Diese Arbeit wurde von der Grant-Agentur der Tschechischen Republik, Projekt P302-12-G157 unterstützt. Experimente wurden auch von der Tschechisch-Norwegisch Forschung Programm CZ09, die von norwegischen Fonds und durch das Ministerium für Bildung, Jugend und Sport der Tschechischen Republik betreut wird unterstützt (gewähren Nummer: 7F14369).

<ol>
	<li>Cadet, J., Mouret, S., Ravanat, J. L., Douki, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photoinduced+damage+to+cellular+DNA:+direct+and+photosensitized+reactions.">Photoinduced damage to cellular DNA: direct and photosensitized reactions.</a> Photochem Photobiol. 88 (5), 1048-1065 (2012).</li><li>Cooke, M. 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=Immunochemical+detection+of+UV-induced+DNA+damage+and+repair.">Immunochemical detection of UV-induced DNA damage and repair.</a> J Immunol Methods. 280 (1-2), 125-133 (2003).</li><li>Lahtz, 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=Gamma+irradiation+does+not+induce+detectable+changes+in+DNA+methylation+directly+following+exposure+of+human+cells.">Gamma irradiation does not induce detectable changes in DNA methylation directly following exposure of human cells.</a> PLoS One. 7 (9), e44858 (2012).</li><li>Cremer, 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=Detection+of+chromosome+aberrations+in+the+human+interphase+nucleus+by+visualization+of+specific+target+DNAs+with+radioactive+and+non-radioactive+in+situ+hybridization+techniques:+diagnosis+of+trisomy+18+with+probe+L1.84.">Detection of chromosome aberrations in the human interphase nucleus by visualization of specific target DNAs with radioactive and non-radioactive in situ hybridization techniques: diagnosis of trisomy 18 with probe L1.84.</a> Hum Genet. 74 (4), 346-352 (1986).</li><li>Zorn, C., Cremer, T., Cremer, C., Zimmer, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser+UV+microirradiation+of+interphase+nuclei+and+post-treatment+with+caffeine.+A+new+approach+to+establish+the+arrangement+of+interphase+chromosomes.">Laser UV microirradiation of interphase nuclei and post-treatment with caffeine. A new approach to establish the arrangement of interphase chromosomes.</a> Hum Genet. 35 (1), 83-89 (1976).</li><li>Bartova, 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=Recruitment+of+Oct4+protein+to+UV-damaged+chromatin+in+embryonic+stem+cells.">Recruitment of Oct4 protein to UV-damaged chromatin in embryonic stem cells.</a> PLoS One. 6 (12), e27281 (2011).</li><li>Stixova, L., 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=HP1beta-dependent+recruitment+of+UBF1+to+irradiated+chromatin+occurs+simultaneously+with+CPDs.">HP1beta-dependent recruitment of UBF1 to irradiated chromatin occurs simultaneously with CPDs.</a> Epigenetics Chromatin. 7 (1), 39 (2014).</li><li>Stixova, L., 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=Advanced+microscopy+techniques+used+for+comparison+of+UVA-+and+gamma-irradiation-induced+DNA+damage+in+the+cell+nucleus+and+nucleolus.">Advanced microscopy techniques used for comparison of UVA- and gamma-irradiation-induced DNA damage in the cell nucleus and nucleolus.</a> Folia Biol (Praha). 60, 76-84 (2014).</li><li>Luijsterburg, M. 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=Heterochromatin+protein+1+is+recruited+to+various+types+of+DNA+damage.">Heterochromatin protein 1 is recruited to various types of DNA damage.</a> J Cell Biol. 185 (4), 577-586 (2009).</li><li>Bartova, 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=Coilin+is+rapidly+recruited+to+UVA-induced+DNA+lesions+and+gamma-radiation+affects+localized+movement+of+Cajal+bodies.">Coilin is rapidly recruited to UVA-induced DNA lesions and gamma-radiation affects localized movement of Cajal bodies.</a> Nucleus. 5 (3), 460-468 (2014).</li><li>Franek, 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=Advanced+Image+Acquisition+and+Analytical+Techniques+for+Studies+of+Living+Cells+and+Tissue+Sections.">Advanced Image Acquisition and Analytical Techniques for Studies of Living Cells and Tissue Sections.</a> Microsc Microanal. 22 (2), 326-341 (2016).</li><li>Lemmer, 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=Using+conventional+fluorescent+markers+for+far-field+fluorescence+localization+nanoscopy+allows+resolution+in+the+10-nm+range.">Using conventional fluorescent markers for far-field fluorescence localization nanoscopy allows resolution in the 10-nm range.