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Ouyang W, Li Q, Niu Q, Qui M, Fu H, Du Y, Mo X. A multiplexed time-resolved fluorescence resonance energy transfer ultrahigh-throughput screening assay for targeting the SMAD4-SMAD3-DNA complex. J Mol Cell Biol 2024; 15:mjad068. [PMID: 37968137 PMCID: PMC11063955 DOI: 10.1093/jmcb/mjad068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 10/07/2023] [Accepted: 11/14/2023] [Indexed: 11/17/2023] Open
Abstract
The transforming growth factor-beta (TGFβ) signaling pathway plays crucial roles in the establishment of an immunosuppressive tumor microenvironment, making anti-TGFβ agents a significant area of interest in cancer immunotherapy. However, the clinical translation of current anti-TGFβ agents that target upstream cytokines and receptors remains challenging. Therefore, the development of small-molecule inhibitors specifically targeting SMAD4, the downstream master regulator of the TGFβ pathway, would offer an alternative approach with significant therapeutic potential for anti-TGFβ signaling. In this study, we present the development of a cell lysate-based multiplexed time-resolved fluorescence resonance energy transfer (TR-FRET) assay in an ultrahigh-throughput screening (uHTS) 1536-well plate format. This assay enables simultaneous monitoring of the protein‒protein interaction between SMAD4 and SMAD3, as well as the protein‒DNA interaction between SMADs and their consensus DNA-binding motif. The multiplexed TR-FRET assay exhibits high sensitivity, allowing the dynamic analysis of the SMAD4-SMAD3-DNA complex at single-amino acid resolution. Moreover, the multiplexed uHTS assay demonstrates robustness for screening small-molecule inhibitors. Through a pilot screening of an FDA-approved bioactive compound library, we identified gambogic acid and gambogenic acid as potential hit compounds. These proof-of-concept findings underscore the utility of our optimized multiplexed TR-FRET platform for large-scale screening to discover small-molecule inhibitors that target the SMAD4-SMAD3-DNA complex as novel anti-TGFβ signaling agents.
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Affiliation(s)
- Wukun Ouyang
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Qianjin Li
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Qiankun Niu
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Min Qui
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
- Emory Chemical Biology Discovery Center, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Haian Fu
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
- Emory Chemical Biology Discovery Center, Emory University School of Medicine, Atlanta, GA 30322, USA
- Department of Hematology and Medical Oncology and Winship Cancer Institute, Emory University, Atlanta, GA 30322, USA
| | - Yuhong Du
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
- Emory Chemical Biology Discovery Center, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Xiulei Mo
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
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Ouyang W, Niu Q, Qui M, Fu H, Du Y, Mo X. A multiplexed time-resolved fluorescence resonance energy transfer ultrahigh-throughput screening assay for targeting SMAD4-SMAD3-DNA complex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.15.549169. [PMID: 37503208 PMCID: PMC10370110 DOI: 10.1101/2023.07.15.549169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
The signaling pathway of transforming growth factor-beta (TGFβ) plays crucial roles in the establishment of an immunosuppressive tumor microenvironment, making anti-TGFβ agents a significant area of interest in cancer immunotherapy. However, the clinical translation of current anti-TGFβ agents that target upstream cytokines and receptors remains challenging. Therefore, the development of small molecule inhibitors specifically targeting SMAD4, the downstream master regulator of TGFβ pathway, would offer an alternative approach with significant therapeutic potential for anti-TGF-β signaling. In this study, we present the development of a cell lysate-based multiplexed time-resolved fluorescence resonance energy transfer (TR-FRET) assay in an ultrahigh-throughput screening (uHTS) 1536-well plate format. This assay enables simultaneous monitoring of the protein-protein interaction (PPI) between SMAD4 and SMAD3, as well as the protein-DNA interaction (PDI) between SMADs and their consensus DNA binding motif. The multiplexed TR-FRET assay exhibits high sensitivity, allowing the dynamic analysis of the SMAD4-SMAD3-DNA complex at single amino acid resolution. Moreover, the multiplexed uHTS assay demonstrates robustness for screening small molecule inhibitors. Through a pilot screening of an FDA-approved and bioactive compound library, we identified gambogic acid and gambogenic acid as potential hit compounds. These proof-of-concept findings underscore the utility of our optimized multiplexed TR-FRET platform for large-scale screening to discover small molecule inhibitors that target the SMAD4-SMAD3-DNA complex as novel anti-TGFβ signaling agents.
