We thank Erin Zoller, Jessica Bene, and Lindsey Hays for input and direction in protocol development. MTW was supported in part by NIH R21 HG008186 and a Trustee Award grant from the Cincinnati Children's Hospital Research Foundation. ZHP was supported in part by T32 GM063483-13.

<ol>
	<li>Hindorff, L. 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=Potential+etiologic+and+functional+implications+of+genome-wide+association+loci+for+human+diseases+and+traits.">Potential etiologic and functional implications of genome-wide association loci for human diseases and traits.</a> Proc Natl Acad Sci U S A. 106 (23), 9362-9367 (2009).</li><li>Maurano, M. T., 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=Systematic+localization+of+common+disease-associated+variation+in+regulatory+DNA.">Systematic localization of common disease-associated variation in regulatory DNA.</a> Science. 337 (6099), 1190-1195 (2012).</li><li>Ward, L. D., Kellis, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interpreting+noncoding+genetic+variation+in+complex+traits+and+human+disease.">Interpreting noncoding genetic variation in complex traits and human disease.</a> Nat Biotechnol. 30 (11), 1095-1106 (2012).</li><li>Paul, D. S., Soranzo, N., Beck, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+interpretation+of+non-coding+sequence+variation:+concepts+and+challenges.">Functional interpretation of non-coding sequence variation: concepts and challenges.</a> Bioessays. 36 (2), 191-199 (2014).</li><li>Zhang, F., Lupski, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Non-coding+genetic+variants+in+human+disease.">Non-coding genetic variants in human disease.</a> Hum Mol Genet. , (2015).</li><li>Lee, T. I., Young, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcriptional+regulation+and+its+misregulation+in+disease.">Transcriptional regulation and its misregulation in disease.</a> Cell. 152 (6), 1237-1251 (2013).</li><li>Slatkin, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Linkage+disequilibrium--understanding+the+evolutionary+past+and+mapping+the+medical+future.">Linkage disequilibrium--understanding the evolutionary past and mapping the medical future.</a> Nat Rev Genet. 9 (6), 477-485 (2008).</li><li>Bush, W. S., Moore, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chapter+11:+Genome-wide+association+studies.">Chapter 11: Genome-wide association studies.</a> PLoS Comput Biol. 8 (12), e1002822 (2012).</li><li>1000 Genomes Project Consortium. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+integrated+map+of+genetic+variation+from+1,092+human+genomes.">An integrated map of genetic variation from 1,092 human genomes.</a> Nature. 491 (7422), 56-65 (2012).</li><li>Chang, C. C., 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=Second-generation+PLINK:+rising+to+the+challenge+of+larger+and+richer+datasets.">Second-generation PLINK: rising to the challenge of larger and richer datasets.</a> Gigascience. 4, 7 (2015).</li><li>Purcell, S., 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=PLINK:+a+tool+set+for+whole-genome+association+and+population-based+linkage+analyses.">PLINK: a tool set for whole-genome association and population-based linkage analyses.</a> Am J Hum Genet. 81 (3), 559-575 (2007).</li><li>ENCODE Project Consortium. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+integrated+encyclopedia+of+DNA+elements+in+the+human+genome.">An integrated encyclopedia of DNA elements in the human genome.</a> Nature. 489 (7414), 57-74 (2012).</li><li>Crawford, G. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genome-wide+mapping+of+DNase+hypersensitive+sites+using+massively+parallel+signature+sequencing+(MPSS).">Genome-wide mapping of DNase hypersensitive sites using massively parallel signature sequencing (MPSS).</a> Genome Res. 16 (1), 123-131 (2006).</li><li>Buenrostro, J. D., Giresi, P. G., Zaba, L. C., Chang, H. Y., Greenleaf, W. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transposition+of+native+chromatin+for+fast+and+sensitive+epigenomic+profiling+of+open+chromatin,+DNA-binding+proteins+and+nucleosome+position.">Transposition of native chromatin for fast and sensitive epigenomic profiling of open chromatin, DNA-binding proteins and nucleosome position.</a> Nat Methods. 10 (12), 1213-1218 (2013).</li><li>Giresi, P. G., Kim, J., McDaniell, R. M., Iyer, V. R., Lieb, 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=FAIRE+Formaldehyde-Assisted+Isolation+of+Regulatory+Elements)+isolates+active+regulatory+elements+from+human+chromatin.">FAIRE Formaldehyde-Assisted Isolation of Regulatory Elements) isolates active regulatory elements from human chromatin.</a> Genome Res. 17 (6), 877-885 (2007).</li><li>Kent, W. J., 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+human+genome+browser+at+UCSC.">The human genome browser at UCSC.</a> Genome Res. 12 (6), 996-1006 (2002).</li><li>Roadmap Epigenomics Consortium. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Integrative+analysis+of+111+reference+human+epigenomes.">Integrative analysis of 111 reference human epigenomes.</a> Nature. 518 (7539), 317-330 (2015).</li><li>Martens, J. H., Stunnenberg, H. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=BLUEPRINT:+mapping+human+blood+cell+epigenomes.">BLUEPRINT: mapping human blood cell epigenomes.</a> Haematologica. 98 (10), 1487-1489 (2013).</li><li>Liu, T., 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=Cistrome:+an+integrative+platform+for+transcriptional+regulation+studies.">Cistrome: an integrative platform for transcriptional regulation studies.</a> Genome Biol. 12 (8), R83 (2011).</li><li>Griffon, 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=Integrative+analysis+of+public+ChIP-seq+experiments+reveals+a+complex+multi-cell+regulatory+landscape.">Integrative analysis of public ChIP-seq experiments reveals a complex multi-cell regulatory landscape.</a> Nucleic Acids Res. 43 (4), e27 (2015).</li><li>Staudt, L. 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+lymphoid-specific+protein+binding+to+the+octamer+motif+of+immunoglobulin+genes.">A lymphoid-specific protein binding to the octamer motif of immunoglobulin genes.</a> Nature. 323 (6089), 640-643 (1986).</li><li>Singh, H., Sen, R., Baltimore, D., Sharp, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+nuclear+factor+that+binds+to+a+conserved+sequence+motif+in+transcriptional+control+elements+of+immunoglobulin+genes.">A nuclear factor that binds to a conserved sequence motif in transcriptional control elements of immunoglobulin genes.</a> Nature. 319 (6049), 154-158 (1986).</li><li>Weirauch, M. T., 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=Determination+and+inference+of+eukaryotic+transcription+factor+sequence+specificity.">Determination and inference of eukaryotic transcription factor sequence specificity.</a> Cell. 158 (6), 1431-1443 (2014).