</a> J Microsc. 235 (2), 163-171 (2009).</li><li>Reits, E. 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M., Suhling, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluorescence+lifetime+and+polarization-resolved+imaging+in+cell+biology.">Fluorescence lifetime and polarization-resolved imaging in cell biology.</a> Curr Opin Biotechnol. 20 (1), 28-36 (2009).</li><li>Shimomura, O., Johnson, F. H., Saiga, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extraction,+purification+and+properties+of+aequorin,+a+bioluminescent+protein+from+the+luminous+hydromedusan,+Aequorea.">Extraction, purification and properties of aequorin, a bioluminescent protein from the luminous hydromedusan, Aequorea.</a> J Cell Comp Physiol. 59, 223-239 (1962).</li><li>Iwabuchi, K., Bartel, P. L., Li, B., Marraccino, R., Fields, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Two+cellular+proteins+that+bind+to+wild-type+but+not+mutant+p53.">Two cellular proteins that bind to wild-type but not mutant p53.</a> Proc Natl Acad Sci U S A. 91 (13), 6098-6102 (1994).</li><li>Ward, I. M., Minn, K., van Deursen, J., Chen, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=p53+Binding+protein+53BP1+is+required+for+DNA+damage+responses+and+tumor+suppression+in+mice.">p53 Binding protein 53BP1 is required for DNA damage responses and tumor suppression in mice.</a> Mol Cell Biol. 23 (7), 2556-2563 (2003).</li><li>Kanda, T., Sullivan, K. F., Wahl, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Histone-GFP+fusion+protein+enables+sensitive+analysis+of+chromosome+dynamics+in+living+mammalian+cells.">Histone-GFP fusion protein enables sensitive analysis of chromosome dynamics in living mammalian cells.</a> Curr Biol. 8 (7), 377-385 (1998).</li><li>Walter, J., Schermelleh, L., Cremer, M., Tashiro, S., Cremer, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chromosome+order+in+HeLa+cells+changes+during+mitosis+and+early+G1,+but+is+stably+maintained+during+subsequent+interphase+stages.">Chromosome order in HeLa cells changes during mitosis and early G1, but is stably maintained during subsequent interphase stages.</a> J Cell Biol. 160 (5), 685-697 (2003).</li><li>Sakaue-Sawano, 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=Tracing+the+silhouette+of+individual+cells+in+S/G2/M+phases+with+fluorescence.">Tracing the silhouette of individual cells in S/G2/M phases with fluorescence.</a> Chem Biol. 15 (12), 1243-1248 (2008).</li><li>Sorokin, D. 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S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+impact+of+heterogeneity+and+dark+acceptor+states+on+FRET:+implications+for+using+fluorescent+protein+donors+and+acceptors.">The impact of heterogeneity and dark acceptor states on FRET: implications for using fluorescent protein donors and acceptors.</a> PLoS One. 7 (11), e49593 (2012).</li><li>Foltankova, V., Matula, P., Sorokin, D., Kozubek, S., Bartova, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hybrid+detectors+improved+time-lapse+confocal+microscopy+of+PML+and+53BP1+nuclear+body+colocalization+in+DNA+lesions.">Hybrid detectors improved time-lapse confocal microscopy of PML and 53BP1 nuclear body colocalization in DNA lesions.</a> Microsc Microanal. 19 (2), 360-369 (2013).</li><li>Suchankova, 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=Distinct+kinetics+of+DNA+repair+protein+accumulation+at+DNA+lesions+and+cell+cycle-dependent+formation+of+gammaH2AX-+and+NBS1-positive+repair+foci.">Distinct kinetics of DNA repair protein accumulation at DNA lesions and cell cycle-dependent formation of gammaH2AX- and NBS1-positive repair foci.</a> Biol Cell. 107 (12), 440-454 (2015).</li><li>B&#225;rtov&#225;, 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=PCNA+is+recruited+to+irradiated+chromatin+in+late+S+phase+and+is+most+pronounced+in+G2+phase+of+the+cell+cycle.">PCNA is recruited to irradiated chromatin in late S phase and is most pronounced in G2 phase of the cell cycle.</a> Protoplasma. , (2017).</li><li>Krejci, 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=Post-Translational+Modifications+of+Histones+in+Human+Sperm.">Post-Translational Modifications of Histones in Human Sperm.</a> J Cell Biochem. 116 (10), 2195-2209 (2015).</li><li>Chou, D. 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Die Autoren erklären, dass es keine Interessenkonflikte gibt.

