NR4A Orphan Receptors as Drug Targets

G-Protein-Coupled Receptors in Drug Discovery: Nanosizing Using Cell-Free Technologies and Molecular Biology Approaches

CrossRef Listing of Deleted DOIs ◽

10.1177/1087057105280517 ◽

2005 ◽

Vol 10 (8) ◽

pp. 765-779 ◽

Cited By ~ 30

Author(s):

Wayne R. Leifert ◽

Amanda L. Aloia ◽

Olgatina Bucco ◽

Richard V. Glatz ◽

Edward J. McMurchie

Keyword(s):

Signal Transduction ◽

G Protein ◽

Drug Targets ◽

G Protein Coupled Receptors ◽

Orphan Receptors ◽

Molecular Switching ◽

Physiological Processes ◽

Current Cell ◽

G Protein Coupled ◽

Signaling Components

Signal transduction by G-protein-coupled receptors (GPCRs) underpins a multitude of physiological processes. Ligand recognition by the receptor leads to activation of a genericmolecular switch involving heterotrimeric G-proteins and guanine nucleotides. Signal transduction has been studied extensively with both cell-based systems and assays comprising isolated signaling components. Interest and commercial investment in GPCRs in areas such as drug targets, orphan receptors, highthroughput screening, biosensors, and so on will focus greater attention on assay development to allow for miniaturization, ultra-high throughput and, eventually, microarray/biochip assay formats. Although cell-based assays are adequate for many GPCRs, it is likely that these formatswill limit the development of higher density GPCRassay platforms mandatory for other applications. Stable, robust, cell-free signaling assemblies comprising receptor and appropriate molecular switching components will form the basis of future GPCR assay platforms adaptable for such applications as microarrays. The authors review current cell-free GPCR assay technologies and molecular biological approaches for construction of novel, functional GPCR assays.

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Minireview: Genomics Versus Orphan Nuclear Receptors—A Half-Time Report

Molecular Endocrinology ◽

10.1210/mend.16.6.0849 ◽

2002 ◽

Vol 16 (6) ◽

pp. 1135-1144

Author(s):

Timothy M. Willson ◽

John T. Moore

Keyword(s):

Nuclear Receptors ◽

Drug Targets ◽

Hormone Receptors ◽

Receptor Gene ◽

Orphan Nuclear Receptors ◽

Orphan Receptors ◽

Genomic Technologies ◽

Full Complement ◽

And Function ◽

The Impact

Abstract Following the successful cloning of the orphan nuclear receptors during the 1990s we entered the 21st century with knowledge of the full complement of human nuclear receptors. Many of these proteins are ligand-activated transcription factors that act as the cognate receptors for steroid, retinoid, and thyroid hormones. In addition to these well characterized endocrine hormone receptors, there are a large number of orphan receptors of which less is known about the nature and function of their ligands. The task of deciphering the physiological function of these orphan receptors has been aided by a new generation of genomic technologies. Through application of chemical, structural, and functional genomics, several orphan nuclear receptors have emerged as pharmaceutical drug targets for the treatment of important human diseases. The significant progress that has been made in the functional analysis of more than half of the nuclear receptor gene family provides an opportunity to review the impact of genomics in this endeavor.

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Constitutive G protein coupling profiles of understudied orphan GPCRs

10.1101/2021.02.16.431425 ◽

2021 ◽

Author(s):

Sumin Lu ◽

Wonjo Jang ◽

Asuka Inoue ◽

Nevin A. Lambert

Keyword(s):