</li><li>Ward, L. D., Kellis, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=HaploReg:+a+resource+for+exploring+chromatin+states,+conservation,+and+regulatory+motif+alterations+within+sets+of+genetically+linked+variants.">HaploReg: a resource for exploring chromatin states, conservation, and regulatory motif alterations within sets of genetically linked variants.</a> Nucleic Acids Res. 40 (Database issue), D930-D934 (2012).</li><li>Boyle, A. 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=Annotation+of+functional+variation+in+personal+genomes+using+RegulomeDB.">Annotation of functional variation in personal genomes using RegulomeDB.</a> Genome Res. 22 (9), 1790-1797 (2012).</li><li>Hume, M. A., Barrera, L. A., Gisselbrecht, S. S., Bulyk, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=UniPROBE,+update+2015:+new+tools+and+content+for+the+online+database+of+protein-binding+microarray+data+on+protein-DNA+interactions.">UniPROBE, update 2015: new tools and content for the online database of protein-binding microarray data on protein-DNA interactions.</a> Nucleic Acids Res. 43 (Database issue), D117-D122 (2015).</li><li>Mathelier, 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=JASPAR+2014:+an+extensively+expanded+and+updated+open-access+database+of+transcription+factor+binding+profiles.">JASPAR 2014: an extensively expanded and updated open-access database of transcription factor binding profiles.</a> Nucleic Acids Res. 42 (Database issue), 142-147 (2014).</li><li>Smith, M. F., Delbary-Gossart, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrophoretic+Mobility+Shift+Assay+(EMSA).">Electrophoretic Mobility Shift Assay (EMSA).</a> Methods Mol Med. 50, 249-257 (2001).</li><li>Franza, B. R., Josephs, S. F., Gilman, M. Z., Ryan, W., Clarkson, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+cellular+proteins+recognizing+the+HIV+enhancer+using+a+microscale+DNA-affinity+precipitation+assay.">Characterization of cellular proteins recognizing the HIV enhancer using a microscale DNA-affinity precipitation assay.</a> Nature. 330 (6146), 391-395 (1987).</li><li>. BCA Protein Assay Kit: User Guide Available from: <a target="_blank" href="https://tools.thermofisher.com/content/sfs/manuals/MAN0011430_Pierce_BCA_Protein_Asy_UG.pdf">https://tools.thermofisher.com/content/sfs/manuals/MAN0011430_Pierce_BCA_Protein_Asy_UG.pdf</a> (2014)</li><li>Wijeratne, A. 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=Phosphopeptide+separation+using+radially+aligned+titania+nanotubes+on+titanium+wire.">Phosphopeptide separation using radially aligned titania nanotubes on titanium wire.</a> ACS Appl Mater Interfaces. 7 (21), 11155-11164 (2015).</li><li>Silva, J. M., McMahon, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Fastest+Western+in+Town:+A+Contemporary+Twist+on+the+Classic+Western+Blot+Analysis.">The Fastest Western in Town: A Contemporary Twist on the Classic Western Blot Analysis.</a> J. Vis. Exp. (84), (2014).</li><li>Lu, X., 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=Lupus+Risk+Variant+Increases+pSTAT1+Binding+and+Decreases+ETS1+Expression.">Lupus Risk Variant Increases pSTAT1 Binding and Decreases ETS1 Expression.</a> Am J Hum Genet. 96 (5), 731-739 (2015).</li><li>Ramana, C. V., Chatterjee-Kishore, M., Nguyen, H., Stark, G. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Complex+roles+of+Stat1+in+regulating+gene+expression.">Complex roles of Stat1 in regulating gene expression.</a> Oncogene. 19 (21), 2619-2627 (2000).</li><li>Fillebeen, C., Wilkinson, N., Pantopoulos, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrophoretic+Mobility+Shift+Assay+(EMSA)+for+the+Study+of+RNA-Protein+Interactions:+The+IRE/IRP+Example.">Electrophoretic Mobility Shift Assay (EMSA) for the Study of RNA-Protein Interactions: The IRE/IRP Example.</a> J. Vis. Exp. (94), e52230 (2014).</li><li>Heng, T. S., Painter, M. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immunological+Genome+Project,+C.+The+Immunological+Genome+Project:+networks+of+gene+expression+in+immune+cells.">Immunological Genome Project, C. The Immunological Genome Project: networks of gene expression in immune cells.</a> Nat Immunol. 9 (10), 1091-1094 (2008).</li><li>Wu, C., 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=BioGPS:+an+extensible+and+customizable+portal+for+querying+and+organizing+gene+annotation+resources.">BioGPS: an extensible and customizable portal for querying and organizing gene annotation resources.</a> Genome Biol. 10 (11), R130 (2009).</li><li>Wu, C., Macleod, I., Su, A. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=BioGPS+and+MyGene.info:+organizing+online,+gene-centric+information.">BioGPS and MyGene.info: organizing online, gene-centric information.</a> Nucleic Acids Res. 41 (Database issue), D561-D565 (2013).</li><li>Wang, J., 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=Sequence+features+and+chromatin+structure+around+the+genomic+regions+bound+by+119+human+transcription+factors.">Sequence features and chromatin structure around the genomic regions bound by 119 human transcription factors.</a> Genome Res. 22 (9), 1798-1812 (2012).</li><li>Holden, N. S., Tacon, C. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Principles+and+problems+of+the+electrophoretic+mobility+shift+assay.">Principles and problems of the electrophoretic mobility shift assay.</a> J Pharmacol Toxicol Methods. 63 (1), 7-14 (2011).</li><li>Xu, J., Liu, H., Park, J. S., Lan, Y., Jiang, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Osr1+acts+downstream+of+and+interacts+synergistically+with+Six2+to+maintain+nephron+progenitor+cells+during+kidney+organogenesis.">Osr1 acts downstream of and interacts synergistically with Six2 to maintain nephron progenitor cells during kidney organogenesis.</a> Development. 141 (7), 1442-1452 (2014).</li><li>Yang, T. -. 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=Genevar:+a+database+and+Java+application+for+the+analysis+and+visualization+of+SNP-gene+associations+in+eQTL+studies.">Genevar: a database and Java application for the analysis and visualization of SNP-gene associations in eQTL studies.</a> Bioinformatics. 26 (19), 2474-2476 (2010).</li><li>Fort, 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=A+liver+enhancer+in+the+fibrinogen+gene+cluster.">A liver enhancer in the fibrinogen gene cluster.</a> Blood. 117 (1), 276-282 (2011).</li><li>Solberg, N., Krauss, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Luciferase+assay+to+study+the+activity+of+a+cloned+promoter+DNA+fragment.">Luciferase assay to study the activity of a cloned promoter DNA fragment.</a> Methods Mol Biol. 977, 65-78 (2013).</li><li>Rahman, 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+repressor+element+in+the+5'-untranslated+region+of+human+Pax5+exon+1A.">A repressor element in the 5'-untranslated region of human Pax5 exon 1A.</a> Gene. 263 (1-2), 59-66 (2001).</li><li>Mali, 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=RNA-Guided+Human+Genome+Engineering+via+Cas9.">RNA-Guided Human Genome Engineering via Cas9.</a> Science. 339 (6121), 823-826 (2013).</li></ol>

החוקרים אין לי מה לחשוף.

