scholarly journals Hormone receptor 4 is required in muscles and distinct ovarian cell types to regulate specific steps of Drosophila oogenesis

Development ◽  
2021 ◽  
pp. dev.198663
Author(s):  
Lesley N. Weaver ◽  
Daniela Drummond-Barbosa
Keyword(s):  
Nuclear Receptors ◽  
Nuclear Receptor ◽  
Hormone Receptor ◽  
Cell Types ◽  
Germline Stem Cell ◽  
Follicle Growth ◽  
Peripheral Tissues ◽  
Ovarian Cell ◽  
Nuclear Receptor Superfamily ◽  
Germline Cyst

The conserved nuclear receptor superfamily has critical roles in many processes, including reproduction. Nuclear receptors with known roles in oogenesis have been studied mostly in the context of their ovary-intrinsic requirement. Recent studies in Drosophila, however, have begun to reveal new roles of nuclear receptor signaling in peripheral tissues in controlling reproduction. Here, we identified Hormone receptor 4 (Hr4) as an oogenesis regulator required in the ovary and muscles. Global Hr4 knockdown leads to increased germline stem cell (GSC) loss, reduced GSC proliferation, early germline cyst death, slowed follicle growth, and vitellogenic follicle degeneration. Tissue-specific knockdown experiments uncovered ovary-intrinsic and peripheral tissue requirements for Hr4. In the ovary, Hr4 is required in the niche for GSC proliferation and in the germline for GSC maintenance. Hr4 functions in muscles to promote GSC maintenance and follicle growth. The specific tissues that require Hr4 for survival of early germline cysts and vitellogenic follicles remain unidentified. These results add to the few examples of muscles controlling gametogenesis and expand our understanding of the complexity of nuclear receptor regulation of various aspects of oogenesis.

scholarly journals The Nuclear Receptor Seven Up Regulates Genes Involved in Immunity and Xenobiotic Response in the Adult Drosophila Female Fat Body

2020 ◽  
Vol 10 (12) ◽  
pp. 4625-4635
Author(s):  
Lesley N. Weaver ◽  
Daniela Drummond-Barbosa
Keyword(s):  
Nuclear Receptors ◽  
Nuclear Receptor ◽  
Adult Female ◽  
Fat Body ◽  
Peripheral Tissues ◽  
Immune Genes ◽  
Xenobiotic Detoxification ◽  
Intrinsic Roles ◽  
Xenobiotic Response ◽  
Adult Drosophila

The physiology of organisms depends on inter-organ communication in response to changes in the environment. Nuclear receptors are broadly expressed transcription factors that respond to circulating molecules to control many biological processes, including immunity, detoxification, and reproduction. Although the tissue-intrinsic roles of nuclear receptors in reproduction have been extensively studied, there is increasing evidence that nuclear receptor signaling in peripheral tissues can also influence oogenesis. We previously showed that the Drosophila nuclear receptor Seven up (Svp) is required in the adult fat body to regulate distinct steps of oogenesis; however, the relevant downstream targets of Svp remain unknown. Here, we took an RNA sequencing approach to identify candidate Svp targets specifically in the adult female fat body that might mediate this response. svp knockdown in the adult female fat body significantly downregulated immune genes involved in the first line of pathogen defense, suggesting a role for Svp in stimulating early immunity. In addition, we found that Svp transcriptionally regulates genes involved in each step of the xenobiotic detoxification response. Based on these findings, we propose a testable model in which Svp functions in the adult female fat body to stimulate early defense against pathogens and facilitate detoxification as part of its mechanisms to promote oogenesis.

scholarly journals A novel orphan receptor specific for a subset of thyroid hormone-responsive elements and its interaction with the retinoid/thyroid hormone receptor subfamily.

1994 ◽  
Vol 14 (10) ◽  
pp. 7025-7035 ◽  
Author(s):  
R Apfel ◽  
D Benbrook ◽  
E Lernhardt ◽  
M A Ortiz ◽  
G Salbert ◽  
...  
Keyword(s):  
Amino Acid ◽  
Thyroid Hormone ◽  
Dna Binding ◽  
Nuclear Receptors ◽  
Nuclear Receptor ◽  
Dna Sequences ◽  
Hormone Receptor ◽  
Thyroid Hormone Receptor ◽  
Orphan Receptor ◽  
Retinoid Receptor

The steroid/hormone nuclear receptor superfamily comprises several subfamilies of receptors that interact with overlapping DNA sequences and/or related ligands. The thyroid/retinoid hormone receptor subfamily has recently attracted much interest because of the complex network of its receptor interactions. The retinoid X receptors (RXRs), for instance, play a very central role in this subfamily, forming heterodimers with several receptors. Here we describe a novel member of this subfamily that interacts with RXR. Using a v-erbA probe, we obtained a cDNA which encodes a novel 445-amino-acid protein, RLD-1, that contains the characteristic domains of nuclear receptors. Northern (RNA) blot analysis showed that in mature rats, the receptor is highly expressed in spleen, pituitary, lung, liver, and fat. In addition, weaker expression is observed in several other tissues. Amino acid sequence alignment and DNA-binding data revealed that the DNA-binding domain of the new receptor is related to that of the thyroid/retinoid subgroup of nuclear receptors. RLD-1 preferentially binds as a heterodimer with RXR to a direct repeat of the half-site sequence 5'-G/AGGTCA-3', separated by four nucleotides (DR-4). Surprisingly, this binding is dependent to a high degree on the nature of the spacing nucleotides. None of the known nuclear receptor ligands activated RLD-1. In contrast, a DR-4-dependent constitutive transcriptional activation of a chloramphenicol acetyltransferase reporter gene by the RLD-1/RXR alpha heterodimer was observed. Our data suggest a highly specific role for this novel receptor within the network of gene regulation by the thyroid/retinoid receptor subfamily.

