Bu çalışma bir FAPESP hibesi (15/06477-9) tarafından desteklendi.

1. Maya toplam özü hazırlığı
<ol><li>1 L YNB-glu ortam (%2 m/v glikoz ile desteklenmiş Maya Nitrojen Temeli)9'da TAP etiketine kaynaşmış birleştirme faktörlerinden birini uygun amino asitler veya çekirdek bazlarla ifade eden maya hücrelerini büyütün, Bu durumda, adenin (20 μg/mL), lösin (30 μg/mL), triptofan (30 μg/mL), OD600 = 1.0'a kadar.</li>
	<li>1 L kültüründen hücreleri 17.000 x g'da üç adet 500 mL santrifüj şişesinde 4 °C'de 10 dakika santrifüjle toplayın ve 10 mL soğuk steril su ile iki kez yıkayın.</li>
	<li>Toplanan maya hücrelerini soğuk tampon A hücre hacminin 1/10'unda yeniden depolar (10 mmol L-1 HEPES pH = 7.9, 1.5 mmol L-1 MgCl2,50 mmol L-1 KCl, %5 v/v gliserol, 0.5 mmol L-1 DTT, EDTA içermeyen Proteaz inhibitör Kokteyli).</li>
	<li>Sıvı nitrojende küçük hücre süspansiyon damlalarını dondurun. Küçük damlalar, yeniden sulandırılmış hücre çözeltisinin pipetleilmesi ve 50 μL'nin doğrudan sıvı nitrojene düşmesiyle elde edilebilir. DİkKAT: Sıvı nitrojen cilt veya gözlerle temas halinde yaralanmalara neden olabilir. Uygun güvenlik ekipmanlarını kullanarak sapla. NOT: Protokol burada duraklatılabilir. Donmuş hücre süspansiyon damlaları -80 °C'de saklanabilir.</li>
	<li>3 dakika boyunca 20 Hz/s'de altı döngü boyunca bir Ball Mill cihazında öğüterek maya hücreleri lysates hazırlayın. NOT: Her döngüden sonra, erimeyi önlemek için donmuş hücreleri barındıran kabı sıvı nitrojene batırın. Protokol burada duraklatılabilir. Dondurulmuş özler -80 °C'de saklanabilir. Maya birleştirme özleri, sferoplastları10'u yutacak homojenizatörler kullanılarak veya harç ve pestle11,12kullanılarak da hazırlanabilir.</li>
	<li>İçerdiği tüpleri oda sıcaklığında suya yerleştirerek, ara sıra sallayarak özü eritin.</li>
	<li>Santrifüj, 4 °C'de 1 saat boyunca 45.000 x g'da santrifüj çıkarır.</li>
	<li>Temizlenen süpernatantın protein içeriğini BCA yöntemi ile ölçün13.</li>
	<li>Özlerin aliquotlarını hazırlayın, sıvı nitrojende hızlı bir şekilde dondurun ve -80 ° C'de saklayın. NOT: Protokol burada duraklatılabilir.</li>
</ol>2. Gliserol gradyan hazırlığı
<ol><li>Tampon A'da biri %10 v/v, diğeri %30 v/v gliserol içeren iki gliserol çözeltisi hazırlayın.</li>
	<li>Çapraz bağlama maddesi glutaraldehitini %30 v/v gliserol çözeltisine %0,1 v/v'ye ekleyin ve homojenize etmek için karıştırın. DİkKAT: Uygun güvenlik ekipmanlarını kullanarak duman kaputunun içindeki glutaraldehiti kullanın.</li>
	<li>12 mL santrifüj tüpünün (14 x 89 mm) altına 6 mL soğuk %10 v/v gliserol çözeltisi ekleyin.</li>
	<li>Tüpün altındaki Degrade Master cihazı ile sağlanan uzun bir iğneye bağlı bir şırınga ile glutaraldehit ile desteklenmiş soğuk 30% v / v gliserol çözeltisinin 6 mL'sini ekleyin, % 10 v / v gliserol çözeltisinin hemen altında. NOT: Alternatif olarak, %10 v/v gliserol çözeltisi% 30 v/v gliserol/glutaraldehit çözeltisinin üstüne dikkatlice pipetlenebilir.</li>
	<li>Sürekli yoğunluk degradesi oluşturmak için Degrade Ana aygıtını kullanın. NOT: Degrade Master cihazında, tüpler uygun bir rafa yerleştirilir ve parametrelerin belirlenmesi için üreticinin önerilerine (zaman/açı/hız) uyularak kısa bir süre döndürülür. Bu çalışmada kullandık: 2:25 dk/81.5°/11 rpm.</li>
	<li>Hücre özlerinin eklenmesinden hemen önce tepeye 200 μL% 7 v / v gliserol / tampon A yastığı ekleyin. NOT: Minderin gliserol konsantrasyonu, doğrusal gradyanı oluşturmak için kullanılan daha az konsantre gliserol çözeltisinden daha düşük olmalıdır.</li>
</ol>3. Santrifüjü çıkarır
<ol><li>Yastık ile her 12 mL lineer gliserol gradyanı 10% –30% glutaraldehitin üzerine yaklaşık 2 mg toplam protein yükleyin.</li>
	<li>Tüpleri önceden soğutulmuş bir salıncak kovası rotorasına yerleştirin. NOT: Ultrasantrifüjlemeden önce karıştırmayı önlemek için tüpleri hafifçe takın.</li>
	<li>4 °C'de 16 saat için 194.000 x g'da santrifüj.</li>
	<li>Aliquot her 12 mL tüp yirmi dört 500 μL fraksiyonlarda uyarlanmış bir EconoSystem kullanarak veya dikkatlice pipetleme ile. NOT: Uyarlanmış bir EconoSystem, peristaltik bir pompa, UV dedektörü ve tüp delinme cihazına bağlı fraksiyon toplayıcıdan oluşur. Çökeltme profili, emiciliğin 280 nm'de ölçülebilmesiyle izlenebilir.</li>
	<li>Glistaltik pompadan %40 v/v gliserol çözeltisi kullanarak gliserol%10-%30 gradyanı tüpten fraksiyon toplayıcıya itin. NOT: Protokol burada duraklatılabilir. Fraksiyonları kullanıma kadar -80 °C'de saklayın.</li>
	<li>Her kesirden 50 μL'yi doğrudan bir nokta lekesi veya yuva lekesi cihazına nitroselüloz zarlarına yükleyin. CBP'ye karşı antikor kullanarak immünoblot ile proteini tespit edin (TAP etiketinin CBP kısmını tespit etmek için 1:6.000) ve ikincil antikor olarak Horseradish Peroxidase (1:15.000) ile konjuge edilen tavşan karşıtı IgG.</li>
</ol>