<html> למרות התקדמות בטכנולוגיות רצף גנוטיפ מאוד שפרה את היכולת שלנו לזהות וריאנטים גנטיים הקשורים למחלה, היכולת שלנו להבין את המנגנונים התפקודיים מושפעים הגירסות אלה מפגרת. מקור עיקרי של הבעיה הוא הרבה הגירסות הקשורים למחלות ממוקמות n על-קידוד האזורים בגנום, אשר סביר ?...

סידור מחקרים המבוססים גנוטיפ, כוללים מחקרים אגודים הגנום כולו (GWAS), מחקרי מוקד המועמד, ומחקרי deep-sequencing, זיהו וריאנטים גנטיים רבים הקשורים סטטיסטי עם מחלה, תכונה, או הפנוטיפ. בניגוד לתחזיות המוקדמות, רוב גרסאות אלה (85-93%) נמצאים באזורים ללא קידוד ואל תשנה את רצף החומצות האמיניות של חלבונים 1,2. פירוש הפונקציה של הגירסות ללא קידוד אלה וקביעת המנגנונים הביולוגיים חיבורם המחלה הקשורה, תכונה, או הפנוטיפ הוכיח מאתגרת 3-6. פיתחנו אסטרטגיה כללית לזהות את המנגנונים המולקולריים המקשרים גרסאות כדי פנוטיפ ביניים חשוב - ביטוי גנים. צינור זה הוא תוכנן במיוחד כדי לזהות אפנון של TF המחייבת וריאנטים גנטיים. אסטרטגיה זו משלבת גישות חישוביות וטכניקות ביולוגיה מולקולרית שמטרתו לחזותהשפעות ביולוגיות של וריאנטים מועמד סיליקון, ולאמת תחזיות אלו באופן אמפירי (איור 1). <img alt="איור 1" src="/files/ftp_upload/54093/54093fig1.jpg" /> איור 1:.. גישה אסטרטגית לניתוח וריאנטים גנטיים ללא קידוד צעדים שאינם כלולים בפרוטוקול מפורט הקשורים כתב היד הזה מוצללות באפור <a href="https://www.jove.com/files/ftp_upload/54093/54093fig1large.jpg" target="_blank">אנא לחץ כאן כדי לצפות בגרסה גדולה יותר של דמות זו.</a> במקרים רבים, חשוב להתחיל על ידי הרחבת הרשימה של וריאנטים לכלול את כל אלה-איזון הצמדה גבוה (LD) עם כל גרסה קשורה מבחינה סטטיסטית. LD הוא מדד של העמותה הלא אקראית של אללים בשתי עמדות כרומוזומליות שונות, אשר ניתן למדוד על ידי נתון r 2 7. r 2 הוא מדד של ליןKage חוסר שיווי משקל בין שתי גרסאות, עם r 2 = 1 המציין הצמדה מושלמת בין שתי גרסאות. אללים ב LD הגבוהה נמצאים לשתף להפריד בכרומוזום פני אוכלוסיות אבות. מערכי genotyping נוכחיים אינם כוללים את כל הסוגים הידועים בגנום האנושי. במקום זאת, הם מנצלים את LD בתוך הגנום האנושי וכוללים משנה של הסוגים הידועים אשר פועלים פרוקסי עבור הגירסות אחרות בתוך אזור מסוים של LD 8. לפיכך, גרסה ללא כל תוצאה ביולוגית עשויה להיות קשורה למחלה מסוימת משום שהיא נמצאת LD עם וריאנט-סיבתית גרסה עם השפעה ביולוגית משמעותית. עניינים טכניים, מומלץ להמיר את המהדורה האחרונה של 1,000 הגנום להקרין 9 קבצים שיחת וריאנט (vcf) לתוך קבצים בינאריים תואמים עמד לירות 10,11, כלי קוד פתוח לניתוח עמותה הגנום כולו. בהמשך לכך, כל וריאנטים גנטיים אחרים עם LD r 2&gt; 0.8 עם כל va קלט גנטיriant ניתן לזהות כמועמדים. חשוב להשתמש אוכלוסיית ההתייחסות המתאימה למשל החורג הזה, אם גרסה זוהתה במקצועות ממוצא אירופאי, נתונים הנבדקים ממוצא דומה אמורים לשמש להרחבת LD. הרחבת LD לעתים קרובות תוצאות בעשרות גרסאות המועמד, וסביר להניח כי רק חלק קטן של אלה תורמים מנגנון המחלה. לעתים קרובות, זה מעשי לבחון כל הניסיון של הגירסות אלה בנפרד. לכן כדאי לנצל את אלף מערכי נתונים גנומי פונקציונליים בפומבי זמינים כמסנן לתעדף את הווריאציות. לדוגמה, הקונסורציום ENCODE 12 ביצע אלפי ניסויים שבב seq המתאר את עקדת TFS ושיתוף גורמים, וסימני היסטון במגוון רחב של הקשרים, יחד עם נתונים נגישות הכרומטין מטכנולוגיות כגון DNase-seq 13, ATAC -seq 14, ו -15 פייר-seq. Databases ושירת אינטרנט כגון דפדפן הגנום UCSC 16, מפת הדרכים epigenomics 17, Blueprint Epigenome 18, Cistrome 19, ולמפות 20 לספק גישה חופשית לנתונים המיוצרים על ידי אלה הניסיונות בטכניקות אחרות על פני מגוון רחב של סוגי תאים ותנאים. כאשר ישנן גרסות רבות מכדי לבחון באופן ניסיוני, נתונים אלה יכולים לשמש כדי לתעדף אלה הממוקמים בתוך אזורי רגולטוריים סבירים בסוגי תאים ורקמות רלוונטיים. יתר על כן, במקרים בהם קיימת גרסה נמצא במרחק שיא שבב seq עבור חלבון מסוים, נתונים אלה יכולים לספק מוביל פוטנציאל כמו ל TF ספציפי (ים) או שיתוף גורמים אשר מחייב העשוי להשפיע. בשלב הבא, גרסות עדיפות וכתוצאה מוקרנות באופן ניסיוני כדי לאמת חלבון גנוטיפ תלוי חזה מחייב שימוש Emsa 21,22. Emsa מודד את שינוי ההגירה של אוליגו על ג&#39;ל TBE הלא צמצום. אוליגו שכותרתו fluorescently הוא מודגרות עםlysate הגרעיני, ומחייב גורמים גרעיניים יהיה לעכב את התנועה של אוליגו על הג&#39;ל. באופן זה, אוליגו אשר מחויב יותר גורמים גרעיניים יציגות כמו אות ניאון חזקה על סריקה. יש לציין, Emsa אינה דורשת תחזיות לגבי החלבונים הספציפיים אשר מחייבים יושפע. ברגע הגירסות מזוהות הנמצאות בתוך אזורי