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Zhong J, Guo Y, Lu S, Song K, Wang Y, Feng L, Zheng Z, Zhang Q, Wei J, Sang P, Shi Y, Cai J, Chen G, Liu CY, Yang X, Zhang J. Rational design of a sensitivity-enhanced tracer for discovering efficient APC-Asef inhibitors. Nat Commun 2022; 13:4961. [PMID: 36002443 PMCID: PMC9402538 DOI: 10.1038/s41467-022-32612-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 08/08/2022] [Indexed: 11/24/2022] Open
Abstract
The adenomatous polyposis coli (APC)–Rho guanine nucleotide exchange factor 4 (Asef) protein–protein interaction (PPI) is essential for colorectal cancer metastasis, making it a promising drug target. Herein, we obtain a sensitivity-enhanced tracer (tracer 7) with a high binding affinity (Kd = 0.078 μM) and wide signal dynamic range (span = 251 mp). By using tracer 7 in fluorescence-polarization assays for APC–Asef inhibitor screening, we discover a best-in-class inhibitor, MAI-516, with an IC50 of 0.041 ± 0.004 μM and a conjugated transcriptional transactivating sequence for generating cell-permeable MAIT-516. MAIT-516 inhibits CRC cell migration by specifically hindering the APC–Asef PPI. Furthermore, MAIT-516 exhibits no cytotoxic effects on normal intestinal epithelial cell and colorectal cancer cell growth. Overall, we develop a sensitivity-enhanced tracer for fluorescence polarization assays, which is used for the precise quantification of high-activity APC–Asef inhibitors, thereby providing insight into PPI drug development. The adenomatous polyposis coli (APC)–Asef protein interaction is essential for colorectal cancer metastasis. Here, the authors present the rational design of a sensitivity-enhanced tracer for fluorescence polarization assays, enabling them to discover more efficient APC–Asef interaction inhibitors.
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Affiliation(s)
- Jie Zhong
- State Key Laboratory of Medical Genomics, National Research Center for Translational Medicine at Shanghai, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Medicinal Chemistry and Bioinformatics Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yuegui Guo
- Department of Colorectal and Anal Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shaoyong Lu
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Kun Song
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ying Wang
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Li Feng
- Medicinal Chemistry and Bioinformatics Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhen Zheng
- Medicinal Chemistry and Bioinformatics Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qiufen Zhang
- Medicinal Chemistry and Bioinformatics Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jiacheng Wei
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Peng Sang
- Department of Chemistry, University of South Florida, Tampa, FL, USA
| | - Yan Shi
- Department of Chemistry, University of South Florida, Tampa, FL, USA
| | - Jianfeng Cai
- Department of Chemistry, University of South Florida, Tampa, FL, USA
| | - Guoqiang Chen
- Research Unit of Stress and Cancer, Chinese Academy of Medical Sciences, Shanghai, China
| | - Chen-Ying Liu
- Department of Colorectal and Anal Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Xiuyan Yang
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China. .,State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China.
| | - Jian Zhang
- State Key Laboratory of Medical Genomics, National Research Center for Translational Medicine at Shanghai, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. .,Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, China. .,Medicinal Chemistry and Bioinformatics Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China. .,School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China.
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Song J, Kim H, Lee CY, Yoon J, Yoo WS, Park HG. Identification of thyroid hormone/thyroid hormone receptor interaction based on aptamer-assisted protein-induced fluorescence enhancement. Biosens Bioelectron 2021; 191:113444. [PMID: 34175646 DOI: 10.1016/j.bios.2021.113444] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 06/08/2021] [Accepted: 06/13/2021] [Indexed: 12/27/2022]
Abstract
We herein describe a novel method to identify thyroid hormone (TH)/thyroid hormone receptor (TR) interaction, termed aptamer-assisted protein-induced fluorescence enhancement (AptPIFE). In this method, a detection probe consisting of an RNA strand incorporating TH-specific aptamer and a Cy3-labeled DNA strand holds TH in close proximity to Cy3. The corresponding TR then binds to the TH near Cy3, consequently stimulating Cy3 to emit a significantly enhanced fluorescence through PIFE phenomenon. Based on this simple yet efficient design principle, we successfully identified the interaction of TH with TR within 10 min, down to 0.37 pM with excellent specificity. The practical and robust applicability of this method was also successfully validated by properly screening TR antagonists and reliably quantifying TH present in real clinical serum samples from patients with hyperthyroidism and healthy volunteers.
