Name: purification of viral dna for the identification of associated viral and cellular proteins
Uploaded: 2017-08-31T15:00:00
Description: Watch this Scientific Journal Video about Purification of Viral DNA for the Identification of Associated Viral and Cellular Proteins at JoVE.com

We acknowledge Hannah Fox for help in the preparation of this manuscript. This work was supported by the NIH grant R01AI030612.

1. Cell Culture, Viral Infection, and EdC Labeling (Figure 1)
The following protocol involves working with viruses. Please refer to your institution&#39;s bio-safety protocols regarding safe handling of viruses and other biological agents. This protocol was approved by the Institutional Review Board of the University of Pittsburgh.
<ol>
	<li>Trypsinize a confluent 150 cm2 tissue culture flask of MRC-5 cells and transfer the cells to a 600 cm2</su...

<ol>
	<li>Knipe, D. M., Howley, P. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Fields virology. , (2013).</li><li>Engel, E. A., Song, R., Koyuncu, O. O., Enquist, L. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Investigating+the+biology+of+alpha+herpesviruses+with+MS-based+proteomics.">Investigating the biology of alpha herpesviruses with MS-based proteomics.</a> Proteomics. 15, 1943-1956 (2015).</li><li>Wagner, L. M., DeLuca, N. 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M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Proteomics+of+herpes+simplex+virus+infected+cell+protein+27:+association+with+translation+initiation+factors.">Proteomics of herpes simplex virus infected cell protein 27: association with translation initiation factors.</a> Virology. 330, 487-492 (2004).</li><li>Greco, T. M., Diner, B. A., Cristea, I. 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+Impact+of+Mass+Spectrometry-Based+Proteomics+on+Fundamental+Discoveries+in+Virology.">The Impact of Mass Spectrometry-Based Proteomics on Fundamental Discoveries in Virology.</a> Annu Rev Virol. 1, 581-604 (2014).</li><li>Conwell, S. E., White, A. E., Harper, J. W., Knipe, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+TRIM27+as+a+novel+degradation+target+of+herpes+simplex+virus+1+ICP0.">Identification of TRIM27 as a novel degradation target of herpes simplex virus 1 ICP0.</a> J Virol. 89, 220-229 (2015).</li><li>Suk, H., Knipe, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Proteomic+analysis+of+the+herpes+simplex+virus+1+virion+protein+16+transactivator+protein+in+infected+cells.">Proteomic analysis of the herpes simplex virus 1 virion protein 16 transactivator protein in infected cells.</a> Proteomics. 15, 1957-1967 (2015).</li><li>Balasubramanian, N., Bai, P., Buchek, G., Korza, G., Weller, S. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Physical+interaction+between+the+herpes+simplex+virus+type+1+exonuclease,+UL12,+and+the+DNA+double-strand+break-sensing+MRN+complex.">Physical interaction between the herpes simplex virus type 1 exonuclease, UL12, and the DNA double-strand break-sensing MRN complex.</a> J Virol. 84, 12504-12514 (2010).</li><li>Sampath, P., Deluca, N. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Binding+of+ICP4,+TATA-binding+protein,+and+RNA+polymerase+II+to+herpes+simplex+virus+type+1+immediate-early,+early,+and+late+promoters+in+virus-infected+cells.">Binding of ICP4, TATA-binding protein, and RNA polymerase II to herpes simplex virus type 1 immediate-early, early, and late promoters in virus-infected cells.</a> J Virol. 82, 2339-2349 (2008).