scholarly journals Coregulator Function: A Key to Understanding Tissue Specificity of Selective Receptor Modulators

2004 ◽  
Vol 25 (1) ◽  
pp. 45-71 ◽  
Author(s):  
Carolyn L. Smith ◽  
Bert W. O’Malley
Keyword(s):  
Estrogen Receptor ◽  
Nuclear Receptors ◽  
Nuclear Receptor ◽  
Critical Role ◽  
Dependent Manner ◽  
Nuclear Receptor Superfamily ◽  
Binding Domains ◽  
Receptor Modulator ◽  
Cellular Environment ◽  
Receptor Modulators

Ligands for the nuclear receptor superfamily control many aspects of biology, including development, reproduction, and homeostasis, through regulation of the transcriptional activity of their cognate receptors. Selective receptor modulators (SRMs) are receptor ligands that exhibit agonistic or antagonistic biocharacter in a cell- and tissue context-dependent manner. The prototypical SRM is tamoxifen, which as a selective estrogen receptor modulator, can activate or inhibit estrogen receptor action. SRM-induced alterations in the conformation of the ligand-binding domains of nuclear receptors influence their abilities to interact with other proteins, such as coactivators and corepressors. It has been postulated, therefore, that the relative balance of coactivator and corepressor expression within a given target cell determines the relative agonist vs. antagonist activity of SRMs. However, recent evidence reveals that the cellular environment also plays a critical role in determining SRM biocharacter. Cellular signaling influences the activity and subcellular localization of coactivators and corepressors as well as nuclear receptors, and this contributes to gene-, cell-, and tissue-specific responses to SRM ligands. Increased understanding of the effect of cellular environment on nuclear receptors and their coregulators has the potential to open the field of SRM discovery and research to many members of the nuclear receptor superfamily.

scholarly journals A Retrospective on Nuclear Receptor Regulation of Inflammation: Lessons from GR and PPARs

PPAR Research ◽  
2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Min-Dian Li ◽  
Xiaoyong Yang
Keyword(s):  
Glucocorticoid Receptor ◽  
Signaling Pathways ◽  
Nuclear Receptors ◽  
Nuclear Receptor ◽  
Receptor Regulation ◽  
Peroxisome Proliferator ◽  
Novel Therapies ◽  
Nuclear Receptor Superfamily ◽  
Founding Member ◽  
Peroxisome Proliferator Activated Receptors

Members of the nuclear receptor superfamily have vital roles in regulating immunity and inflammation. The founding member, glucocorticoid receptor (GR), is the prototype to demonstrate immunomodulation via transrepression of the AP-1 and NF-κB signaling pathways. Peroxisome proliferator-activated receptors (PPARs) have emerged as key regulators of inflammation. This review examines the history and current advances in nuclear receptor regulation of inflammation by the crosstalk with AP-1 and NF-κB signaling, focusing on the roles of GR and PPARs. A better understanding of the molecular mechanism by which nuclear receptors inhibit proinflammatory signaling pathways will enable novel therapies to treat chronic inflammation.

The evolution of the nuclear receptor superfamily

2004 ◽  
Vol 40 ◽  
pp. 11-26 ◽  
Author(s):  
Héctor Escriva ◽  
Stéphanie Bertrand ◽  
Vincent Laudet
Keyword(s):  
Transcription Factors ◽  
Nuclear Receptors ◽  
Nuclear Receptor ◽  
Evolutionary History ◽  
Hormone Receptors ◽  
Nuclear Receptor Superfamily ◽  
Complete Genomes ◽  
High Degree ◽  
Animal Genomes

Nuclear receptors form a superfamily of ligand-activated transcription factors implicated in various physiological functions from development to homoeostasis. Nuclear receptors share a common evolutionary history revealed by their conserved structure and by their high degree of sequence conservation. Here we review the latest advances on the evolution of nuclear receptors by addressing the following questions. What is known about the appearance and diversification of nuclear hormone receptors? How did their different functional characteristics evolve? What can we infer from the analysis of complete genomes? In summary, the study of the evolution of nuclear receptors will be very important not only for understanding their functions in vivo but also for obtaining insights into the evolution of animal genomes as a whole.