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Affiliation(s)
- Jayeon Song
- Department of Chemical and Biomolecular Engineering (BK21+ Program), KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Hansol Kim
- Department of Chemical and Biomolecular Engineering (BK21+ Program), KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Chang Yeol Lee
- Department of Chemical and Biomolecular Engineering (BK21+ Program), KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Junhyeok Yoon
- Department of Chemical and Biomolecular Engineering (BK21+ Program), KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Won Sang Yoo
- Department of Internal Medicine, Dankook University College of Medicine, 119, Dandae-ro, Dongnam-gu, Cheonan-si, 31116, Republic of Korea.
| | - Hyun Gyu Park
- Department of Chemical and Biomolecular Engineering (BK21+ Program), KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea.
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Using TR-FRET to Investigate Protein-Protein Interactions: A Case Study of PXR-Coregulator Interaction. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2017; 110:31-63. [PMID: 29412999 DOI: 10.1016/bs.apcsb.2017.06.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Time-resolved fluorescence resonance energy transfer (TR-FRET) protein-protein interaction assays, especially in the format of receptor coregulator (coactivator and corepressor) recruitment/repression assays, have been widely used in nuclear receptor research to characterize the modes of action, efficacies, and binding affinities of ligands (including their properties as agonists, antagonists, and inverse agonists). However, there has been only limited progress in using this assay format for pregnane X receptor (PXR). In this chapter, we discuss TR-FRET protein-protein interaction assays and focus on a novel PXR TR-FRET coactivator interaction assay that we have developed based on a PXR coactivator cocrystal study. This new PXR TR-FRET coactivator interaction assay can characterize the binding affinities of PXR ligands and also differentiate antagonists from agonists. This assay is very robust, with the signal remaining stable over a long incubation time (up to 300min has been tested). It can tolerate high concentrations of DMSO (up to 5%) and has a high signal-to-noise ratio (six under typical assay conditions). This newly developed PXR TR-FRET coactivator interaction assay has potential application in high-throughput screening to identify and characterize novel PXR agonists and antagonists.
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7
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Madak-Erdogan Z, Kim SH, Gong P, Zhao YC, Zhang H, Chambliss KL, Carlson KE, Mayne CG, Shaul PW, Korach KS, Katzenellenbogen JA, Katzenellenbogen BS. Design of pathway preferential estrogens that provide beneficial metabolic and vascular effects without stimulating reproductive tissues. Sci Signal 2016; 9:ra53. [PMID: 27221711 PMCID: PMC4896643 DOI: 10.1126/scisignal.aad8170] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
There is great medical need for estrogens with favorable pharmacological profiles that support desirable activities for menopausal women, such as metabolic and vascular protection, but that lack stimulatory activities on the breast and uterus. We report the development of structurally novel estrogens that preferentially activate a subset of estrogen receptor (ER) signaling pathways and result in favorable target tissue-selective activity. Through a process of structural alteration of estrogenic ligands that was designed to preserve their essential chemical and physical features but greatly reduced their binding affinity for ERs, we obtained "pathway preferential estrogens" (PaPEs), which interacted with ERs to activate the extranuclear-initiated signaling pathway preferentially over the nuclear-initiated pathway. PaPEs elicited a pattern of gene regulation and cellular and biological processes that did not stimulate reproductive and mammary tissues or breast cancer cells. However, in ovariectomized mice, PaPEs triggered beneficial responses both in metabolic tissues (adipose tissue and liver) that reduced body weight gain and fat accumulation and in the vasculature that accelerated repair of endothelial damage. This process of designed ligand structure alteration represents a novel approach to develop ligands that shift the balance in ER-mediated extranuclear and nuclear pathways to obtain tissue-selective, non-nuclear PaPEs, which may be beneficial for postmenopausal hormone replacement. The approach may also have broad applicability for other members of the nuclear hormone receptor superfamily.