</li><li>Amelio, A. L., McAnany, P. K., Bloom, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+chromatin+insulator-like+element+in+the+herpes+simplex+virus+type+1+latency-associated+transcript+region+binds+CCCTC-binding+factor+and+displays+enhancer-blocking+and+silencing+activities.">A chromatin insulator-like element in the herpes simplex virus type 1 latency-associated transcript region binds CCCTC-binding factor and displays enhancer-blocking and silencing activities.</a> J Virol. 80, 2358-2368 (2006).</li><li>Cliffe, A. R., Knipe, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Herpes+simplex+virus+ICP0+promotes+both+histone+removal+and+acetylation+on+viral+DNA+during+lytic+infection.">Herpes simplex virus ICP0 promotes both histone removal and acetylation on viral DNA during lytic infection.</a> J Virol. 82, 12030-12038 (2008).</li><li>Herrera, F. J., Triezenberg, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=VP16-dependent+association+of+chromatin-modifying+coactivators+and+underrepresentation+of+histones+at+immediate-early+gene+promoters+during+herpes+simplex+virus+infection.">VP16-dependent association of chromatin-modifying coactivators and underrepresentation of histones at immediate-early gene promoters during herpes simplex virus infection.</a> J Virol. 78, 9689-9696 (2004).</li><li>Kent, J. R., 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=During+lytic+infection+herpes+simplex+virus+type+1+is+associated+with+histones+bearing+modifications+that+correlate+with+active+transcription.">During lytic infection herpes simplex virus type 1 is associated with histones bearing modifications that correlate with active transcription.</a> J Virol. 78, 10178-10186 (2004).</li><li>Oh, J., Fraser, N. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temporal+association+of+the+herpes+simplex+virus+genome+with+histone+proteins+during+a+lytic+infection.">Temporal association of the herpes simplex virus genome with histone proteins during a lytic infection.</a> J Virol. 82, 3530-3537 (2008).</li><li>Catez, F., 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=HSV-1+genome+subnuclear+positioning+and+associations+with+host-cell+PML-NBs+and+centromeres+regulate+LAT+locus+transcription+during+latency+in+neurons.">HSV-1 genome subnuclear positioning and associations with host-cell PML-NBs and centromeres regulate LAT locus transcription during latency in neurons.</a> PLoS Pathog. 8, e1002852 (2012).</li><li>Everett, R. D., Murray, J., Orr, A., Preston, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Herpes+simplex+virus+type+1+genomes+are+associated+with+ND10+nuclear+substructures+in+quiescently+infected+human+fibroblasts.">Herpes simplex virus type 1 genomes are associated with ND10 nuclear substructures in quiescently infected human fibroblasts.</a> J Virol. 81, 10991-11004 (2007).</li><li>Tang, Q., 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+of+minimum+herpes+simplex+virus+type+1+components+necessary+to+localize+transcriptionally+active+DNA+to+ND10.">Determination of minimum herpes simplex virus type 1 components necessary to localize transcriptionally active DNA to ND10.</a> J Virol. 77, 5821-5828 (2003).</li><li>Ishov, A. M., Maul, G. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+periphery+of+nuclear+domain+10+(ND10)+as+site+of+DNA+virus+deposition.">The periphery of nuclear domain 10 (ND10) as site of DNA virus deposition.</a> J Cell Biol. 134, 815-826 (1996).</li><li>Maroui, M. 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=Latency+Entry+of+Herpes+Simplex+Virus+1+Is+Determined+by+the+Interaction+of+Its+Genome+with+the+Nuclear+Environment.">Latency Entry of Herpes Simplex Virus 1 Is Determined by the Interaction of Its Genome with the Nuclear Environment.</a> PLoS Pathog. 12, e1005834 (2016).