMs such as phosphorylation can be detected by mass spectrometry; ii). It is important to have sufficient quantities of the protein of interest, and this can compensate for the lack of purity of the immunoprecipitate; iii). In order to detect PTMs of a protein of interest, this protein has to be immunoprecipitated to get a sufficient quantity of protein.

We describe here a protocol for the purification and characterization of plant protein complexes. We demonstrate that by immunoprecipitating a single protein within a complex, so we can identify its post-translational modifications and its interacting partners.

Plant protein kompleksleri, çevirim sonrası değişikliklerin belirlenmesi

Plants adapt quickly to changing environments due to elaborate perception and signaling systems. During pathogen attack, plants rapidly respond to ...

Identification of Kinase-substrate Pairs Using High Throughput Screening

We have developed a screening platform to identify dedicated human protein kinases for phosphorylated substrates which can be used to elucidate novel signal transduction pathways. Our approach features the use of a library of purified GST-tagged human protein kinases and a recombinant protein substrate of interest. We have used this technology to identify MAP/microtubule affinity-regulating kinase 2 (MARK2) as the kinase for a glucose-regulated site on CREB-Regulated Transcriptional Coactivator 2 (CRTC2), a protein required for beta cell proliferation, as well as the Axl family of tyrosine kinases as regulators of cell metastasis by phosphorylation of the adaptor protein ELMO. We describe this technology and discuss how it can help to establish a comprehensive map of how cells respond to environmental stimuli.

Protein phosphorylation is a central feature of how cells interpret and respond to information in their extracellular milieu. Here, we present a high throughput screening protocol using kinases purified from mammalian cells to rapidly identify kinases that phosphorylate a substrate(s) of interest.

Yüksek Verimli Tarama kullanma Kinaz-substrat Çiftlerinin Kimlik


We have developed a screening platform to identify dedicated human protein kinases for phosphorylated substrates which can be used to elucidate novel ...

Experimental Approaches to Study Mitochondrial Localization and Function of a Nuclear Cell Cycle Kinase, Cdk1

Although mitochondria possess their own transcriptional machinery, merely 1% of mitochondrial proteins are synthesized inside the organelle. The nuclear-encoded proteins are transported into mitochondria guided by their mitochondria targeting sequences (MTS); however, a majority of mitochondrial localized proteins lack an identifiable MTS. Nevertheless, the fact that MTS can instruct proteins to go into the mitochondria provides a valuable tool for studying mitochondrial functions of normally nuclear and/or cytoplasmic proteins. We have recently identified the cell cycle kinase CyclinB1/Cdk1 complex in the mitochondria. To specifically study the mitochondrial functions of this complex, mitochondrial overexpression and knock-down of this complex without interfering with its nuclear or cytoplasmic functions were essential. By tagging CyclinB1/Cdk1 with MTS, we were able to achieve mitochondrial overexpression of this complex to study its mitochondrial targets as well as functions. Via tagging dominant-negative Cdk1 with MTS, inhibition of Cdk1 activity was accomplished particularly in the mitochondria. Potential mitochondrial targets of CyclinB1/Cdk1 complex were identified using a gel-based proteomics approach. Unlike traditional 2D gel analysis, we employed 2-dimensional difference gel electrophoresis (2D-DIGE) technology followed by phosphoprotein staining to fluorescently label differentially phosphorylated proteins in mitochondrial Cdk1 expressing cells. Identification of phosphoprotein spots that were altered in wild type versus dominant negative Cdk1 bearing mitochondria revealed the identity of mitochondrial targets of Cdk1. Finally, to determine the effect of CyclinB1/Cdk1 mitochondrial localization in cell cycle progression, a cell proliferation assay using a synthetic thymidine analogue EdU (5-ethynyl-2&#8242;-deoxyuridine) was used to monitor the cells as they go through the cell cycle and replicate their DNA. Altogether, we demonstrated a variety of approaches available to study mitochondrial localization and activity of a cell cycle kinase. These are advanced, yet easy to follow methods that will be beneficial to many cell biology researchers.

Here, we outline how to study mitochondrial localization of a (cell cycle) kinase, and how to determine its sub-mitochondrial location as well as potential mitochondrial substrates/targets. Forced expression of proteins into the mitochondria provides a useful tool for studying the functional consequences of mitochondrial localization of a protein of interest.

Siklin bağımlı kinaz 1 tanımlaması belirli fosforilasyon siteleri bir Vitro kinaz tarafından tahlil

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