Regulation of cytochrome P450 (CYP) genes by nuclear receptors

2000 ◽  
Vol 347 (2) ◽  
pp. 321-337 ◽  
Author(s):  
Paavo HONKAKOSKI ◽  
Masahiko NEGISHI
Keyword(s):  
Cytochrome P450 ◽  
Ligand Binding ◽  
Nuclear Receptors ◽  
Nuclear Receptor ◽  
Target Genes ◽  
Physiological Functions ◽  
Nuclear Receptor Superfamily ◽  
Cyp Isoforms ◽  
Exogenous Compounds

Members of the nuclear-receptor superfamily mediate crucial physiological functions by regulating the synthesis of their target genes. Nuclear receptors are usually activated by ligand binding. Cytochrome P450 (CYP) isoforms often catalyse both formation and degradation of these ligands. CYPs also metabolize many exogenous compounds, some of which may act as activators of nuclear receptors and disruptors of endocrine and cellular homoeostasis. This review summarizes recent findings that indicate that major classes of CYP genes are selectively regulated by certain ligand-activated nuclear receptors, thus creating tightly controlled networks.

scholarly journals Mutual Information Identifies Sequence Positions Conserved within the Nuclear Receptor Superfamily: Approach Reveals Functionally Important Regions for DNA Binding Specificity

2011 ◽  
Vol 9 (1) ◽  
pp. nrs.09001 ◽  
Author(s):  
Scooter Willis ◽  
Patrick Griffin
Keyword(s):  
Dna Binding ◽  
Mutual Information ◽  
Nuclear Receptors ◽  
Nuclear Receptor ◽  
Binding Specificity ◽  
Oligomeric State ◽  
Dimer Interface ◽  
Nuclear Receptor Superfamily ◽  
Dna Binding Specificity ◽  
Flanking Region

Members of the nuclear receptor superfamily differentiate in terms of specificity for DNA recognition and binding, oligomeric state, and ligand binding. The wide range of specificities are impressive given the high degree of sequence conservation in the DNA binding domain (DBD) and moderate sequence conservation with high structural similarity within the ligand binding domains (LBDs). Determining sequence positions that are conserved within nuclear receptor subfamilies can provide important indicators into the structural dynamics that translate to oligomeric state of the active receptor, DNA binding specificity and ligand affinity and selectivity. Here we present a method to analyze sequence data from all nuclear receptors that facilitates detection of co-evolving pairs using Mutual Information (MI). Using this method we demonstrate that MI can reveal functionally important sequence positions within the superfamily and the approach identified three sequence positions that have conserved sequence patterns across all nuclear receptors and subfamilies. Interestingly, two of the sequence positions identified are located within the DBD CII and the third was within Helix c of the DBD. These sequences are located within the heterodimer interface of PPARγ (CII) and RXR α (Helix c) based on PDB:3DZU. Helix c of PPARγ, which is not involved in the DBD dimer interface, binds the minor groove in the 5’ flanking region in a consensus PPARγ response element (PPRE) and the corresponding RXR α (CII) is found in the 3’ flanking region of RXRE (3DZU). As these three sequence positions represent unique identifiers for all nuclear receptors and they are located within the dimer interface of PPARγ-RXRα DBD (3DZU) interfacing with the flanking regions of the NRRE, we conclude they are critical sequence positions perhaps dictating nuclear receptor (NR) DNA binding specificity.

scholarly journals Urban Renewal in the Nucleus: Is Protein Turnover by Proteasomes Absolutely Required for Nuclear Receptor-Regulated Transcription?

2004 ◽  
Vol 18 (3) ◽  
pp. 493-499 ◽  
Author(s):  
Zafar Nawaz ◽  
Bert W. O’Malley
Keyword(s):  
Protein Degradation ◽  
Nuclear Receptors ◽  
Nuclear Receptor ◽  
Gene Transcription ◽  
Hormone Receptor ◽  
Target Genes ◽  
Nuclear Hormone Receptor ◽  
Ubiquitin Proteasome Pathway ◽  
Ubiquitin Proteasome ◽  
Proteasome Pathway

Abstract The importance of the ubiquitin proteasome pathway in higher eukaryotes has been well established in cell cycle regulation, signal transduction, and cell differentiation, but has only recently been linked to nuclear hormone receptor-regulated gene transcription. Characterization of a number of ubiquitin proteasome pathway enzymes as coactivators and observations that several nuclear receptors are ubiquitinated and degraded in the course of their nuclear activities provide evidence that ubiquitin proteasome-mediated protein degradation plays an integral role in eukaryotic transcription. In addition to receptors, studies have revealed that coactivators are ubiquitinated and degraded via the proteasome. The notion that the ubiquitin proteasome pathway is involved in gene transcription is further strengthened by the fact that ubiquitin proteasome pathway enzymes are recruited to the promoters of target genes and that proteasome-dependent degradation of nuclear receptors is required for efficient transcriptional activity. These findings suggest that protein degradation is coupled with nuclear receptor coactivation activity. It is possible that the ubiquitin proteasome pathway modulates transcription by promoting remodeling and turnover of the nuclear receptor-transcription complex. In this review, we discus the possible role of the ubiquitin proteasome pathway in nuclear hormone receptor-regulated gene transcription.

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