|Counterscreen for agonists of nuclear receptor subfamily 2, group E, member 3 (NR2E3): TR-FRET-based biochemical high throughput assay to identify agonists of the interaction between peroxisome proliferator-activated receptor gamma (PPARg) and nuclear receptor co-repressor 2 (NCOR2) - BioAssay Summary
Name: Counterscreen for agonists of nuclear receptor subfamily 2, group E, member 3 (NR2E3): TR-FRET-based biochemical high throughput assay to identify agonists of the interaction between peroxisome proliferator-activated receptor gamma (PPARg) and nuclear receptor co-repressor 2 (NCOR2). ..more
BioActive Compounds: 164
Depositor Specified Assays
Source (MLPCN Center Name): The Scripps Research Institute Molecular Screening Center
Affiliation: The Scripps Research Institute, TSRI
Assay Provider: Konstantin Petrukhin, Columbia University
Network: Molecular Library Probe Production Centers Network (MLPCN)
Grant Proposal Number: 1 R21 NS061718-01 Fast Track
Grant Proposal PI: Konstantin Petrukhin, Columbia University
External Assay ID: PPARG-NCOR2_AG_TR-FRET_1536_3X%INH CSRUN
Name: Counterscreen for agonists of nuclear receptor subfamily 2, group E, member 3 (NR2E3): TR-FRET-based biochemical high throughput assay to identify agonists of the interaction between peroxisome proliferator-activated receptor gamma (PPARg) and nuclear receptor co-repressor 2 (NCOR2).
Nuclear receptors are small molecule- and hormone-regulated transcription factors with discrete DNA-binding and ligand-binding domains, and are essential during development and for maintenance of proper cell function in adults. Small pharmacological compounds that bind to the cleft of the ligand-binding domain could alter receptor conformation and subsequently modify transcription of target genes. Such ligands (agonists and antagonists) have been designed for 23 nuclear receptors among the 48 identified in the human genome (1-3). NR2E3 is an orphan nuclear receptor expressed exclusively in rod and cone photoreceptor cells of the retina (4-7). In its unliganded state, NR2E3 acts as a transcriptional repressor (4, 8, 9) due to interaction with co-repressors such as retinal RetCOR (10), NCOR (11) or SMRT (11). Defects in this gene are a cause of several retinopathies (12-15). Studies showing that mice with a spontaneous deletion in the Nr2e3 gene develop late-onset, progressive retinal degeneration (7), suggest that this nuclear receptor is essential for photoreceptor development and survival. The identification of selective NR2E3 agonists would provide useful tools for the understanding of the biological role of NR2E3 in retinal diseases.
1. Evans, R.M., The nuclear receptor superfamily: a rosetta stone for physiology. Mol Endocrinol, 2005. 19(6): p. 1429-38.
2. Kliewer, S.A., Lehmann, J.M., and Willson, T.M., Orphan nuclear receptors: shifting endocrinology into reverse. Science, 1999. 284(5415): p. 757-60.
3. Li, Y., Lambert, M.H., and Xu, H.E., Activation of nuclear receptors: a perspective from structural genomics. Structure, 2003. 11(7): p. 741-6.
4. Chen, J., Rattner, A., and Nathans, J., The rod photoreceptor-specific nuclear receptor Nr2e3 represses transcription of multiple cone-specific genes. J Neurosci, 2005. 25(1): p. 118-29.
5. Cheng, H., Khanna, H., Oh, E.C., Hicks, D., Mitton, K.P., and Swaroop, A., Photoreceptor-specific nuclear receptor NR2E3 functions as a transcriptional activator in rod photoreceptors. Hum Mol Genet, 2004. 13(15): p. 1563-75.
6. Haider, N.B., Naggert, J.K., and Nishina, P.M., Excess cone cell proliferation due to lack of a functional NR2E3 causes retinal dysplasia and degeneration in rd7/rd7 mice. Hum Mol Genet, 2001. 10(16): p. 1619-26.
7. Akhmedov, N.B., Piriev, N.I., Chang, B., Rapoport, A.L., Hawes, N.L., Nishina, P.M., Nusinowitz, S., Heckenlively, J.R., Roderick, T.H., Kozak, C.A., Danciger, M., Davisson, M.T., and Farber, D.B., A deletion in a photoreceptor-specific nuclear receptor mRNA causes retinal degeneration in the rd7 mouse. Proc Natl Acad Sci U S A, 2000. 97(10): p. 5551-6.
