אנו מודים לצוות בתוך המכון לגנטיקה אנושית על הגדרות ספריית הכנה ורצף. אנו מודים עינת שניר על המומחיות שלה בהכנת שברי ספרייה גנומית של הספריה פלסמיד Y2H כאן. עבודה זו נתמכה על ידי מכוני הבריאות הלאומיים: NIH R21 EB021870-01A1, על ידי ה-NSF מחקר פרויקט מענק: 1517110.

<ol>
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V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mapping+the+Protein-Protein+Interactome+Networks+Using+Yeast+Two-Hybrid+Screens.">Mapping the Protein-Protein Interactome Networks Using Yeast Two-Hybrid Screens.</a> Advances in Experimental Medicine and Biology. 883, 187-214 (2015).</li><li>Weimann, M., 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+Y2H-seq+approach+defines+the+human+protein+methyltransferase+interactome.">A Y2H-seq approach defines the human protein methyltransferase interactome.</a> Nature Methods. 10 (4), 339-342 (2013).</li><li>Yachie, N., 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=Pooled-matrix+protein+interaction+screens+using+Barcode+Fusion+Genetics.">Pooled-matrix protein interaction screens using Barcode Fusion Genetics.</a> Molecular Systems Biology. 12 (4), 863 (2016).</li><li>Trigg, S. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CrY2H-seq:+a+massively+multiplexed+assay+for+deep-coverage+interactome+mapping.">CrY2H-seq: a massively multiplexed assay for deep-coverage interactome mapping.</a> Nature Methods. , (2017).</li><li>Estojak, J., Brent, R., Golemis, E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Correlation+of+two-hybrid+affinity+data+with+in+vitro+measurements.">Correlation of two-hybrid affinity data with in vitro measurements.</a> Molecular and Cellular Biology. 15 (10), 5820-5829 (1995).</li><li>Rajagopala, S. V., Hughes, K. T., Uetz, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Benchmarking+yeast+two-hybrid+systems+using+the+interactions+of+bacterial+motility+proteins.">Benchmarking yeast two-hybrid systems using the interactions of bacterial motility proteins.</a> Proteomics. 9 (23), 5296-5302 (2009).</li><li>James, P., Halladay, J., Craig, E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genomic+libraries+and+a+host+strain+designed+for+highly+efficient+two-hybrid+selection+in+yeast.">Genomic libraries and a host strain designed for highly efficient two-hybrid selection in yeast.</a> Genetics. 144 (4), 1425-1436 (1996).</li><li>Barbas, C. F., Burton, D. R., Scott, J. K., Silverman, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitation+of+DNA+and+RNA.">Quantitation of DNA and RNA.</a> CSH Protoc. 2007, pdb ip47 (2007).</li><li>Sambrook, J., Russell, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=SDS-Polyacrylamide+Gel+Electrophoresis+of+Proteins.">SDS-Polyacrylamide Gel Electrophoresis of Proteins.</a> Cold Spring Harbor Protocols. 2006 (4), (2006).</li><li>Towbin, H., Staehelin, T., Gordon, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrophoretic+transfer+of+proteins+from+polyacrylamide+gels+to+nitrocellulose+sheets:+procedure+and+some+applications.">Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications.</a> Proceedings of the National Academy of Sciences USA. 76 (9), 4350-4354 (1979).</li><li>Alegria-Schaffer, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Western+blotting+using+chemiluminescent+substrates.">Western blotting using chemiluminescent substrates.</a> Methods in Enzymology. 541, 251-259 (2014).</li><li>Lee, P. Y., Costumbrado, J., Hsu, C. Y., Kim, Y. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Agarose+gel+electrophoresis+for+the+separation+of+DNA+fragments.">Agarose gel electrophoresis for the separation of DNA fragments.</a> Journal of Visualized Experiments. (62), (2012).</li><li>Harper, J. W., Adami, G. R., Wei, N., Keyomarsi, K., Elledge, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+p21+Cdk-interacting+protein+Cip1+is+a+potent+inhibitor+of+G1+cyclin-dependent+kinases.">The p21 Cdk-interacting protein Cip1 is a potent inhibitor of G1 cyclin-dependent kinases.</a> Cell. 75 (4), 805-816 (1993).</li></ol>

המחברים אין לחשוף

כאן אנו מספקים מדריך כיצד לבצע מבחני Y2H אצווה באמצעות שיטות אופטימיזציה. ישנם כמה צעדים קריטיים במסגרת ההליך כדי לסייע להבטיח כי האוכלוסייה של שמרים כי להימצא תחת הבחירה הוא נציג של הספרייה ההתחלה, כי מספיק של האוכלוסייה שמרים המוצא משמש בתהליך הבחירה כדי להגביל את השתנות . חשוב לציין, אמו?...

