Inactivation of the Nuclear Receptor Coactivator RAP250 in Mice Results in Placental Vascular Dysfunction

ABSTRACT Coactivators constitute a diverse group of proteins that are essential for optimal transcriptional activity of nuclear receptors. In the past few years many coactivators have been identified but it is still unclear whether these proteins interact indiscriminately with all nuclear receptors and whether there is some redundancy in their functions. We have previously cloned and characterized RAP250 (ASC-2/PRIP/TRBP/NRC), an LXXLL-containing coactivator for nuclear receptors. In order to study its biological role, Rap250 null mice were generated by gene targeting. Here we show that genetic disruption of Rap250 results in embryonic lethality at embryonic day (E) 13.5. Histological examination of placentas revealed a dramatically reduced spongiotrophoblast layer, a collapse of blood vessels in the region bordering the spongiotrophoblast, and labyrinthine layers in placentas from Rap250−/− embryos. These findings suggest that the lethality of Rap250−/− embryos is the result of obstructed placental blood circulation. Moreover, the transcriptional activity of PPARγ is reduced in fibroblasts derived from Rap250−/− embryos, suggesting that RAP250 is an essential coactivator for this nuclear receptor in the placenta. Our results demonstrate that RAP250 is necessary for placental development and thus essential for embryonic development.

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Development of Peptide Antagonists for the Androgen Receptor Using Combinatorial Peptide Phage Display

Molecular Endocrinology ◽

10.1210/me.2005-0072 ◽

2005 ◽

Vol 19 (10) ◽

pp. 2478-2490 ◽

Cited By ~ 53

Author(s):

Ching-yi Chang ◽

Jennifer Abdo ◽

Tanya Hartney ◽

Donald P. McDonnell

Keyword(s):

Androgen Receptor ◽

Phage Display ◽

Nuclear Receptors ◽

Nuclear Receptor ◽

Transcriptional Activity ◽

Binding Pocket ◽

Orphan Nuclear Receptors ◽

Nuclear Receptor Coactivator ◽

Pharmacological Significance ◽

Peptide Phage Display

Abstract Under the auspices of the Nuclear Receptor Signaling Atlas (NURSA) , we have undertaken to evaluate the feasibility of targeting nuclear receptor-coactivator surfaces for new drug discovery. The underlying objective of this approach is to provide the research community with reagents that can be used to modulate the transcriptional activity of nuclear receptors. Using combinatorial peptide phage display, we have been able to develop peptide antagonists that target specific nuclear receptor (NR)-coactivator binding surfaces. It can be appreciated that reagents of this nature will be of use in the study of orphan nuclear receptors for whom classical ligands have not yet been identified. In addition, because the interaction of coactivators with the receptor is an obligate step for NR transcriptional activity, it is anticipated that peptides that block these interactions will enable the definition of the biological and pharmacological significance of individual NR-coactivator interactions. In this report, we describe the use of this approach to develop antagonists of the androgen receptor by targeting its coactivator-binding pocket and their use to study the coactivator-binding surface of this receptor. Based on our findings, we believe that molecules that function by disrupting the androgen receptor-cofactor interactions will have use in the treatment of prostate cancer.

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Identification of a nuclear receptor/coactivator developmental signaling pathway in the nematode parasite Strongyloides stercoralis

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2021864118 ◽

2021 ◽

Vol 118 (8) ◽

pp. e2021864118

Author(s):

Mi Cheong Cheong ◽

Zhu Wang ◽

Tegegn G. Jaleta ◽

Xinshe Li ◽

James B. Lok ◽

...

Keyword(s):

Signaling Pathway ◽

Nuclear Receptor ◽

Transcriptional Activity ◽

Strongyloides Stercoralis ◽

Parasite Development ◽

Binding Motif ◽

Nuclear Receptor Coactivator ◽

Interacting Protein ◽

Third Stage ◽

Infectious Stage

DAF-12 is nematode-specific nuclear receptor that has been proposed to govern development of the infectious stage of parasitic species, including Strongyloides stercoralis. Here, we identified a parasite-specific coactivator, called DAF-12 interacting protein-1 (DIP-1), that is required for DAF-12 ligand-dependent transcriptional activity. DIP-1 is found only in Strongyloides spp. and selectively interacts with DAF-12 through an atypical receptor binding motif. Using CRISPR/Cas9-directed mutagenesis, we demonstrate that DAF-12 is required for the requisite developmental arrest and the ligand-dependent reactivation of infectious S. stercoralis infective third-stage larvae, and that these effects require the DIP-1 coactivator. These studies reveal the existence of a distinct nuclear receptor/coactivator signaling pathway that governs parasite development.