</li><li>Sirbu, B. M., Couch, F. B., Cortez, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Monitoring+the+spatiotemporal+dynamics+of+proteins+at+replication+forks+and+in+assembled+chromatin+using+isolation+of+proteins+on+nascent+DNA.">Monitoring the spatiotemporal dynamics of proteins at replication forks and in assembled chromatin using isolation of proteins on nascent DNA.</a> Nat Protoc. 7, 594-605 (2012).</li><li>Leung, K. H., Abou El Hassan, M., Bremner, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+rapid+and+efficient+method+to+purify+proteins+at+replication+forks+under+native+conditions.">A rapid and efficient method to purify proteins at replication forks under native conditions.</a> BioTechniques. 55, 204-206 (2013).</li><li>Hobbs, W. E., DeLuca, N. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Perturbation+of+cell+cycle+progression+and+cellular+gene+expression+as+a+function+of+herpes+simplex+virus+ICP0.">Perturbation of cell cycle progression and cellular gene expression as a function of herpes simplex virus ICP0.</a> J Virol. 73, 8245-8255 (1999).</li><li>Lomonte, P., Everett, R. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Herpes+simplex+virus+type+1+immediate-early+protein+Vmw110+inhibits+progression+of+cells+through+mitosis+and+from+G(1)+into+S+phase+of+the+cell+cycle.">Herpes simplex virus type 1 immediate-early protein Vmw110 inhibits progression of cells through mitosis and from G(1) into S phase of the cell cycle.</a> J Virol. 73, 9456-9467 (1999).</li><li>Dembowski, J. A., DeLuca, N. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selective+recruitment+of+nuclear+factors+to+productively+replicating+herpes+simplex+virus+genomes.">Selective recruitment of nuclear factors to productively replicating herpes simplex virus genomes.</a> PLoS Pathog. 11, e1004939 (2015).</li><li>Dembowski, J. A., Dremel, S. E., DeLuca, N. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Replication-Coupled+Recruitment+of+Viral+and+Cellular+Factors+to+Herpes+Simplex+Virus+Type+1+Replication+Forks+for+the+Maintenance+and+Expression+of+Viral+Genomes.">Replication-Coupled Recruitment of Viral and Cellular Factors to Herpes Simplex Virus Type 1 Replication Forks for the Maintenance and Expression of Viral Genomes.</a> PLoS Pathog. 13, e1006166 (2017).</li><li>Bjornberg, O., Nyman, P. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+dUTPases+from+herpes+simplex+virus+type+1+and+mouse+mammary+tumour+virus+are+less+specific+than+the+Escherichia+coli+enzyme.">The dUTPases from herpes simplex virus type 1 and mouse mammary tumour virus are less specific than the Escherichia coli enzyme.</a> J Gen Virol. 77 (Pt 12), 3107-3111 (1996).</li><li>Chiou, S. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=DNA-+and+protein-scission+activities+of+ascorbate+in+the+presence+of+copper+ion+and+a+copper-peptide+complex.">DNA- and protein-scission activities of ascorbate in the presence of copper ion and a copper-peptide complex.</a> J Biochem. 94, 1259-1267 (1983).</li><li>Kennedy, D. 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=Cellular+consequences+of+copper+complexes+used+to+catalyze+bioorthogonal+click+reactions.">Cellular consequences of copper complexes used to catalyze bioorthogonal click reactions.</a> J Am Chem Soc. 133, 17993-18001 (2011).</li><li>Snel, B., Lehmann, G., Bork, P., Huynen, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=STRING:+a+web-server+to+retrieve+and+display+the+repeatedly+occurring+neighbourhood+of+a+gene.">STRING: a web-server to retrieve and display the repeatedly occurring neighbourhood of a gene.</a> Nucleic Acids Res. 28, 3442-3444 (2000).</li></ol>