G Protein ◽

Drug Targets ◽

Protein Complexes ◽

Resonance Energy Transfer ◽

Resonance Energy ◽

Receptor Ligands ◽

Orphan Receptors ◽

G Protein Coupling ◽

Protein Coupling ◽

Orphan Gpcrs

AbstractA large number of GPCRs are potentially valuable drug targets but remain understudied. Many of these lack well-validated activating ligands and are considered “orphan” receptors, and G protein coupling profiles have not been defined for many orphan GPCRs. Here we asked if constitutive receptor activity can be used to determine G protein coupling profiles of orphan GPCRs. We monitored nucleotide-sensitive interactions between 48 understudied orphan GPCRs and five G proteins (240 combinations) using bioluminescence resonance energy transfer (BRET). No receptor ligands were used, but GDP was used as a common G protein ligand to disrupt receptor-G protein complexes. Constitutive BRET between the same receptors and β-arrestins was also measured. We found sufficient GDP-sensitive BRET to generate G protein coupling profiles for 22 of the 48 receptors we studied. Altogether we identified 48 coupled receptor-G protein pairs, many of which have not been described previously. We conclude that receptor-G protein complexes that form spontaneously in the absence of guanine nucleotides can be used to profile G protein coupling of constitutively active GPCRs. This approach may prove useful for studying G protein coupling of other GPCRs for which activating ligands are not available.

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Strategies to identify ligands for orphan G-protein-coupled receptors

Biochemical Society Transactions ◽

10.1042/bst0300789 ◽

2002 ◽

Vol 30 (4) ◽

pp. 789-793 ◽

Cited By ~ 20

Author(s):

G. Milligan

Keyword(s):

Drug Design ◽

G Protein ◽

Small Molecule ◽

Drug Targets ◽

G Protein Coupled Receptors ◽

Orphan Receptors ◽

Protein Targets ◽

Small Molecule Drug ◽

Natural Ligands ◽

G Protein Coupled

G-protein-coupled receptors are the most tractable class of protein targets for small molecule drug design. Sequencing of the human genome allied to bio-informatic analysis has identified a large number of putative receptors for which the natural ligands remain undefined. A range of currently employed and developing strategies to identify ligands that interact with these orphan receptors and to validate them as drug targets are described and discussed.

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Efficient Lead Finding, Activity Enhancement and Preliminary Selectivity Control of Nuclear Receptor Ligands Bearing a Phenanthridinone Skeleton

International Journal of Molecular Sciences ◽

10.3390/ijms19072090 ◽

2018 ◽

Vol 19 (7) ◽

pp. 2090 ◽

Cited By ~ 1

Author(s):

Yuko Nishiyama ◽

Shinya Fujii ◽

Makoto Makishima ◽

Yuichi Hashimoto ◽

Minoru Ishikawa

Keyword(s):

Nuclear Receptors ◽

Drug Targets ◽

Retinoic Acid Receptor ◽

Receptor Ligands ◽

Orphan Receptors ◽

Sar Studies ◽

Activity Enhancement ◽

X Receptors ◽

Nuclear Receptor Ligands ◽

Lead Finding

Background: Nuclear receptors (NRs) are considered as potential drug targets because they control diverse biological functions. However, steroidal ligands for NRs have the potential to cross-react with other nuclear receptors, so development of non-steroidal NR ligands is desirable to obtain safer agents for clinical use. We anticipated that efficient lead finding and enhancement of activity toward nuclear receptors recognizing endogenous steroidal ligands might be achieved by exhaustive evaluation of a steroid surrogate library coupled with examination of structure-activity relationships (SAR). Method: We evaluated our library of RORs (retinoic acid receptor-related orphan receptors) inverse agonists and/or PR (progesterone receptor) antagonists based on the phenanthridinone skeleton for antagonistic activities toward liver X receptors (LXRs), androgen receptor (AR) and glucocorticoid receptor (GR) and examined their SAR. Results: Potent LXRβ, AR, and GR antagonists were identified. SAR studies led to a potent AR antagonist (IC50: 0.059 μM). Conclusions: Our approach proved effective for efficient lead finding, activity enhancement and preliminary control of selectivity over other receptors. The phenanthridinone skeleton appears to be a promising steroid surrogate.