<ol>
	<li>Kastner, B., Will, C. L., Stark, H., L&#252;hrmann, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structural+insights+into+nuclear+pre-mRNA+splicing+in+higher+eukaryotes.">Structural insights into nuclear pre-mRNA splicing in higher eukaryotes.</a> Cold Spring Harbor Perspectives in Biology. 11 (11), 032417 (2019).</li><li>Yan, C., Wan, R., Shi, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+mechanisms+of+pre-mRNA+splicing+through+structural+biology+of+the+spliceosome.">Molecular mechanisms of pre-mRNA splicing through structural biology of the spliceosome.</a> Cold Spring Harbor Perspectives in Biology. 11 (1), 032409 (2019).</li><li>Cordin, O., Hahn, D., Beggs, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structure,+function+and+regulation+of+spliceosomal+RNA+helicases.">Structure, function and regulation of spliceosomal RNA helicases.</a> Current Opinion in Cell Biology. 24, 431-438 (2012).</li><li>Kastner, B., 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=GraFix:+sample+preparation+for+single-particle+electron+cryomicroscopy.">GraFix: sample preparation for single-particle electron cryomicroscopy.</a> Nature Methods. 5 (1), 53-55 (2008).</li><li>Stark, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Grafix:+stabilization+of+fragile+macromolecular+complexes+for+single+particle+cryo-EM.">Grafix: stabilization of fragile macromolecular complexes for single particle cryo-EM.</a> Methods in Enzymology. 481, 109-126 (2010).</li><li>Yan, C., Wan, R., Bai, R., Huang, G., Shi, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structure+of+a+yeast+activated+spliceosome+at+3.5+&#197;+resolution.">Structure of a yeast activated spliceosome at 3.5 &#197; resolution.</a> Science. 353 (6302), 895-904 (2016).</li><li>Ohi, M. D., 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=Proteomics+analysis+revelas+stable+multiprotein+complexes+in+both+fission+and+budding+yeasts+containing+Myb-related+Cdc5p/Cef1p,+novel+pre-mRNA+splicing+factors,+and+snRNAs.">Proteomics analysis revelas stable multiprotein complexes in both fission and budding yeasts containing Myb-related Cdc5p/Cef1p, novel pre-mRNA splicing factors, and snRNAs.</a> Molecular and Cellular Biology. 22 (7), 2011-2024 (2002).</li><li>Lourenco, R. F., Leme, A. F. P., Oliveira, C. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Proteomic+analysis+of+yeast+mutant+RNA+exosome+complexes.">Proteomic analysis of yeast mutant RNA exosome complexes.</a> Journal of Proteome Research. 12 (12), 5912-5922 (2013).</li><li>Rigaut, G., 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=A+generic+protein+purification+method+for+protein+complex+characterizatioin+and+proteome+exploration.">A generic protein purification method for protein complex characterizatioin and proteome exploration.</a> Nature Biotechnology. 17, 1030-1032 (1999).</li><li>Cheng, S. C., Newman, A., Lin, R. J., McFarland, G. D., Abelson, J. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+and+fractionation+of+yeast+splicing+extract.">Preparation and fractionation of yeast splicing extract.</a> Methods in Enzymology. 181, 89-96 (1990).</li><li>Umen, J. G., Guthrie, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+role+for+a+U5+snRNP+protein+in+3'+splice+site+selection.">A novel role for a U5 snRNP protein in 3' splice site selection.</a> Genes &amp; Development. 9, 855-868 (1995).</li><li>Dunn, E. A., Rader, S. D., Hertel, K. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+yeast+whole+cell+splicing+extract.">Preparation of yeast whole cell splicing extract.</a> Spliceosomal Pre-mRNA Splicing: Methods and Protocols. Methods in Molecular Biology. 1126, 123-135 (2014).</li><li>Hill, H. D., Straka, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protein+determination+using+bicinchoninic+acid+in+the+presence+of+sulfhydryl+reagents.">Protein determination using bicinchoninic acid in the presence of sulfhydryl reagents.</a> Analalytical Biochemistry. 170 (1), 203-208 (1988).</li><li>Cepeda, L. 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=The+ribosome+assembly+factor+Nop53+controls+association+of+the+RNA+exosome+with+pre-60S+particles+in+yeast.">The ribosome assembly factor Nop53 controls association of the RNA exosome with pre-60S particles in yeast.</a> The Journal of Biological Chemistry. 294 (50), 19365-19380 (2019).</li><li>Lin, R. J., Newman, A. J., Cheng, S. C., Abelson, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Yeast+mRNA+splicing+in+vitro.">Yeast mRNA splicing in vitro.</a> The Journal of Biological Chemistry. 260 (27), 14780-14792 (1985).</li></ol>

