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Choi SR, Narayanasamy P. Investigating Novel IspE Inhibitors of the MEP Pathway in Mycobacterium. Microorganisms 2023; 12:18. [PMID: 38276186 PMCID: PMC10819746 DOI: 10.3390/microorganisms12010018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 12/18/2023] [Accepted: 12/19/2023] [Indexed: 01/27/2024] Open
Abstract
In a recent effort to mitigate harm from human pathogens, many biosynthetic pathways have been extensively evaluated for their ability to inhibit pathogen growth and to determine drug targets. One of the important products/targets of such pathways is isopentenyl diphosphate. Isopentenyl diphosphate is the universal precursor of isoprenoids, which are essential for the normal functioning of microorganisms. In general, two biosynthetic pathways lead to the formation of isopentenyl diphosphate: (1) the mevalonate pathway in animals; and (2) the non-mevalonate or methylerythritol phosphate (MEP) in many bacteria, and some protozoa and plants. Because the MEP pathway is not found in mammalian cells, it is considered an attractive target for the development of antimicrobials against a variety of human pathogens, including Mycobacterium tuberculosis (M.tb). In the MEP pathway, 4-diphosphocytidyl-2-c-methyl-d-erythritol kinase (IspE) phosphorylates 4-diphosphocytidyl-2-C-methyl-D-erythritol (CDPME) to form 4-diphosphocytidyl-2-C-methyl-D-erythritol 2-phosphate (CDPME2P). A virtual high-throughput screening against 15 million compounds was carried out by docking IspE protein. We identified an active heterotricyclic compound which showed enzymatic activity; namely, IC50 of 6 µg/mL against M.tb IspE and a MIC of 12 µg/mL against M.tb (H37Rv). Hence, we designed and synthesized similar new heterotricyclic compounds and tested them against mycobacterium, observing a MIC of 5 µg/mL against M. avium. This study will provide the critical insight necessary for developing novel antimicrobials that target the MEP pathways in pathogens.
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Affiliation(s)
| | - Prabagaran Narayanasamy
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA
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2
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Bonazzi S, d'Hennezel E, Beckwith REJ, Xu L, Fazal A, Magracheva A, Ramesh R, Cernijenko A, Antonakos B, Bhang HEC, Caro RG, Cobb JS, Ornelas E, Ma X, Wartchow CA, Clifton MC, Forseth RR, Fortnam BH, Lu H, Csibi A, Tullai J, Carbonneau S, Thomsen NM, Larrow J, Chie-Leon B, Hainzl D, Gu Y, Lu D, Meyer MJ, Alexander D, Kinyamu-Akunda J, Sabatos-Peyton CA, Dales NA, Zécri FJ, Jain RK, Shulok J, Wang YK, Briner K, Porter JA, Tallarico JA, Engelman JA, Dranoff G, Bradner JE, Visser M, Solomon JM. Discovery and characterization of a selective IKZF2 glue degrader for cancer immunotherapy. Cell Chem Biol 2023; 30:235-247.e12. [PMID: 36863346 DOI: 10.1016/j.chembiol.2023.02.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 12/15/2022] [Accepted: 02/09/2023] [Indexed: 03/04/2023]
Abstract
Malignant tumors can evade destruction by the immune system by attracting immune-suppressive regulatory T cells (Treg) cells. The IKZF2 (Helios) transcription factor plays a crucial role in maintaining function and stability of Treg cells, and IKZF2 deficiency reduces tumor growth in mice. Here we report the discovery of NVP-DKY709, a selective molecular glue degrader of IKZF2 that spares IKZF1/3. We describe the recruitment-guided medicinal chemistry campaign leading to NVP-DKY709 that redirected the degradation selectivity of cereblon (CRBN) binders from IKZF1 toward IKZF2. Selectivity of NVP-DKY709 for IKZF2 was rationalized by analyzing the DDB1:CRBN:NVP-DKY709:IKZF2(ZF2 or ZF2-3) ternary complex X-ray structures. Exposure to NVP-DKY709 reduced the suppressive activity of human Treg cells and rescued cytokine production in exhausted T-effector cells. In vivo, treatment with NVP-DKY709 delayed tumor growth in mice with a humanized immune system and enhanced immunization responses in cynomolgus monkeys. NVP-DKY709 is being investigated in the clinic as an immune-enhancing agent for cancer immunotherapy.
