Name: cell aggregation assays to evaluate the binding of the drosophila notch with trans-ligands and its inhibition by cis-ligands
Uploaded: 2018-01-02T14:00:00
Description: Watch this Scientific Journal Video about Cell Aggregation Assays to Evaluate the Binding of the Drosophila Notch with Trans-Ligands and its Inhibition by Cis-Ligands at JoVE.com

The authors acknowledge support from the NIH/NIGMS (R01GM084135 to HJN) and Mizutani Foundation for Glycoscience (grant #110071 to HJN), and are grateful to Tom V. Lee for discussions and suggestions on the assays, and Spyros Artavanis-Tsakonas, Hugo Bellen, Robert Fleming, Ken Irvine and The Drosophila Genomics Resource Center (DGRC) for plasmids and cell lines.

1. Preparation of Double Stranded RNA (dsRNA) for Shams Knockdown
<ol>
	<li>PCR amplification of the products
	<ol>
		<li>Use wild-type yellow white (y w) genomic DNA and pAc5.1-EGFP as template and the following primer pairs to amplify the DNA fragments used in dsRNA synthesis. Use the following PCR thermal profile: Denaturation (95 &#176;C, 30 s), Annealing (58 &#176;C, 30 s) and Extension (72 &#176;C, 1 min). 
		Enhanced Green Fluorescent Protein (<e...