Mikroskopiertechniken stellen grundlegende Werkzeuge in den Forschungslabors. Hier eine kurze Beschreibung der Methoden für die Untersuchung von Protein-Einstellung verwendet und Kinetik bei DNA-Läsionen wird vorgestellt. Wir vor allem unsere experimentelle Erfahrung auf dem Gebiet der lokalen Microirradiation lebender Zellen zur Kenntnis genommen, und wir besprechen die Untersuchung von Protein-Kinetik von FRAP und Protein-Protein Interaktion auf DNA-Läsionen mit Akzeptor-bleichen Bund28 und s...

DNA-Schädigung führt zum Auftreten von bestehend aus Cyclobutan Pyrimidine Dimere (CPDs), 8-oxo-7,8-dihydro-2'-deoxyguanosine und Einzel-Strang DNA-Läsionen oder Doppel-Strang bricht1,2. Γ-Strahlen sind die Form von ionisierender Strahlung mit der höchsten Energie und hohe Penetranz, damit diese Quelle der Strahlung ist weit verbreitet in Strahlentherapie3. Auf der anderen Seite induziert experimentell DNA-Schäden durch UV-Laser imitiert natürliche Belichtung mit UV-Licht. UVA-Microirradiation darstellt als eine mikroskopische Methode, ein experimentelles Werkzeug zur Untersuchung von DNA-Schäden in einzelne lebende Zellen. Microirradiation wurde erstmals vor 40 Jahren verwendet, um die Organisation von Chromosom Regionen4,5zu offenbaren. Diese Technik ist stark abhängig von entweder die funktionellen Eigenschaften der konfokalen Mikroskopen oder die technischen Grenzen des modernen Nanoskopie. DNA-Läsionen zu induzieren, können Zellen durch 5' Bromodeoxyuridine (BrdU) oder Hoechst 33342 vor UV-Bestrahlung presensitized. Bártová Et al. 6 zuvor beschrieben die presensitization Schritt, und vor kurzem haben wir diese Microirradiation-Technik zur Vermeidung von Zelltod oder Apoptose optimiert. Beispielsweise führt der Einsatz von 405nm UV Laser (ohne Hoechst 33342 Presensitization) zur Induktion von 53BP1-positiven Doppel-Strangbrüchen (DSB) auf Kosten von Cyclobutan Pyrimidine Dimere (CPDs). Auf der anderen Seite presensitization Schritte in Kombination mit UV-Microirradiation verursachen sehr hohe CPDs und DSB gleichzeitig7,8. Diese Methodik ist schwierig, auf die Studie eines einzelnen DNA-Reparatur-Signalwegs anzuwenden.
Mit Microirradiation ist es möglich, Protein-Rekrutierung, Kinetik und Interaktion auf DNA-Läsionen in lebenden Zellen zu analysieren. Ein Beispiel für diese Methode wurde von Luijsterburg Et Al. veröffentlicht. 9 für Heterochromatin Protein 1β, und wir zeigten vor kurzem zum ersten Mal, das der Pluripotenz Faktor Oct4 und ein Protein assoziiert mit Cajal Körpern, coilin, UV-induzierten DNA-Läsionen6,10eingestellt werden. Protein-Kinetik bei dieser DNA-Läsionen können auch untersucht werden, mit Hilfe der FRAP (Fluoreszenz Erholung nach Immunofluoreszenz)11,12,13 oder FRET (Fluoreszenz Resonanz Energietransfer) Techniken14 ,15. Diese Methoden haben das Potenzial, einfache Diffusion von Proteinen an DNA-Läsionen oder Protein-Protein-Wechselwirkungen zu offenbaren. Ein nützliches Werkzeug für zusätzliche Charakterisierung von Proteinen ist FLIM (Fluoreszenz Lifetime Imaging Microscopy) oder die Kombination mit Bund Technologie (Bund-FLIM)16. Diese Methoden ermöglichen die Untersuchung von Prozessen in lebenden Zellen, die stabil sind oder vorübergehend mit dem Ausdruck des Proteins des Interesses von ein fluoreszierendes Molekül17getaggt. Hier ist ein Beispiel für exponentielle Abfallzeit (τ) für GLP-Tags p53 Protein und seine Interaktionspartner, mCherry Verschlagwortet mit 53BP1, spielen eine wichtige Rolle im DNA-Schaden Antwort18,19 . Der Parameter τ ist die Lebensdauer der Fluorochrom von FLIM Berechnungen zur Verfügung gestellt spezifisch für einen bestimmten Fluoreszenz-Farbstoff, seine Bindung-Fähigkeiten und seiner zellulären Umgebung. Daher kann diese Methode uns Unterscheidungen zwischen Protein Subpopulationen, ihre Bindung Fähigkeiten und ihre funktionellen Eigenschaften nach, z. B. DNA-Schäden zeigen.
Hier ein Überblick über die methodischen Ansätze der moderne Mikroskopiertechniken, die in unserem Labor verwendet wird, um Zeit-spezifischen Protein Rekrutierung, Kinetik, Diffusion und Protein-Protein-Interaktionen auf dem Gelände von Microirradiated Chromatin zu studieren wird vorgestellt. Die Schritt für Schritt Methode für die Induktion von lokalen DNA-Läsionen in lebenden Zellen und eine Beschreibung der Methoden, die nützlich für die Studien von DNA-Schäden im Zusammenhang mit Veranstaltungen im lokal induzierte DNA-Läsionen verursacht durch UV-Laser sind vorgegeben.