רגולטוריים חזה ומסוגלים גורמים גרעיניים מחייבים באופן דיפרנציאלי, שיטות חישוביות מועסקות לחזות את TF (ים) הספציפי אשר מחייב הם עשויים להשפיע. אנחנו מעדיפים להשתמש CIS-BP 23,24, RegulomeDB 25, UniProbe 26, ו JASPAR 27. לאחר מועמד TFS מזוהים, תחזיות אלו ניתן לבדוק באופן ספציפי באמצעות נוגדנים נגד TFS אלה (Emsa-supershifts ו DAPA-מערבונים). Emsa-supershift תהיה כרוכה בתוספת של נוגדן TF-ספציפית lysate ו אוליגו גרעיני. תוצאה חיובית של גידול Emsa-supershift הוא represented כמעבר נוסף בלהקה Emsa, או הפסד של הלהקה (הנסקרת תוך התייחסות 28). בשנות ה DAPA משלימים, דופלקס אוליגו-biotinylated 5&#39;המכיל את וריאנט ואת 20 בסיס-זוג איגוף נוקלאוטידים מודגרת עם lysate גרעיני מסוג תא הרלוונטיים (ים) כדי ללכוד כל הגורמים גרעיני כבילת oligos במיוחד. אוליגו המורכב גורם דופלקס-גרעיני הוא משותק על ידי streptavidin microbeads בטור מגנטי. הגורמים גרעיני כבול נאספים ישירות דרך elution 29,48. תחזיות כריכה ניתן להעריך מכן על ידי כתם מערבי באמצעות נוגדנים ספציפיים לחלבון. במקרים בם אין תחזיות ברורות, או תחזיות רבות מדי, elutions מ ומורד למשוך גרסה של ניסויי DAPA ניתן לשלוח גרעין פרוטאומיקה לזהות TFS המועמד באמצעות ספקטרומטר מסה, אשר לאחר מכן ניתן לאמת באמצעות שתואר לעיל אלה שיטות. בשאר של articlדואר, הפרוטוקול המפורט לניתוח Emsa ו DAPA של וריאנטים גנטיים מסופק.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Custom DNA Oligonucleotides</td>
			<td>Integrated DNA Technologies</td>
			<td></td>
			<td>http://www.idtdna.com/site/order/oligoentry</td>
		</tr>
		<tr>
			<td>Potassium Chloride</td>
			<td>Fisher Scientific</td>
			<td>BP366-500</td>
			<td>KCl, for CE buffer</td>
		</tr>
		<tr>
			<td>HEPES (1M)</td>
			<td>Fisher Scientific</td>
			<td>15630-080</td>
			<td>For CE and NE buffer</td>
		</tr>
		<tr>
			<td>EDTA (0.5M), pH 8.0</td>
			<td>Life Technologies</td>
			<td>R1021</td>
			<td>For CE, NE, and annealing buffer</td>
		</tr>
		<tr>
			<td>Sodium Chloride</td>
			<td>Fisher Scientific</td>
			<td>BP358-1</td>
			<td>NaCl, for NE buffer</td>
		</tr>
		<tr>
			<td>Tris-HCl (1M), pH 8.0</td>
			<td>Invitrogen</td>
			<td>BP1756-100</td>
			<td>For annealing buffer</td>
		</tr>
		<tr>
			<td>Phosphate Buffered Saline (1X)</td>
			<td>Fisher Scientific</td>
			<td>MT21040CM</td>
			<td>PBS, for cell wash</td>
		</tr>
		<tr>
			<td>DL-Dithiothreitol solution (1M)</td>
			<td>Sigma</td>
			<td>646563</td>
			<td>Reducing agent</td>
		</tr>
		<tr>
			<td>PMSF</td>
			<td>Thermo Scientific</td>
			<td>36978</td>
			<td>Protease Inhibitor</td>
		</tr>
		<tr>
			<td>Phosphatase Inhibitor Cocktail&#160;</td>
			<td>Thermo Scientific</td>
			<td>78420</td>
			<td>Prevents dephosphorylation of TFs</td>
		</tr>
		<tr>
			<td>Nonidet P-40 Substitute</td>
			<td>IBI Scientific</td>
			<td>IB01140</td>
			<td>NP-40, for nuclear extraction</td>
		</tr>
		<tr>
			<td>BCA Protein Assay Kit</td>
			<td>Thermo Scientific</td>
			<td>23225</td>
			<td>For measuring protein concentration</td>
		</tr>
		<tr>
			<td>Odyssey EMSA Buffer Kit</td>
			<td>Licor</td>
			<td>829-07910</td>
			<td>Contains all necessary EMSA buffers</td>
		</tr>
		<tr>
			<td>TBE Gels, 6%, 12 Wells</td>
			<td>Invitrogen</td>
			<td>EC6265BOX</td>
			<td>For EMSA</td>
		</tr>
		<tr>
			<td>TBE Buffer (10X)</td>
			<td>Thermo Scientific</td>
			<td>B52</td>
			<td>For EMSA</td>
		</tr>
		<tr>
			<td>FactorFinder Starting Kit</td>
			<td>Miltenyi Biotec</td>
			<td>130-092-318</td>
			<td>Contains all necessary DAPA buffers</td>
		</tr>
		<tr>
			<td>Licor Odyssey CLx</td>
			<td>Licor</td>
			<td></td>
			<td>Recommended scanner for DAPA/EMSA</td>
		</tr>
		<tr>
			<td>Antibiotic-Antimycotic</td>
			<td>Gibco</td>
			<td>15240-062</td>
			<td>Contains 10,000 units/mL of penicillin, 10,000 &#181;g/mL of streptomycin, and 25 &#181;g/mL of Fungizone&#174; Antimycotic</td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum</td>
			<td>Gibco</td>
			<td>26140-079</td>
			<td>FBS, for culture media</td>
		</tr>
		<tr>
			<td>RPMI 1640 Medium</td>
			<td>Gibco</td>
			<td>22400-071</td>
			<td>Contains L-glutamine and 25mM HEPES</td>
		</tr>
	</tbody>
</table>