<ol>
	<li>de Celis, J. F., Bray, S., Garcia-Bellido, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Notch+signalling+regulates+veinlet+expression+and+establishes+boundaries+between+veins+and+interveins+in+the+Drosophila+wing.">Notch signalling regulates veinlet expression and establishes boundaries between veins and interveins in the Drosophila wing.</a> Development. 124 (10), 1919-1928 (1997).</li><li>Fortini, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Notch+signaling:+the+core+pathway+and+its+posttranslational+regulation.">Notch signaling: the core pathway and its posttranslational regulation.</a> Dev Cell. 16 (5), 633-647 (2009).</li><li>del Alamo, D., Rouault, H., Schweisguth, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanism+and+significance+of+cis-inhibition+in+Notch+signalling.">Mechanism and significance of cis-inhibition in Notch signalling.</a> Curr Biol. 21 (1), R40-R47 (2011).</li><li>Sprinzak, D., 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=Cis-interactions+between+Notch+and+Delta+generate+mutually+exclusive+signalling+states.">Cis-interactions between Notch and Delta generate mutually exclusive signalling states.</a> Nature. 465 (7294), 86-90 (2010).</li><li>Kopan, R., Ilagan, M. X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+canonical+Notch+signaling+pathway:+unfolding+the+activation+mechanism.">The canonical Notch signaling pathway: unfolding the activation mechanism.</a> Cell. 137 (2), 216-233 (2009).</li><li>Huppert, S. S., Jacobsen, T. L., Muskavitch, 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=Feedback+regulation+is+central+to+Delta-Notch+signalling+required+for+Drosophila+wing+vein+morphogenesis.">Feedback regulation is central to Delta-Notch signalling required for Drosophila wing vein morphogenesis.</a> Development. 124 (17), 3283-3291 (1997).</li><li>Lee, T. V., 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=Negative+regulation+of+notch+signaling+by+xylose.">Negative regulation of notch signaling by xylose.</a> PLoS Genet. 9 (6), e1003547 (2013).</li><li>Lee, T. V., Pandey, A., Jafar-Nejad, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Xylosylation+of+the+Notch+receptor+preserves+the+balance+between+its+activation+by+trans-Delta+and+inhibition+by+cis-ligands+in+Drosophila.">Xylosylation of the Notch receptor preserves the balance between its activation by trans-Delta and inhibition by cis-ligands in Drosophila.</a> PLoS Genet. 13 (4), e1006723 (2017).</li><li>Jacobsen, T. L., Brennan, K., Arias, A. M., Muskavitch, 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=Cis-interactions+between+Delta+and+Notch+modulate+neurogenic+signalling+in+Drosophila.">Cis-interactions between Delta and Notch modulate neurogenic signalling in Drosophila.</a> Development. 125 (22), 4531-4540 (1998).</li><li>Schneider, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+lines+derived+from+late+embryonic+stages+of+Drosophila+melanogaster.">Cell lines derived from late embryonic stages of Drosophila melanogaster.</a> J Embryol Exp Morphol. 27 (2), 353-365 (1972).</li><li>Fehon, R. G., 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=Molecular+interactions+between+the+protein+products+of+the+neurogenic+loci+Notch+and+Delta,+two+EGF-homologous+genes+in+Drosophila.">Molecular interactions between the protein products of the neurogenic loci Notch and Delta, two EGF-homologous genes in Drosophila.</a> Cell. 61 (3), 523-534 (1990).</li><li>Fleming, R. 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=An+extracellular+region+of+Serrate+is+essential+for+ligand-induced+cis-inhibition+of+Notch+signaling.">An extracellular region of Serrate is essential for ligand-induced cis-inhibition of Notch signaling.</a> Development. 140 (9), 2039-2049 (2013).</li><li>Saj, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+combined+ex+vivo+and+in+vivo+RNAi+screen+for+notch+regulators+in+Drosophila+reveals+an+extensive+notch+interaction+network.">A combined ex vivo and in vivo RNAi screen for notch regulators in Drosophila reveals an extensive notch interaction network.</a> Dev Cell. 18 (5), 862-876 (2010).</li><li>Fiuza, U. M., Klein, T., Martinez Arias, A., Hayward, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanisms+of+ligand-mediated+inhibition+in+Notch+signaling+activity+in+Drosophila.">Mechanisms of ligand-mediated inhibition in Notch signaling activity in Drosophila.</a> Dev Dyn. 239 (3), 798-805 (2010).</li><li>Ahimou, F., Mok, L. P., Bardot, B., Wesley, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+adhesion+force+of+Notch+with+Delta+and+the+rate+of+Notch+signaling.">The adhesion force of Notch with Delta and the rate of Notch signaling.</a> J Cell Biol. 167 (6), 1217-1229 (2004).</li><li>Livak, K. J., Schmittgen, T. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+relative+gene+expression+data+using+real-time+quantitative+PCR+and+the+2(-Delta+Delta+C(T))+Method.">Analysis of relative gene expression data using real-time quantitative PCR and the 2(-Delta Delta C(T)) Method.</a> Methods. 25 (4), 402-408 (2001).</li><li>Okajima, T., Xu, A., Irvine, K. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modulation+of+notch-ligand+binding+by+protein+O-fucosyltransferase+1+and+fringe.">Modulation of notch-ligand binding by protein O-fucosyltransferase 1 and fringe.</a> J Biol Chem. 278 (43), 42340-42345 (2003).</li><li>Acar, 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=Rumi+is+a+CAP10+domain+glycosyltransferase+that+modifies+Notch+and+is+required+for+Notch+signaling.">Rumi is a CAP10 domain glycosyltransferase that modifies Notch and is required for Notch signaling.</a> Cell. 132 (2), 247-258 (2008).</li><li>Bruckner, K., Perez, L., Clausen, H., Cohen, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glycosyltransferase+activity+of+Fringe+modulates+Notch-Delta+interactions.">Glycosyltransferase activity of Fringe modulates Notch-Delta interactions.</a> Nature. 406 (6794), 411-415 (2000).</li><li>Yamamoto, 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=A+mutation+in+EGF+repeat-8+of+Notch+discriminates+between+Serrate/Jagged+and+Delta+family+ligands.">A mutation in EGF repeat-8 of Notch discriminates between Serrate/Jagged and Delta family ligands.</a> Science. 338 (6111), 1229-1232 (2012).</li></ol>

Canonical Notch signaling depends on the interactions between the Notch receptor and its ligands5. Although most studies on the Notch pathway primarily consider the binding of Notch and ligands in neighboring cells (trans), Notch and same-cell ligands do interact, and these so-called cis-interactions can play an inhibitory role in Notch signaling3,4. Accordingly, to decipher the mechanisms underlying the effects of a modi...