This protocol includes multiple steps which, if not followed carefully, can result in significantly reduced protein yield or contamination with cellular DNA. It is critical that stationary cells are used for all experiments to ensure that cellular DNA is not labeled and purified. This can be confirmed by the absence of cellular DNA polymerases in the protein sample because HSV-1 does not utilize cellular DNA polymerase for genome synthesis. During EdC labeling and nuclei harvesting steps, samples should be staggered to e...

Viruses have a limited capacity to carry out essential functions and therefore depend on host factors to facilitate critical aspects of infection including viral gene expression, replication, repair, recombination, and transport. The activities of these host factors are often augmented by virally encoded proteins. In addition, viruses must avoid detection and interference by cellular responses to viral infection. Therefore, virus host interactions dictate the outcome of infection. Of paramount importance is understanding how viruses alter the cellular environment to adapt the cellular machinery to facilitate viral processes. Of particular interest is identifying which factors and processes act on viral genomes throughout the infectious cycle.
Herpes simplex virus type 1 (HSV-1) is a double stranded DNA virus that infects a substantial proportion of the human population. Within the first hour of infection, the viral genome enters the nucleus, where an ordered cascade of viral gene expression ensues in coordination with viral DNA (vDNA) replication1. In the nucleus, genomes are subject to epigenetic regulation, undergo repair and recombination, and are packaged into capsids, such that the first progeny virions are produced within less than six hours. The comprehensive evaluation of viral genome associated proteins throughout the course of infection will lay the groundwork to investigate the molecular details of processes that act on viral genomes, and will provide insight into which viral and cellular factors are involved in various stages of infection.
Previous methods for the investigation of host factors involved in viral infection include affinity purification of viral proteins for the analysis of associated cellular proteins2,3,4,5,6,7,8,9. These assays have been instrumental for the identification of cellular factors involved in host antiviral responses, as well as viral chromatin modification, gene expression, and DNA repair. However, it is difficult to ascertain whether interactions depend on the association with vDNA, and proteomics only provide insight into interactions that occur as a function of a specific viral factor. Chromatin immunoprecipitation (ChIP) has been used to identify where specific viral and cellular proteins bind to viral genomes10,11,12,13,14,15 and fluorescent in situ hybridization (FISH) combined with immunocytochemistry has enabled the visualization of cellular factors that colocalize with vDNA16,17,18,19,20. These assays allow for spatial and temporal analysis. However, limitations include the need for highly specific antibodies, limited sensitivity, and the need for previous insight into virus host interactions. We therefore developed a method based on iPOND (isolation of proteins on nascent DNA)21 and aniPOND (accelerated native iPOND)22 to selectively label and purify vDNA from infected cells for the unbiased identification of viral genome associated proteins by mass spectrometry. iPOND has been instrumental for the investigation of cellular replication fork dynamics.
For the selective purification of viral genomes from infected cells, replicating vDNA is labeled with ethynyl modified nucleosides, 5-ethynyl-2&#180;-deoxyuridine (EdU) or 5-ethynyl-2&#180;-deoxycytidine (EdC) (Figure 1), followed by covalent conjugation to biotin azide via click chemistry to facilitate single step purification of viral genomes and associated proteins on streptavidin-coated beads (Figure 2B). Importantly, infections are carried out in stationary cells, which are not engaged in cellular DNA replication to enable specific labeling of vDNA. Furthermore, HSV-1 infection causes cell cycle arrest and inhibits cellular DNA replication23,24. Virus can be prelabeled before infection for the analysis of proteins associated with incoming viral genomes (Figure 1A) or labeled during DNA replication for the analysis of proteins associated with newly synthesized vDNA (Figure 1B)25. Furthermore, pulse chase analysis can be used to investigate the nature of proteins associated with viral replication forks (Figure 1C)26. In addition, ethynyl-modified vDNA can be covalently conjugated to a fluorophore for spatial investigation of protein dynamics (Figure 2A and Figure 3). Imaging allows for the direct visualization of vDNA and is a complimentary approach for the validation of vDNA-protein interactions, and can be adapted to track viral genomes throughout infection. We anticipate that these approaches could be further modified to study any aspect of herpesviral infection, including latency and reactivation, and to study other DNA viruses. Moreover, labeling with 5-ethynyl uridine (EU) could allow for the analysis of RNA viral genomes.