הבנה מלאה של התהליכים הביולוגיים תא מסתמך על מציאת הרשתות אינטראקציית חלבון העומדים בבסיס המנגנונים המולקולריים שלהם. גישה אחת כדי לזהות אינטראקציות חלבון הוא וזמינותו (Y2H) 2-היברידית שמרים, אשר עובד על ידי הרכבת פקטור שעתוק chimeric מתפקדת ברגע חלבון שני, תחומי עניין לאגד בזו1. מסך Y2H טיפוסי מבוצע על-ידי יצירת אוכלוסייה של שמרים כי בתים בשני ספריה של פלסמידים קידוד חלבונים שמעצבת דבוקה מפעיל גנים ברמת השעתוק (למשל., "טרף" חלבון כימרי) ולא על פלסמיד נתון "פיתיון" המורכבת של החלבון עניין התמזגו לתחום איגוד ה-DNA (למשל, התחום Gal4 DNA-איגוד המאגד רצף הפעלת נגד הזרם-Gal4). אחד היתרונות העיקריים של הגישה Y2H היא כי קל יחסית זול לבצע במעבדה טיפוסי מצויד עבור עבודה שוטפת ביולוגית מולקולרית2. עם זאת, כאשר מבוצעת באופן מסורתי, משתמש דוגמאות בודדות מושבות שעולות בעת הבחירה עבור השפעה חיובית הדדית Y2H. זה קשות מגביל את המספר של ספריית "טרף" שיבוטים זה יבדקו. בעיה זו היא הופכת למורכבת יותר כאשר השפע של טרף אינטראקציה מסוימת היא גבוהה מאוד ביחס לאחרים, צמצום הסיכוי של גילוי האינטראקציה של פלסמידים לטרף השפע נמוכה.
פתרון אחד לשימוש העיקרון Y2H ב כיסוי מקיף של פרוטאום הוא השימוש בגישה בתבנית מטריצה שבה מערך המכיל טרף בודדים הידועים פלסמידים יכולים דיגיטלית להיחקר. עם זאת, גישה כזו דורשת תשתית אינו נגיש בקלות או חסכונית לחוקרים בודדים אשר מעוניינים מגדיר את interactome של מספר קטן של חלבונים או תחומים3. בנוסף, ספריות טרף מאוד מורכב יכול לקודד שברים מרובים של חלבונים שמעצבת להרחיב גודל כזה מערכים מטריקס גדלים מעשית. חלופה אחת היא לבצע מבחני עם ספריות מורכבים בקבוצות להעריך את הנוכחות של אינטראקציה שיבוטים שימוש מסיבי מקביל בתפוקה גבוהה רצף4. זה ניתן ליישם assay הנוכחות של פלסמידים טרף העולות מושבות מרובות באמצעות טיפוסי Y2H מעוצב הגישה שמרים אילו תאים דיור בזוג אינטראקציה של חלבונים פיוז'ן רשאים לגדול על צלחת5,6. זה הרעיון הכללי יכול להיות הדגישה להגדיל השאילתה של שני פיתיון מרובים, טרף רכיבים באותו זמן7,8.
עדיין, חקירות רבות דורשות שקל יותר עדיין מתרכז יותר מאמץ רק כמה חלבון "פיתיונות', יכולים ליהנות יותר על-ידי שאילתת ממצה, חצי כמותית של ספריה טרף מורכבת אחת. יש שפותחה ואנו לאימות גישה לביצוע מחקרים אינטראקציה חלבון בהיקף נרחב באמצעות עיקרון Y2H אצווה תבנית4. זה משתמש קצב התרחבות פלסמיד מסוים טרף כמייצג העוצמה היחסית של האינטראקציה Y2H9. רצף עמוק של פלסמידים כל בתוך אוכלוסיה נתון הצמיחה רגילה או תנאי הגידול סלקטיבי מייצר מפה מלאה של שיבוטים המניבים אינטראקציות Y2H חזקות או חלשות. הרפרטואר של interactors יכול להיות שהושג, בהשוואה ישירות על פני פלסמידים מרובים פיתיון. זרימת העבודה וכתוצאה מכך כינה DEEPN (דינמי העשרה עבור הערכה של חלבונים רשתות) וכך ניתן לזהות interactomes דיפרנציאלית מספריות טרף אותו לזהות חלבונים, המאפשר השוואה בין חלבון אחד לעומת אחר.
. הנה, נדגים DEEPN להציג שיפור שיטות מעבדה זה להקל על השימוש בו, אשר מתוארים באיור1. שיפורים משמעותיים כוללים:
דור של אוכלוסיות השמרים טרף. אחת מהדרישות מפתח של DEEPN מייצר אוכלוסיות של שמרים עם פלסמידים שונים פיתיון שיש מאותה התפלגות של ספריות טרף פלסמיד. אוכלוסיות בסיסית המקבילה של הספרייה פלסמיד טרף חיוניים לייצור מדויק השוואות בין interactomes של פיתיונות שונים. זו מושגת בצורה הטובה ביותר כאשר פלסמיד ספריית שוכן כבר בקרב אוכלוסיה שמרים הפלואידי, לגור פלסמיד הפיתיון נתון של האוכלוסייה הזאת מושגת על ידי הזדווגות לייצר דיפלואידי. כאן, אנו מספקים מדריך ברור באיך להכין כזה אוכלוסיות באמצעות ספריות מסחריים בבניין שמרים הפלואידי. אמנם מצאנו שיטות לייצר מספר רב של diploids, היעילות הכוללת ההזדווגות של מסחרי ספריית המכילים שמרים זנים אלו היה נמוך. לכן, אנחנו נבנה זן חדש אשר יכול בית ספריות טרף המניבה diploids הרבה יותר לכל ההזדווגות התגובה.
ניו סט פתיונות פלסמידים. פלסמידים הנוכחי רבים המבטאים "פיתיון" פיוז'ן חלבונים מורכבת של החלבון של עניין לתחום ה-DNA מחייב הם מבוססי 2µ, ומאפשר להם להגביר את מספר העותק שלהם. מספר עותק זה יכול להיות משתנה מאוד באוכלוסייה, להוביל השתנות בתגובה תעתיק Y2H. זה בתורו יכול להטות את היכולת לאמוד את עוצמת האינטראקציה חלבון נתון בהתבסס על התגובה צמיחה של תאים תחת בחירת. זו יכולה להיות חלקית כתובת על-ידי שימוש של פלסמיד עותק נמוכה, אשר חלקם תוארו קודם לכן כגון זמינים מסחרית pDEST3210. ואנחנו נבנה על חדש פיתיון פלסמיד (pTEF-GBD) מייצרת Gal4 DNA-מחייב תחום היתוך חלבונים בתוך פלסמיד מבוססי צנטרומר עותק נמוך TRP1 נושא את הגן ההתנגדות Kanr המאפשר גם שיבוט של פיתיון קטעים שני במעלה הזרם, במורד הזרם של התחום מחייב Gal4 DNA.
ספריית קטע חדש בצפיפות גבוהה Y2H. אנו נבנה על פלסמיד חדש לספריות טרף Y2H הבית, השתמשו בו כדי לבנות ספרייה Y2H מורכב מסיבים של אקראי הוטו שברי DNA גנומי האפייה. ניתוח רצף הראו כי בספריה זו היה מעל 1 מיליון רכיבים שונים, הרבה יותר מורכב מאשר שמרים שתואר לעיל גנומית Y2H פלסמיד ספריות11. עם הספרייה החדשה, הצלחנו להראות זרימת העבודה DEEPN יציבה מספיק כדי להכיל את ספריות מורכב עם הרבה פלסמידים שונים באופן אמין, לשחזור.