Yazarların çıkar çatışmaları yok.

Protein-protein ve ribonik asitler-protein etkileşimleri çapraz bağlama ajanları kullanılarak stabilize edilebilir. Elde eden kompleksin gliserol gradyanı üzerinde ultrasantrifüjasyona dayanacak şekilde kararlı olması önemlidir. Ayrıca, arabellek koşulları etkileşime izin vermeli, ancak belirli olmayan bağlamayı önlemek için yeterince katı olmalıdır. Burada gösterilen deneylerde, in vitro birleştirme reaksiyonları için önceden kurulmuş bir tampon çözeltisi kullandık15</su...

Birleştirme, çok sayıda faktörün koordineli bir şekilde bağlanmasını ve serbest bırakılmasını gerektiren son derece dinamik bir işlemdir. Bu birleştirme faktörleri arasında RNA bağlayıcı proteinler, ATPases, helicases, protein kinazları ve fosfatazlar, ubiquitin ligases, diğerleri arasında1,2,3; ve moleküler yeniden düzenlemelerin gerçekleşmesine izin vermek için, bu faktörlerin bazıları çok geçici olarak spliceosome alt komitelerine bağlanır ve bu RNP ara komplekslerinin izolasyonu ve tanımlanmasını çok zorlaştırır.
İşte, Grafix yöntemi4,5'i, maya birleştirme faktörü Cwc24'ün Bact complex6 ile etkileşimini stabilize etmek için kullandık, bu alt sıkıştırıcıya birlikte bağlı diğer faktörlerin tanımlanmasına izin vermek ve ubiquitin ligase Prp19, Cwc24'ün on dokuz (NTC) kompleksine bağlanmasında veya serbest bırakılmasında ve aktivasyondan önce intronun 5' ucuna kadar herhangi bir rol oynar ve ilk transesterifikasyon reaksiyonu alır yer. Makromolekülleri gliserol gradyanı boyunca artan bir çapraz bağlantı konsantrasyonuna maruz kalmanın avantajı, kompleksler arası çaprazbağlantılardan 4,5ve dolayısıyla agregaların oluşumunu önlemesidir.
Bu yöntem, büyük komplekslerin izolasyonuna izin vermesine rağmen, büyük dinamik kompleksler içinde geçici etkileşimleri sürdürmek için güvenilir olmayabileceği protein koimmunoprecipitation ve çekme tahlillerinin tamamlayıcısı olarak kullanılmıştır7,8. Gliserol gradyanındaki fiksasyon reaktiflerinin kullanımı, bu faktörlerin bağlanmasını stabilize ederek, belirli proteinlerin birleştirme altcomplexes ile etkileşimlerinin onaylanmasını sağlar. Seçilen çapraz bağlantı kimyasal olarak geri döndürülemez olduğundan, geri kazanılan fraksiyonlarda bulunan proteinler gradyan santrifüjlemeden sonra nokta lekesi ile analiz edildi.

<table>
	<tbody>
		<tr>
			<td>Anti-Calmodulin Binding Protein Epitope</td>
			<td>Millipore</td>
			<td>07-482</td>
			<td></td>
		</tr>
		<tr>
			<td>ECL anti-Rabbit IgG</td>
			<td>GE Healthcare</td>
			<td>NA934</td>
			<td></td>
		</tr>
		<tr>
			<td>EconoSystem</td>
			<td>Bio-Rad</td>
			<td>1-800-424-6723</td>
			<td>Parts of the EconoSystem used: peristaltic pump, the UV detector and the fraction collector</td>
		</tr>
		<tr>
			<td>EDTA-free Protease Inhibitor Cocktail</td>
			<td>Roche</td>
			<td>11873580001</td>
			<td></td>
		</tr>
		<tr>
			<td>Fraction Recovery System</td>
			<td>Beckman Coulter</td>
			<td>270-331580</td>
			<td>Tube-perforating device that was connected to the parts of the EconoSystem</td>
		</tr>
		<tr>
			<td>Gradient Master Model 107ip</td>
			<td>Biocomp</td>
			<td>107-201M</td>
			<td></td>
		</tr>
		<tr>
			<td>Mixer Mill MM 200</td>
			<td>Retsch</td>
			<td>207460001</td>
			<td>Ball Mill device</td>
		</tr>
		<tr>
			<td>Rotor F12-6x500Lex</td>
			<td>Thermo Scientific</td>
			<td>096-062375</td>
			<td></td>
		</tr>
		<tr>
			<td>Sorvall RC 6 Plus Centrifuge</td>
			<td>Thermo Scientific</td>
			<td>36-101-0816</td>
			<td></td>
		</tr>
		<tr>
			<td>Swinging Bucket Rotor P40ST</td>
			<td>Hitachi</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Ultracentrifuge CP 80 NX</td>
			<td>Hitachi</td>
			<td>901069</td>
			<td></td>
		</tr>
		<tr>
			<td>Ultra-Clear Centrifuge Tubes (14 x 89 mm)</td>
			<td>Beckman Coulter</td>
			<td>344059</td>
			<td></td>
		</tr>
	</tbody>
</table>