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Affiliation(s)
- Simone Bonazzi
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA.
| | - Eva d'Hennezel
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA.
| | | | - Lei Xu
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Aleem Fazal
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Anna Magracheva
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Radha Ramesh
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | | | | | - Hyo-Eun C Bhang
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | | | - Jennifer S Cobb
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | | | - Xiaolei Ma
- Novartis Institutes for Biomedical Research, Emeryville, CA, USA
| | | | | | - Ry R Forseth
- Novartis Institutes for Biomedical Research, East Hanover, NJ, USA
| | | | - Hongbo Lu
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Alfredo Csibi
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Jennifer Tullai
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Seth Carbonneau
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Noel M Thomsen
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Jay Larrow
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | | | - Dominik Hainzl
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Yi Gu
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Darlene Lu
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Matthew J Meyer
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Dylan Alexander
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | | | | | - Natalie A Dales
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | | | - Rishi K Jain
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Janine Shulok
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Y Karen Wang
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Karin Briner
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | | | | | | | - Glenn Dranoff
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - James E Bradner
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Michael Visser
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
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3
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Morfa CJ, Bassoni D, Szabo A, McAnally D, Sharir H, Hood BL, Vasile S, Wehrman T, Lamerdin J, Smith LH. A Pharmacochaperone-Based High-Throughput Screening Assay for the Discovery of Chemical Probes of Orphan Receptors. Assay Drug Dev Technol 2018; 16:384-396. [PMID: 30251873 DOI: 10.1089/adt.2018.868] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
G-protein-coupled receptors (GPCRs) have varying and diverse physiological roles, transmitting signals from a range of stimuli, including light, chemicals, peptides, and mechanical forces. More than 130 GPCRs are orphan receptors (i.e., their endogenous ligands are unknown), representing a large untapped reservoir of potential therapeutic targets for pharmaceutical intervention in a variety of diseases. Current deorphanization approaches are slow, laborious, and usually require some in-depth knowledge about the receptor pharmacology. In this study we describe a cell-based assay to identify small molecule probes of orphan receptors that requires no a priori knowledge of receptor pharmacology. Built upon the concept of pharmacochaperones, where cell-permeable small molecules facilitate the trafficking of mutant receptors to the plasma membrane, the simple and robust technology is readily accessible by most laboratories and is amenable to high-throughput screening. The assay consists of a target harboring a synthetic point mutation that causes retention of the target in the endoplasmic reticulum. Coupled with a beta-galactosidase enzyme-fragment complementation reporter system, the assay identifies compounds that act as pharmacochaperones causing forward trafficking of the mutant GPCR. The assay can identify compounds with varying mechanisms of action including agonists and antagonists. A universal positive control compound circumvents the need for a target-specific ligand. The veracity of the approach is demonstrated using the beta-2-adrenergic receptor. Together with other existing assay technologies to validate the signaling pathways and the specificity of ligands identified, this pharmacochaperone-based approach can accelerate the identification of ligands for these potentially therapeutically useful receptors.
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Affiliation(s)
- Camilo J Morfa
- 1 Conrad Prebys Center for Chemical Genomics, Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, Florida
| | | | - Andras Szabo
- 1 Conrad Prebys Center for Chemical Genomics, Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, Florida
| | - Danielle McAnally
- 1 Conrad Prebys Center for Chemical Genomics, Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, Florida
| | - Haleli Sharir
- 1 Conrad Prebys Center for Chemical Genomics, Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, Florida
| | - Becky L Hood
- 1 Conrad Prebys Center for Chemical Genomics, Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, Florida
| | - Stefan Vasile
- 1 Conrad Prebys Center for Chemical Genomics, Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, Florida
| | - Tom Wehrman
- 2 Eurofins DiscoverX Corporation , Fremont, California
| | - Jane Lamerdin
- 2 Eurofins DiscoverX Corporation , Fremont, California
| | - Layton H Smith
- 1 Conrad Prebys Center for Chemical Genomics, Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, Florida
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4
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Charter NW, Horecka J, Loh CY, Doan A, Wehrman T, Olson KR. Rapid, Antibody-Free Detection of Recombinant Proteins on Blots Using Enzyme Fragment Complementation. Methods Mol Biol 2016; 1314:51-61. [PMID: 26139254 DOI: 10.1007/978-1-4939-2718-0_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Alternative, antibody-free techniques to western analysis of protein blots can offer reduced assay times for routine analysis of expression of recombinant proteins. We have adapted the commercially available enzyme fragment complementation technology to provide a rapid protein detection method for protein blots based on significantly reducing the number of incubation and washing steps used in traditional approaches, and eliminating the requirement for antibodies. In this chapter, we highlight the use of this assay for measuring recombinant protein expressed in mammalian cells for a range of applications, including dot blot screening of large numbers of different cell samples, assessment of protein integrity through detection of degradation bands, and characterization of posttranslational protein modifications such as glycosylation.