<table>
	<tbody>
		<tr>
			<td>Cell cultivation</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>HeLa</td>
			<td>ATCC</td>
			<td>CCL-2TM</td>
			<td></td>
		</tr>
		<tr>
			<td>ES-D3 [D3]</td>
			<td>ATCC</td>
			<td>CRL-11632TM</td>
			<td></td>
		</tr>
		<tr>
			<td>HeLa -Fucci cells</td>
			<td></td>
			<td></td>
			<td>http://ruo.mbl.co.jp/bio/e/product/flprotein/fucci.html</td>
		</tr>
		<tr>
			<td>DMEM</td>
			<td>PAN-Biotech</td>
			<td>P03-0710</td>
			<td></td>
		</tr>
		<tr>
			<td>DMEM high glucose</td>
			<td>Sigma-Aldrich</td>
			<td>D6429-500ML</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal bovine serum (FBS)</td>
			<td>HyClone</td>
			<td>SV30180.03</td>
			<td></td>
		</tr>
		<tr>
			<td>ES Cell FBS</td>
			<td>Gibco</td>
			<td>16141-079</td>
			<td></td>
		</tr>
		<tr>
			<td>Non-Essential Amino Acids (NEAA)</td>
			<td>Gibco</td>
			<td>11140-035</td>
			<td></td>
		</tr>
		<tr>
			<td>mLIF (mouse Leukemia Inhibitor Factor)</td>
			<td>Merck Millipore</td>
			<td>ESG1107</td>
			<td></td>
		</tr>
		<tr>
			<td>MTG (1-Thioglycerol)</td>
			<td>Sigma-Aldrich</td>
			<td>M6145-25ML</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin Solution</td>
			<td>Biosera</td>
			<td>XC-A4122/100</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypsin - EDTA</td>
			<td>Biosera</td>
			<td>XC-T1717/100</td>
			<td>dilute with 1 &#215; PBS in ratio 1:6</td>
		</tr>
		<tr>
			<td>Nunclon cell culture dishes</td>
			<td>Sigma-Aldrich</td>
			<td>P7866</td>
			<td>cultivation of mESCs D3 cells</td>
		</tr>
		<tr>
			<td>&#181;-Dish 35m+A15:I35m Grid-500</td>
			<td>Ibidi GmbH</td>
			<td>81166</td>
			<td>microscopic dish</td>
		</tr>
		<tr>
			<td>0.2% Gelatine</td>
			<td>Sigma-Aldrich</td>
			<td>G1890-100G</td>
			<td>dilute in destille water and autoclaved</td>
		</tr>
		<tr>
			<td>Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td>Cell transfection</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>GFP-p53 plasmid</td>
			<td>Addgene</td>
			<td>12091</td>
			<td></td>
		</tr>
		<tr>
			<td>mCherry-PCNA plasmid</td>
			<td></td>
			<td></td>
			<td>generous gift from Cristina Cardoso, Technische Universit&#228;t Darmstadt</td>
		</tr>
		<tr>
			<td>mCherry-53BP1 plasmid</td>
			<td>Addgene</td>
			<td>19835</td>
			<td></td>
		</tr>
		<tr>
			<td>Metafecetene</td>
			<td>Biontex Laboratories GmbH</td>
			<td>T020&#8211;2.0</td>
			<td></td>
		</tr>
		<tr>
			<td>10 &#215; PBS</td>
			<td>Thermo Fisher Scientific</td>
			<td>AM9625</td>
			<td>for transfection use 1 &#215; PBS diluted in nuclease-free water</td>
		</tr>
		<tr>
			<td>5-bromo-2&#8217;-deoxy-uridine</td>
			<td>Sigma-Aldrich</td>
			<td>11296736001</td>
			<td></td>
		</tr>
		<tr>
			<td>Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td>Confocal microscopy</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Microscope Leica TCS SP5</td>
			<td>Leica Microsystems</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Microscope Leica TCS SP8</td>
			<td>Leica Microsystems</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>White-light laser</td>
			<td>Leica Microsystems</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>355-nm laser</td>
			<td>Coherent Inc.</td>
			<td></td>
			<td>laser power 80 mW</td>
		</tr>
		<tr>
			<td>405-nm laser</td>
			<td>Leica Microsystems</td>
			<td></td>
			<td>laser power 50 mW</td>
		</tr>
		<tr>
			<td>Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td>Immunofluorescence staining</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Coverslip</td>
			<td>VWR International Ltd</td>
			<td>631-1580</td>
			<td></td>
		</tr>
		<tr>
			<td>4% paraformaldehyde</td>
			<td>Affymetrix</td>
			<td>19943 1 LT</td>
			<td></td>
		</tr>
		<tr>
			<td>Triton X100</td>
			<td>MP Biomedicals</td>
			<td>2194854</td>
			<td></td>
		</tr>
		<tr>
			<td>Saponin from quillaja bark</td>
			<td>Sigma-Aldrich</td>
			<td>S4521</td>
			<td></td>
		</tr>
		<tr>
			<td>BSA</td>
			<td>Sigma-Aldrich</td>
			<td>A2153</td>
			<td></td>
		</tr>
		<tr>
			<td>53BP1</td>
			<td>Abcam</td>
			<td>ab21083</td>
			<td>primary antibody</td>
		</tr>
		<tr>
			<td>AlexaFluore 647</td>
			<td>Thermo Fisher Scientific</td>
			<td>A27040</td>
			<td>secondary antibody</td>
		</tr>
		<tr>
			<td>Vectashield</td>
			<td>Vector Laboratories Ltd</td>
			<td>H-1000</td>
			<td>mounting medium</td>
		</tr>
	</tbody>
</table>

advanced confocal microscopy techniques to study protein-protein interactions and kinetics at dna lesions