utilization of grafix for the detection of transient interactors of saccharomyces cerevisiae spliceosome subcomplexes

Pre-mRNA birleştirme, karmaşık bileşenlerin montajı, RNA işlemesi ve serbest bırakılması sırasında spliceosome alt komkomplexlerinin birçok moleküler yeniden düzenlenmesini içeren çok dinamik bir süreçtir. Gliserol gradyan santrifüjleme fonksiyonel ve yapısal çalışmalar için protein veya RNP (RiboNucleoProtein) komplekslerinin ayrılması için kullanılmıştır. Burada, ilk olarak tek parçacıklı kriyo-elektron mikroskopisi için makromoleküler kompleksleri arındırmak ve stabilize etmek, spliceosome kompleksine geçici olarak bağlanan birleştirme faktörleri arasındaki etkileşimleri tanımlamak için geliştirilen Grafix'in (Gradyan Fiksasyonu) kullanımını açıklıyoruz. Bu yöntem, kompleksleri stabilize etmek için numunelerin artan bir sabitleme reaktif konsantrasyonuna santrifüjlenmesine dayanmaktadır. Gliserol gradyanlarına yüklenen maya toplam özlerinin santrifüjlenmesinden sonra, geri kazanılan fraksiyonlar spliceosome alt komplekslerinin tanımlanması ve bireysel birleştirme faktörlerinin varlığının belirlenmesi için nokta lekesi ile analiz edilir.

Cwc24-TAP'ın sedimantasyon profilini analiz etmek ve Grafix yönteminin birleştirme altkompanlarına bağlanmasını stabilize etmek için etkili olup olmadığını belirlemek için, Cwc24-TAP'ı ifade eden hücrelerin toplam maya özlerini gliserol gradyanları üzerinde santrifüjleme yoluyla, çapraz bağlama ajanı olarak glutaraldehitin varlığında veya yokluğunda ayırdık. Yirmi dört 500 μL fraksiyon örnekleri daha sonra TAP etiketinin CBP kısmına karşı antikor içeren yuva lekesi ile analiz edildi. S...

Watch this Scientific Journal Video about Utilization of Grafix for the Detection of Transient Interactors of Saccharomyces cerevisiae Spliceosome Subcomplexes at JoVE.com

Utilization of Grafix for the Detection of Transient Interactors of Saccharomyces cerevisiae Spliceosome Subcomplexes

Burada, bir çapraz bağlayıcı varlığında gliserol gradyan santrifüjleme olan Grafix'in (Gradyan Fiksasyonu), spliceosome kompleksine geçici olarak bağlanan birleştirme faktörleri arasındaki etkileşimleri tanımlamak için kullanımını açıklıyoruz.

Saccharomyces cerevisiae Spliceosome Subcomplexes Geçici Interactors Tespiti için Grafix kullanımı

Pre-mRNA splicing is a very dynamic process that involves many molecular rearrangements of the spliceosome subcomplexes during assembly, RNA processing, ...

utilization-grafix-for-detection-transient-interactors-saccharomyces

Research

JoVE Journal

Biochemistry

Utilization of Grafix for the Detection of Transient Interactors of Saccharomyces cerevisiae Spliceosome Subcomplexes

3.5K Görüntüleme.  University of Sao Paulo. Burada, bir çapraz bağlayıcı varlığında gliserol gradyan santrifüjleme olan Grafix'in (Gradyan Fiksasyonu), spliceosome kompleksine geçici olarak bağlanan birleştirme faktörleri arasındaki etkileşimleri tanımlamak için kullanımını açıklıyoruz.