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The Cooperative Function of Nuclear Receptor Coactivator 1 (NCOA1) and NCOA3 in Placental Development and Embryo Survival

Molecular Endocrinology ◽

10.1210/me.2010-0201 ◽

2010 ◽

Vol 24 (10) ◽

pp. 1917-1934 ◽

Cited By ~ 23

Author(s):

Xian Chen ◽

Zhaoliang Liu ◽

Jianming Xu

Keyword(s):

Nuclear Receptor ◽

Placental Development ◽

Embryo Survival ◽

Nuclear Receptor Coactivator

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NRIP, a Novel Nuclear Receptor Interaction Protein, Enhances the Transcriptional Activity of Nuclear Receptors

Journal of Biological Chemistry ◽

10.1074/jbc.m412169200 ◽

2005 ◽

Vol 280 (20) ◽

pp. 20000-20009 ◽

Cited By ~ 16

Author(s):

Tzung-Chieh Tsai ◽

Yung-Lu Lee ◽

Wei-Chih Hsiao ◽

Yeou-Ping Tsao ◽

Show-Li Chen

Keyword(s):

Nuclear Receptors ◽

Nuclear Receptor ◽

Transcriptional Activity ◽

Receptor Interaction

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The Nuclear Receptor-Coactivator Interaction Surface as a Target for Peptide Antagonists of the Peroxisome Proliferator-Activated Receptors

Molecular Endocrinology ◽

10.1210/me.2007-0201 ◽

2007 ◽

Vol 21 (10) ◽

pp. 2361-2377 ◽

Cited By ~ 32

Author(s):

Niharika B. Mettu ◽

Thomas B. Stanley ◽

Mary A. Dwyer ◽

Michelle S. Jansen ◽

John E. Allen ◽

...

Keyword(s):

Nuclear Receptors ◽

Nuclear Receptor ◽

Target Genes ◽

Binding Motif ◽

Peroxisome Proliferator ◽

Constitutive Activity ◽

Phage Display Technology ◽

Nuclear Receptor Coactivator ◽

Peroxisome Proliferator Activated Receptors ◽

Interaction Surface

Abstract The peroxisome proliferator-activated receptors (PPARα, PPARδ, and PPARγ) constitute a family of nuclear receptors that regulates metabolic processes involved in lipid and glucose homeostasis. Although generally considered to function as ligand-regulated receptors, all three PPARs exhibit a high level of constitutive activity that may result from their stimulation by intracellularly produced endogenous ligands. Consequently, complete inhibition of PPAR signaling requires the development of inverse agonists. However, the currently available small molecule antagonists for the PPARs function only as partial agonists, or their efficacy is not sufficient to inhibit the constitutive activity of these receptors. Due to the lack of efficacious antagonists that interact with the ligand-binding domain of the PPARs, we decided to target an interaction that is central to nuclear receptor-mediated gene transcription: the nuclear receptor-coactivator interaction. We utilized phage display technology to identify short LXXLL-containing peptides that bind to the PPARs. Analysis of these peptides revealed a consensus binding motif consisting of HPLLXXLL. Cross-screening of these peptides for binding to other nuclear receptors enabled the identification of a high-affinity PPAR-selective peptide that has the ability to repress PPARγ1-dependent transcription of transfected reporter genes. Most importantly, when introduced into HepG2 cells, the peptide inhibited the expression of endogenous PPARγ1 target genes, adipose differentiation-related protein and mitochondrial 3-hydroxy-3-methylglutaryl coenzyme A synthase 2. This work lends support for the rational development of peptidomimetics that block receptor-mediated transcription by targeting the nuclear receptor-coactivator interaction surface.

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