8. Gerber, S., Rozet, J.M., Takezawa, S.I., dos Santos, L.C., Lopes, L., Gribouval, O., Penet, C., Perrault, I., Ducroq, D., Souied, E., Jeanpierre, M., Romana, S., Frezal, J., Ferraz, F., Yu-Umesono, R., Munnich, A., and Kaplan, J., The photoreceptor cell-specific nuclear receptor gene (PNR) accounts for retinitis pigmentosa in the Crypto-Jews from Portugal (Marranos), survivors from the Spanish Inquisition. Hum Genet, 2000. 107(3): p. 276-84.
9. Kobayashi, M., Hara, K., Yu, R.T., and Yasuda, K., Expression and functional analysis of Nr2e3, a photoreceptor-specific nuclear receptor, suggest common mechanisms in retinal development between avians and mammals. Dev Genes Evol, 2008. 218(8): p. 439-44.
10. Takezawa, S., Yokoyama, A., Okada, M., Fujiki, R., Iriyama, A., Yanagi, Y., Ito, H., Takada, I., Kishimoto, M., Miyajima, A., Takeyama, K., Umesono, K., Kitagawa, H., and Kato, S., A cell cycle-dependent co-repressor mediates photoreceptor cell-specific nuclear receptor function. EMBO J, 2007. 26(3): p. 764-74.
11. Kapitskaya, M., Cunningham, M.E., Lacson, R., Kornienko, O., Bednar, B., and Petrukhin, K., Development of the high throughput screening assay for identification of agonists of an orphan nuclear receptor. Assay Drug Dev Technol, 2006. 4(3): p. 253-62.
12. Bernal, S., Solans, T., Gamundi, M.J., Hernan, I., de Jorge, L., Carballo, M., Navarro, R., Tizzano, E., Ayuso, C., and Baiget, M., Analysis of the involvement of the NR2E3 gene in autosomal recessive retinal dystrophies. Clin Genet, 2008. 73(4): p. 360-6.
13. Coppieters, F., Leroy, B.P., Beysen, D., Hellemans, J., De Bosscher, K., Haegeman, G., Robberecht, K., Wuyts, W., Coucke, P.J., and De Baere, E., Recurrent mutation in the first zinc finger of the orphan nuclear receptor NR2E3 causes autosomal dominant retinitis pigmentosa. Am J Hum Genet, 2007. 81(1): p. 147-57.
14. Gire, A.I., Sullivan, L.S., Bowne, S.J., Birch, D.G., Hughbanks-Wheaton, D., Heckenlively, J.R., and Daiger, S.P., The Gly56Arg mutation in NR2E3 accounts for 1-2% of autosomal dominant retinitis pigmentosa. Mol Vis, 2007. 13: p. 1970-5.
15. Sharon, D., Sandberg, M.A., Caruso, R.C., Berson, E.L., and Dryja, T.P., Shared mutations in NR2E3 in enhanced S-cone syndrome, Goldmann-Favre syndrome, and many cases of clumped pigmentary retinal degeneration. Arch Ophthalmol, 2003. 121(9): p. 1316-23.
nuclear receptor subfamily 2, group E, member 3, NR2E3; RetCOR, corepressor, photoreceptor-specific nuclear receptor; PNR, blindness, age-related macular degeneration, AMD, PPAR, PPARg, PPAR gamma, peroxisome proliferator-activated receptor gamma, NCOR2, nuclear receptor co-repressor 2, counterscreen, triplicate, biochemical, TRFRET, orphan nuclear receptor, fluorescence, TR-FRET, agonist, activator, HTS, 1536, Scripps, Scripps Florida, Research Institute Molecular Screening Center, SRIMSC, Molecular Libraries Probe Production Centers Network, MLPCN.
The purpose of this biochemical assay is to determine whether compounds identified as active in a previous set of experiments entitled, "TR-FRET-based primary biochemical high throughput screening assay to identify agonists of nuclear receptor subfamily 2, group E, member 3 (NR2E3)" (AID 2300), are nonselective due to activation of the interaction between PPARgamma-NCOR2. This TR-FRET-format assay employs GST-PPARg and its interaction partner, a biotinylated corepressor NCOR2. These reagents are added together in the presence of test compounds and Eu(K)-anti GST antibody and Streptavidin-D2. Interaction between the NCOR2 and PPARg partners brings the fluorophores together, leading to well FRET. As designed, test compounds that act as PPARg agonists will cause release of PPARg from the corepressor NCOR, thereby preventing interaction of the fluorescent tags, leading to reduced well FRET. Compounds are tested in triplicate at a final nominal concentration of 3.98 uM.