Video: Utilization of Grafix for the Detection of Transient Interactors of Saccharomyces cerevisiae Spliceosome Subcomplexes

Studying RNA Interactors of Protein Kinase RNA-Activated during the Mammalian Cell Cycle

Protein kinase RNA-activated (PKR) is a member of the innate immune response proteins and recognizes the double-stranded secondary structure of viral RNAs. When bound to viral double-stranded RNAs (dsRNAs), PKR undergoes dimerization and subsequent autophosphorylation. Phosphorylated PKR (pPKR) becomes active and induces phosphorylation of the alpha subunit of eukaryotic initiation factor 2 (eIF2&#945;) to suppress global translation. Increasing evidence suggests that PKR can be activated under physiological conditions such as during the cell cycle or under various stress conditions without infection. However, our understanding of the RNA activators of PKR is limited due to the lack of a standardized experimental method to capture and analyze PKR-interacting dsRNAs. Here, we present an experimental protocol to specifically enrich and analyze PKR bound RNAs during the cell cycle using HeLa cells. We utilize the efficient crosslinking activity of formaldehyde to fix PKR-RNA complexes and isolate them via immunoprecipitation. PKR co-immunoprecipitated RNAs can then be further processed to generate a high-throughput sequencing library. One major class of PKR-interacting cellular dsRNAs is mitochondrial RNAs (mtRNAs), which can exist as intermolecular dsRNAs through complementary interaction between the heavy-strand and the light-strand RNAs. To study the strandedness of these duplex mtRNAs, we also present a protocol for strand-specific qRT-PCR. Our protocol is optimized for the analysis of PKR-bound RNAs, but it can be easily modified to study cellular dsRNAs or RNA-interactors of other dsRNA binding proteins.

We present experimental approaches for studying RNA-interactors of double-stranded RNA binding protein kinase RNA-activated (PKR) during the mammalian cell cycle using HeLa cells. This method utilizes formaldehyde to crosslink RNA-PKR complexes and immunoprecipitation to enrich PKR-bound RNAs. These RNAs can be further analyzed through high-throughput sequencing or qRT-PCR.

RNA Interactors Protein kinaz memeli hücre döngüsü sırasında RNA-harekete geçirmek, eğitim

Protein kinase RNA-activated (PKR) is a member of the innate immune response proteins and recognizes the double-stranded secondary structure of viral ...

Biyokimya

Study on the Metabolism of Six Systemic Insecticides in a Newly Established Cell Suspension Culture Derived from Tea (Camellia Sinensis L.) Leaves

A platform for studying insecticide metabolism using in vitro tissues of tea plant was developed. Leaves from sterile tea plantlets were induced to form loose callus on Murashige and Skoog (MS) basal media with the plant hormones 2,4-dichlorophenoxyacetic acid (2,4-D, 1.0 mg L-1) and kinetin (KT, 0.1 mg L-1). Callus formed after 3 or 4 rounds of subculturing, each lasting 28 days. Loose callus (about 3 g) was then inoculated into B5 liquid media containing the same plant hormones and was cultured in a shaking incubator (120 rpm) in the dark at 25 &#177; 1 &#176;C. After 3&#8722;4 subcultures, a cell suspension derived from tea leaf was established at a subculture ratio ranging between 1:1 and 1:2 (suspension mother liquid: fresh medium). Using this platform, six insecticides (5 &#181;g mL-1 each thiamethoxam, imidacloprid, acetamiprid, imidaclothiz, dimethoate, and omethoate) were added into the tea leaf-derived cell suspension culture. The metabolism of the insecticides was tracked using liquid chromatography and gas chromatography. To validate the usefulness of the tea cell suspension culture, the metabolites of thiamethoxan and dimethoate present in treated cell cultures and intact plants were compared using mass spectrometry. In treated tea cell cultures, seven metabolites of thiamethoxan and two metabolites of dimethoate were found, while in treated intact plants, only two metabolites of thiamethoxam and one of dimethoate were found. The use of a cell suspension simplified the metabolic analysis compared to the use of intact tea plants, especially for a difficult matrix such as tea.

Study on the Metabolism of Six Systemic Insecticides in a Newly Established Cell Suspension Culture Derived from Tea Camellia Sinensis L. Leaves

This work presents a protocol for establishing a cell suspension culture derived from tea (Camellia sinensis L.) leaves that can be used to study the metabolism of external compounds that can be taken up by the whole plant, such as insecticides.

Çay (Camellia sinensis L.) türetilmiştir yeni kurulan hücre süspansiyon kültürü altı sistemik Böcek Ilacı metabolizması üzerinde çalışma Yaprak -ları

A platform for studying insecticide metabolism using in vitro tissues of tea plant was developed. Leaves from sterile tea plantlets were induced to form ...

Quantitative Analysis of the Cellular Lipidome of Saccharomyces Cerevisiae Using Liquid Chromatography Coupled with Tandem Mass Spectrometry

Lipids are structurally diverse amphipathic molecules that are insoluble in water. Lipids are essential contributors to the organization and function of biological membranes, energy storage and production, cellular signaling, vesicular transport of proteins, organelle biogenesis, and regulated cell death. Because the budding yeast Saccharomyces cerevisiae is a unicellular eukaryote amenable to thorough molecular analyses, its use as a model organism helped uncover mechanisms linking lipid metabolism and intracellular transport to complex biological processes within eukaryotic cells. The availability of a versatile analytical method for the robust, sensitive, and accurate quantitative assessment of major classes of lipids within a yeast cell is crucial for getting deep insights into these mechanisms. Here we present a protocol to use liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) for the quantitative analysis of major cellular lipids of S. cerevisiae. The LC-MS/MS method described is versatile and robust. It enables the identification and quantification of numerous species (including different isobaric or isomeric forms) within each of the 10 lipid classes. This method is sensitive and allows identification and quantitation of some lipid species at concentrations as low as 0.2 pmol/&#181;L. The method has been successfully applied to assessing lipidomes of whole yeast cells and their purified organelles. The use of alternative mobile phase additives for electrospray ionization mass spectrometry in this method can increase the efficiency of ionization for some lipid species and can be therefore used to improve their identification and quantitation.