<table>
	<tbody>
		<tr>
			<td>Illumina HiSeq 4000</td>
			<td>Illumina</td>
			<td></td>
			<td>deep sequencing platform</td>
		</tr>
		<tr>
			<td>Monoclonal anti-HA antibodies</td>
			<td>Biolegend</td>
			<td>901514</td>
			<td>Primary Antibody to detect expression of HA in pGal4AD constructs</td>
		</tr>
		<tr>
			<td>Polyclonal anti-myc antibodies</td>
			<td>QED Biosciences Inc</td>
			<td>18826</td>
			<td>Primary Antibody to detect expression of MYC in pTEF-GBD constructs</td>
		</tr>
		<tr>
			<td>NarI</td>
			<td>New England BioLabs</td>
			<td>R0191S</td>
			<td></td>
		</tr>
		<tr>
			<td>EcoRI-HF</td>
			<td>New England BioLabs</td>
			<td>R3101S</td>
			<td></td>
		</tr>
		<tr>
			<td>BamHI-HF</td>
			<td>New England BioLabs</td>
			<td>R3236S</td>
			<td></td>
		</tr>
		<tr>
			<td>XhoI</td>
			<td>New England BioLabs</td>
			<td>R0146S</td>
			<td></td>
		</tr>
		<tr>
			<td>Polyethylene Glycol 3350, powder</td>
			<td>J.T. Baker</td>
			<td>U2211-08</td>
			<td></td>
		</tr>
		<tr>
			<td>Salmon Sperm DNA</td>
			<td>Trevigen, Inc sold by Fisher Scientific</td>
			<td>50-948-286</td>
			<td>carrier DNA for yeast transformation section 3.2.1.</td>
		</tr>
		<tr>
			<td>Kanamycin Monosulfate</td>
			<td>Research Products International</td>
			<td>K22000</td>
			<td></td>
		</tr>
		<tr>
			<td>LE Agarose</td>
			<td>GeneMate</td>
			<td>E-3120-500</td>
			<td>used for making DNA agarose gels</td>
		</tr>
		<tr>
			<td>Sodium Chloride</td>
			<td>Research Products International</td>
			<td>S23025</td>
			<td></td>
		</tr>
		<tr>
			<td>Tryptone</td>
			<td>Research Products International</td>
			<td>T60060</td>
			<td></td>
		</tr>
		<tr>
			<td>D-Sorbitol</td>
			<td>Research Products International</td>
			<td>S23080</td>
			<td></td>
		</tr>
		<tr>
			<td>Lithium Acetate Dihydrate</td>
			<td>MP Biomedicals</td>
			<td>155256</td>
			<td></td>
		</tr>
		<tr>
			<td>Calcium Chloride</td>
			<td>ThermoFisher</td>
			<td>C79</td>
			<td></td>
		</tr>
		<tr>
			<td>EDTA Sodium Salt</td>
			<td>Research Products International</td>
			<td>E57020</td>
			<td></td>
		</tr>
		<tr>
			<td>Yeast Extract Powder</td>
			<td>Research Products International</td>
			<td>Y20020</td>
			<td></td>
		</tr>
		<tr>
			<td>Yeast Nitrogen Base (ammonium sulfate) w/o amino acids</td>
			<td>Research Products International</td>
			<td>Y20040</td>
			<td></td>
		</tr>
		<tr>
			<td>CSM-Trp-Leu+40ADE</td>
			<td>Formedium</td>
			<td>DCS0789</td>
			<td></td>
		</tr>
		<tr>
			<td>CSM-Trp-Leu-His+40ADE</td>
			<td>Formedium</td>
			<td>DCS1169</td>
			<td></td>
		</tr>
		<tr>
			<td>CSM-Leu-Met</td>
			<td>Formedium</td>
			<td>DCS0549</td>
			<td></td>
		</tr>
		<tr>
			<td>CSM-Trp-Met</td>
			<td>Bio 101, Inc</td>
			<td>4520-922</td>
			<td></td>
		</tr>
		<tr>
			<td>L-Methionine</td>
			<td>Formedium</td>
			<td>DOC0168</td>
			<td></td>
		</tr>
		<tr>
			<td>Adenine</td>
			<td>Research Products International</td>
			<td>A11500</td>
			<td></td>
		</tr>
		<tr>
			<td>D-(+)-Glucose</td>
			<td>Research Products International</td>
			<td>G32045</td>
			<td></td>
		</tr>
		<tr>
			<td>Bacto Agar</td>
			<td>BD</td>
			<td>214010</td>
			<td>used for making media plates in section 1</td>
		</tr>
		<tr>
			<td>Peptone</td>
			<td>Research Products International</td>
			<td>P20240</td>
			<td></td>
		</tr>
		<tr>
			<td>3-amino-1,2,4 Triazole</td>
			<td>Sigma</td>
			<td>A8056</td>
			<td></td>
		</tr>
		<tr>
			<td>2-Mercaptoehanol (BME)</td>
			<td>Sigma-Aldrich</td>
			<td>M6250</td>
			<td></td>
		</tr>
		<tr>
			<td>Zymolyase 100T</td>
			<td>USBiological</td>
			<td>Z1004</td>
			<td></td>
		</tr>
		<tr>
			<td>Potassium phosphate dibasic</td>
			<td>Sigma</td>
			<td>P8281</td>
			<td></td>
		</tr>
		<tr>
			<td>Phenol:Chloroform:IAA</td>
			<td>Ambion</td>
			<td>AM9732</td>
			<td></td>
		</tr>
		<tr>
			<td>Ammonium Acetate</td>
			<td>Sigma-Aldrich</td>
			<td>238074</td>
			<td></td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td>Decon Laboratories, INC</td>
			<td>2716</td>
			<td></td>
		</tr>
		<tr>
			<td>RNAse A</td>
			<td>ThermoFisher</td>
			<td>EN0531</td>
			<td></td>
		</tr>
		<tr>
			<td>Urea</td>
			<td>Research Products International</td>
			<td>U20200</td>
			<td></td>
		</tr>
		<tr>
			<td>SDS</td>
			<td>Research Products International</td>
			<td>L22010</td>
			<td></td>
		</tr>
		<tr>
			<td>glycerol</td>
			<td>Sigma Aldrich</td>
			<td>G5516</td>
			<td></td>
		</tr>
		<tr>
			<td>Tris-HCl</td>
			<td>Gibco</td>
			<td>15506-017</td>
			<td></td>
		</tr>
		<tr>
			<td>bromophenol blue</td>
			<td>Amresco</td>
			<td>449</td>
			<td></td>
		</tr>
		<tr>
			<td>Gibson Assembly Cloning Kit</td>
			<td>New England Biolabs</td>
			<td>E5510S</td>
			<td>Rapid assembly method for cloning of plasmids in section 2</td>
		</tr>
		<tr>
			<td>NEBNext High-Fidelity 2x PCR Master Mix</td>
			<td>New England Biolabs</td>
			<td>M0541S</td>
			<td>Used for amplification of products for Gibson Assembly in Section 2.3 as well assample preparation for DEEPN deep sequencing in section 6.2.1</td>
		</tr>
		<tr>
			<td>Ethidium Bromide</td>
			<td>Amresco</td>
			<td>0492-5G</td>
			<td></td>
		</tr>
		<tr>
			<td>QIAquick PCR purification kit</td>
			<td>Qiagen</td>
			<td>28104</td>
			<td>Used for purification of pcr products in section 6.2.3</td>
		</tr>
		<tr>
			<td>Qiaquick DNA Gel Extraction Kit</td>
			<td>Qiagen</td>
			<td>28704</td>
			<td>Used for purification of digested pTEF-GBD in section 2.1</td>
		</tr>
		<tr>
			<td>KAPA Hyper Prep kit</td>
			<td>KAPA Biosystems</td>
			<td>KK8500</td>
			<td>preparation kit for deep sequencing</td>
		</tr>
		<tr>
			<td>Codon optimization</td>
			<td>http://www.jcat.de</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Codon optimization</td>
			<td>https://www.idtdna.com/CodonOpt</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>gBlocks</td>
			<td>Integrated DNA Technologies</td>
			<td></td>
			<td>DNA fragments used for cloning in Section 2.2</td>
		</tr>
		<tr>
			<td>Strings</td>
			<td>Thermofisher</td>
			<td></td>
			<td>DNA fragments used for cloning in Section 2.2</td>
		</tr>
		<tr>
			<td>GenCatch Plasmid DNA mini-prep Kit</td>
			<td>EPOCH Life Sciences</td>
			<td></td>
			<td>Used to prepare quantities of DNA in Section 2.3</td>
		</tr>
		<tr>
			<td>Covaris E220</td>
			<td>Covaris</td>
			<td></td>
			<td>high performance ultra-sonicator in section 7</td>
		</tr>
		<tr>
			<td>oligo nucelotide 5&#8217;- CGGTCTT 
			CAATTTCTCAAGTTTCAG -3&#8217;</td>
			<td>Integrated DNA Technologies or Thermofisher</td>
			<td></td>
			<td>used for pcr amplification and sequencing 5&#39; insert pTEF-GBD during plasmid construction</td>
		</tr>
		<tr>
			<td>oligo nucelotide 5&#8217;-GAGTAACG 
			ACATTCCCAGTTGTTC-3&#8217;</td>
			<td>Integrated DNA Technologies or Thermofisher</td>
			<td></td>
			<td>used for pcr amplification and sequencing 5&#39; insert pTEF-GBD during plasmid construction</td>
		</tr>
		<tr>
			<td>oligo nucelotide 5&#8217;-CACCGTAT 
			TTCTGCCACCTCTTCC-3&#8217;</td>
			<td>Integrated DNA Technologies or Thermofisher</td>
			<td></td>
			<td>used for pcr amplification and sequencing 3&#39; insert pTEF-GBD during plasmid construction</td>
		</tr>
		<tr>
			<td>oligo nucelotide 5&#8217;-GCAACCGC 
			ACTATTTGGAGCGCTG-3&#8217;</td>
			<td>Integrated DNA Technologies or Thermofisher</td>
			<td></td>