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Affiliation(s)
- Zeynep Madak-Erdogan
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Sung Hoon Kim
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Ping Gong
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Yiru C Zhao
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Hui Zhang
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9063, USA
| | - Ken L Chambliss
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9063, USA
| | - Kathryn E Carlson
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Christopher G Mayne
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Philip W Shaul
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9063, USA
| | - Kenneth S Korach
- National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | | | - Benita S Katzenellenbogen
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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Sy M, Nonat A, Hildebrandt N, Charbonnière LJ. Lanthanide-based luminescence biolabelling. Chem Commun (Camb) 2016; 52:5080-95. [DOI: 10.1039/c6cc00922k] [Citation(s) in RCA: 155] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Multiplexing, time-resolution, FRET…lanthanide-based biolabels reveal exceptional spectroscopic properties for bioanalytical applications.
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Affiliation(s)
- Mohamadou Sy
- Laboratoire d'Ingénierie Moléculaire Appliquée à l'Analyse
- IPHC
- UMR 7178 CNRS
- Université de Strasbourg
- ECPM
| | - Aline Nonat
- Laboratoire d'Ingénierie Moléculaire Appliquée à l'Analyse
- IPHC
- UMR 7178 CNRS
- Université de Strasbourg
- ECPM
| | - Niko Hildebrandt
- NanoBioPhotonics, Institut d'Electronique Fondamentale
- Université Paris-Saclay
- Université Paris-Sud
- CNRS
- Orsay
| | - Loïc J. Charbonnière
- Laboratoire d'Ingénierie Moléculaire Appliquée à l'Analyse
- IPHC
- UMR 7178 CNRS
- Université de Strasbourg
- ECPM
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Lipchik AM, Perez M, Cui W, Parker LL. Multicolored, Tb³⁺-Based Antibody-Free Detection of Multiple Tyrosine Kinase Activities. Anal Chem 2015. [PMID: 26207839 DOI: 10.1021/acs.analchem.5b02233] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Kinase signaling is a major mechanism driving many cancers. While many inhibitors have been developed and are employed in the clinic, resistance due to crosstalk and pathway reprogramming is an emerging problem. High-throughput assays to detect multiple pathway kinases simultaneously could better model these complex relationships and enable drug development to combat this type of resistance. We developed a strategy to take advantage of time-resolved luminescence of Tb(3+)-chelated phosphotyrosine-containing peptides, which facilitated efficient energy transfer to small molecule fluorophores conjugated to the peptides to produce orthogonally colored biosensors for two different kinases. This enabled multiplexed detection with high signal-to-noise in a high-throughput-compatible format. This proof-of-concept study provides a platform that could be applied to other lanthanide metal and fluorophore combinations to achieve even greater multiplexing without the need for phosphospecific antibodies.
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Affiliation(s)
- Andrew M Lipchik
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy and Purdue Center for Cancer Research, Purdue University, 201 S. University Street, West Lafayette, Indiana 47907, United States
| | - Minervo Perez
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy and Purdue Center for Cancer Research, Purdue University, 201 S. University Street, West Lafayette, Indiana 47907, United States
| | - Wei Cui
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy and Purdue Center for Cancer Research, Purdue University, 201 S. University Street, West Lafayette, Indiana 47907, United States
| | - Laurie L Parker
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy and Purdue Center for Cancer Research, Purdue University, 201 S. University Street, West Lafayette, Indiana 47907, United States