Quantitative Analysis of the Cellular Lipidome of Saccharomyces Cerevisiae Using Liquid Chromatography Coupled with Tandem Mass Spectrometry

We present a protocol using liquid chromatography coupled with tandem mass spectrometry to identify and quantify major cellular lipids in Saccharomyces cerevisiae. The described method for a quantitative assessment of major lipid classes within a yeast cell is versatile, robust, and sensitive.

Tandem Kütle Spektrometresi Ile Birleşen Sıvı Kromatografi kullanarak Saccharomyces Cerevisiae'nin Hücresel Lipidomukan Analizi

Lipids are structurally diverse amphipathic molecules that are insoluble in water. Lipids are essential contributors to the organization and function of ...

Labelling and Visualization of Mitochondrial Genome Expression Products in Baker's Yeast Saccharomyces cerevisiae

Mitochondria are essential organelles of eukaryotic cells capable of aerobic respiration. They contain circular genome and gene expression apparatus. A mitochondrial genome of baker&#8217;s yeast encodes eight proteins: three subunits of the cytochrome c oxidase (Cox1p, Cox2p, and Cox3p), three subunits of the ATP synthase (Atp6p, Atp8p, and Atp9p), a subunit of the ubiquinol-cytochrome c oxidoreductase enzyme, cytochrome b (Cytb), and mitochondrial ribosomal protein Var1p. The purpose of the method described here is to specifically label these proteins with 35S methionine, separate them by electrophoresis and visualize the signals as discrete bands on the screen. The procedure involves several steps. First, yeast cells are cultured in a galactose-containing medium until they reach the late logarithmic growth stage. Next, cycloheximide treatment blocks cytoplasmic translation and allows 35S methionine incorporation only in mitochondrial translation products. Then, all proteins are extracted from yeast cells and separated by polyacrylamide gel electrophoresis. Finally, the gel is dried and incubated with the storage phosphor screen. The screen is scanned on a phosphorimager revealing the bands. The method can be applied to compare the biosynthesis rate of a single polypeptide in the mitochondria of a mutant yeast strain versus the wild type, which is useful for studying mitochondrial gene expression defects. This protocol gives valuable information about the translation rate of all yeast mitochondrial mRNAs. However, it requires several controls and additional experiments to make proper conclusions.

Labelling and Visualization of Mitochondrial Genome Expression Products in Baker's Yeast Saccharomyces cerevisiae

Baker&#8217;s yeast mitochondrial genome encodes eight polypeptides. The goal of the current protocol is to label all of them and subsequently visualize them as separate bands.

Fırıncı Maya saccharomyces cerevisiae Mitokondriyal Genom İfade Ürünlerinin Etiketlenmesi ve Görselleştirilmesi

Mitochondria are essential organelles of eukaryotic cells capable of aerobic respiration. They contain circular genome and gene expression apparatus. A ...

Quantitative Metabolomics of Saccharomyces Cerevisiae Using Liquid Chromatography Coupled with Tandem Mass Spectrometry

Metabolomics is a methodology used for the identification and quantification of many low-molecular-weight intermediates and products of metabolism within a cell, tissue, organ, biological fluid, or organism. Metabolomics traditionally focuses on water-soluble metabolites. The water-soluble metabolome is the final product of a complex cellular network that integrates various genomic, epigenomic, transcriptomic, proteomic, and environmental factors. Hence, the metabolomic analysis directly assesses the outcome of the action for all these factors in a plethora of biological processes within various organisms. One of these organisms is the budding yeast Saccharomyces cerevisiae, a unicellular eukaryote with the fully sequenced genome. Because S. cerevisiae is amenable to comprehensive molecular analyses, it is used as a model for dissecting mechanisms underlying many biological processes within the eukaryotic cell. A versatile analytical method for the robust, sensitive, and accurate quantitative assessment of the water-soluble metabolome would provide the essential methodology for dissecting these mechanisms. Here we present a protocol for the optimized conditions of metabolic activity quenching in and water-soluble metabolite extraction from S. cerevisiae cells. The protocol also describes the use of liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) for the quantitative analysis of the extracted water-soluble metabolites. The LC-MS/MS method of non-targeted metabolomics described here is versatile and robust. It enables the identification and quantification of more than 370 water-soluble metabolites with diverse structural, physical, and chemical properties, including different structural isomers and stereoisomeric forms of these metabolites. These metabolites include various energy carrier molecules, nucleotides, amino acids, monosaccharides, intermediates of glycolysis, and tricarboxylic cycle intermediates. The LC-MS/MS method of non-targeted metabolomics is sensitive and allows the identification and quantitation of some water-soluble metabolites at concentrations as low as 0.05 pmol/&#181;L. The method has been successfully used for assessing water-soluble metabolomes of wild-type and mutant yeast cells cultured under different conditions.