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Affiliation(s)
- Neil W Charter
- DiscoveRx Corporation, 42501 Albrae St., Fremont, CA, 94538, USA,
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5
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Villagomez R, Hatti-Kaul R, Sterner O, Almanza G, Linares-Pastén JA. Effect of natural and semisynthetic pseudoguianolides on the stability of NF-κB:DNA complex studied by agarose gel electrophoresis. PLoS One 2015; 10:e0115819. [PMID: 25615602 PMCID: PMC4304792 DOI: 10.1371/journal.pone.0115819] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 11/27/2014] [Indexed: 12/31/2022] Open
Abstract
The nuclear factor κB (NF-κB) is a promising target for drug discovery. NF-κB is a heterodimeric complex of RelA and p50 subunits that interact with the DNA, regulating the expression of several genes; its dysregulation can trigger diverse diseases including inflammation, immunodeficiency, and cancer. There is some experimental evidence, based on whole cells studies, that natural sesquiterpene lactones (Sls) can inhibit the interaction of NF-κB with DNA, by alkylating the RelA subunit via a Michael addition. In the present work, 28 natural and semisynthetic pseudoguianolides were screened as potential inhibitors of NF-κB in a biochemical assay that was designed using pure NF-κB heterodimer, pseudoguianolides and a ~1000 bp palindromic DNA fragment harboring two NF-κB recognition sequences. By comparing the relative amount of free DNA fragment to the NF-κB - DNA complex, in a routine agarose gel electrophoresis, the destabilizing effect of a compound on the complex is estimated. The results of the assay and the following structure-activity relationship study, allowed the identification of several relevant structural features in the pseudoguaianolide skeleton, which are necessary to enhance the dissociating capacity of NF-κB-DNA complex. The most active compounds are substituted at C-3 (α-carbonyl), in addition to having the α-methylene-γ-lactone moiety which is essential for the alkylation of RelA.
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Affiliation(s)
- Rodrigo Villagomez
- Centre for Analysis and Synthesis, Lund University, P.O. Box 124, 221 00 Lund, Sweden
- Instituto de Investigaciones Químicas, Facultad de Ciencias Puras y Naturales, Universidad Mayor de San Andrés, P.O. Box 303 La Paz, Bolivia
| | - Rajni Hatti-Kaul
- Biotechnology, Dept. of Chemistry, Lund University, P.O. Box 124, SE-22 100 Lund, Sweden
| | - Olov Sterner
- Centre for Analysis and Synthesis, Lund University, P.O. Box 124, 221 00 Lund, Sweden
| | - Giovanna Almanza
- Instituto de Investigaciones Químicas, Facultad de Ciencias Puras y Naturales, Universidad Mayor de San Andrés, P.O. Box 303 La Paz, Bolivia
| | - Javier A. Linares-Pastén
- Biotechnology, Dept. of Chemistry, Lund University, P.O. Box 124, SE-22 100 Lund, Sweden
- * E-mail:
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6
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Ramkumar KM, Sekar TV, Foygel K, Elango B, Paulmurugan R. Reporter protein complementation imaging assay to screen and study Nrf2 activators in cells and living animals. Anal Chem 2013; 85:7542-9. [PMID: 23826874 PMCID: PMC3759980 DOI: 10.1021/ac401569j] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
NF-E2-related factor-2 (Nrf2) activators promote cellular defense mechanism and facilitate disease prevention associated with oxidative stress. In the present study, Nrf2 activators were identified using cell-based luciferase enzyme fragment complementation (EFC) assay, and the mechanism of Nrf2 activation was studied by molecular imaging. Among the various Nrf2 activators tested, pterostilbene (PTS) showed effective Nrf2 activation, as seen by luminometric screening, and validation in a high throughput-intact cell-imaging platform. Further, PTS increased the expression of Nrf2 downstream target genes, which was confirmed using luciferase reporter driven by ARE-NQO1 and ARE-GST1 promoters. Daily administration of PTS disturbed Nrf2/Keap1 interaction and reduced complemented luciferase signals in HEK293TNKS mouse tumor xenografts. This study reveals the potentials of Nrf2 activators as chemosensitizing agents' for therapeutic intervention in cancer treatment. Hence, the validated assay can be used to evaluate the identified activators preclinically in small animal models by noninvasive molecular imaging approach.