Canonical Notch signaling is a short-range cell to cell communication mechanism that requires physical contact of neighboring cells to facilitate the interaction between Notch receptors and their ligands1. Interaction of Notch receptor (present on the surface of signal-receiving cells) with ligands (present on the surface of signal-sending cells) initiates Notch signaling and is known as trans-activation2. On the other hand, interaction between Notch and its ligands in the same cell leads to the inhibition of Notch pathway and is known as cis-inhibition3. The balance between trans- and cis-interactions is required to ensure optimum ligand-dependent Notch signaling4. Drosophila has one Notch receptor and two ligands (Delta and Serrate) as opposed to mammals, which have four Notch receptors and five ligands [jagged 1 (JAG1), JAG2, delta-like 1 (DLL1), DLL3 and DLL4]5. Having this simplicity, the Drosophila model offers the ease to dissect/study the effects of pathway modifiers on Notch-ligand interactions and subsequently on Notch signaling. In certain contexts during animal development (including wing development in Drosophila), both cis- and trans-interactions are involved to achieve proper Notch signaling and cell fate1,6. It is important to distinguish the effects of Notch pathway modifiers in these contexts on cis- versus trans-interactions of Notch with its ligands.
Our group previously reported that addition of a carbohydrate residue called xylose to Drosophila Notch negatively regulates Notch signaling in certain contexts, including wing development7. Loss of shams (the enzyme that xylosylates Notch) leads to a &#34;loss of wing vein&#34; phenotype7. More recently, gene dosage experiments and clonal analysis were used to show that loss of shams enhances Delta-mediated Notch singling. To distinguish whether the enhanced Notch signaling in shams mutants is a result of decreased cis-inhibition or increased trans-activation, ectopic overexpression studies of Notch ligands in larval wing imaginal discs using the dpp-GAL4 driver were performed. These experiments provided evidence suggesting that Shams regulates trans-activation of Notch by Delta without affecting Notch cis-inhibition by ligands8. However, feed-back regulations and effects of endogenous ligands might complicate the interpretation of ectopic overexpression studies1,6,9.
To resolve this issue, Drosophila S2 cells10 were used, which provide a simple in vitro system for Notch-ligand interaction studies11,12. S2 cells do not express endogenous Notch receptor and Delta ligand11 and express a low level of Serrate13, which does not affect Notch-ligand aggregation experiments8. Therefore, S2 cells can be stably or transiently transfected by Notch and/or individual ligands (Delta or Serrate) to generate cells that exclusively express the Notch receptor or one of its ligands, or a combination of them. Mixing of Notch-expressing S2 cells with ligand-expressing S2 cells results in the formation of heterotypic aggregates mediated by receptor-ligand binding11,12,14. Quantification of the aggregate formation provides a measure of trans-binding between Notch and its ligands15 (Figure 1). Similarly, S2 cells can be co-transfected with Notch and Delta or Serrate ligands (i.e. cis-ligands). Cis-ligands in these Notch-expressing S2 cells abrogate the binding of Notch with trans-ligands and result in decreased aggregate formation8,12,14. The relative decrease in aggregate formation caused by cis-ligands provides a measure of the inhibitory effect of cis-ligands on binding between Notch and trans-ligands (Figure 2). Accordingly, cell aggregation assays were utilized to examine the effect of loss of xylosylation on trans- and cis-interactions between Notch and its ligands.
Here, we present a detailed protocol for cell aggregation assays aimed to evaluate the binding of Notch with trans-ligands and its inhibition by cis-ligands using Drosophila S2 cells. As an example, we provide the data that allowed us to determine the effect of Notch xylosylation on binding between Notch and trans-Delta8. These straightforward assays provide a semi-quantitative assessment of Notch-ligand interactions in vitro and help determine the molecular mechanisms underlying the in vivo effects of Notch pathway modifiers.