<table border="0" cellpadding="0" cellspacing="0" width="1930">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">MRC-5 cells</td>
			<td style="width:197px;">ATCC</td>
			<td style="width:101px;">CCL-171</td>
			<td style="width:1215px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Fetal Bovine Serum (FBS)</td>
			<td style="width:197px;">Gibco</td>
			<td style="width:101px;">26140-179</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Dulbecco&#39;s Modified Eagle Medium (DMEM)</td>
			<td style="width:197px;">Gibco</td>
			<td style="width:101px;">12800-082</td>
			<td>substituted with 10% FBS, 2 mM L-glutamine, 12 mM&#160; (for growth in flasks) or 30 mM (for growth in dishes) sodium-bicarbinate</td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:419px;">600 cm2 tissue culture dish</td>
			<td style="width:197px;">Thermo Fisher Scientific</td>
			<td align="right" style="width:101px;">166508</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Tris Buffered Saline (TBS), pH 7.4</td>
			<td style="width:197px;"></td>
			<td style="width:101px;"></td>
			<td>137 mM NaCl, 5 mM KCl, 491 mM MgCl, 680 mM CaCl, 25.1 mM Tricine</td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:419px;">HSV-1 stock</td>
			<td style="width:197px;"></td>
			<td style="width:101px;"></td>
			<td>stocks with titers greater than 1x109 PFU/mL work best</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Sephadex G-25&#160; column (PD-10 Desalting Column)</td>
			<td style="width:197px;">GE Healthcare</td>
			<td align="right" style="width:101px;">17085101</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Dimethyl sulfoxide (DMSO)</td>
			<td style="width:197px;">Fisher Scientific</td>
			<td style="width:101px;">D128-1</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">5&#180;-Ethynyl-2&#180;-deoxycytidine (EdC)</td>
			<td style="width:197px;">Sigma-Aldrich</td>
			<td style="width:101px;">T511307</td>
			<td>Dissolve in DMSO to prepare 40 mM stock, aliquot, and store at -20 &#176;C&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">2&#180;-deoxycytidine (deoxyC)</td>
			<td style="width:197px;">Sigma-Aldrich</td>
			<td style="width:101px;">D3897</td>
			<td>Dissolve in water to prepare 40 mM stock, aliquot, and store at -20 &#176;C&#160;</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:419px;">Nuclear Extraction Buffer (NEB)</td>
			<td style="width:197px;"></td>
			<td style="width:101px;"></td>
			<td>prepare fresh (20 mM Hepes pH 7.2, 50 mM NaCl, 3 mM MgCl2, 300 mM Sucrose, 0.5% Igepal)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Cell scraper</td>
			<td style="width:197px;">Bellco glass</td>
			<td style="width:101px;">7731-22000</td>
			<td>Autoclave before use</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Trypan blue solution</td>
			<td style="width:197px;">Sigma-Aldrich</td>
			<td style="width:101px;">T8154</td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:419px;">PBS, pH 7.2 (10x)</td>
			<td style="width:197px;"></td>
			<td style="width:101px;"></td>
			<td>1.37 M NaCl, 27 mM KCl, 100 mM Na2HPO4, 18 mM KH2PO4 (dilute to 1x in sterile water before use)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Copper (II) sulfate pentahydrate (CuSO4-5H2O)</td>
			<td style="width:197px;">Fisher Scientific</td>
			<td style="width:101px;">C489</td>
			<td>Prepare 100 mM stock and store at 4 &#176;C for up to 1 month</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">(+) Sodium L-ascorbate</td>
			<td style="width:197px;">Sigma-Aldrich</td>
			<td style="width:101px;">A4034</td>
			<td>Freshly prepare 100 mM stock and store on ice until use</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Biotin azide</td>
			<td style="width:197px;">Invitrogen</td>
			<td style="width:101px;">B10184</td>
			<td>Prepare 10 mM stock in DMSO, aliquot, and store at -20 &#176;C for up to 1 year&#160;</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:419px;">Click Reaction Mix</td>
			<td style="width:197px;"></td>
			<td style="width:101px;"></td>
