We thank Alberto Reinders for his work in optimizing the CCMS conditions for P. aeruginosa. We also thank Pablo Manfredifor the annotation of the P. aeruginosa proteins. This work was supported by the Swiss National Science Foundation (SNF) Sinergia grant CRSII3_127433.

1. Lysate Preparation
<ol>
	<li>Grow P. aeruginosa cells in LB to the desired OD. 
	NOTE: For guidance: use &#8776; 100 ml&#160;culture/sample for stationary phase cultures and &#8776; 500 ml cultur /sample for log phase cultures (OD600nm = 0.5).</li>
	<li>Pellet by centrifugation for 20 min at 5,000 x g.</li>
	<li>Resuspend 0.5-1 g of pellet in 1 ml lysis buffer (6.7 mM MES, 6.7 mM HEPES, 200 mM NaCl, 6.7 mM KAc, DDT 1 mM, pH 7.5) and add protease inhibitor (complete mini, EDTA-free) ...

<ol>
	<li>Nesper, J., Reinders, A., Glatter, T., Schmidt, A., Jenal, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+capture+compound+for+the+identification+and+analysis+of+cyclic+di-GMP+binding+proteins.">A novel capture compound for the identification and analysis of cyclic di-GMP binding proteins.</a> J Proteomics. 75, 4874-4878 (2012).</li><li>Hengge, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Principles+of+c-di-GMP+signalling+in+bacteria.">Principles of c-di-GMP signalling in bacteria.</a> Nature reviews. Microbiology. 7, 263-273 (2009).</li><li>Sondermann, H., Shikuma, N. J., Yildiz, F. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=You've+come+a+long+way:+c-di-GMP+signaling.">You've come a long way: c-di-GMP signaling.</a> Curr. Opin. Microbiol. 15, 140-146 (2012).</li><li>Schirmer, T., Jenal, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structural+and+mechanistic+determinants+of+c-di-GMP+signalling.">Structural and mechanistic determinants of c-di-GMP signalling.</a> Nature reviews. Microbiology. 7, 724-735 (2009).</li><li>Furukawa, S., Kuchma, S., O'Toole, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Keeping+their+options+open:+acute+versus+persistent+infections.">Keeping their options open: acute versus persistent infections.</a> J. Bacteriol. 188, 1211-1217 (2006).</li><li>Christen, M., Christen, B., Folcher, M., Schauerte, A., Jenal, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+and+characterization+of+a+cyclic+di-GMP-specific+phosphodiesterase+and+its+allosteric+control+by+GTP.">Identification and characterization of a cyclic di-GMP-specific phosphodiesterase and its allosteric control by GTP.</a> J. Biol. Chem. 280, 30829-30837 (2005).</li><li>Ryan, R. P., Fouhy, Y., Lucey, J. F., Dow, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cyclic+di-GMP+signaling+in+bacteria:+recent+advances+and+new+puzzles.">Cyclic di-GMP signaling in bacteria: recent advances and new puzzles.</a> J. Bacteriol. 188, 8327-8334 (2006).</li><li>Habazettl, J., Allan, M. G., Jenal, U., Grzesiek, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Solution+structure+of+the+PilZ+domain+protein+PA4608+complex+with+cyclic+di-GMP+identifies+charge+clustering+as+molecular+readout.">Solution structure of the PilZ domain protein PA4608 complex with cyclic di-GMP identifies charge clustering as molecular readout.</a> J. Biol. Chem. 286, 14304-14314 (2011).</li><li>Fazli, 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=The+CRP/FNR+family+protein+Bcam1349+is+a+c-di-GMP+effector+that+regulates+biofilm+formation+in+the+respiratory+pathogen+Burkholderia+cenocepacia.">The CRP/FNR family protein Bcam1349 is a c-di-GMP effector that regulates biofilm formation in the respiratory pathogen Burkholderia cenocepacia.</a> Molecular Microbiology. 82, 327-341 (2011).</li><li>Hickman, J. W., Harwood, C. S. <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+FleQ+from+Pseudomonas+aeruginosa+as+a+c-di-GMP-responsive+transcription+factor.">Identification of FleQ from Pseudomonas aeruginosa as a c-di-GMP-responsive transcription factor.</a> Molecular Microbiology. 69, 376-389 (2008).</li><li>Sudarsan, N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Riboswitches+in+eubacteria+sense+the+second+messenger+cyclic+di-GMP.">Riboswitches in eubacteria sense the second messenger cyclic di-GMP.</a> Science. 321, 411-413 (2008).</li><li>Lenz, 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=Profiling+of+methyltransferases+and+other+S-adenosyl-L-homocysteine-binding+Proteins+by+Capture+Compound+Mass+Spectrometry+(CCMS).">Profiling of methyltransferases and other S-adenosyl-L-homocysteine-binding Proteins by Capture Compound Mass Spectrometry (CCMS).