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Hildebrandt N, Wegner KD, Algar WR. Luminescent terbium complexes: Superior Förster resonance energy transfer donors for flexible and sensitive multiplexed biosensing. Coord Chem Rev 2014. [DOI: 10.1016/j.ccr.2014.01.020] [Citation(s) in RCA: 146] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Zhao RL, Sun B, Liu Y, Li JH, Xiong WL, Liang DC, Guo G, Zuo AJ, Zhang JY. Cloning and identification of a novel thyroid hormone receptor β isoform expressed in the pituitary gland. Mol Cell Biochem 2014; 389:141-50. [PMID: 24481752 DOI: 10.1007/s11010-013-1935-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 12/18/2013] [Indexed: 12/11/2022]
Abstract
We have previously identified a novel Trβ isoform (TrβΔ) in the rat, in which a novel exon N (108 bps) was found between exon 3 and exon 4 of TrβΔ, which represents the only difference between TrβΔ and Trβ1. In this study, we searched for an elongated Trβ2-like subtype with one additional exon N. We successfully isolated the entire mRNA/cDNA of a novel elongated Trβ2 isoform via PCR in the rat pituitary gland. The mRNA/cDNA was only 108 bps (exon N) longer than that Trβ2, and the extension of the sequence was between exon 3 and 4 of Trβ. The whole sequence of this novel Trβ isoform has been published in NCBI GenBank (HM043807.1); it is named TRbeta2Delta (Trβ2Δ). In adult rat pituitary tissue, quantitative real-time RT-PCR analysis showed that the mRNA levels of Trβ2Δ and Trβ2 were roughly equal (P > 0.05). We cloned, expressed, and purified the His-Trβ2Δ protein [recombinant TRβ2Δ (rTRβ2Δ)]. SDS-PAGE and western blotting revealed that the molecular weight of rTRβ2Δ was 58.2 kDa. Using a radioligand binding assay and an electrophoretic mobility shift assay, rTRβ2Δ-bound T3 with high affinity and recognized thyroid hormone response element (TRE) binding sites. Finally, in vitro transfection experiments further confirmed that rTRβ2Δ binding T3 significantly promotes the transcription of target genes via the TRE. Here, we have provided evidence suggesting that rTRβ2Δ is a novel functional TR isoform.
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Affiliation(s)
- Rong-Lan Zhao
- Institute of Endocrinology, Metabolic Disease Hospital, Tianjin Medical University, Key Laboratory of Hormone and Development, National Health Ministry of China, Tianjin, 300070, People's Republic of China,
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Jiang Y, Gong P, Madak-Erdogan Z, Martin T, Jeyakumar M, Carlson K, Khan I, Smillie TJ, Chittiboyina AG, Rotte SCK, Helferich WG, Katzenellenbogen JA, Katzenellenbogen BS. Mechanisms enforcing the estrogen receptor β selectivity of botanical estrogens. FASEB J 2013; 27:4406-18. [PMID: 23882126 DOI: 10.1096/fj.13-234617] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Because little is known about the actions of botanical estrogens (BEs), widely consumed by menopausal women, we investigated the mechanistic and cellular activities of some major BEs. We examined the interactions of genistein, daidzein, equol, and liquiritigenin with estrogen receptors ERα and ERβ, with key coregulators (SRC3 and RIP140) and chromatin binding sites, and the regulation of gene expression and proliferation in MCF-7 breast cancer cells containing ERα and/or ERβ. Unlike the endogenous estrogen, estradiol (E2), BEs preferentially bind to ERβ, but their ERβ-potency selectivity in gene stimulation (340- to 830-fold vs. E2) is enhanced at several levels (coregulator recruitment, chromatin binding); nevertheless, at high (0.1 or 1 μM) concentrations, BEs also fully activate ERα. Because ERα drives breast cancer cell proliferation and ERβ dampens this, the relative levels of these two ERs in target cells and the BE dose greatly affect gene expression and proliferative response and will be crucial determinants of the potential benefits vs. risks of BEs. Our findings reveal key and novel mechanistic differences in the estrogenic activities of BEs vs. E2, with BEs displaying patterns of activity distinctly different from those seen with E2 and provide valuable information to inform future studies.
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Affiliation(s)
- Yan Jiang
- 1Department of Molecular and Integrative Physiology, University of Illinois and College of Medicine at Urbana-Champaign, Urbana, IL 61801, USA.