screening for functional non-coding genetic variants using electrophoretic mobility shift assay (emsa) and dna-affinity precipitation assay (dapa)

Population and family-based genetic studies typically result in the identification of genetic variants that are statistically associated with a clinical disease or phenotype. For many diseases and traits, most variants are non-coding, and are thus likely to act by impacting subtle, comparatively hard to predict mechanisms controlling gene expression. Here, we describe a general strategic approach to prioritize non-coding variants, and screen them for their function. This approach involves computational prioritization using functional genomic databases followed by experimental analysis of differential binding of transcription factors (TFs) to risk and non-risk alleles. For both electrophoretic mobility shift assay (EMSA) and DNA affinity precipitation assay (DAPA) analysis of genetic variants, a synthetic DNA oligonucleotide (oligo) is used to identify factors in the nuclear lysate of disease or phenotype-relevant cells. For EMSA, the oligonucleotides with or without bound nuclear factors (often TFs) are analyzed by non-denaturing electrophoresis on a tris-borate-EDTA (TBE) polyacrylamide gel. For DAPA, the oligonucleotides are bound to a magnetic column and the nuclear factors that specifically bind the DNA sequence are eluted and analyzed through mass spectrometry or with a reducing sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) followed by Western blot analysis. This general approach can be widely used to study the function of non-coding genetic variants associated with any disease, trait, or phenotype.

בסעיף זה, תוצאות נציגים למה לצפות ניתנות בעת ביצוע Emsa או DAPA, ואת ההשתנות לגבי איכות lysate מאופיינת. לדוגמא, הוצע כי הקפאת דגימות חלבון הפשרה מספר פעמים עלולה לגרום denaturation. על מנת לחקור את שחזור של ניתוח Emsa בהקשר של אלה &quot;להקפיא להפשיר&quot; מחזורים, שני 35 ...

Watch this Scientific Journal Video about Screening for Functional Non-coding Genetic Variants Using Electrophoretic Mobility Shift Assay EMSA and DNA-affinity Precipitation Assay DAPA at JoVE.com

Screening for Functional Non-coding Genetic Variants Using Electrophoretic Mobility Shift Assay EMSA and DNA-affinity Precipitation Assay DAPA

We present a strategic plan and protocol for identifying non-coding genetic variants affecting transcription factor (TF) DNA binding. A detailed experimental protocol is provided for electrophoretic mobility shift assay (EMSA) and DNA affinity precipitation assay (DAPA) analysis of genotype-dependent TF DNA binding.

הקרנה עבור וריאנטים גנטיים ללא קידוד תפקודיים באמצעות ניידות Electrophoretic Shift Assay (Emsa) ו Assay משקע זיקת DNA (DAPA)

Population and family-based genetic studies typically result in the identification of genetic variants that are statistically associated with a clinical ...

screening-for-functional-non-coding-genetic-variants-using

Research

JoVE Journal

Biology

Screening for Functional Non-coding Genetic Variants Using Electrophoretic Mobility Shift Assay (EMSA) and DNA-affinity Precipitation Assay (DAPA)

12.9K Views.  Cincinnati Children's Hospital. We present a strategic plan and protocol for identifying non-coding genetic variants affecting transcription factor (TF) DNA binding. A detailed experimental protocol is provided for electrophoretic mobility shift assay (EMSA) and DNA affinity precipitation assay (DAPA) analysis of genotype-dependent TF DNA binding.

Video: Screening for Functional Non-coding Genetic Variants Using Electrophoretic Mobility Shift Assay EMSA and DNA-affinity Precipitation Assay DAPA

Light/dark Transition Test for Mice

Although all of the mouse genome sequences have been determined, we do not yet know the functions of most of these genes. Gene-targeting techniques, however, can be used to delete or manipulate a specific gene in mice. The influence of a given gene on a specific behavior can then be determined by conducting behavioral analyses of the mutant mice. As a test for behavioral phenotyping of mutant mice, the light/dark transition test is one of the most widely used tests to measure anxiety-like behavior in mice. The test is based on the natural aversion of mice to brightly illuminated areas and on their spontaneous exploratory behavior in novel environments. The test is sensitive to anxiolytic drug treatment. The apparatus consists of a dark chamber and a brightly illuminated chamber. Mice are allowed to move freely between the two chambers. The number of entries into the bright chamber and the duration of time spent there are indices of bright-space anxiety in mice. To obtain phenotyping results of a strain of mutant mice that can be readily reproduced and compared with those of other mutants, the behavioral test methods should be as identical as possible between laboratories. The procedural differences that exist between laboratories, however, make it difficult to replicate or compare the results among laboratories. Here, we present our protocol for the light/dark transition test as a movie so that the details of the protocol can be demonstrated. In our laboratory, we have assessed more than 60 strains of mutant mice using the protocol shown in the movie. Those data will be disclosed as a part of a public database that we are now constructing.

Visualization of the protocol will facilitate understanding of the details of the entire experimental procedure, allowing for standardization of the protocols used across laboratories and comparisons of the behavioral phenotypes of various strains of mutant mice assessed using this test.

The light/dark transition test is one of the most widely used tests to measure anxiety-like behavior in mice. Here, we present a movie that shows detailed procedures on how we conduct the test.

אור / חושך מעבר מבחן עכברים

Although all of the mouse genome sequences have been determined, we do not yet know the functions of most of these genes. Gene-targeting techniques, ...