</a> J Vis Exp. , (2010).</li><li>K&#246;ster, H., 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=Capture+compound+mass+spectrometry:+a+technology+for+the+investigation+of+small+molecule+protein+interactions.">Capture compound mass spectrometry: a technology for the investigation of small molecule protein interactions.</a> Assay Drug Dev Technol. 5, 381-390 (2007).</li><li>D&#252;vel, 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=A+chemical+proteomics+approach+to+identify+c-di-GMP+binding+proteins+in+Pseudomonas+aeruginosa.">A chemical proteomics approach to identify c-di-GMP binding proteins in Pseudomonas aeruginosa.</a> Journal of Microbiological Methods. 88, 229-236 (2012).</li><li>Christen, 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=Allosteric+control+of+cyclic+di-GMP+signaling.">Allosteric control of cyclic di-GMP signaling.</a> J. Biol. Chem. 281, 32015-32024 (2006).</li><li>Balasubramanian, D., Mathee, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+transcriptome+analyses+of+Pseudomonas+aeruginosa.">Comparative transcriptome analyses of Pseudomonas aeruginosa.</a> Human genomics. 3, 349-361 (2009).</li><li>Smyth, G. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Linear+models+and+empirical+bayes+methods+for+assessing+differential+expression+in+microarray+experiments.">Linear models and empirical bayes methods for assessing differential expression in microarray experiments.</a> Stat Appl Genet Mol Biol. 3 (3), (2004).</li><li>Baraquet, C., Harwood, C. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cyclic+diguanosine+monophosphate+represses+bacterial+flagella+synthesis+by+interacting+with+the+Walker+A+motif+of+the+enhancer-binding+protein+FleQ.">Cyclic diguanosine monophosphate represses bacterial flagella synthesis by interacting with the Walker A motif of the enhancer-binding protein FleQ.</a> Proc. Natl. Acad. Sci. U.S.A. 110, 18478-18483 (2013).</li><li>Nesper, J., Reinders, A., Glatter, T., Schmidt, A., Jenal, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+capture+compound+for+the+identification+and+analysis+of+cyclic+di-GMP+binding+proteins.">A novel capture compound for the identification and analysis of cyclic di-GMP binding proteins.</a> J Proteomics. 75, 4874-4878 (2012).</li><li>Roelofs, K. G., Wang, J., Sintim, H. O., Lee, V. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+radial+capillary+action+of+ligand+assay+for+high-throughput+detection+of+protein-metabolite+interactions.">Differential radial capillary action of ligand assay for high-throughput detection of protein-metabolite interactions.</a> Proc. Natl. Acad. Sci. U.S.A. 108, 15528-15533 (2011).</li><li>DeSantis, K., Reed, A., Rahhal, R., Reinking, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+differential+scanning+fluorimetry+as+a+high-throughput+assay+to+identify+nuclear+receptor+ligands.">Use of differential scanning fluorimetry as a high-throughput assay to identify nuclear receptor ligands.</a> Nuclear receptor signaling. 10, e002 (2012).</li><li>Seidel, S. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microscale+thermophoresis+quantifies+biomolecular+interactions+under+previously+challenging+conditions.">Microscale thermophoresis quantifies biomolecular interactions under previously challenging conditions.</a> Methods. 59, 301-315 (2013).</li><li>Merighi, M., Lee, V. T., Hyodo, M., Hayakawa, Y., Lory, 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+second+messenger+bis-(3&#8216;-5&#8217;)-cyclic-GMP+and+its+PilZ+domain-containing+receptor+Alg44+are+required+for+alginate+biosynthesis+in+Pseudomonas+aeruginosa.">The second messenger bis-(3&#8216;-5&#8217;)-cyclic-GMP and its PilZ domain-containing receptor Alg44 are required for alginate biosynthesis in Pseudomonas aeruginosa.</a> Molecular Microbiology. 65, 876-895 (2007).</li><li>Qi, Y., 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=Binding+of+cyclic+diguanylate+in+the+non-catalytic+EAL+domain+of+FimX+induces+a+long-range+conformational+change.">Binding of cyclic diguanylate in the non-catalytic EAL domain of FimX induces a long-range conformational change.</a> J. Biol. Chem. 286, 2910-2917 (2011).</li></ol>