Lokale Microirradiation mit Lasern stellt ein nützliches Werkzeug für Studien zur DNA-Reparatur-bezogenen Prozesse in lebenden Zellen. Hier beschreiben wir einen methodischen Ansatz zur Analyse von Protein-Kinetik bei DNA-Läsionen über Zeit oder Proteinprotein Interaktionen auf lokal Microirradiated Chromatin. Wir zeigen auch, wie zu erkennen, einzelne Phasen des Zellzyklus mit dem Fucci zellulären System Zelle-Zyklus-abhängige Protein Kinetik bei DNA-Läsionen zu studieren. Eine methodische Beschreibung des Einsatzes von zwei UV-Lasern (355 nm und 405 nm), verschiedene Arten von DNA-Schäden zu induzieren auch vorgestellt. Nur die Zellen Microirradiated von 405 nm Diodenlaser führte normalerweise durch Mitose und waren frei von Cyclobutan Pyrimidine Dimere (CPDs). Wir zeigen auch, wie Microirradiated Zellen zu einem gegebenen Zeitpunkt auszuführende Immunodetection der körpereigene Proteine des Interesses behoben werden können. Für die DNA-Reparatur-Studien, beschreiben wir zusätzlich die Verwendung von biophysikalischen Methoden einschließlich FRAP (Fluoreszenz Erholung nach Immunofluoreszenz) und FLIM (Fluoreszenz Lifetime Imaging Microscopy) in Zellen mit spontan auftretender DNA Beschädigung Brennpunkte. Wir zeigen auch eine Anwendung der FLIM-FRET (Fluoreszenz Resonanz Energietransfer) in experimentellen Studien von Protein-Protein-Wechselwirkungen.

Verwenden erweiterte konfokalen Mikroskopie, beobachteten wir eine Ansammlung von mCherry-Tags 53BP1 und mCherry-PCNA Proteine bei der DNA-Läsionen. Analysen wurden von lokalen Microirradiation von lebenden Zellen durchgeführt. Der nuklearen Verteilungsmuster der DNA-Reparatur-Proteine in einzelne Zellzyklus Phasen zu erkennen, wir nutzten die Fucci zelluläre System, mit dem es möglich festzustellen, die G1, frühen S, ist und G2-Phasen der Zelle Zyklus (Abbildung...

Watch this Scientific Journal Video about Advanced Confocal Microscopy Techniques to Study Protein-protein Interactions and Kinetics at DNA Lesions at JoVE.com

Advanced Confocal Microscopy Techniques to Study Protein-protein Interactions and Kinetics at DNA Lesions

Laser Microirradiation ist ein nützliches Werkzeug für Studien zur DNA-Reparatur in lebenden Zellen. Ein methodischer Ansatz für die Nutzung der UVA Laser induzieren verschiedene DNA-Läsionen wird angezeigt. Wir haben eine Methode zur lokalen Microirradiation optimiert, die den normalen Zellzyklus unterhält; so fahren Sie bestrahlte Zellen durch Mitose.

Fortgeschrittene Mikroskopiertechniken der konfokalen zur Untersuchung von Protein-Protein-Wechselwirkungen und die Kinetik bei DNA-Läsionen

Local microirradiation with lasers represents a useful tool for studies of DNA-repair-related processes in live cells. Here, we describe a methodological ...

advanced-confocal-microscopy-techniques-to-study-protein-protein

Research

JoVE Journal

Biology

10.9K Aufrufe.  Institute of Biophysics of the Czech Academy of Sciences. Laser Microirradiation ist ein nützliches Werkzeug für Studien zur DNA-Reparatur in lebenden Zellen. Ein methodischer Ansatz für die Nutzung der UVA Laser induzieren verschiedene DNA-Läsionen wird angezeigt. Wir haben eine Methode zur lokalen Microirradiation optimiert, die den normalen Zellzyklus unterhält; so fahren Sie bestrahlte Zellen durch Mitose.

Serie: Advanced Confocal Microscopy Techniques to Study Protein-protein Interactions and Kinetics at DNA Lesions

Imaging Protein-protein Interactions in vivo

Protein-protein interactions are a hallmark of all essential cellular processes. However, many of these interactions are transient, or energetically weak, preventing their identification and analysis through traditional biochemical methods such as co-immunoprecipitation. In this regard, the genetically encodable fluorescent proteins (GFP, RFP, etc.) and their associated overlapping fluorescence spectrum have revolutionized our ability to monitor weak interactions in vivo using F&ouml;rster resonance energy transfer (FRET)1-3. Here, we detail our use of a FRET-based proximity assay for monitoring receptor-receptor interactions on the endothelial cell surface.

Imaging Protein-protein Interactions in vivo

This protocol describes how to image protein-protein interactions using a FRET-based proximity assay.

Imaging Protein-Protein-Wechselwirkungen In vivo</em

Protein-protein interactions are a hallmark of all essential cellular processes. However, many of these interactions are transient, or energetically weak, ...