Assay for Neural Induction in the Chick Embryo

The chick embryo is a valuable tool in the study of early embryonic development. Its transparency, accessibility and ease of manipulation, make it an ideal tool for studying the formation and initial patterning of the nervous system. This video demonstrates how to graft organizer tissue into a host, a method by which Hensen s node (the organizer in the chick embryo) is grafted to a host competent ectoderm. The organizer graft instructs overlying na ve tissue to adopt a neural fate via neural inducing signals. This mechanism is referred to as neural induction, and constitutes the initial step in the formation of brain and spinal cord in amniotes. This method is essentially used for the characterization of putative neural inducing molecules in chick. This video demonstrates the different steps in the assay for neural induction; First, the donnor embryo is explanted and pinned on a dish. Then, the host embryo is prepared for New culture. The graft is excised and transplanted to the host area pellucida margin. The host is cultured for 18-22 hrs. The assembly is fixed and processed for further applications (e.g. in situ hybridization). This method was originally devised by Waddington 1,2 and Gallera 3,4.

Neural induction is the first step in the formation of the brain. It is a mechanism by which Hensen's node (organizer), instructs adjacent tissue to adopt a neural fate, i.e. to give rise to the nervous system. This video demonstrates an assay for neural induction in chick embryo.

Assay עבור אינדוקציה עצבית בעובר צ&#39;יק

The chick embryo is a valuable tool in the study of early embryonic development. Its transparency, accessibility and ease of manipulation, make it an ...

Elevated Plus Maze for Mice

Although the mouse genome is now completely sequenced, the functions of most of the genes expressed in the brain are not known. The influence of a given gene on a specific behavior can be determined by behavioral analysis of mutant mice. If a target gene is expressed in the brain, behavioral phenotype of the mutant mice could elucidate the genetic mechanism of normal behaviors. The elevated plus maze test is one of the most widely used tests for measuring anxiety-like behavior. The test is based on the natural aversion of mice for open and elevated areas, as well as on their natural spontaneous exploratory behavior in novel environments. The apparatus consists of open arms and closed arms, crossed in the middle perpendicularly to each other, and a center area. Mice are given access to all of the arms and are allowed to move freely between them. The number of entries into the open arms and the time spent in the open arms are used as indices of open space-induced anxiety in mice. Unfortunately, the procedural differences that exist between laboratories make it difficult to duplicate and compare results among laboratories. Here, we present a detailed movie demonstrating our protocol for the elevated plus maze test. In our laboratory, we have assessed more than 90 strains of mutant mice using the protocol shown in the movie. These data will be disclosed as a part of a public database that we are now constructing.
Visualization of the protocol will promote better understanding of the details of the entire experimental procedure, allowing for standardization of the protocols used in different laboratories and comparisons of the behavioral phenotypes of various strains of mutant mice assessed using this test. 


The elevated plus maze test is one of the most widely used tests for measuring anxiety-like behavior in mice. Here, we present a movie showing the detailed procedures for conducting the test.

מבוך פלוס גבוהות עבור עכברים

Although the mouse genome is now completely sequenced, the functions of most of the genes expressed in the brain are not known. The influence of a given ...

Dissection of Hippocampal Dentate Gyrus from Adult Mouse

The hippocampus is one of the most widely studied areas in the brain because of its important functional role in memory processing and learning, its remarkable neuronal cell plasticity, and its involvement in epilepsy, neurodegenerative diseases, and psychiatric disorders. The hippocampus is composed of distinct regions; the dentate gyrus, which comprises mainly granule neurons, and Ammon's horn, which comprises mainly pyramidal neurons, and the two regions are connected by both anatomic and functional circuits. Many different mRNAs and proteins are selectively expressed in the dentate gyrus, and the dentate gyrus is a site of adult neurogenesis; that is, new neurons are continually generated in the adult dentate gyrus. To investigate mRNA and protein expression specific to the dentate gyrus, laser capture microdissection is often used. This method has some limitations, however, such as the need for special apparatuses and complicated handling procedures. In this video-recorded protocol, we demonstrate a dissection technique for removing the dentate gyrus from adult mouse under a stereomicroscope. Dentate gyrus samples prepared using this technique are suitable for any assay, including transcriptomic, proteomic, and cell biology analyses. We confirmed that the dissected tissue is dentate gyrus by conducting real-time PCR of dentate gyrus-specific genes, tryptophan 2,3-dioxygenase (TDO2) and desmoplakin (Dsp), and Ammon's horn enriched genes, Meis-related gene 1b (Mrg1b) and TYRO3 protein tyrosine kinase 3 (Tyro3). The mRNA expressions of TDO2 and Dsp in the dentate gyrus samples were detected at obviously higher levels, whereas Mrg1b and Tyro3 were lower levels, than those in the Ammon's horn samples. To demonstrate the advantage of this method, we performed DNA microarray analysis using samples of whole hippocampus and dentate gyrus. The mRNA expression of TDO2 and Dsp, which are expressed selectively in the dentate gyrus, in the whole hippocampus of alpha-CaMKII+/- mice, exhibited 0.037 and 0.10-fold changes compared to that of wild-type mice, respectively. In the isolated dentate gyrus, however, these expressions exhibited 0.011 and 0.021-fold changes compared to that of wild-type mice, demonstrating that gene expression changes in dentate gyrus can be detected with greater sensitivity. Taken together, this convenient and accurate dissection technique can be reliably used for studies focused on the dentate gyrus.

A dissection technique for removal of the dentate gyrus from adult mouse under a stereomicroscope was demonstrated in this video-recorded protocol.

Dissection של gyrus משוננת בהיפוקמפוס מתוך עכבר למבוגרים

The hippocampus is one of the most widely studied areas in the brain because of its important functional role in memory processing and learning, its ...

Crystallizing Membrane Proteins for Structure Determination using Lipidic Mesophases

A detailed protocol for crystallizing membrane proteins by using lipidic mesophases is described. This method has variously been referred to as the lipidic cubic phase or in meso method. The method has been shown to be quite versatile in that it has been used to solve X-ray crystallographic structures of prokaryotic and eukaryotic proteins, proteins that are monomeric, homo- and hetero-multimeric, chromophore-containing and chromophore-free, and alpha-helical and beta-barrel proteins. Recent successes using in meso crystallization are the human engineered beta2-adrenergic and adenosine A2a G protein-coupled receptors. Protocols are presented for reconstituting the membrane protein into the monoolein-based mesophase, and for setting up crystallizations in the manual mode. Additional steps in the overall process, such as crystal harvesting, are to be addressed in future video articles. The time required to prepare the protein-loaded mesophase and to set up a crystallization plate manually is about one hour.