Quantitative Metabolomics of Saccharomyces Cerevisiae Using Liquid Chromatography Coupled with Tandem Mass Spectrometry

We present a protocol for the identification and quantitation of major classes of water-soluble metabolites in the yeast Saccharomyces cerevisiae. The described method is versatile, robust, and sensitive. It allows the separation of structural isomers and stereoisomeric forms of water-soluble metabolites from each other.

Sıvı KromatografiSi Kullanan Saccharomyces Cerevisiae'nin Nicel Metabolomikleri Tandem Kütle Spektrometresi ile Birleştiğinde

Metabolomics is a methodology used for the identification and quantification of many low-molecular-weight intermediates and products of metabolism within ...

Analysis of Neutral Lipid Synthesis in Saccharomyces cerevisiae by Metabolic Labeling and Thin Layer Chromatography

Neutral lipids (NLs) are a class of hydrophobic, chargeless biomolecules that play key roles in energy and lipid homeostasis. NLs are synthesized de novo&#160;from acetyl-CoA and are primarily present in eukaryotes in the form of triglycerides (TGs) and sterol-esters (SEs). The enzymes responsible for the synthesis of NLs are highly conserved from Saccharomyces cerevisiae (yeast) to humans, making yeast a useful model organism to dissect the function and regulation of NL metabolism enzymes. While much is known about how acetyl-CoA is converted into a diverse set of NL species, mechanisms for regulating NL metabolism enzymes, and how mis-regulation can contribute to cellular pathologies, are still being discovered. Numerous methods for the isolation and characterization of NL species have been developed and used over decades of research; however, a quantitative and simple protocol for the comprehensive characterization of major NL species has not been discussed. Here, a simple and adaptable method to quantify the de novo&#160;synthesis of major NL species in yeast is presented. We apply 14C-acetic acid metabolic labeling coupled with thin layer chromatography to separate and quantify a diverse range of physiologically important NLs. Additionally, this method can be easily applied to study in vivo reaction rates of NL enzymes or degradation of NL species over time.

Analysis of Neutral Lipid Synthesis in Saccharomyces cerevisiae by Metabolic Labeling and Thin Layer Chromatography

Here, a protocol is presented for the metabolic labeling of yeast with 14C-acetic acid, which is coupled with thin layer chromatography for the separation of neutral lipids.

Metabolik Etiketleme ve İnce Tabaka Kromatografisi ile Saccharomyces serevizisinde Nötr Lipid Sentezinin Analizi

Neutral lipids (NLs) are a class of hydrophobic, chargeless biomolecules that play key roles in energy and lipid homeostasis. NLs are synthesized de ...

Preparation and Cryo-FIB micromachining of Saccharomyces cerevisiae for Cryo-Electron Tomography

Today, cryo-electron tomography (cryo-ET) is the only technique that can provide near-atomic resolution structural data on macromolecular complexes in situ. Owing to the strong interaction of an electron with the matter, high-resolution cryo-ET studies are limited to specimens with a thickness of less than 200 nm, which restricts the applicability of cryo-ET only to the peripheral regions of a cell. A complex workflow that comprises the preparation of thin cellular cross-sections by cryo-focused ion beam micromachining (cryo-FIBM) was introduced during the last decade to enable the acquisition of cryo-ET data from the interior of larger cells. We present a protocol for the preparation of cellular lamellae from a sample vitrified by plunge freezing utilizing Saccharomyces cerevisiae as a prototypical example of a eukaryotic cell with wide utilization in cellular and molecular biology research. We describe protocols for vitrification of S. cerevisiae into isolated patches of a few cells or a continuous monolayer of the cells on a TEM grid and provide a protocol for lamella preparation by cryo-FIB for these two samples.

Preparation and Cryo-FIB micromachining of Saccharomyces cerevisiae for Cryo-Electron Tomography

We present a protocol for lamella preparation of plunge frozen biological specimens by cryo-focused ion beam micromachining for high-resolution structural studies of macromolecules in situ with cryo-electron tomography. The presented protocol provides guidelines for the preparation of high-quality lamellae with high reproducibility for structural characterization of macromolecules inside the&#160;Saccharomyces cerevisiae.

Kriyo-Elektron Tomografisi için Saccharomyces cerevisiae'nin Hazırlanması ve Kriyo-FIB mikromakinesi

Today, cryo-electron tomography (cryo-ET) is the only technique that can provide near-atomic resolution structural data on macromolecular complexes in ...

Assessment of Submitochondrial Protein Localization in Budding Yeast Saccharomyces cerevisiae

Despite recent advances in the characterization of yeast mitochondrial proteome, the submitochondrial localization of a significant number of proteins remains elusive. Here, we describe a robust and effective method for determining the suborganellar localization of yeast mitochondrial proteins, which is considered a fundamental step during mitochondrial protein function elucidation. This method involves an initial step that consists of obtaining highly pure intact mitochondria. These mitochondrial preparations are then subjected to a subfractionation protocol consisting of hypotonic shock (swelling) and incubation with proteinase K (protease). During swelling, the outer mitochondrial membrane is selectively disrupted, allowing the proteinase K to digest proteins of the intermembrane space compartment. In parallel, to obtain information about the topology of membrane proteins, the mitochondrial preparations are initially sonicated, and then subjected to alkaline extraction with sodium carbonate. Finally, after centrifugation, the pellet and supernatant fractions from these different treatments are analyzed by SDS-PAGE and western blot. The submitochondrial localization as well as the membrane topology of the protein of interest is obtained by comparing its western blot profile with known standards.