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Affiliation(s)
| | - Thillai Veerapazham Sekar
- Molecular Imaging Program at Stanford, Bio-X Program, Department of Radiology, Stanford University School of Medicine, Stanford, California, USA
| | - Kira Foygel
- Molecular Imaging Program at Stanford, Bio-X Program, Department of Radiology, Stanford University School of Medicine, Stanford, California, USA
| | | | - Ramasamy Paulmurugan
- Molecular Imaging Program at Stanford, Bio-X Program, Department of Radiology, Stanford University School of Medicine, Stanford, California, USA
- Corresponding Author: Ramasamy Paulmurugan, Ph.D. Department of Radiology, Stanford University School of Medicine 1501, South California Avenue, #2217 Palo Alto, CA 94304 Phone: 650-725-6097; Fax: 650-721-6921
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7
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Xie W, Pao C, Graham T, Dul E, Lu Q, Sweitzer TD, Ames RS, Li H. Development of a Cell-Based High Throughput Luciferase Enzyme Fragment Complementation Assay to Identify Nuclear-Factor-E2-Related Transcription Factor 2 Activators. Assay Drug Dev Technol 2012; 10:514-24. [DOI: 10.1089/adt.2011.436] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- Wensheng Xie
- Department of Biological Reagents and Assay Development, Platform Technology and Science, GlaxoSmithKline Pharmaceuticals, Collegeville, Pennsylvania
| | - Christina Pao
- Department of Biological Reagents and Assay Development, Platform Technology and Science, GlaxoSmithKline Pharmaceuticals, Collegeville, Pennsylvania
| | - Taylor Graham
- Department of Biological Reagents and Assay Development, Platform Technology and Science, GlaxoSmithKline Pharmaceuticals, Collegeville, Pennsylvania
| | - Ed Dul
- Department of Biological Reagents and Assay Development, Platform Technology and Science, GlaxoSmithKline Pharmaceuticals, Collegeville, Pennsylvania
| | - Quinn Lu
- Department of Biological Reagents and Assay Development, Platform Technology and Science, GlaxoSmithKline Pharmaceuticals, Collegeville, Pennsylvania
| | - Thomas D. Sweitzer
- Department of Biological Reagents and Assay Development, Platform Technology and Science, GlaxoSmithKline Pharmaceuticals, Collegeville, Pennsylvania
| | - Robert S. Ames
- Department of Biological Reagents and Assay Development, Platform Technology and Science, GlaxoSmithKline Pharmaceuticals, Collegeville, Pennsylvania
| | - Hu Li
- Department of Biological Reagents and Assay Development, Platform Technology and Science, GlaxoSmithKline Pharmaceuticals, Collegeville, Pennsylvania
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8
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Rapid, antibody-free detection of recombinant proteins on blots using enzyme fragment complementation. Methods Mol Biol 2009. [PMID: 19378077 DOI: 10.1007/978-1-59745-542-8_40] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Alternative, antibody-free techniques to western analysis of protein blots can offer reduced assay times for routine analysis of expression of recombinant proteins. We have adapted the commercially available enzyme fragment complementation technology to provide a rapid protein detection method for protein blots based on significantly reducing the number of incubation and washing steps used in traditional approaches, and eliminating the requirement for antibodies. In this article, we highlight the use of this assay for measuring recombinant protein expressed in mammalian cells for a range of applications, including dot blot screening of large numbers of different cell samples, assessment of protein integrity through detection of degradation bands, and characterization of post-translational protein modifications such as glycosylation.