The authors have nothing to disclose.

Special care should be taken at several steps of the protocol. The protein concentration is a critical parameter with a concentration of 10 mg/ml being difficult to reach when cells are grown under specific growth conditions (e.g. biofilms or small colony variants). Thus, the pellet resuspension should be performed in a low volume of lysis buffer. Protein concentrations can be decreased to 8 mg/ml. Compared to the method published by Nesper et al.1, we added various nucleotides to the capture...

c-di-GMP is a key second messenger used by most bacteria to control various aspects of their growth and behavior. For instance, c-di-GMP regulates cell cycle progression, motility and the expression of exopolysaccharides and surface adhesins2-4. Through the coordination of such processes c-di-GMP promotes biofilm formation, a process which is associated with chronic infections of a range of pathogenic bacteria5. c-di-GMP is synthetized by enzymes called diguanylate cyclases (DGCs) that harbor a catalytic GGDEF domain4. Some DGCs possess an inhibitory site that down regulates the cyclase activity upon c-di-GMP binding. The degradation of c-di-GMP is catalyzed by two distinct classes of phosphodiesterases (PDEs) harboring either a catalytic EAL or HD-GYP domain6,7.
The majority of the known effector proteins that directly bind c-di-GMP belong to one of only three classes of proteins: catalytically inactive GGDEF or EAL domains and PilZ domains, small molecular switches that undergo conformational changes upon c-di-GMP binding8. DGCs, PDEs and PilZ proteins are well characterized and their domains can be predicted in silico relatively safely. A particular interest is now focused on the identification of new classes of c-di-GMP effectors. Some c-di-GMP effectors with different binding motifs were described recently such as the CRP/FNR protein family Bcam1349 in Burkholderia cenocepacia or the transcriptional regulator FleQ in P. aeruginosa9,10. In addition, c-di-GMP-specific riboswitches were recently identified and shown to control gene expression in a c-di-GMP-dependent manner11. The c-di-GMP binding motifs of different effectors are only poorly conserved making bioinformatic predictions of such proteins difficult. To address this issue, we developed a biochemical method, which is based on the use of a c-di-GMP specific Capture Compound combined with mass spectrometry 1,12,13.
We have recently engineered a novel trivalent c-di-GMP Capture Compound (cdG-CC, Figure 1)1. This chemical scaffold is composed of: 1) a c-di-GMP moiety used as bait to capture c-di-GMP binding proteins, 2) a UV-photoactivatable reactive group used to cross link the cdG-CC to the bound proteins and 3) a biotin to isolate the captured proteins using streptavidin-coated magnetic beads. The cdG-CC can be used to directly and specifically capture c-di-GMP effectors from complex mixture of macromolecules as cell lysates. Capture Compound based and chemical proteomics based approaches have previously been reported to be applicable to a wide range of organisms, e.g. Caulobacter crescentus, Salmonella enterica serovar typhimurium and P. aeruginosa1,14.
In this methodological paper, we provide an in depth description of the CCMS procedure using extracts of P. aeruginosa as an example. This study establishes CCMS as a powerful and versatile tool to biochemically identify novel components involved in small molecule signaling.