Herein is described the procedure implemented in the Caffrey Membrane Structural and Functional Biology Group to set up manually crystallization trials of membrane proteins in lipidic mesophases.

גיבוש חלבונים בממברנה עבור קביעת מבנה באמצעות Mesophases Lipidic

A detailed protocol for crystallizing membrane proteins by using lipidic mesophases is described. This method has variously been referred to as the ...

An Allele-specific Gene Expression Assay to Test the Functional Basis of Genetic Associations

The number of significant genetic associations with common complex traits is constantly increasing. However, most of these associations have not been understood at molecular level. One of the mechanisms mediating the effect of DNA variants on phenotypes is gene expression, which has been shown to be particularly relevant for complex traits1.
This method tests in a cellular context the effect of specific DNA sequences on gene expression. The principle is to measure the relative abundance of transcripts arising from the two alleles of a gene, analysing cells which carry one copy of the DNA sequences associated with disease (the risk variants)2,3. Therefore, the cells used for this method should meet two fundamental genotypic requirements: they have to be heterozygous both for DNA risk variants and for DNA markers, typically coding polymorphisms, which can distinguish transcripts based on their chromosomal origin (Figure 1). DNA risk variants and DNA markers do not need to have the same allele frequency but the phase (haplotypic) relationship of the genetic markers needs to be understood. It is also important to choose cell types which express the gene of interest. This protocol refers specifically to the procedure adopted to extract nucleic acids from fibroblasts but the method is equally applicable to other cells types including primary cells.
DNA and RNA are extracted from the selected cell lines and cDNA is generated. DNA and cDNA are analysed with a primer extension assay, designed to target the coding DNA markers4. The primer extension assay is carried out using the MassARRAY (Sequenom)5 platform according to the manufacturer's specifications. Primer extension products are then analysed by matrix-assisted laser desorption/ionization time of-flight mass spectrometry (MALDI-TOF/MS). Because the selected markers are heterozygous they will generate two peaks on the MS profiles. The area of each peak is proportional to the transcript abundance and can be measured with a function of the MassARRAY Typer software to generate an allelic ratio (allele 1: allele 2) calculation. The allelic ratio obtained for cDNA is normalized using that measured from genomic DNA, where the allelic ratio is expected to be 1:1 to correct for technical artifacts. Markers with a normalised allelic ratio significantly different to 1 indicate that the amount of transcript generated from the two chromosomes in the same cell is different, suggesting that the DNA variants associated with the phenotype have an effect on gene expression. Experimental controls should be used to confirm the results.

Genetic associations often remain unexplained at a functional level. This method aims to assess the effect of phenotype-associated genetic markers on gene expression by analyzing cells heterozygous for transcribed SNPs. The technology allows accurate measurement by MALDI-TOF mass spectrometry to quantify allele-specific primer extension products.

אלל ספציפי Gene Expression Assay כדי לבדוק את בסיס פונקציונלי של אגודות גנטי

The number of significant genetic associations with common complex traits is constantly increasing. However, most of these associations have not been ...

A Fluorescent Screening Assay for Identifying Modulators of GIRK Channels

G protein-gated inward rectifier K+ (GIRK) channels function as cellular mediators of a wide range of hormones and neurotransmitters and are expressed in the brain, heart, skeletal muscle and endocrine tissue1,2. GIRK channels become activated following the binding of ligands (neurotransmitters, hormones, drugs, etc.) to their plasma membrane-bound, G protein-coupled receptors (GPCRs). This binding causes the stimulation of G proteins (Gi and Go) which subsequently bind to and activate the GIRK channel. Once opened the GIRK channel allows the movement of K+ out of the cell causing the resting membrane potential to become more negative. As a consequence, GIRK channel activation in neurons decreases spontaneous action potential formation and inhibits the release of excitatory neurotransmitters. In the heart, activation of the GIRK channel inhibits pacemaker activity thereby slowing the heart rate.
GIRK channels represent novel targets for the development of new therapeutic agents for the treatment neuropathic pain, drug addiction, cardiac arrhythmias and other disorders3. However, the pharmacology of these channels remains largely unexplored. Although a number of drugs including anti-arrhythmic agents, antipsychotic drugs and antidepressants block the GIRK channel, this inhibition is not selective and occurs at relatively high drug concentrations3.
Here, we describe a real-time screening assay for identifying new modulators of GIRK channels. In this assay, neuronal AtT20 cells, expressing GIRK channels, are loaded with membrane potential-sensitive fluorescent dyes such as bis-(1,3-dibutylbarbituric acid) trimethine oxonol [DiBAC4(3)] or HLB 021-152 (Figure 1). The dye molecules become strongly fluorescent following uptake into the cells (Figure 1). Treatment of the cells with GPCR ligands stimulates the GIRK channels to open. The resulting K+ efflux out of the cell causes the membrane potential to become more negative and the fluorescent signal to decrease (Figure 1). Thus, drugs that modulate K+ efflux through the GIRK channel can be assayed using a fluorescent plate reader. Unlike other ion channel screening assays, such atomic absorption spectrometry4 or radiotracer analysis5, the GIRK channel fluorescent assay provides a fast, real-time and inexpensive screening procedure.

A real-time screening procedure for identifying drugs that interact with G protein-gated inward rectifier K+ (GIRK) channels is described. The assay utilizes membrane potential-sensitive fluorescent dyes to measure GIRK channel activity. This technique is adaptable for use on a number of cell lines.

Assay הקרנת פלורסנט לזיהוי מאפננים של ערוצים GIRK

G protein-gated inward rectifier K+ (GIRK) channels function as cellular mediators of a wide range of hormones and neurotransmitters and are expressed in ...