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9
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Zhao X, Jones A, Olson KR, Peng K, Wehrman T, Park A, Mallari R, Nebalasca D, Young SW, Xiao SH. A homogeneous enzyme fragment complementation-based beta-arrestin translocation assay for high-throughput screening of G-protein-coupled receptors. ACTA ACUST UNITED AC 2008; 13:737-47. [PMID: 18660457 DOI: 10.1177/1087057108321531] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
G-protein-coupled receptors (GPCRs) represent one of the largest gene families in the human genome and have long been regarded as valuable targets for small-molecule drugs. The authors describe a new functional assay that directly monitors GPCR activation. It is based on the interaction between beta-arrestin and ligand-activated GPCRs and uses enzyme fragment complementation technology. In this format, a GPCR of interest is fused to a small (approximately 4 kDa), optimized alpha fragment peptide (termed ProLink) derived from beta-galactosidase, and beta-arrestin is fused to an N-terminal deletion mutant of beta-galactosidase (termed the enzyme acceptor [EA]). Upon activation of the receptor, the beta-arrestin-EA fusion protein binds the activated GPCR. This interaction drives enzyme fragment complementation, resulting in an active beta-galactosidase enzyme, and thus GPCR activation can be determined by quantifying beta-galactosidase activity. In this report, the authors demonstrate the utility of this technology to monitor GPCR activation and validate the approach using a Galphai-coupled GPCR, somatostatin receptor 2. Potential application to high-throughput screens in both agonist and antagonist screening modes is exemplified.
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Affiliation(s)
- Xiaoning Zhao
- Lead Discovery Department, Chemistry Research and Discovery, Amgen, Inc., South San Francisco, California 94080, USA.
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10
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Robers MB, Horton RA, Bercher MR, Vogel KW, Machleidt T. High-throughput cellular assays for regulated posttranslational modifications. Anal Biochem 2007; 372:189-97. [PMID: 17961489 DOI: 10.1016/j.ab.2007.09.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2007] [Revised: 08/21/2007] [Accepted: 09/07/2007] [Indexed: 10/22/2022]
Abstract
We have developed a set of high-throughput screening (HTS)-compatible assays capable of measuring regulated, target-specific posttranslational modifications in a mammalian cell-based format. We chose the NFkappaB signal transduction cascade as a model system to validate this approach because specific target proteins in this signaling pathway undergo a multitude of posttranslational modifications in response to pathway stimulation. In this pathway, TNFalpha induces the phosphorylation, ubiquitination, and proteasomal degradation of IkappaBalpha, which leads to the release and translocation of the NFkappaB transcriptional complex into the nucleus. To measure these cellular processes, we describe the use of a stable cell line expressing a fusion of green fluorescent protein (GFP) with IkappaBalpha that can be interrogated for either ubiquitination or phosphorylation using a unique set of terbium-labeled antibodies in a time-resolved Förster resonance energy transfer (TR-FRET)-based readout. Concurrently, we have engineered a beta-lactamase-IkappaBalpha reporter cell line that can be used to quantify proteasomal degradation of IkappaBalpha in living cells. Both TR-FRET and beta-lactamase reporter technologies provide a convenient, sensitive, and robust means to interrogate the chronological steps in NFkappaB signaling in a physiologically relevant cellular context without the need to overexpress any enzyme involved in this pathway. Cellular HTS assays that interrogate such processes will provide a unique integrated approach to dissecting intermediate steps in NFkappaB activation and could serve as examples of broadly applicable pathway analysis tools for target-based drug discovery.
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11
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Olson KR, Eglen RM. Beta galactosidase complementation: a cell-based luminescent assay platform for drug discovery. Assay Drug Dev Technol 2007; 5:137-44. [PMID: 17355206 DOI: 10.1089/adt.2006.052] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Many cell-based assays interrogating cell pathway activation employ protocols that require microscopic imaging techniques. However, such assays are not in general widely adopted for primary screening. Protein complementation, particularly of enzymes, provides an alternative approach for cell pathway analysis, with a principal advantage that is amenable to high throughput screening using microtiter plate protocols. Notably, alpha complementation of the enzyme beta-galactosidase has been exploited as a technology in this regard, using substrates that generates luminescent signals. This review describes the various uses of this flexible technology to cell-based assay development.