<table border="0" cellpadding="0" cellspacing="0" width="1179">
	<tbody>
		<tr height="20">
			<td height="20" style="height:20px;width:236px;">caproBox</td>
			<td style="width:223px;">caprotec bioanalytics</td>
			<td style="width:207px;">1-5010-001 (220 V)</td>
			<td style="width:515px;">UV lamps coupled to a cooling 96-plate cooling block, for the photoactivation</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:236px;">caproMag</td>
			<td style="width:223px;">caprotec bioanalytics</td>
			<td style="width:207px;">included in the CCMS Starter Kit</td>
			<td style="width:515px;">For easy handling of magnetic particles without pipetting</td>
		</tr>
		<tr height="60">
			<td height="60" style="height:60px;width:236px;">c-di-GMP caproKit</td>
			<td style="width:223px;">caprotec bioanalytics</td>
			<td style="width:207px;">upon request</td>
			<td style="width:515px;">The kit contains the c-di-GMP-capture compound, c-di-GMP (for the competition control), streptavidin coated magnetic beads, capture buffer, and washing buffer</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:236px;">Disposable PD-10 Desalting Columns</td>
			<td style="width:223px;">GE Healthcare</td>
			<td style="width:207px;">17-0851-01&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:236px;">12-tube PCR strips</td>
			<td style="width:223px;">Thermo Scientific</td>
			<td style="width:207px;">AB-1114</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">UIS250v sonicator with VialTweeter</td>
			<td style="width:223px;">Hielscher ultrasound technology</td>
			<td style="width:207px;">UIS250v and VialTweeter</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:236px;">Miniature French Pressure Cell</td>
			<td style="width:223px;">Thermo Electron Corporation</td>
			<td style="width:207px;">FA-003</td>
			<td></td>
		</tr>
	</tbody>
</table>

capture compound mass spectrometry - a powerful tool to identify novel c-di-gmp effector proteins

Considerable progress has been made during the last decade towards the identification and characterization of enzymes involved in the synthesis (diguanylate cyclases) and degradation (phosphodiesterases) of the second messenger c-di-GMP. In contrast, little information is available regarding the molecular mechanisms and cellular components through which this signaling molecule regulates a diverse range of cellular processes. Most of the known effector proteins belong to the PilZ family or are degenerated diguanylate cyclases or phosphodiesterases that have given up on catalysis and have adopted effector function. Thus, to better define the cellular c-di-GMP network in a wide range of bacteria experimental methods are required to identify and validate novel effectors for which reliable in silico predictions fail.
We have recently developed a novel Capture Compound Mass Spectrometry (CCMS) based technology as a powerful tool to biochemically identify and characterize c-di-GMP binding proteins. This technique has previously been reported to be applicable to a wide range of organisms1. Here we give a detailed description of the protocol that we utilize to probe such signaling components. As an example, we use Pseudomonas aeruginosa, an opportunistic pathogen in which c-di-GMP plays a critical role in virulence and biofilm control. CCMS identified 74% (38/51) of the known or predicted components of the c-di-GMP network. This study explains the CCMS procedure in detail, and establishes it as a powerful and versatile tool to identify novel components involved in small molecule signaling.

To identify novel c-di-GMP effectors in P. aeruginosa we systematically used CCMS to analyze the soluble and membrane fractions of P. aeruginosa strain PAO1 from a log phase culture (OD600 = 0.5). Here we summarize and discuss representative results of this fishing expedition. Four independent biological replicas were used. For each experiment two different cdG-CC concentrations were used (5 &#181;M and 10 &#181;M). To probe for specificity, experiments were carried out in the presence or abs...

Watch this Scientific Journal Video about Capture Compound Mass Spectrometry - A Powerful Tool to Identify Novel c-di-GMP Effector Proteins at JoVE.com

Capture Compound Mass Spectrometry - A Powerful Tool to Identify Novel c-di-GMP Effector Proteins

The ubiquitous second messenger c-di-GMP controls growth and behavior of many bacteria. We have developed a novel Capture Compound Mass Spectrometry based technology to biochemically identify and characterize c-di-GMP binding proteins in virtually any bacterial species.

Considerable progress has been made during the last decade towards the identification and characterization of enzymes involved in the synthesis ...

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11.5K ビュー.  Biozentrum of the University of Basel. The ubiquitous second messenger c-di-GMP controls growth and behavior of many bacteria. We have developed a novel Capture Compound Mass Spectrometry based technology to biochemically identify and characterize c-di-GMP binding proteins in virtually any bacterial species.