Forschung

Biologie

Fluorescence-based Measurement of Store-operated Calcium Entry in Live Cells: from Cultured Cancer Cell to Skeletal Muscle Fiber

Store operated Ca2+ entry (SOCE), earlier termed capacitative Ca2+ entry, is a tightly regulated mechanism for influx of extracellular Ca2+ into cells to replenish depleted endoplasmic reticulum (ER) or sarcoplasmic reticulum (SR) Ca2+ stores1,2. Since Ca2+ is a ubiquitous second messenger, it is not surprising to see that SOCE plays important roles in a variety of cellular processes, including proliferation, apoptosis, gene transcription and motility. Due to its wide occurrence in nearly all cell types, including epithelial cells and skeletal muscles, this pathway has received great interest3,4. However, the heterogeneity of SOCE characteristics in different cell types and the physiological function are still not clear5-7.
The functional channel properties of SOCE can be revealed by patch-clamp studies, whereas a large body of knowledge about this pathway has been gained by fluorescence-based intracellular Ca2+ measurements because of its convenience and feasibility for high-throughput screening. The objective of this report is to summarize a few fluorescence-based methods to measure the activation of SOCE in monolayer cells, suspended cells and muscle fibers5,8-10. The most commonly used of these fluorescence methods is to directly monitor the dynamics of intracellular Ca2+ using the ratio of F340nm and F380nm (510 nm for emission wavelength) of the ratiometric Ca2+ indicator Fura-2. To isolate the activity of unidirectional SOCE from intracellular Ca2+ release and Ca2+ extrusion, a Mn2+ quenching assay is frequently used. Mn2+ is known to be able to permeate into cells via SOCE while it is impervious to the surface membrane extrusion processes or to ER uptake by Ca2+ pumps due to its very high affinity with Fura-2. As a result, the quenching of Fura-2 fluorescence induced by the entry of extracellular Mn2+ into the cells represents a measurement of activity of SOCE9. Ratiometric measurement and the Mn+2 quenching assays can be performed on a cuvette-based spectrofluorometer in a cell population mode or in a microscope-based system to visualize single cells. The advantage of single cell measurements is that individual cells subjected to gene manipulations can be selected using GFP or RFP reporters, allowing studies in genetically modified or mutated cells. The spatiotemporal characteristics of SOCE in structurally specialized skeletal muscle can be achieved in skinned muscle fibers by simultaneously monitoring the fluorescence of two low affinity Ca2+ indicators targeted to specific compartments of the muscle fiber, such as Fluo-5N in the SR and Rhod-5N in the transverse tubules9,11,12.

The extent of store-operated Ca2+ entry (SOCE) can be monitored using fluorescent Ca2+ indicators. Mn2+ quenching of such indicators assays SOCE in cultured cells and skeletal muscle fibers. A technique allowing spatial and temporal resolution of SOCE by confocal imaging of mechanically skinned muscle fibers is also described.

Fluoreszenz-basierte Messung von Calcium-Shop-Eintrag in lebenden Zellen: aus kultivierten Krebszelle zu Skelettmuskelfaser

Store operated Ca2+ entry (SOCE), earlier termed capacitative Ca2+ entry, is a tightly regulated mechanism for influx of extracellular Ca2+ into cells to ...

The MultiBac Protein Complex Production Platform at the EMBL

Proteomics research revealed the impressive complexity of eukaryotic proteomes in unprecedented detail. It is now a commonly accepted notion that proteins in cells mostly exist not as isolated entities but exert their biological activity in association with many other proteins, in humans ten or more, forming assembly lines in the cell for most if not all vital functions.1,2 Knowledge of the function and architecture of these multiprotein assemblies requires their provision in superior quality and sufficient quantity for detailed analysis. The paucity of many protein complexes in cells, in particular in eukaryotes, prohibits their extraction from native sources, and necessitates recombinant production. The baculovirus expression vector system (BEVS) has proven to be particularly useful for producing eukaryotic proteins, the activity of which often relies on post-translational processing that other commonly used expression systems often cannot support.3 BEVS use a recombinant baculovirus into which the gene of interest was inserted to infect insect cell cultures which in turn produce the protein of choice. MultiBac is a BEVS that has been particularly tailored for the production of eukaryotic protein complexes that contain many subunits.4 A vital prerequisite for efficient production of proteins and their complexes are robust protocols for all steps involved in an expression experiment that ideally can be implemented as standard operating procedures (SOPs) and followed also by non-specialist users with comparative ease. The MultiBac platform at the European Molecular Biology Laboratory (EMBL) uses SOPs for all steps involved in a multiprotein complex expression experiment, starting from insertion of the genes into an engineered baculoviral genome optimized for heterologous protein production properties to small-scale analysis of the protein specimens produced.5-8 The platform is installed in an open-access mode at EMBL Grenoble and has supported many scientists from academia and industry to accelerate protein complex research projects.

Protein complexes catalyze key cellular functions. Detailed functional and structural characterization of many essential complexes requires recombinant production. MultiBac is a baculovirus/insect cell system particularly tailored for expressing eukaryotic proteins and their complexes. MultiBac was implemented as an open-access platform, and standard operating procedures developed to maximize its utility.

Die MultiBac Protein Complex Produktion Platform am EMBL

Proteomics  research revealed the impressive complexity of eukaryotic proteomes in  unprecedented detail. It is now a commonly accepted notion that ...