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12
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Fung P, Peng K, Kobel P, Dotimas H, Kauffman L, Olson K, Eglen RM. A Homogeneous Cell-Based Assay to Measure Nuclear Translocation Using β-Galactosidase Enzyme Fragment Complementation. Assay Drug Dev Technol 2006; 4:263-72. [PMID: 16834532 DOI: 10.1089/adt.2006.4.263] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Positional complementation describes the use of homogeneous assays using beta- galactosidase (beta gal) enzyme fragment complementation to detect cellular protein translocation. This phenomenon occurs when the protein of interest, recombinantly expressed as a fusion protein with a modified alpha fragment of beta gal, translocates to a cellular compartment expressing an enzyme acceptor fragment of the enzyme. When these fragments interact, high-affinity complementation occurs, and a signal is generated that is then detected upon cell lysis. In the present paper the use of positional complementation is exemplified by measuring nuclear translocation of the glucocorticoid receptor in Chinese hamster ovary-K1 cells. The approach thus provides for homogeneous protocols, in an endpoint microtiter plate assay format, without the use of either imaging or reporter gene techniques. Consequently, these characteristics suggest that the technique is suitable for automated instrumentation protocols used in high throughput screening campaigns designed to identify activators or inhibitors of nuclear translocation.
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Affiliation(s)
- P Fung
- DiscoveRx Corp., Fremont, CA 94538, USA
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13
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Affiliation(s)
- Peter B Simpson
- Automated Imaging and Electrophysiology Group, Department of Molecular and Cellular Neuroscience, Neuroscience Research Centre, Merck Sharp & Dohme, Terlings Park, Harlow, Essex CM20 2QR, UK.
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14
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Horecka J, Charter NW, Bosano BL, Fung P, Kobel P, Peng K, Eglen RM. Antibody-free method for protein detection on blots using enzyme fragment complementation. Biotechniques 2006; 40:381-3. [PMID: 16568826 DOI: 10.2144/000112119] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- Joe Horecka
- DiscoveRx Corporation, Fremont, CA 94538, USA
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15
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Lamarcq LH, Scherer BJ, Phelan ML, Kalnine NN, Nguyen YH, Kabakova T, Chen X, Tan M, Chang C, Berlon C, Campos-Gonzalez R, Gao GJ, Golz S, Vysotski ES, Farmer AA. Large-scale, high-throughput validation of short hairpin RNA sequences for RNA interference. ACTA ACUST UNITED AC 2006; 11:236-46. [PMID: 16490771 DOI: 10.1177/1087057105284342] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A method for high-throughput cloning and analysis of short hairpin RNAs (shRNAs) is described. Using this approach, 464 shRNAs against 116 different genes were screened for knockdown efficacy, enabling rapid identification of effective shRNAs against 74 genes. Statistical analysis of the effects of various criteria on the activity of the shRNAs confirmed that some of the rules thought to govern small interfering RNA (siRNA) activity also apply to shRNAs. These include moderate GC content, absence of internal hairpins, and asymmetric thermal stability. However, the authors did not find strong support for position specific rules. In addition, analysis of the data suggests that not all genes are equally susceptible to RNA interference (RNAi).
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16
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Wehrman TS, Casipit CL, Gewertz NM, Blau HM. Enzymatic detection of protein translocation. Nat Methods 2005; 2:521-7. [PMID: 15973423 DOI: 10.1038/nmeth771] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2005] [Accepted: 05/23/2005] [Indexed: 11/09/2022]
Abstract
Fundamental to eukaryotic cell signaling is the regulation of protein function by directed localization. Detection of these events has been largely qualitative owing to the limitations of existing technologies. Here we describe a method for quantitatively assessing protein translocation using proximity-induced enzyme complementation. The complementation assay for protein translocation (CAPT) is derived from beta-galactosidase and comprises one enzyme fragment, omega, which is localized to a particular subcellular region, and a small complementing peptide, alpha, which is fused to the protein of interest. The concentration of alpha in the immediate vicinity of omega correlates with the amount of enzyme activity obtained in a dose- and time-dependent manner, thus acting as a genetically encoded biosensor for local protein concentration. Using CAPT, inducible protein movement from the cytosol to the nucleus or plasma membrane was quantitatively monitored in multiwell format and in live mammalian cells by flow cytometry.
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Affiliation(s)
- Tom S Wehrman
- Baxter Laboratory for Genetic Pharmacology, Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California 94305, USA
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