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			<td height="22" style="height:23px;width:415px;">BioWhittaker Schneider&#8217;s Drosophila medium, Modified</td>
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			<td height="19" style="height:19px;width:415px;">HyClone Penicillin-Streptomycin 100X solution</td>
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			<td height="21" style="height:21px;width:415px;">CELLSTAR 6 well plate</td>
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			<td style="width:396px;"></td>
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			<td height="21" style="height:21px;width:415px;">CELLSTAR 24 well plate</td>
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			<td height="21" style="height:21px;width:415px;">VWR mini shaker</td>
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			<td>12520-956</td>
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			<td height="21" style="height:21px;width:415px;">Hemocytometer</td>
			<td style="width:187px;">Fisher Sceintific&#160;</td>
			<td>267110</td>
			<td style="width:396px;"></td>
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			<td height="21" style="height:21px;width:415px;">FuGENE HD Transfection Reagent</td>
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			<td style="width:396px;"></td>
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			<td height="21" style="height:21px;width:415px;">MEGAscrip T7 Transcription Kit</td>
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			<td height="19" style="height:19px;width:415px;">Quick-RNA MiniPrep (RNA purification Kit)</td>
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			<td height="21" style="height:21px;width:415px;">VistaVision Inverted microscope</td>
			<td>VWR</td>
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			<td style="width:396px;"></td>
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		<tr height="22">
			<td height="22" style="height:23px;width:415px;">9MP USB2.0 Microscope Digital Camera + Advanced Software</td>
			<td style="width:187px;">AmScope</td>
			<td style="width:131px;">MU-900</td>
			<td style="width:396px;">Image acquisition using ToupView software</td>
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			<td height="20" style="height:21px;width:415px;">PureLink Quick Gel Extraction Kit</td>
			<td style="width:187px;">Invitrogen</td>
			<td style="width:131px;">K210012</td>
			<td style="width:396px;"></td>
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			<td height="19" style="height:19px;width:415px;">Fetal Bovine Serum</td>
			<td style="width:187px;">GenDepot</td>
			<td style="width:131px;">F0600-050</td>
			<td style="width:396px;"></td>
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		<tr height="21">
			<td height="21" style="height:21px;width:415px;">Methotrexate</td>
			<td style="width:187px;">Sigma-Aldrich</td>
			<td style="width:131px;">A6770-10</td>
			<td style="width:396px;"></td>
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		<tr height="21">
			<td height="21" style="height:21px;width:415px;">Hygromycin B</td>
			<td style="width:187px;">Invitrogen</td>
			<td style="width:131px;">HY068-L6</td>
			<td style="width:396px;"></td>
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		<tr height="21">
			<td height="21" style="height:22px;width:415px;">Copper sulphate</td>
			<td style="width:187px;">Macron Fine Chemicals</td>
			<td style="width:131px;">4448-02</td>
			<td style="width:396px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:415px;">S2 cells</td>
			<td style="width:187px;">Invitrogen</td>
			<td style="width:131px;">R69007</td>
			<td style="width:396px;"></td>
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		<tr height="20">
			<td height="20" style="height:21px;width:415px;">S2-SerrateTom cells</td>
			<td style="width:187px;"></td>
			<td style="width:131px;"></td>
			<td style="width:396px;">Gift from R. Fleming (Fleming et al, Development, 2013)</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:415px;">S2-Delta cells</td>
			<td style="width:187px;">DGRC</td>
			<td style="width:131px;">152</td>
			<td style="width:396px;"></td>
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			<td height="21" style="height:21px;width:415px;">S2-Notch cells</td>
			<td style="width:187px;">DGRC</td>
			<td style="width:131px;">154</td>
			<td style="width:396px;"></td>
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		<tr height="21">
			<td height="21" style="height:21px;width:415px;">pMT-Delta vector</td>
			<td style="width:187px;">DGRC</td>
			<td style="width:131px;">1021</td>
			<td style="width:396px;">Gift from S. Artavanis-Tsakonas</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:21px;width:415px;">pMT-Serrate vector</td>
			<td style="width:187px;"></td>
			<td style="width:131px;"></td>
			<td style="width:396px;">Gift from Ken Irvine (Okajima et al, JBC, 2003)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:415px;">pMT-Notch vector</td>
			<td style="width:187px;">DGRC</td>
			<td style="width:131px;">1022</td>
			<td style="width:396px;">Gift from S. Artavanis-Tsakonas</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:415px;">pAc5.1-EGFP</td>
			<td style="width:187px;"></td>
			<td style="width:131px;"></td>
			<td style="width:396px;">Gift from Hugo Bellen</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:415px;">TaqMan RNA-to-Ct 1-Step Kit</td>
			<td style="width:187px;">Applied Biosystem</td>
			<td style="width:131px;">1611091</td>
			<td style="width:396px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:415px;">TaqMan Gene Expression Assay for CG9996 (Shams)</td>
			<td style="width:187px;">Applied Biosystem</td>
			<td>Dm02144576_g1&#160;</td>
			<td style="width:396px;">with FAM-MGB dye</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:415px;">TaqMan Gene Expression Assay for CG7939 (RpL32)</td>
			<td style="width:187px;">Applied Biosystem</td>
			<td>Dm02151827_g1</td>
			<td style="width:396px;">with FAM-MGB dye</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:415px;">Applied Biosystems 7900HT Fast Real-Time PCR system</td>
			<td style="width:187px;">Applied Biosystem</td>
			<td style="width:131px;">4351405</td>
			<td style="width:396px;">96-well Block module</td>
		</tr>
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</table>

cell aggregation assays to evaluate the binding of the drosophila notch with trans-ligands and its inhibition by cis-ligands