			<td>used for pcr amplification and sequencing 3&#39; insert pTEF-GBD during plasmid construction</td>
		</tr>
		<tr>
			<td>oligonucleotide 5&#8217;-GTTCCGATG 
			CCTCTGCGAGTG-3&#8217;</td>
			<td>Integrated DNA Technologies or Thermofisher</td>
			<td></td>
			<td>5&#39; Pimer used for insert amplification of pGAL4AD</td>
		</tr>
		<tr>
			<td>oligonucelotide 5&#8217;-GCACATGCT 
			AGCGTCAAATACC-3&#8217;</td>
			<td>Integrated DNA Technologies or Thermofisher</td>
			<td></td>
			<td>3&#39; Pimer used for insert amplification of pGAL4AD</td>
		</tr>
		<tr>
			<td>oligonucelotide 5&#8217;-ACCCAAGCA 
			GTGGTATCAACG-3&#8217;</td>
			<td>Integrated DNA Technologies or Thermofisher</td>
			<td></td>
			<td>5&#39; Pimer used for insert amplification of pGADT7</td>
		</tr>
		<tr>
			<td>oligonucelotide 5&#8217;- TATTTAGA 
			AGTGTCAACAACGTA -3&#8217;</td>
			<td>Integrated DNA Technologies or Thermofisher</td>
			<td></td>
			<td>3&#39; Pimer used for insert amplification of pGADT7</td>
		</tr>
		<tr>
			<td>PJ69-4A MatA yeast strain</td>
			<td>http://depts.washington.edu/yeastrc/ James P, Halladay J, Craig EA: Genomic Libraries and a host strain designed for highly efficient two-hybrid selection in yeast. GENETICS 1996 144:1425-1436</td>
			<td></td>
			<td>MATA leu2-3,112 ura3-52 trp1-901 his3-200 gal4D, gal80D, GAL-ADE2 lys2::GAL1-HIS3 met2::GAL7</td>
		</tr>
		<tr>
			<td>pTEF-GBD</td>
			<td>Dr. Robert Piper Lab</td>
			<td></td>
			<td>Gal4-DNA binding doimain expression plasmid</td>
		</tr>
		<tr>
			<td>PLY5725 MATalpha yeast strain</td>
			<td>Dr. Robert Piper Lab</td>
			<td></td>
			<td>MATalpha his3&#8710;1 leu2&#8710;0 lys2&#8710;0 ura3&#8710;0 gal4&#8710; trp1&#8710; Gal80&#8710;</td>
		</tr>
		<tr>
			<td>pGal4AD (pPL6343)</td>
			<td>Dr. Robert Piper Lab</td>
			<td></td>
			<td>Gal4-activation domain expression plasmid</td>
		</tr>
		<tr>
			<td>100 mm petri dishes</td>
			<td>Kord-Vallmark sold by VWR</td>
			<td>2900</td>
			<td></td>
		</tr>
		<tr>
			<td>125 mL PYREX Erlenmeyer flask</td>
			<td>Fisher Scientific</td>
			<td>S63270</td>
			<td></td>
		</tr>
		<tr>
			<td>250 mL PYREX Erlenmeyer flask</td>
			<td>Fisher Scientific</td>
			<td>S63271</td>
			<td></td>
		</tr>
		<tr>
			<td>1,000 mL PYREX Erlenmeyer flask</td>
			<td>Fisher Scientific</td>
			<td>S63274</td>
			<td></td>
		</tr>
		<tr>
			<td>2,000 mL PYREX Erlenmeyer flask</td>
			<td>Fisher Scientific</td>
			<td>S63275</td>
			<td></td>
		</tr>
		<tr>
			<td>20 X 150 mm Disposable Culture Tube</td>
			<td>Thermofisher</td>
			<td>14-961-33</td>
			<td></td>
		</tr>
		<tr>
			<td>pipet-aid</td>
			<td>Drummond</td>
			<td>4-000-100</td>
			<td></td>
		</tr>
		<tr>
			<td>5 mL Serological Pipette</td>
			<td>Denville</td>
			<td>P7127</td>
			<td></td>
		</tr>
		<tr>
			<td>10 mL Serological Pipette</td>
			<td>Denville</td>
			<td>P7128</td>
			<td></td>
		</tr>
		<tr>
			<td>25 mL Serological Pipette</td>
			<td>Denville</td>
			<td>P7129</td>
			<td></td>
		</tr>
		<tr>
			<td>1,000 mL PYREX Griffin Beaker</td>
			<td>Fisher Scientific</td>
			<td>02-540P</td>
			<td></td>
		</tr>
		<tr>
			<td>1,000 mL PYREX Reuasable Media Storage Bottle</td>
			<td>Fisher Scientific</td>
			<td>06-414-1D</td>
			<td></td>
		</tr>
		<tr>
			<td>1,000 mL graduated cylinder</td>
			<td>Fisher Scientific</td>
			<td>08-572-6G</td>
			<td></td>
		</tr>
		<tr>
			<td>SpectraMax 190</td>
			<td>Molecular Devices</td>
			<td></td>
			<td>used to measure the Optical Density of cells</td>
		</tr>
		<tr>
			<td>NanoDrop 2000</td>
			<td>Thermo Scientific</td>
			<td>ND-2000</td>
			<td>Spectrophotometer used to quantify amount of DNA</td>
		</tr>
		<tr>
			<td>Electronic UV transilluminator</td>
			<td>Ultra Lum</td>
			<td>MEB 20</td>
			<td>used to visualize DNA in an Ethidium Bromide agarose gel</td>
		</tr>
		<tr>
			<td>P1000 Gilson PIPETMAN</td>
			<td>Fisher Scientific</td>
			<td>F123602G</td>
			<td></td>
		</tr>
		<tr>
			<td>P200 Gilson PIPETMAN</td>
			<td>Fisher Scientific</td>
			<td>F123601G</td>
			<td></td>
		</tr>
		<tr>
			<td>P20 Gilson PIPETMAN</td>
			<td>Fisher Scientific</td>
			<td>F123600G</td>
			<td></td>
		</tr>
		<tr>
			<td>P10 Gilson PIPETMAN</td>
			<td>Fisher Scientific</td>
			<td>F144802G</td>
			<td></td>
		</tr>
		<tr>
			<td>1250 &#181;L Low Retention Pipette Tips</td>
			<td>GeneMate</td>
			<td>P-1236-1250</td>
			<td></td>
		</tr>
		<tr>
			<td>200 &#181;LLow Retention Pipette Tips</td>
			<td>VWR</td>
			<td>10017-044</td>
			<td></td>
		</tr>
		<tr>
			<td>10 &#181;L XL Low Retention Pipette Tips</td>
			<td>VWR</td>
			<td>10017-042</td>
			<td></td>
		</tr>
		<tr>
			<td>50 mL conical tube</td>
			<td>VWR</td>
			<td>490001-627</td>
			<td></td>
		</tr>
		<tr>
			<td>15 mL conical tube</td>
			<td>VWR</td>
			<td>490001-621</td>
			<td></td>
		</tr>
		<tr>
			<td>cell scraper</td>
			<td>Denville Scientific</td>
			<td>TC9310</td>
			<td></td>
		</tr>
		<tr>
			<td>1.5 mL Microcentrifuge tubes</td>
			<td>USA Scientific</td>
			<td>1615-5500</td>
			<td></td>
		</tr>
		<tr>
			<td>HCl</td>
			<td>Fluka Analytical</td>
			<td>318949-1L</td>
			<td></td>
		</tr>
		<tr>
			<td>NaOH</td>
			<td>J.T. Baker</td>
			<td>5674-02</td>
			<td></td>
		</tr>
		<tr>
			<td>Wooden applicators</td>
			<td>Solon Care</td>
			<td>55900</td>
			<td></td>
		</tr>
		<tr>
			<td>Eppendorf microcentrifuge 5424</td>
			<td>Fisher Scientific</td>
			<td>05-400-005</td>
			<td>microcentrifuge</td>
		</tr>
		<tr>
			<td>Sorvall ST16R</td>
			<td>Thermo Fisher Scientific</td>
			<td>75004381</td>
			<td>benchtop centrifuge</td>
		</tr>
		<tr>
			<td>Amersham ECL Rabbit IgG, HRP-linked whole Ab (from donkey)</td>
			<td>GE Healthcare</td>
			<td>NA934-1ML</td>
			<td>Secondary Antibody</td>
		</tr>
		<tr>
			<td>Amersham ECL Mouse IgG, HRP-linked whole Ab (from sheep)</td>
			<td>GE Healthcare</td>
			<td>NA931-1ML</td>
			<td>Secondary Antibody</td>
		</tr>
		<tr>
			<td>SuperSignal West Pico Chemiluminescent Substrate</td>
			<td>Thermo Fisher Scientific</td>
			<td>34080</td>
			<td>ECL detection solution</td>
		</tr>
		<tr>
			<td>Isotemp Incubator</td>
			<td>Thermo Fisher Scientific</td>
			<td></td>
			<td>Incubator</td>
		</tr>
		<tr>
			<td>Mutitron 2</td>
			<td>INFORS HT</td>
			<td></td>
			<td>Shaking incubator</td>
		</tr>
		<tr>
			<td>Isotemp Digital-Control Water Bath Model 205</td>
			<td>Fisher Scientific</td>
			<td></td>
			<td>water bath</td>
		</tr>
		<tr>
			<td>Y2H mouse cDNA library in Y187 (pan tissue)</td>
			<td>Clontech</td>
			<td>630482</td>
			<td>commercially available cDNA Library</td>
		</tr>
		<tr>
			<td>Y2H mouse cDNA library in Y187 (mouse brain)</td>
			<td>Clontech</td>
			<td>630488</td>
			<td>commercially available cDNA Library</td>
		</tr>
		<tr>
			<td>pGADT7 AD Vector</td>
			<td>Clontech</td>
			<td>630442</td>
			<td>commercially available AD Vector housing many cDNA libraries</td>
		</tr>
		<tr>
			<td>pGBKT7 DNA-BD Vector</td>
			<td>Clontech</td>
			<td>630443</td>
			<td>commercially available DNA-BD Vector</td>
		</tr>
		<tr>
			<td>Biolase DNA Polymerase</td>
			<td>Bioline</td>
			<td>BIO-21042</td>
			<td>DNA polymerase used for section 2.4</td>
		</tr>
		<tr>
			<td>GeneMate GCL-60 Thermal Cycler</td>
			<td>BioExpress</td>
			<td>P-6050-60</td>
			<td>pcr machine</td>
		</tr>
		<tr>
			<td>TempAssure 0.5 mL PCR tubes</td>
			<td>USA Scientific</td>
			<td>1405-8100</td>
			<td></td>
		</tr>
	</tbody>
</table>