Assessment of Submitochondrial Protein Localization in Budding Yeast Saccharomyces cerevisiae

Despite recent advances, many yeast mitochondrial proteins still remain with their functions completely unknown. This protocol provides a simple and reliable method to determine the submitochondrial localization of proteins, which has been fundamental for the elucidation of their molecular functions.

Tomurcuklanan Maya Sakkaromices cerevisiae'de Submitochondrial Protein Lokalizasyonunun Değerlendirilmesi

Despite recent advances in the characterization of yeast mitochondrial proteome, the submitochondrial localization of a significant number of proteins ...

Purification of Endogenous Drosophila Transient Receptor Potential Channels

Drosophila phototransduction is one of the fastest known G protein-coupled signaling pathways. To ensure the specificity and efficiency of this cascade, the calcium (Ca2+)-permeable cation channel, transient receptor potential (TRP), binds tightly to the scaffold protein, inactivation-no-after-potential D (INAD), and forms a large signaling protein complex with eye-specific protein kinase C (ePKC) and phospholipase C&#946;/No receptor potential A (PLC&#946;/NORPA). However, the biochemical properties of the Drosophila TRP channel remain unclear. Based on the assembling mechanism of INAD protein complex, a modified affinity purification plus competition strategy was developed to purify the endogenous TRP channel. First, the purified histidine (His)-tagged NORPA 863-1095 fragment was bound to Ni-beads and used as bait to pull down the endogenous INAD protein complex from Drosophila head homogenates. Then, excessive purified glutathione S-transferase (GST)-tagged TRP 1261-1275 fragment was added to the Ni-beads to compete with the TRP channel. Finally, the TRP channel in the supernatant was separated from the excessive TRP 1261-1275 peptide by size-exclusion chromatography. This method makes it possible to study the gating mechanism of the Drosophila TRP channel from both biochemical and structural angles. The electrophysiology properties of purified Drosophila TRP channels can also be measured in the future.

Purification of Endogenous Drosophila Transient Receptor Potential Channels

Based on the assembling mechanism of the INAD protein complex, in this protocol, a modified affinity purification plus competition strategy was developed to purify the endogenous Drosophila TRP channel.

Endojen Drosophila Geçici Reseptör Potansiyel Kanallarının Saflaştırılması

Drosophila phototransduction is one of the fastest known G protein-coupled signaling pathways. To ensure the specificity and efficiency of this cascade, ...

Motility of Single Molecules and Clusters of Bi-Directional Kinesin-5 Cin8 Purified from S. cerevisiae Cells

The mitotic bipolar kinesin-5 motors perform essential functions in spindle dynamics. These motors exhibit a homo-tetrameric structure with two pairs of catalytic motor domains, located at opposite ends of the active complex. This unique architecture enables kinesin-5 motors to crosslink and slide apart antiparallel spindle microtubules (MTs), thus providing the outwardly-directed force that separates the spindle poles apart. Previously, kinesin-5 motors were believed to be exclusively plus-end directed. However, recent studies revealed that several fungal kinesin-5 motors are minus-end directed at the single-molecule level and can switch directionality under various experimental conditions. The Saccharomyces cerevisiae kinesin-5 Cin8 is an example of such bi-directional motor protein: in high ionic strength conditions single molecules of Cin8 move in the minus-end direction of the MTs. It was also shown that Cin8 forms motile clusters, predominantly at the minus-end of the MTs, and such clustering allows Cin8 to switch directionality and undergo slow, plus-end directed motility. This article provides a detailed protocol for all steps of working with GFP-tagged kinesin-5 Cin8, from protein overexpression in S. cerevisiae cells and its purification to in vitro single-molecule motility assay. A newly developed method described here helps to differentiate between single molecules and clusters of Cin8, based on their fluorescence intensity. This method enables separate analysis of motility of single molecules and clusters of Cin8, thus providing the characterization of the dependence of Cin8 motility on its cluster size.

Motility of Single Molecules and Clusters of Bi-Directional Kinesin-5 Cin8 Purified from S. cerevisiae Cells

The bi-directional mitotic kinesin-5 Cin8 accumulates in clusters that split and merge during their motility. Accumulation in clusters also changes the velocity and directionality of Cin8. Here, a protocol for motility assays with purified Cin8-GFP and analysis of motile properties of single molecules and clusters of Cin8 is described.

Tek Moleküllerin Motilitesi ve S. cerevisiae Hücrelerinden Saflaştırılmış Çift Yönlü Kinesin-5 Cin8 Kümeleri

The mitotic bipolar kinesin-5 motors perform essential functions in spindle dynamics. These motors exhibit a homo-tetrameric structure with two pairs of ...