			<td>prepare immediately before use by adding reagents in the indicated order (10 mL: 8.8 mL 1x PBS, 200 mL 100 mM CuSO4, 25mL 10 mM Biotin Azide, 1 mL 100 mM sodium ascorbate)&#160;&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">cOmplete Protease Inhibitor Cocktail</td>
			<td style="width:197px;">Roche</td>
			<td align="right" style="width:101px;">11697498001</td>
			<td>Dissolve in 1 mL water to prepare 50x stock, can store at 4 &#176;C for up to 1 week, or directly add 1 pill to 50 mL buffer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">freezing buffer</td>
			<td style="width:197px;"></td>
			<td style="width:101px;"></td>
			<td>prepare fresh (7 mL 100% glycerol, 3 mL NEB, 200 &#956;L 50x protease inhibitor)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Buffer B1</td>
			<td style="width:197px;"></td>
			<td style="width:101px;"></td>
			<td>prepare fresh (25 mM NaCl, 2 mM EDTA, 50 mM Tris-HCl pH 8, 1% Igepal, 1x protease inhibitor)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Buffer B2</td>
			<td style="width:197px;"></td>
			<td style="width:101px;"></td>
			<td>prepare fresh (150 mM NaCl, 2 mM EDTA, 50 mM Tris-HCl pH 8, 0.5% Igepal, 1x protease inhibitor)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Buffer B3</td>
			<td style="width:197px;"></td>
			<td style="width:101px;"></td>
			<td>prepare fresh (150 mM NaCl, 2 mM EDTA, 50 mM Tris-HCl pH 8, 1x protease inhibitor)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Vibra Cell Ultra Sonic Processer equipped with a 3 mm microtip probe</td>
			<td style="width:197px;">Sonics</td>
			<td style="width:101px;">VCX 130</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Cell strainer</td>
			<td style="width:197px;">Falcon</td>
			<td align="right" style="width:101px;">352360</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Dynabeads MyOne Streptavidin T1</td>
			<td style="width:197px;">Life Technologies</td>
			<td align="right" style="width:101px;">65601</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">DynaMag-2 Magnet</td>
			<td style="width:197px;">Life Technologies</td>
			<td style="width:101px;">12321D</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Mini-Tube Rotator</td>
			<td style="width:197px;">Fisher Scientific</td>
			<td style="width:101px;">260750F</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">2X Laemmli sample buffer</td>
			<td style="width:197px;"></td>
			<td style="width:101px;"></td>
			<td>Mix 400 mg of SDS, 2 mL 100% glycerol, 1.25 mL of 1 M Tris (pH 6.8), and 10 mg of bromophenol blue in 8 mL water. Store at 4&#160; &#176;C for up to 6 months. Before use add 1 M DTT to a final concentration of 200 mM.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">cap locks for 1.5 mL tube</td>
			<td style="width:197px;">Fisher Scientific</td>
			<td style="width:101px;">NC9679153</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Standard western blotting reagents</td>
			<td style="width:197px;"></td>
			<td style="width:101px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">NOVEX Colloidal Blue Staining Kit</td>
			<td style="width:197px;">Invitrogen</td>
			<td style="width:101px;">LC6025</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">12-well tissue culture dish</td>
			<td style="width:197px;">Corning</td>
			<td align="right" style="width:101px;">3513</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Coverslips</td>
			<td style="width:197px;">Fisher Scientific</td>
			<td style="width:101px;">12-545-100</td>
			<td>Autoclave before use</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Microscope slides</td>
			<td style="width:197px;">Fisher Scientific</td>
			<td style="width:101px;">12-552-5</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:419px;">16% paraformaldehyde</td>
			<td style="width:197px;">Electron Microscopy Sciences</td>
			<td align="right" style="width:101px;">15710</td>
			<td>dilute to 3.7% in 1x PBS before use</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Bovine serum albumin (BSA)</td>
			<td style="width:197px;">Fisher Scientific</td>
			<td style="width:101px;">BP1605</td>
			<td>prepare 3% in 1x PBS</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Permeabilization buffer (0.5% Triton-X 100)</td>