a yeast 2-hybrid screen in batch to compare protein interactions

הקרנה עבור אינטראקציות חלבון-חלבון באמצעות שמרים 2-היברידית וזמינותו כבר זמן רב כלי יעיל, אך השימוש בה במידה רבה הוגבלה לגילוי של interactors גבוהה-זיקה כי הם מאוד מועשרים בספריה של מועמדים אינטראקציה. בתבנית מסורתית, שמרים 2-היברידית וזמינותו יכולות להניב מושבות רבות מדי לנתח כאשר ניצח ב לכתחילה נמוך שבו זיקה נמוכה interactors שעשויים להימצא. יתר על כן, ללא חקירה מקיפה ושלמה של הספרייה אותו נגד פלסמידים שונים פיתיון, ניתוח השוואתי אינה יכולה להיות מושגת. למרות חלק מבעיות אלו ניתן לטפל באמצעות ספריות טרף ערוכים, עלות והתשתיות הדרושים להפעלת מסכי כזה יכול להיות אסורה. כחלופה, אנו הסתגלו שמרים 2-היברידית וזמינותו לחשוף בו זמנית עשרות ארעי, אינטראקציות חלבון סטטי בתוך מסך אחד ניצול אסטרטגיה כינה DEEPN (העשרה דינמי עבור הערכה של חלבונים רשתות), אשר משלבת רצפי DNA תפוקה גבוהה וחישוביות לעקוב אחר ההתפתחות של אוכלוסיה של פלסמידים אשר קידוד שותפים אינטראקציה. כאן, אנו מתארים ריאגנטים מותאם אישית ופרוטוקולים לאפשר מסך DEEPN להורג בקלות וביעילות.