Mapping Bacterial Functional Networks and Pathways in Escherichia Coli using Synthetic Genetic Arrays

Phenotypes are determined by a complex series of physical (e.g. protein-protein) and functional (e.g. gene-gene or genetic) interactions (GI)1. While physical interactions can indicate which bacterial proteins are associated as complexes, they do not necessarily reveal pathway-level functional relationships1. GI screens, in which the growth of double mutants bearing two deleted or inactivated genes is measured and compared to the corresponding single mutants, can illuminate epistatic dependencies between loci and hence provide a means to query and discover novel functional relationships2. Large-scale GI maps have been reported for eukaryotic organisms like yeast3-7, but GI information remains sparse for prokaryotes8, which hinders the functional annotation of bacterial genomes. To this end, we and others have developed high-throughput quantitative bacterial GI screening methods9, 10.
Here, we present the key steps required to perform quantitative E. coli Synthetic Genetic Array (eSGA) screening procedure on a genome-scale9, using natural bacterial conjugation and homologous recombination to systemically generate and measure the fitness of large numbers of double mutants in a colony array format. Briefly, a robot is used to transfer, through conjugation, chloramphenicol (Cm) - marked mutant alleles from engineered Hfr (High frequency of recombination) 'donor strains' into an ordered array of kanamycin (Kan) - marked F- recipient strains. Typically, we use loss-of-function single mutants bearing non-essential gene deletions (e.g. the 'Keio' collection11) and essential gene hypomorphic mutations (i.e. alleles conferring reduced protein expression, stability, or activity9, 12, 13) to query the functional associations of non-essential and essential genes, respectively. After conjugation and ensuing genetic exchange mediated by homologous recombination, the resulting double mutants are selected on solid medium containing both antibiotics. After outgrowth, the plates are digitally imaged and colony sizes are quantitatively scored using an in-house automated image processing system14. GIs are revealed when the growth rate of a double mutant is either significantly better or worse than expected9. Aggravating (or negative) GIs often result between loss-of-function mutations in pairs of genes from compensatory pathways that impinge on the same essential process2. Here, the loss of a single gene is buffered, such that either single mutant is viable. However, the loss of both pathways is deleterious and results in synthetic lethality or sickness (i.e. slow growth). Conversely, alleviating (or positive) interactions can occur between genes in the same pathway or protein complex2 as the deletion of either gene alone is often sufficient to perturb the normal function of the pathway or complex such that additional perturbations do not reduce activity, and hence growth, further. Overall, systematically identifying and analyzing GI networks can provide unbiased, global maps of the functional relationships between large numbers of genes, from which pathway-level information missed by other approaches can be inferred9.

Mapping Bacterial Functional Networks and Pathways in Escherichia Coli using Synthetic Genetic Arrays

Systematic, large-scale synthetic genetic (gene-gene or epistasis) interaction screens can be used to explore genetic redundancy and pathway cross-talk. Here, we describe a high-throughput quantitative synthetic genetic array screening technology, termed eSGA that we developed for elucidating epistatic relationships and exploring genetic interaction networks in Escherichia coli.

מיפוי רשתות פונקציונליות חיידקיים ומסלולים ב<em&gt; חיידקי Escherichia</em&gt; באמצעות מערכים גנטיים סינטטיים

Phenotypes  are determined by a complex series of physical (e.g. protein-protein) and  functional (e.g. gene-gene or genetic) interactions (GI)1. While ...

High-throughput Functional Screening using a Homemade Dual-glow Luciferase Assay

We present a rapid and inexpensive high-throughput screening protocol to identify transcriptional regulators of alpha-synuclein, a gene associated with Parkinson&#39;s disease. 293T cells are transiently transfected with plasmids from an arrayed ORF expression library, together with luciferase reporter plasmids, in a one-gene-per-well microplate format. Firefly luciferase activity is assayed after 48 hr to determine the effects of each library gene upon alpha-synuclein transcription, normalized to expression from an internal control construct (a hCMV promoter directing Renilla luciferase). This protocol is facilitated by a bench-top robot enclosed in a biosafety cabinet, which performs aseptic liquid handling in 96-well format. Our automated transfection protocol is readily adaptable to high-throughput lentiviral library production or other functional screening protocols requiring triple-transfections of large numbers of unique library plasmids in conjunction with a common set of helper plasmids. We also present an inexpensive and validated alternative to commercially-available, dual luciferase reagents which employs PTC124, EDTA, and pyrophosphate to suppress firefly luciferase activity prior to measurement of Renilla luciferase. Using these methods, we screened 7,670 human genes and identified 68 regulators of alpha-synuclein. This protocol is easily modifiable to target other genes of interest.

We present a rapid and inexpensive screening method for identifying transcriptional regulators using high-throughput robotic transfections and a homemade dual-glow luciferase assay. This protocol rapidly generates direct side-by-side functional data for thousands of genes and is easily modifiable to target any gene of interest.

הקרנה פונקציונלית תפוקה גבוהה באמצעות assay בלוציפראז Dual-זוהר תוצרת בית

We present a rapid and inexpensive high-throughput screening protocol to identify transcriptional regulators of alpha-synuclein, a gene associated with ...

Electrophoretic Mobility Shift Assay (EMSA) for the Study of RNA-Protein Interactions: The IRE/IRP Example

RNA/protein interactions are critical for post-transcriptional regulatory pathways. Among the best-characterized cytosolic RNA-binding proteins are iron regulatory proteins, IRP1 and IRP2. They bind to iron responsive elements (IREs) within the untranslated regions (UTRs) of several target mRNAs, thereby controlling the mRNAs translation or stability. IRE/IRP interactions have been widely studied by EMSA. Here, we describe the EMSA protocol for analyzing the IRE-binding activity of IRP1 and IRP2, which can be generalized to assess the activity of other RNA-binding proteins as well. A crude protein lysate containing an RNA-binding protein, or a purified preparation of this protein, is incubated with an excess of32 P-labeled RNA probe, allowing for complex formation. Heparin is added to preclude non-specific protein to probe binding. Subsequently, the mixture is analyzed by non-denaturing electrophoresis on a polyacrylamide gel. The free probe migrates fast, while the RNA/protein complex exhibits retarded mobility; hence, the procedure is also called &#8220;gel retardation&#8221; or &#8220;bandshift&#8221; assay. After completion of the electrophoresis, the gel is dried and RNA/protein complexes, as well as free probe, are detected by autoradiography. The overall goal of the protocol is to detect and quantify IRE/IRP and other RNA/protein interactions. Moreover, EMSA can also be used to determine specificity, binding affinity, and stoichiometry of the RNA/protein interaction under investigation.

Electrophoretic Mobility Shift Assay EMSA for the Study of RNA-Protein Interactions: The IRE/IRP Example

Here we present a protocol to analyze RNA/protein interactions. The electrophoretic mobility shift assay (EMSA) is based on the differential migration of RNA/protein complexes and free RNA during native gel electrophoresis. By using a radiolabeled RNA probe, RNA/protein complexes can be visualized by autoradiography.

Shift electrophoretic הניידות Assay (Emsa) לחקר RNA אינטראקציות חלבון: IRE / IRP דוגמא

RNA/protein interactions are critical for post-transcriptional regulatory pathways. Among the best-characterized cytosolic RNA-binding proteins are iron ...