			<td style="width:197px;">Sigma-Aldrich</td>
			<td style="width:101px;">T8787</td>
			<td>prepare 0.5% Triton-X 100 in 1x PBS</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:419px;">Click reaction cocktail - Click-iT EdU Alexa Fluor 488 Imaging Kit</td>
			<td style="width:197px;">Molecular Probes</td>
			<td style="width:101px;">C10337</td>
			<td>prepare according to manufactorer&#39;s protocol</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Hoechst 33342</td>
			<td style="width:197px;">Life Technologies</td>
			<td style="width:101px;">H1399</td>
			<td>prepare 10 mg/mL in water, can store at 4 &#176;C for up to 1 year</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">mouse anti-ICP8 primary antibody</td>
			<td style="width:197px;">Abcam</td>
			<td style="width:101px;">ab20194</td>
			<td>Use a 1:200 dilution in 1x PBS</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">mouse anti-UL42 primary antibody (2H4)</td>
			<td style="width:197px;">Abcam</td>
			<td style="width:101px;">ab19311</td>
			<td>Use a 1:200 dilution in 1x PBS</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Goat anti-mouse 594-conjugated secondary antibody</td>
			<td style="width:197px;">Life Technologies</td>
			<td style="width:101px;">a11005</td>
			<td>Use a 1:500 dilution in 1x PBS</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Immu-mount</td>
			<td style="width:197px;">Thermo Fisher Scientific</td>
			<td align="right" style="width:101px;">9990402</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">2x SDS-bicarb solution</td>
			<td style="width:197px;"></td>
			<td style="width:101px;"></td>
			<td>2% SDS, 200 mM NaHCO3</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Phenol:chloroform:isoamyl alcohol</td>
			<td style="width:197px;"></td>
			<td style="width:101px;"></td>
			<td>mix 25:24:1 at least 1 day before use, store at 4 &#176;C in the dark</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">chloroform:isoamyl alcohol</td>
			<td style="width:197px;"></td>
			<td style="width:101px;"></td>
			<td>mix 24:1 at least 1 day before use, store at room temperature in the dark</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">10x Tris EDTA (TE), pH 8.0</td>
			<td style="width:197px;"></td>
			<td style="width:101px;"></td>
			<td>100 mM Tris, 10 mM EDTA (dilute to 1x before use)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Qiaquick PCR purification kit</td>
			<td style="width:197px;">Qiagen</td>
			<td align="right" style="width:101px;">28104</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">3 M sodium acetate pH 5.2</td>
			<td style="width:197px;"></td>
			<td style="width:101px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Qubit 2.0 Fluorometer</td>
			<td style="width:197px;">Invitrogen</td>
			<td style="width:101px;">Q32866</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Qubit dsDNA HS Assay Kit</td>
			<td style="width:197px;">Invitrogen</td>
			<td style="width:101px;">Q32851</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Qubit assay tubes</td>
			<td style="width:197px;">Invitrogen</td>
			<td style="width:101px;">Q32856</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Fluorescence microscope equipped with imaging software</td>
			<td style="width:197px;"></td>
			<td style="width:101px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Microcentrifuge for 1.5 mL tubes</td>
			<td style="width:197px;"></td>
			<td style="width:101px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Tabletop centrifuge for 15 and 50 mL tubes</td>
			<td style="width:197px;"></td>
			<td style="width:101px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Cell culture incubator</td>
			<td style="width:197px;"></td>
			<td style="width:101px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Biosafety cabinet</td>
			<td style="width:197px;"></td>
			<td style="width:101px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:419px;">Heat blocks</td>
			<td style="width:197px;"></td>
			<td style="width:101px;"></td>
			<td>65 &#176;C and 95 &#176;C</td>
		</tr>
	</tbody>
</table>