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Starck M, Kadjane P, Bois E, Darbouret B, Incamps A, Ziessel R, Charbonnière LJ. Towards Libraries of Luminescent Lanthanide Complexes and Labels from Generic Synthons. Chemistry 2011; 17:9164-79. [DOI: 10.1002/chem.201100390] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Indexed: 01/23/2023]
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Horton RA, Vogel KW. Multiplexing Terbium- and Europium-Based TR-FRET Readouts to Increase Kinase Assay Capacity. ACTA ACUST UNITED AC 2010; 15:1008-15. [DOI: 10.1177/1087057110368993] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Identification and characterization of kinase inhibitor potency and selectivity is often an iterative process in which a library of compounds is first screened against a single kinase, and hits from that screen are then profiled against other kinases to determine specificity. By developing kinase assays that employ either a terbium- or a europium-based time-resolved fluorescence resonance energy transfer (TR-FRET) readout, one can take advantage of the distinct emission properties of these labels to develop assays for 2 kinases that can be performed simultaneously in the same well. This not only increases the information content provided per assay well but can immediately provide information on compound specificity. The authors have applied this strategy to the development of multiplexed assays for 2 examples systems: EGFR and IKKβ, as well as lipid kinase family members mTOR and PIK3C3. They demonstrate the ability of these multiplexed assays to characterize selective kinase inhibitors in a dose-response mode, with no difference in results obtained from traditional single kinase assays performed separately.
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Kim SH, Gunther JR, Katzenellenbogen JA. Monitoring a coordinated exchange process in a four-component biological interaction system: development of a time-resolved terbium-based one-donor/three-acceptor multicolor FRET system. J Am Chem Soc 2010; 132:4685-92. [PMID: 20230029 PMCID: PMC2860875 DOI: 10.1021/ja100248q] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hormonal regulation of cellular function involves the binding of small molecules with receptors that then coordinate subsequent interactions with other signal transduction proteins. These dynamic, multicomponent processes are difficult to track in cells and even in reconstituted in vitro systems, and most methods can monitor only two-component interactions, often with limited capacity to follow dynamic changes. Through a judicious choice of three organic acceptor fluorophores paired with a terbium donor fluorophore, we have developed the first example of a one-donor/three-acceptor multicolor time-resolved fluorescence energy transfer (TR-FRET) system, and we have exemplified its use by monitoring a ligand-regulated protein-protein exchange process in a four-component biological system. By careful quantification of the emission from each of the three acceptors at the four channels for terbium donor emission, we demonstrate that any of these donor channels can be used to estimate the magnitude of the three FRET signals in this terbium-donor triple-acceptor system with minimal bleedthrough. Using this three-channel terbium-based, TR-FRET assay system, we show in one experiment that the addition of a fluorescein-labeled estrogen agonist displaces a SNAPFL-labeled antiestrogen from the ligand binding pocket of a terbium-labeled estrogen receptor, at the same time causing a Cy5-labeled coactivator to be recruited to the estrogen receptor. This experiment demonstrates the power of a four-color TR-FRET experiment, and it shows that the overall process of estrogen receptor ligand exchange and coactivator binding is a dynamic but precisely coordinated process.
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Affiliation(s)
- Sung Hoon Kim
- Department of Chemistry, University of Illinois, 600 S. Mathews Ave., Urbana, IL 61801
| | - Jillian R. Gunther
- Department of Chemistry, University of Illinois, 600 S. Mathews Ave., Urbana, IL 61801
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Hilal T, Puetter V, Otto C, Parczyk K, Bader B. A dual estrogen receptor TR-FRET assay for simultaneous measurement of steroid site binding and coactivator recruitment. ACTA ACUST UNITED AC 2010; 15:268-78. [PMID: 20150592 DOI: 10.1177/1087057109359196] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The human estrogen receptors (hER) are members of the nuclear hormone receptor (NHR) superfamily and represent important drug targets for the pharmaceutical industry. Initially, ligand binding assays were used to identify novel ligands using receptors purified from native tissues. With the advent of molecular cloning techniques, cell-based transactivation assays have been the gold standard for many years of drug discovery. With the elucidation of the structural mechanisms underlying the activation of NHRs, cell-free assays with purified receptors have become important tools to directly assess different binding sites (e.g., the hormone binding site or the cofactor binding site). The available cell-free assays have so far facilitated the study of one binding site at a time. With the introduction of Terbium (Tb(3+))-based time-resolved fluorescence energy transfer (TR-FRET), it has become possible to measure 2 different interactions within 1 test tube in parallel. The authors have applied this technology to develop a dual readout system for the simultaneous monitoring of steroid hormone site binding and cofactor peptide recruitment. They took advantage of a commercially available fluorescent tracer as an indicator for classical steroid site binding and designed a novel peptide derived from the peroxisome proliferator-activated receptor gamma coactivator-1a (PGC1a) as an indicator for functional agonistic behavior of a test compound. The established assay is able to differentiate between agonists, antagonists, partial agonists, and compounds binding to the cofactor recruitment site. The IC(50) values obtained for a number of reference compounds in the multiplexed assay are in concordance with published data. The simple 1-step mix-and-measure protocol gives excellent quality and robustness and can be miniaturized to 5-microL volume.