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Nuclear Receptors as Drug Targets: New Developments in Coregulators, Orphan Receptors and Major Therapeutic Areas

Expert Opinion on Therapeutic Targets ◽

10.1517/14728222.7.5.679 ◽

2003 ◽

Vol 7 (5) ◽

pp. 679-684 ◽

Cited By ~ 16

Author(s):

Frances M Sladek

Keyword(s):

Nuclear Receptors ◽

Drug Targets ◽

Orphan Receptors ◽

New Developments

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Multiplex GPCR Assay in Reverse Transfection Cell Microarrays

CrossRef Listing of Deleted DOIs ◽

10.1177/1087057103261880 ◽

2004 ◽

Vol 9 (3) ◽

pp. 196-207 ◽

Cited By ~ 30

Author(s):

Yuji M. Mishina ◽

Christopher J. Wilson ◽

Linda Bruett ◽

Jesse J. Smith ◽

Chatanika Stoop-Myer ◽

...

Keyword(s):

G Protein ◽

Drug Targets ◽

Receptor Activation ◽

Calcium Flux ◽

Orphan Receptors ◽

Ligand Selectivity ◽

Ligand Interactions ◽

Cell Microarrays ◽

Reverse Transfection ◽

Targeted Drug Discovery

G protein-coupled receptors (GPCRs) are a superfamily of proteins that include some of the most important drug targets in the pharmaceutical industry. Despite the success of this group of drugs, there remains a need to identify GPCR-targeted drugs with greater selectivity, to develop screening assays for validated targets, and to identify ligands for orphan receptors. To address these challenges, the authors have created a multiplexed GPCR assay that measures greater than 3000 receptor: ligand interactions in a single microplate. The multiplexed assay is generated by combining reverse transfection in a 96-well plate format with a calcium flux readout. This assay quantitatively measures receptor activation and inhibition and permits the determination of compound potency and selectivity for entire families of GPCRs in parallel. To expand the number of GPCR targets that may be screened in this system, receptors are cotransfected with plasmids encoding a promiscuous G protein, permitting the analysis of receptors that do not normally mobilize intracellular calcium upon activation. The authors demonstrate the utility of reverse transfection cell microarrays to GPCR-targeted drug discovery with examples of ligand selectivity screening against a panel of GPCRs as well as dose-dependent titrations of selected agonists and antagonists.

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Constitutive G protein coupling profiles of understudied orphan GPCRs

PLoS ONE ◽

10.1371/journal.pone.0247743 ◽

2021 ◽

Vol 16 (4) ◽

pp. e0247743

Author(s):

Sumin Lu ◽

Wonjo Jang ◽

Asuka Inoue ◽

Nevin A. Lambert

Keyword(s):

G Protein ◽

Drug Targets ◽

Protein Complexes ◽

Resonance Energy Transfer ◽

Resonance Energy ◽

Receptor Ligands ◽

Orphan Receptors ◽

G Protein Coupling ◽

Protein Coupling ◽

Orphan Gpcrs

A large number of GPCRs are potentially valuable drug targets but remain understudied. Many of these lack well-validated activating ligands and are considered “orphan” receptors, and G protein coupling profiles have not been defined for many orphan GPCRs. Here we asked if constitutive receptor activity can be used to determine G protein coupling profiles of orphan GPCRs. We monitored nucleotide-sensitive interactions between 48 understudied orphan GPCRs and five G proteins (240 combinations) using bioluminescence resonance energy transfer (BRET). No receptor ligands were used, but GDP was used as a common G protein ligand to disrupt receptor-G protein complexes. Constitutive BRET between the same receptors and β-arrestins was also measured. We found sufficient GDP-sensitive BRET to generate G protein coupling profiles for 22 of the 48 receptors we studied. Altogether we identified 48 coupled receptor-G protein pairs, many of which have not been described previously. We conclude that receptor-G protein complexes that form spontaneously in the absence of guanine nucleotides can be used to profile G protein coupling of constitutively-active GPCRs. This approach may prove useful for studying G protein coupling of other GPCRs for which activating ligands are not available.

Download Full-text