וזמינותו Y2H כבר בשימוש נרחב לאיתור אינטראקציות חלבון: חלבון, פותחו מספר עיבודים ומערכות. ברוב המקרים, שאותם שיקולי המסייעות להבטיח הצלחה עם הגישות הקודמות האלה חשובים עבור DEEPN. חלק חשוב אמות כוללות: הבטחת ביטוי של תחום ה-DNA מחייב חלבונים פיוז'ן, הבטחת רקע נמוך של כדין שלו + צ...

Watch this Scientific Journal Video about A Yeast 2-Hybrid Screen in Batch to Compare Protein Interactions at JoVE.com

A Yeast 2-Hybrid Screen in Batch to Compare Protein Interactions

מסך 2-היברידית שמרים אצווה כדי להשוות בין אינטראקציות חלבון

עיבוד אצווה של שמרים 2-היברידית מסכים מאפשר השוואה ישירה של הפרופילים האינטראקציה של מספר חלבונים הפיתיון עם סט מורכב של חלבונים פיוז'ן טרף. כאן, אנו מתארים שיטות מעודן, ריאגנטים החדש וכיצד ליישם ושימושם עבור מסכי כזה.

Screening for protein-protein interactions using the yeast 2-hybrid assay has long been an effective tool, but its use has largely been limited to the ...

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Research

JoVE Journal

Biochemistry

13.3K Views.  University of Iowa. עיבוד אצווה של שמרים 2-היברידית מסכים מאפשר השוואה ישירה של הפרופילים האינטראקציה של מספר חלבונים הפיתיון עם סט מורכב של חלבונים פיוז'ן טרף. כאן, אנו מתארים שיטות מעודן, ריאגנטים החדש וכיצד ליישם ושימושם עבור מסכי כזה.

Video: A Yeast 2-Hybrid Screen in Batch to Compare Protein Interactions

Fluorescence Anisotropy as a Tool to Study Protein-protein Interactions

Protein-protein interactions play an essential role in the function of a living organism. Once an interaction has been identified and validated it is necessary to characterize it at the structural and mechanistic level. Several biochemical and biophysical methods exist for such purpose. Among them, fluorescence anisotropy is a powerful technique particularly used when the fluorescence intensity of a fluorophore-labeled protein remains constant upon protein-protein interaction. In this technique, a fluorophore-labeled protein is excited with vertically polarized light of an appropriate wavelength that selectively excites a subset of the fluorophores according to their relative orientation with the incoming beam. The resulting emission also has a directionality whose relationship in the vertical and horizontal planes defines anisotropy (r) as follows: r=(IVV-IVH)/(IVV+2IVH), where IVV and IVH are the fluorescence intensities of the vertical and horizontal components, respectively. Fluorescence anisotropy is sensitive to the rotational diffusion of a fluorophore, namely the apparent molecular size of a fluorophore attached to a protein, which is altered upon protein-protein interaction. In the present text, the use of fluorescence anisotropy as a tool to study protein-protein interactions was exemplified to address the binding between the protein mutated in the Shwachman-Diamond Syndrome (SBDS) and the Elongation factor like-1 GTPase (EFL1). Conventionally, labeling of a protein with a fluorophore is carried out on the thiol groups (cysteine) or in the amino groups (the N-terminal amine or lysine) of the protein. However, SBDS possesses several cysteines and lysines that did not allow site directed labeling of it. As an alternative technique, the dye 4&#39;,5&#39;-bis(1,3,2 dithioarsolan-2-yl) fluorescein was used to specifically label a tetracysteine motif, Cys-Cys-Pro-Gly-Cys-Cys, genetically engineered in the C-terminus of the recombinant SBDS protein. Fitting of the experimental data provided quantitative and mechanistic information on the binding mode between these proteins.

Protein interactions are at the heart of a cell&#39;s function. Calorimetric and spectroscopic techniques are commonly used to characterize them. Here we describe fluorescence anisotropy as a tool to study the interaction between the protein mutated in the Shwachman-Diamond Syndrome (SBDS) and the Elongation factor-like 1 GTPase (EFL1).

Anisotropy קרינה ככלי לחקר אינטראקציות חלבון-חלבון

Protein-protein interactions play an essential role in the function of a living organism. Once an interaction has been identified and validated it is ...

Using Scaffold Liposomes to Reconstitute Lipid-proximal Protein-protein Interactions In Vitro

Studies of integral membrane proteins in vitro are frequently complicated by the presence of a hydrophobic transmembrane domain. Further complicating these studies, reincorporation of detergent-solubilized membrane proteins into liposomes is a stochastic process where protein topology is impossible to enforce. This paper offers an alternative method to these challenging techniques that utilizes a liposome-based scaffold. Protein solubility is enhanced by deletion of the transmembrane domain, and these amino acids are replaced with a tethering moiety, such as a His-tag. This tether interacts with an anchoring group (Ni2+ coordinated by nitrilotriacetic acid (NTA(Ni2+)) for His-tagged proteins), which enforces a uniform protein topology at the surface of the liposome. An example is presented wherein the interaction between Dynamin-related protein 1 (Drp1) with an integral membrane protein, Mitochondrial Fission Factor (Mff), was investigated using this scaffold liposome method. In this work, we have demonstrated the ability of Mff to efficiently recruit soluble Drp1 to the surface of liposomes, which stimulated its GTPase activity. Moreover, Drp1 was able to tubulate the Mff-decorated lipid template in the presence of specific lipids. This example demonstrates the effectiveness of scaffold liposomes using structural and functional assays and highlights the role of Mff in regulating Drp1 activity.

Using Scaffold Liposomes to Reconstitute Lipid-proximal Protein-protein Interactions In Vitro

This paper describes a method for assessing the interactions and assemblies of integral membrane proteins in vitro with various partner factors in a lipid-proximal environment.

באמצעות הפיגום ליפוזומים כדי לשקם אינטראקציות ליפידים-הפרוקסימלי חלבונים<em&gt; במבחנה</em

Studies of integral membrane proteins in vitro are frequently complicated by the presence of a hydrophobic transmembrane domain. Further complicating ...