Prior to the start of the assay 5 uL of Assay Buffer (10 mM Tris-HCL, pH 7.5, 0.05% NP-40 alternative, 6% glycerol, 100 mM potassium fluoride, 1 mM dithiothreitiol and 0.05% w/v bovine serum albumin) were dispensed into columns 1 and 2 of 1536-well assay plates. Next, 5 uL of 1.05X Assay Mixture containing 7.35 nM PPARg and 315 nM NCOR in Assay Buffer were dispensed into the remaining 46 columns. The compounds were then pinned into each assay plate. Next, 1 uL of 6X Detection Mix containing 4.5 nM Eu(K)-anti-GST and 42 nM Streptavidin-D2 in Assay Buffer was dispensed into all wells. After dispensing, the final concentrations of the reagents were: 7.0 nM GST-PPARg, 300 nM Biotin-NCOR, 0.75 nM Eu(K)-anti-GST and 42 nM StreptavidinD2. The plates were then incubated for 5 hours at 4 C and well FRET was measured. After excitation at 340 nm, well fluorescence was monitored at 617 nm (Eu(K)) and 671 nm (D2) with the ViewLux microplate reader (Perkin Elmer). For each well, a fluorescence ratio was calculated according to the following mathematical expression:
Ratio = I671nm / I617nm * 10,000
I671nm represents the measured fluorescence emission at 671 nm.
I617nm represents the measured fluorescence emission at 617 nm.
The percent inhibition for each compound was calculated using as follows:
%_Inhibition = 100 * ( 1 - ( ( Ratio_Test_Compound - Median_Ratio_High_Control ) / ( Median_Ratio_Low_Control - Median_Ratio_High_Control ) )
Test_Compound is defined as wells containing test compound.
Positive_Control is defined as wells containing no protein
Negative_Control is defined as wells containing 0.6% DMSO.
The average percent inhibition and standard deviation of each compound tested were calculated. Any compound that exhibited an average percent inhibition greater than the hit cutoff calculated for the primary screen was declared active. IC50 of positive control Rosiglitazone was on average 50 nM.
PubChem Activity Outcome and Score:
The reported PubChem Activity Score has been normalized to 100% observed primary inhibition. % Inhibition values of greater than or equal to 100 are reported as activity score 100. Negative % inhibition values are reported as activity score zero.
The PubChem Activity Score range for active compounds is 100-20, and for inactive compounds 20-0.
List of Reagents:
GST-PPAR gamma (supplied by Assay Provider)
Biotinylated NCOR2 (supplied by Assay Provider)
Eu(K)-antiGST (Cisbio, 61GSTKLB)
Streptavidin-D2 (Cisbio, 61OSADAB)
Tris-HCl, pH 7.5, 1 M solution (Invitrogen, 15567-027)
BSA, 30% solution (Sigma, A8327-50ML)
Biotin (Sigma, B4501-1G)
Rosiglitazone (control) (vendor, part)
Glycerol (Invitrogen, 15514-011)
NP-40 alternative, 10% solution (Calbiochem, 492018)
DTT, 1M solution (Fluka, 43816)
Potassium fluoride powder (Fluka, 60238)
1536-well plates (Greiner, part 789173)
Due to the increasing size of the MLPCN compound library, this assay may have been run as two or more separate campaigns, each campaign testing a unique set of compounds. In this case the results of each separate campaign were assigned "Active/Inactive" status based upon that campaign's specific compound activity cutoff value. All data reported were normalized on a per-plate basis. Possible artifacts of this assay can include, but are not limited to: dust or lint located in or on wells of the microtiter plate, compounds that modulate well fluorescence. All test compound concentrations reported above and below are nominal; the specific test concentration(s) for a particular compound may vary based upon the actual sample provided by the MLSMR. The MLSMR was not able to provide all compounds selected for testing in this AID.
** Test Concentration.
Data Table (Concise)