Notch signaling is an evolutionarily conserved cell-cell communication system used broadly in animal development and adult maintenance. Interaction of the Notch receptor with ligands from neighboring cells induces activation of the signaling pathway (trans-activation), while interaction with ligands from the same cell inhibits signaling (cis-inhibition). Proper balance between trans-activation and cis-inhibition helps establish optimal levels of Notch signaling in some contexts during animal development. Because of the overlapping expression domains of Notch and its ligands in many cell types and the existence of feedback mechanisms, studying the effects of a given post-translational modification on trans- versus cis-interactions of Notch and its ligands in vivo is difficult. Here, we describe a protocol for using Drosophila S2 cells in cell-aggregation assays to assess the effects of knocking down a Notch pathway modifier on the binding of Notch to each ligand in trans and in cis. S2 cells stably or transiently transfected with a Notch-expressing vector are mixed with cells expressing each Notch ligand (S2-Delta or S2-Serrate). Trans-binding between the receptor and ligands results in the formation of heterotypic cell aggregates and is measured in terms of the number of aggregates per mL composed of &#62;6 cells. To examine the inhibitory effect of cis-ligands, S2 cells co-expressing Notch and each ligand are mixed with S2-Delta or S2-Serrate cells and the number of aggregates is quantified as described above. The relative decrease in the number of aggregates due to the presence of cis-ligands provides a measure of cis-ligand-mediated inhibition of trans-binding. These straightforward assays can provide semi-quantitative data on the effects of genetic or pharmacological manipulations on the binding of Notch to its ligands, and can help deciphering the molecular mechanisms underlying the in vivo effects of such manipulations on Notch signaling.

Our in vivo observations suggested that loss of the xylosyltransferase gene shams results in gain of Notch signaling due to increased Delta-mediated trans-activation of Notch without affecting the cis-inhibition of Notch by ligands8. To test this notion, in vitro cell aggregation assays were performed. First, shams expression in S2 cells was knocked down using shams dsRNA. EGFP dsRNA was used a...

Watch this Scientific Journal Video about Cell Aggregation Assays to Evaluate the Binding of the Drosophila Notch with Trans-Ligands and its Inhibition by Cis-Ligands at JoVE.com

Cell Aggregation Assays to Evaluate the Binding of the Drosophila Notch with Trans-Ligands and its Inhibition by Cis-Ligands

Complexity of in vivo systems makes it difficult to distinguish between the activation and inhibition of Notch receptor by trans- and cis-ligands, respectively. Here, we present a protocol based on in vitro cell-aggregation assays for qualitative and semi-quantitative evaluation of the binding of Drosophila Notch to trans-ligands vs cis-ligands.

Cell Aggregation Assays to Evaluate the Binding of the Drosophila Notch with Trans-Ligands and its Inhibition by Cis-Ligands

Notch signaling is an evolutionarily conserved cell-cell communication system used broadly in animal development and adult maintenance. Interaction of the ...

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Methods to Examine the Lymph Gland and Hemocytes in Drosophila Larvae

Methods to Examine the Lymph Gland and Hemocytes in Drosophila Larvae

Many parallels exist between the Drosophila and mammalian hematopoietic systems, even though Drosophila lack the lymphoid lineage that characterize ...

Stimulation of Notch Signaling in Mouse Osteoclast Precursors

Notch signaling is a key component of multiple physiological and pathological processes. The nature of Notch signaling, however, makes in vitro ...

Bioengineering of Humanized Bone Marrow Microenvironments in Mouse and Their Visualization by Live Imaging

Human hematopoietic stem cells (HSCs) reside in the bone marrow (BM) niche, an intricate, multifactorial network of components producing cytokines, growth ...

Dissection and Immunofluorescent Staining of Mushroom Body and Photoreceptor Neurons in Adult Drosophila melanogaster Brains

Dissection and Immunofluorescent Staining of Mushroom Body and Photoreceptor Neurons in Adult Drosophila melanogaster Brains

Nervous system development involves a sequential series of events that are coordinated by several signaling pathways and regulatory networks. Many of the ...

Three-dimensional Rendering and Analysis of Immunolabeled, Clarified Human Placental Villous Vascular Networks

Nutrient and gas exchange between mother and fetus occurs at the interface of the maternal intervillous blood and the vast villous capillary network that ...

Probing Cell Mechanics with Bead-Free Optical Tweezers in the Drosophila Embryo

Probing Cell Mechanics with Bead-Free Optical Tweezers in the Drosophila Embryo

Morphogenesis requires coordination between genetic patterning and mechanical forces to robustly shape the cells and tissues. Hence, a challenge to ...

A Cell-based Assay to Investigate Non-muscle Myosin II Contractility via the Folded-gastrulation Signaling Pathway in Drosophila S2R+ Cells

A Cell-based Assay to Investigate Non-muscle Myosin II Contractility via the Folded-gastrulation Signaling Pathway in Drosophila S2R+ Cells

We have developed a cell-based assay using Drosophila cells that recapitulates apical constriction initiated by folded gastrulation (Fog), a secreted ...