Flow Cytometric Analysis of Bimolecular Fluorescence Complementation: A High Throughput Quantitative Method to Study Protein-protein Interaction

Among methods to study protein-protein interaction inside cells, Bimolecular Fluorescence Complementation (BiFC) is relatively simple and sensitive. BiFC is based on the production of fluorescence using two non-fluorescent fragments of a fluorescent protein (Venus, a Yellow Fluorescent Protein variant, is used here). Non-fluorescent Venus fragments (VN and VC) are fused to two interacting proteins (in this case, AKAP-Lbc and PDE4D3), yielding fluorescence due to VN-AKAP-Lbc-VC-PDE4D3 interaction and the formation of a functional fluorescent protein inside cells.
BiFC provides information on the subcellular localization of protein complexes and the strength of protein interactions based on fluorescence intensity. However, BiFC analysis using microscopy to quantify the strength of protein-protein interaction is time-consuming and somewhat subjective due to heterogeneity in protein expression and interaction. By coupling flow cytometric analysis with BiFC methodology, the fluorescent BiFC protein-protein interaction signal can be accurately measured for a large quantity of cells in a short time. Here, we demonstrate an application of this methodology to map regions in PDE4D3 that are required for the interaction with AKAP-Lbc. This high throughput methodology can be applied to screening factors that regulate protein-protein interaction.

Flow cytometric analysis of Bimolecular Fluorescence Complementation provides a high throughput quantitative method to study protein-protein interaction. This methodology can be applied to mapping protein binding sites and for screening factors that regulate protein-protein interaction.

Durchflusszytometrieanalyse bimolekularer Fluorescence Komplementierung: A High Throughput Quantitative Methode zur Protein-Protein Interaction Study

Among methods to study protein-protein interaction inside cells, Bimolecular Fluorescence Complementation (BiFC) is relatively simple and sensitive. BiFC ...

Analyzing Craniofacial Morphogenesis in Zebrafish Using 4D Confocal Microscopy

Time-lapse imaging is a technique that allows for the direct observation of the process of morphogenesis, or the generation of shape. Due to their optical clarity and amenability to genetic manipulation, the zebrafish embryo has become a popular model organism with which to perform time-lapse analysis of morphogenesis in living embryos. Confocal imaging of a live zebrafish embryo requires that a tissue of interest is persistently labeled with a fluorescent marker, such as a transgene or injected dye. The process demands that the embryo is anesthetized and held in place in such a way that healthy development proceeds normally. Parameters for imaging must be set to account for three-dimensional growth and to balance the demands of resolving individual cells while getting quick snapshots of development. Our results demonstrate the ability to perform long-term in vivo imaging of fluorescence-labeled zebrafish embryos and to detect varied tissue behaviors in the cranial neural crest that cause craniofacial abnormalities. Developmental delays caused by anesthesia and mounting are minimal, and embryos are unharmed by the process. Time-lapse imaged embryos can be returned to liquid medium and subsequently imaged or fixed at later points in development. With an increasing abundance of transgenic zebrafish lines and well-characterized fate mapping and transplantation techniques, imaging any desired tissue is possible. As such, time-lapse in vivo imaging combines powerfully with zebrafish genetic methods, including analyses of mutant and microinjected embryos.

Time-lapse confocal imaging is a powerful technique useful for characterizing embryonic development. Here, we describe the methodology and characterize craniofacial morphogenesis in wild-type, as well as pdgfra, smad5, and smo mutant embryos.

Analyse Craniofacial Morphogenese in Zebrafisch Mit 4D konfokale Mikroskopie

Time-lapse imaging is a technique that allows for the direct observation of the process of morphogenesis, or the generation of shape. Due to their optical ...

Combining Single-molecule Manipulation and Imaging for the Study of Protein-DNA Interactions

The paper describes the combination of optical tweezers and single molecule fluorescence detection for the study of protein-DNA interaction. The method offers the opportunity of investigating interactions occurring in solution (thus avoiding problems due to closeby surfaces as in other single molecule methods), controlling the DNA extension and tracking interaction dynamics as a function of both mechanical parameters and DNA sequence. The methods for establishing successful optical trapping and nanometer localization of single molecules are illustrated. We illustrate the experimental conditions allowing the study of interaction of lactose repressor (lacI), labeled with Atto532, with a DNA molecule containing specific target sequences (operators) for LacI binding. The method allows the observation of specific interactions at the operators, as well as one-dimensional diffusion of the protein during the process of target search. The method is broadly applicable to the study of protein-DNA interactions but also to molecular motors, where control of the tension applied to the partner track polymer (for example actin or microtubules) is desirable.

Here we describe the instrumentation and methods for detecting single fluorescently-labeled protein molecules interacting with a single DNA molecule suspended between two optically trapped microspheres.

Die Kombination von Einzelmolekül-Imaging und Manipulation für das Studium der Protein-DNA-Wechselwirkungen

The paper describes the combination of optical tweezers and single molecule fluorescence detection for the study of protein-DNA interaction. The method ...

Probing High-density Functional Protein Microarrays to Detect Protein-protein Interactions

High-density functional protein microarrays containing ~4,200 recombinant yeast proteins are examined for kinase protein-protein interactions using an affinity purified yeast kinase fusion protein containing a V5-epitope tag for read-out. Purified kinase is obtained through culture of a yeast strain optimized for high copy protein production harboring a plasmid containing a Kinase-V5 fusion construct under a GAL inducible promoter. The yeast is grown in restrictive media with a neutral carbon source for 6 hr followed by induction with 2% galactose. Next, the culture is harvested and kinase is purified using standard affinity chromatographic techniques to obtain a highly purified protein kinase for use in the assay. The purified kinase is diluted with kinase buffer to an appropriate range for the assay and the protein microarrays are blocked prior to hybridization with the protein microarray. After the hybridization, the arrays are probed with monoclonal V5 antibody to identify proteins bound by the kinase-V5 protein. Finally, the arrays are scanned using a standard microarray scanner, and data is extracted for downstream informatics analysis1,2 to determine a high confidence set of protein interactions for downstream validation in vivo.