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Affiliation(s)
- Tarek Hilal
- Lead Generation and Optimization, Screening, Bayer Schering Pharma AG, Muellerstr. 178, 13342 Berlin, Germany
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Moore TW, Mayne CG, Katzenellenbogen JA. Minireview: Not picking pockets: nuclear receptor alternate-site modulators (NRAMs). Mol Endocrinol 2009; 24:683-95. [PMID: 19933380 DOI: 10.1210/me.2009-0362] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Because of their central importance in gene regulation and mediating the actions of many hormones, the nuclear receptors (NRs) have long been recognized as very important biological and pharmaceutical targets. Of all the surfaces available on a given NR, the singular site for regulation of receptor activity has almost invariably been the ligand-binding pocket of the receptor, the site where agonists, antagonists, and selective NR modulators interact. With our increasing understanding of the multiple molecular components involved in NR action, researchers have recently begun to look to additional interaction sites on NRs for regulating their activities by novel mechanisms. The alternate NR-associated interaction sites that have been targeted include the coactivator-binding groove and allosteric sites in the ligand-binding domain, the zinc fingers of the DNA-binding domain, and the NR response element in DNA. The studies thus far have been performed with the estrogen receptors, the androgen receptor (AR), the thyroid hormone receptors, and the pregnane X receptor. Phenotypic and conformation-based screens have also identified small molecule modulators that are believed to function through the NRs but have, as yet, unknown sites and mechanisms of action. The rewards from investigation of these NR alternate-site modulators should be the discovery of new therapeutic approaches and novel agents for regulating the activities of these important NR proteins.
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Affiliation(s)
- Terry W Moore
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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Shukla SJ, Nguyen DT, Macarthur R, Simeonov A, Frazee WJ, Hallis TM, Marks BD, Singh U, Eliason HC, Printen J, Austin CP, Inglese J, Auld DS. Identification of pregnane X receptor ligands using time-resolved fluorescence resonance energy transfer and quantitative high-throughput screening. Assay Drug Dev Technol 2009; 7:143-69. [PMID: 19505231 DOI: 10.1089/adt.2009.193] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The human pregnane X nuclear receptor (PXR) is a xenobiotic-regulated receptor that is activated by a range of diverse chemicals, including antibiotics, antifungals, glucocorticoids, and herbal extracts. PXR has been characterized as an important receptor in the metabolism of xenobiotics due to induction of cytochrome P450 isozymes and activation by a large number of prescribed medications. Developing methodologies that can efficiently detect PXR ligands will be clinically beneficial to avoid potential drug-drug interactions. To facilitate the identification of PXR ligands, a time-resolved fluorescence resonance energy transfer (TR-FRET) assay was miniaturized to a 1,536-well microtiter plate format to employ quantitative high-throughput screening (qHTS). The optimized 1,536-well TR-FRET assay showed Z'-factors of >or=0.5. Seven- to 15-point concentration-response curves (CRCs) were generated for 8,280 compounds using both terbium and fluorescein emission data, resulting in the generation of 241,664 data points. The qHTS method allowed us to retrospectively examine single concentration screening datasets to assess the sensitivity and selectivity of the PXR assay at different compound screening concentrations. Furthermore, nonspecific assay artifacts such as concentration-based quenching of the terbium signal and compound fluorescence were identified through the examination of CRCs for specific emission channels. The CRC information was also used to define chemotypes associated with PXR ligands. This study demonstrates the feasibility of profiling thousands of compounds against PXR using the TR-FRET assay in a high-throughput format.
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Affiliation(s)
- Sunita J Shukla
- NIH Chemical Genomics Center, National Institutes of Health, Bethesda, Maryland, USA
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