purification of viral dna for the identification of associated viral and cellular proteins

The goal of this protocol is to isolate herpes simplex virus type 1 (HSV-1) DNA from infected cells for the identification of associated viral and cellular proteins by mass spectrometry. Although proteins that interact with viral genomes play major roles in determining the outcome of infection, a comprehensive analysis of viral genome associated proteins was not previously feasible. Here we demonstrate a method that enables the direct purification of HSV-1 genomes from infected cells. Replicating viral DNA is selectively labeled with modified nucleotides that contain an alkyne functional group. Labeled DNA is then specifically and irreversibly tagged via the covalent attachment of biotin azide via a copper(I)-catalyzed azide-alkyne cycloaddition or click reaction. Biotin-tagged DNA is purified on streptavidin-coated beads and associated proteins are eluted and identified by mass spectrometry. This method enables the selective targeting and isolation of HSV-1 replication forks or whole genomes from complex biological environments. Furthermore, adaptation of this approach will allow for the investigation of various aspects of herpesviral infection, as well as the examination of the genomes of other DNA viruses.

The use of click chemistry for the purification of DNA from cells was first accomplished by the iPOND method21. The purpose of iPOND is to purify cellular replication forks for the identification of associated proteins. We have adapted this technique to specifically study vDNA protein interactions during infection. Manipulation of the approach to label viral genomes with EdC (Figure 1), combined with synchronized infections, has allowe...

Watch this Scientific Journal Video about Purification of Viral DNA for the Identification of Associated Viral and Cellular Proteins at JoVE.com

Purification of Viral DNA for the Identification of Associated Viral and Cellular Proteins

The goal of this protocol is to specifically tag and selectively isolate viral DNA from infected cells for the characterization of viral genome associated proteins.

The goal of this protocol is to isolate herpes simplex virus type 1 (HSV-1) DNA from infected cells for the identification of associated viral and ...

Research

JoVE Journal

Immunology and Infection

Isolation of Fidelity Variants of RNA Viruses and Characterization of Virus Mutation Frequency

RNA viruses use RNA dependent RNA polymerases to replicate their genomes. The intrinsically high error rate of these enzymes is a large contributor to the ...

Separation of Single-stranded DNA, Double-stranded DNA and RNA from an Environmental Viral Community Using Hydroxyapatite Chromatography

Viruses, particularly bacteriophages (phages), are the most numerous biological entities on Earth1,2.  Viruses modulate host cell abundance and diversity, ...

Preparation of Viral DNA from Nucleocapsids

Viruses are obligate cellular parasites, and thus the study of their DNA requires isolating viral material away from host cell contaminants and DNA. ...

Production and Titering of Recombinant Adeno-associated Viral Vectors

In recent years recombinant adeno-associated viral vectors (AAV) have become increasingly valuable for in vivo studies in animals, and are also currently ...

A TIRF Microscopy Technique for Real-time, Simultaneous Imaging of the TCR and its Associated Signaling Proteins

Signaling is initiated through the T Cell Receptor (TCR) when it is engaged by antigenic peptide fragments bound by Major Histocompatibility Complex ...

Establishing a Liquid-covered Culture of Polarized Human Airway Epithelial Calu-3 Cells to Study Host Cell Response to Respiratory Pathogens In vitro

Establishing a Liquid-covered Culture of Polarized Human Airway Epithelial Calu-3 Cells to Study Host Cell Response to Respiratory Pathogens In vitro

The  apical and basolateral surfaces of airway epithelial cells demonstrate  directional responses to pathogen exposure in  vivo. Thus, ideal in vitro ...

Phage Phenomics: Physiological Approaches to Characterize Novel Viral Proteins

Current investigations into phage-host interactions are dependent on extrapolating knowledge from (meta)genomes. Interestingly, 60 - 95% of all phage ...

Early Viral Entry Assays for the Identification and Evaluation of Antiviral Compounds

Cell-based systems are useful for discovering antiviral agents. Dissecting the viral life cycle, particularly the early entry stages, allows a mechanistic ...

The Development of Lyophilized Loop-mediated Isothermal Amplification Reagents for the Detection of Coxiella burnetii

The Development of Lyophilized Loop-mediated Isothermal Amplification Reagents for the Detection of Coxiella burnetii

Coxiella burnetii, the agent causing Q fever, is an obligate intracellular bacterium. PCR based diagnostic assays have been developed for detecting C. ...

Measuring Influenza Neuraminidase Inhibition Antibody Titers by Enzyme-linked Lectin Assay

Antibodies to neuraminidase (NA), the second most abundant surface protein on influenza virus, contribute toward protection against influenza. Traditional ...