Time-resolved ElectroSpray Ionization Hydrogen-deuterium Exchange Mass Spectrometry for Studying Protein Structure and Dynamics

Intrinsically disordered proteins (IDPs) have long been a challenge to structural biologists due to their lack of stable secondary structure elements. Hydrogen-Deuterium Exchange (HDX) measured at rapid time scales is uniquely suited to detect structures and hydrogen bonding networks that are briefly populated, allowing for the characterization of transient conformers in native ensembles. Coupling of HDX to mass spectrometry offers several key advantages, including high sensitivity, low sample consumption and no restriction on protein size. This technique has advanced greatly in the last several decades, including the ability to monitor HDX labeling times on the millisecond time scale. In addition, by incorporating the HDX workflow onto a microfluidic platform housing an acidic protease microreactor, we are able to localize dynamic properties at the peptide level. In this study, Time-Resolved ElectroSpray Ionization Mass Spectrometry (TRESI-MS) coupled to HDX was used to provide a detailed picture of residual structure in the tau protein, as well as the conformational shifts induced upon hyperphosphorylation.

Conformational flexibility plays a critical role in protein function. Herein, we describe the use of time-resolved electrospray ionization mass spectrometry coupled to hydrogen-deuterium exchange for probing the rapid structural changes that drive function in ordered and disordered proteins.

המרת מימן-דאוטריום electrospray יינון זמן נפתרה ספקטרומטריית מסה לימוד מבנה החלבון Dynamics

Intrinsically disordered proteins (IDPs) have long been a challenge to structural biologists due to their lack of stable secondary structure elements. ...

A Modified Yeast-one Hybrid System for Heteromeric Protein Complex-DNA Interaction Studies

Over the years, the yeast one-hybrid assay has proven to be an important technique for the identification and validation of physical interactions between proteins such as transcription factors (TFs) and their DNA target. The method presented here utilizes the underlying concept of the Y1H but is modified further to study and validate protein complexes binding to their target DNA. Hence, it is referred to as the modified yeast one-hybrid (Y1.5H) assay. This assay is cost effective and can be easily performed in a regular laboratory setting. Albeit using a heterologous system, the described method could be a valuable tool to test and validate the heteromeric protein complex binding to their DNA target(s) for functional genomics in any system of study, especially plant genomics.

The modified yeast one-hybrid assay described here is an extension of the classical yeast one-hybrid (Y1H) assay to study and validate the heteromeric protein complex-DNA interaction in a heterologous system for any functional genomics study.

A השתנה- Hybrid מערכת אחת עבור חלבון Heteromeric מורכבות- DNA אינטראקציה מחקרים

Over the years, the yeast one-hybrid assay has proven to be an important technique for the identification and validation of physical interactions between ...

Biotinylated Cell-penetrating Peptides to Study Intracellular Protein-protein Interactions

Here we present a protocol to study intracellular protein-protein interactions that is based on the widely used biotin-avidin pull-down system. The modification presented includes the combination of this technique with cell-penetrating sequences. We propose to design cell-penetrating baits that can be incubated with living cells instead of cell lysates and therefore the interactions found will reflect those that occur within the intracellular context. Connexin43 (Cx43), a protein that forms gap junction channels and hemichannels is down-regulated in high-grade gliomas. The Cx43 region comprising amino acids 266-283 is responsible for the inhibition of the oncogenic activity of c-Src in glioma cells. Here we use TAT as the cell-penetrating sequence, biotin as the pull-down tag and the region of Cx43 comprised between amino acids 266-283 as the target to find intracellular interactions in the hard-to-transfect human glioma stem cells. One of the limitations of the proposed method is that the molecule used as bait could fail to fold properly and, consequently, the interactions found could not be associated with the effect. However, this method can be especially interesting for the interactions involved in signal transduction pathways because they are usually carried out by intrinsically disordered regions and, therefore, they do not require an ordered folding. In addition, one of the advantages of the proposed method is that the relevance of each residue on the interaction can be easily studied. This is a modular system; therefore, other cell-penetrating sequences, other tags, and other intracellular targets can be employed. Finally, the scope of this protocol is far beyond protein-protein interaction because this system can be applied to other bioactive cargoes such as RNA sequences, nanoparticles, viruses or any molecule that can be transduced with cell-penetrating sequences and fused to pull-down tags to study their intracellular mechanism of action.

This is a protocol to study intracellular protein-protein interactions based on the biotin-avidin pull-down system with the novelty of combining cell-penetrating sequences. The main advantage is that the target sequence is incubated with living cells instead of cell lysates and therefore the interactions will occur within the cellular context.

חודר Biotinylated תא פפטידים ללמוד אינטראקציות חלבון תאיים

Here we present a protocol to study intracellular protein-protein interactions that is based on the widely used biotin-avidin pull-down system. The ...

A Fluorescence Fluctuation Spectroscopy Assay of Protein-Protein Interactions at Cell-Cell Contacts

A variety of biological processes involves cell-cell interactions, typically mediated by proteins that interact at the interface between neighboring cells. Of interest, only few assays are capable of specifically probing such interactions directly in living cells. Here, we present an assay to measure the binding of proteins expressed at the surfaces of neighboring cells, at cell-cell contacts. This assay consists of two steps: mixing of cells expressing the proteins of interest fused to different fluorescent proteins, followed by fluorescence fluctuation spectroscopy measurements at cell-cell contacts using a confocal laser scanning microscope. We demonstrate the feasibility of this assay in a biologically relevant context by measuring the interactions of the amyloid precursor-like protein 1 (APLP1) across cell-cell junctions. We provide detailed protocols on the data acquisition using fluorescence-based techniques (scanning fluorescence cross-correlation spectroscopy, cross-correlation number and brightness analysis) and the required instrument calibrations. Further, we discuss critical steps in the data analysis and how to identify and correct external, spurious signal variations, such as those due to photobleaching or cell movement.
In general, the presented assay is applicable to any homo- or heterotypic protein-protein interaction at cell-cell contacts, between cells of the same or different types and can be implemented on a commercial confocal laser scanning microscope. An important requirement is the stability of the system, which needs to be sufficient to probe diffusive dynamics of the proteins of interest over several minutes.

This protocol describes a fluorescence fluctuation spectroscopy-based approach to investigate interactions among proteins mediating cell-cell interactions, i.e. proteins localized in cell junctions, directly in living cells. We provide detailed guidelines on instrument calibration, data acquisition and analysis, including corrections to possible artefact sources.

Assay ספקטרוסקופיה התנודות זריחה של אינטראקציות חלבון-חלבון באנשי קשר תא-תא

A variety of biological processes involves cell-cell interactions, typically mediated by proteins that interact at the interface between neighboring ...