Using protein microarrays containing nearly the entire S. cerevisiae proteome is probed for rapid unbiased interrogation of thousands of protein-protein interactions in parallel. This method can be utilized for protein-small molecule, posttranslational modification, and other assays in high-throughput.

Probing hoher Dichte Funktionale Protein-Microarrays, um Protein-Protein Wechselwirkungen erkennen

High-density functional protein microarrays containing ~4,200 recombinant yeast proteins are examined for kinase protein-protein interactions using an ...

Characterization of Calcification Events Using Live Optical and Electron Microscopy Techniques in a Marine Tubeworm

Characterizing the first event of biological production of calcium carbonate requires a combination of microscopy approaches. First, intracellular pH distribution and calcium ions can be observed using live microscopy over time. This allows identification of the life stage and the tissue with the feature of interest for further electron microscopy studies. Life stage and tissues of interest are typically higher in pH and Ca signals. 
Here, using H. elegans, we present a protocol to characterize the presence of calcium carbonate structures in a biological specimen on the scanning electron microscope (SEM), using energy-dispersive X-ray spectroscopy (EDS) to visualize elemental composition, using electron backscatter diffraction (EBSD) to determine the presence of crystalline structures, and using transmission electron microscopy (TEM) to analyze the composition and structure of the material. In this protocol, a focused ion beam (FIB) is used to isolate samples with dimension suitable for TEM analysis. As FIB is a site specific technique, we demonstrate how information from the previous techniques can be used to identify the region of interest, where Ca signals are highest.

We demonstrate the use of various microscopy methods that are useful in observing the calcification of a tubeworm, Hydroides elegans, as well as locating and characterizing the first calcified material. Live microscopy and electron microscopy are used together to provide functional and material information that are important in studying biomineralization.

Charakterisierung von Verkalkungen Events Verwendung von Live-optische und Elektronenmikroskopie-Techniken in einem Marine-Tubeworm

Characterizing the first event of biological production of calcium carbonate requires a combination of microscopy approaches. First, intracellular pH ...

Study of Protein-protein Interactions in Autophagy Research

Protein-protein interactions are important for understanding cellular signaling cascades and identifying novel pathway components and protein dynamics. The majority of cellular activities require physical interactions between proteins. To analyze and map these interactions, various experimental techniques as well as bioinformatics tools were developed. Autophagy is a cellular recycling mechanism that allows the cells to cope with different stressors, including nutrient deprivation, chemicals, and hypoxia. In order to better understand autophagy-related signaling events and to discover novel factors that regulate protein complexes in autophagy, we performed protein-protein interaction screens. Validation of these screening results requires the use of immunofluorescence and immunoprecipitation techniques. In this system, specific autophagy-related protein-protein interactions that we discovered were tested in Neuro2A (N2A) and HEK293T cell lines. Details of the technical procedures used are explained in this visualized experiment paper.

Presented here are two antibody-based protein-protein interaction research techniques: immunofluorescence and immunoprecipitation. These techniques are suitable for studying physical interactions between proteins for the discovery of novel components of cellular signaling pathways and for understanding protein dynamics.

Untersuchung von Protein-Protein-Interaktionen in der Autophagie-Forschung

Protein-protein interactions are important for understanding cellular signaling cascades and identifying novel pathway components and protein dynamics. ...

FLIM-FRET Measurements of Protein-Protein Interactions in Live Bacteria.

Protein-protein interactions (PPIs) control various key processes in cells. Fluorescence lifetime imaging microscopy (FLIM) combined with F&#246;rster resonance energy transfer (FRET) provide accurate information about PPIs in live cells. FLIM-FRET relies on measuring the fluorescence lifetime decay of a FRET donor at each pixel of the FLIM image, providing quantitative and accurate information about PPIs and their spatial cellular organizations. We propose here a detailed protocol for FLIM-FRET measurements that we applied to monitor PPIs in live Pseudomonas aeruginosa in the particular case of two interacting proteins expressed with highly different copy numbers to demonstrate the quality and robustness of the technique at revealing critical features of PPIs. This protocol describes in detail all the necessary steps for PPI characterization - starting from bacterial mutant constructions up to the final analysis using recently developed tools providing advanced visualization possibilities for a straightforward interpretation of complex FLIM-FRET data.

We describe here a protocol to characterize protein-protein interactions between two highly-differently expressed proteins in live Pseudomonas aeruginosa using FLIM-FRET measurements. The protocol includes bacteria strain constructions, bacteria immobilization, imaging and post-imaging data analysis routines.

FLIM-FRET Messungen von Protein-Protein-Wechselwirkungen in lebenden Bakterien.

Protein-protein interactions (PPIs) control various key processes in cells. Fluorescence lifetime imaging microscopy (FLIM) combined with F&#246;rster ...