A Fluorogenic Peptide Cleavage Assay to Screen for Proteolytic Activity: Applications for coronavirus spike protein activation

Enveloped viruses such as coronaviruses or influenza virus require proteolytic cleavage of their fusion protein to be able to infect the host cell. Often viruses exhibit cell and tissue tropism and are adapted to specific cell or tissue proteases. Moreover, these viruses can introduce mutations or insertions into their genome during replication that may affect the cleavage, and thus can contribute to adaptations to a new host. Here, we present a fluorogenic peptide cleavage assay that allows a rapid screening of peptides mimicking the cleavage site of viral fusion proteins. The technique is very flexible and can be used to investigate the proteolytic activity of a single protease on many different substrates, and in addition, it also allows exploration of the activity of multiple proteases on one or more peptide substrates. In this study, we used peptides mimicking the cleavage site motifs of the coronavirus spike protein. We tested human and camel derived Middle East Respiratory Syndrome coronaviruses (MERS-CoV) to demonstrate that single and double substitutions in the cleavage site can alter the activity of furin and dramatically change cleavage efficiency. We also used this method in combination with bioinformatics to test furin cleavage activity of feline coronavirus spike proteins from different serotypes and strains. This peptide-based method is less labor- and time intensive than conventional methods used for the analysis of proteolytic activity for viruses, and results can be obtained within a single day.

We present a fluorogenic peptide cleavage assay that allows a rapid screening of the proteolytic activity of proteases on peptides representing the cleavage site of viral fusion peptides. This method can also be used on any other amino acid motif within a protein sequence to test for the protease activity.

Fluorogenic פפטיד Assay המחשוף, למסך לפעילות הפרוטאוליטי: יישומים עבור הקורונה ספייק הפעלת חלבון

Enveloped viruses such as coronaviruses or influenza virus require proteolytic cleavage of their fusion protein to be able to infect the host cell. Often ...

Analysis of Protein Folding, Transport, and Degradation in Living Cells by Radioactive Pulse Chase

Radioactive pulse-chase labeling is a powerful tool for studying the conformational maturation, the transport to their functional cellular location, and the degradation of target proteins in live cells. By using short (pulse) radiolabeling times (&lt;30 min) and tightly controlled chase times, it is possible to label only a small fraction of the total protein pool and follow its folding. When combined with nonreducing/reducing SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoprecipitation with (conformation-specific) antibodies, folding processes can be examined in great detail. This system has been used to analyze the folding of proteins with a huge variation in properties such as soluble proteins, single and multi-pass transmembrane proteins, heavily N- and O-glycosylated proteins, and proteins with and without extensive disulfide bonding. Pulse-chase methods are the basis of kinetic studies into a range of additional features, including co- and posttranslational modifications, oligomerization, and polymerization, essentially allowing the analysis of a protein from birth to death. Pulse-chase studies on protein folding are complementary with other biochemical and biophysical methods for studying proteins in vitro by providing increased temporal resolution and physiological information. The methods as described within this paper are adapted easily to study the folding of almost any protein that can be expressed in mammalian or insect-cell systems.

Here we describe a protocol for a general pulse-chase method that allows the kinetic analysis of folding, transport, and degradation of proteins to be followed in live cells.

ניתוח של קיפול חלבונים, תחבורה, והשפלה בתאים חיים על ידי הדופק רדיואקטיבי צ'ייס

Radioactive pulse-chase labeling is a powerful tool for studying the conformational maturation, the transport to their functional cellular location, and ...

Application of Biolayer Interferometry (BLI) for Studying Protein-Protein Interactions in Transcription

A transcription factor&#160;(TF) is a protein that regulates gene expression by interacting with the RNA polymerase, another TF, and/or template DNA. GrgA is a novel transcription activator found specifically in the obligate intracellular bacterial pathogen Chlamydia. Protein pulldown assays using affinity beads have revealed that GrgA binds two &#963; factors, namely &#963;66 and &#963;28, which recognize different sets of promoters for genes whose products are differentially required at developmental stages. We have used BLI to confirm and further characterize the interactions. BLI demonstrates several advantages over pulldown: 1) It reveals real-time association and dissociation between binding partners, 2) It generates quantitative kinetic parameters, and 3) It can detect bindings that pulldown assays often fail to detect. These characteristics have enabled us to deduce the physiological roles of GrgA in gene expression regulation in Chlamydia, and possible detailed interaction mechanisms. We envision that this relatively affordable technology can be extremely useful for studying transcription and other biological processes.

Application of Biolayer Interferometry BLI for Studying Protein-Protein Interactions in Transcription

Interactions of transcription factors (TFs) with the RNA polymerase are usually studied using pulldown assays. We apply a Biolayer Interferometry (BLI) technology to characterize the interaction of GrgA with the chlamydial RNA polymerase. Compared to pulldown assays, BLI detects real-time association and dissociation, offers higher sensitivity, and is highly quantitative.

יישום של ביואולייר אינטרפרומטריה (בלי) ללימוד אינטראקציות חלבונים-חלבונים בתמלול

A transcription factor&#160;(TF) is a protein that regulates gene expression by interacting with the RNA polymerase, another TF, and/or template DNA. GrgA ...

Use of Microscale Thermophoresis to Measure Protein-Lipid Interactions

The ability to determine the binding affinity of lipids to proteins is an essential part of understanding protein-lipid interactions in membrane trafficking, signal transduction and cytoskeletal remodeling. Classic tools for measuring such interactions include surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC). While powerful tools, these approaches have setbacks. ITC requires large amounts of purified protein as well as lipids, which can be costly and difficult to produce. Furthermore, ITC as well as SPR are very time consuming, which could add significantly to the cost of performing these experiments. One way to bypass these restrictions is to use the relatively new technique of microscale thermophoresis (MST). MST is fast and cost effective using small amounts of sample to obtain a saturation curve for a given binding event. There currently are two types of MST systems available. One type of MST requires labeling with a fluorophore in the blue or red spectrum. The second system relies on the intrinsic fluorescence of aromatic amino acids in the UV range. Both systems detect the movement of molecules in response to localized induction of heat from an infrared laser. Each approach has its advantages and disadvantages. Label-free MST can use untagged native proteins; however, many analytes, including pharmaceuticals, fluoresce in the UV range, which can interfere with determination of accurate KD values. In comparison, labeled MST allows for a greater diversity of measurable pairwise interactions utilizing fluorescently labeled probes attached to ligands with measurable absorbances in the visible range as opposed to UV, limiting the potential for interfering signals from analytes.

Microscale thermophoresis obtains binding constants quickly at low material cost. Either labeled or label free microscale thermophoresis is commercially available; however, label free thermophoresis is not capable of the diversity of interaction measurements that can be performed using fluorescent labels. We provide a protocol for labeled thermophoresis measurements.

מסך 2-היברידית שמרים אצווה כדי להשוות בין אינטראקציות חלבון

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