Coordination of larval and prepupal gene expression by the DHR3 orphan receptor during Drosophila metamorphosis

Development ◽  
1997 ◽  
Vol 124 (9) ◽  
pp. 1757-1769 ◽  
Author(s):  
G.T. Lam ◽  
C. Jiang ◽  
C.S. Thummel
Keyword(s):  
Receptor Gene ◽  
Polytene Chromosomes ◽  
Ectopic Expression ◽  
Orphan Receptor ◽  
Competence Factor ◽  
Direct Cross ◽  
Hormonal Signal ◽  
Puparium Formation ◽  
Direct Target ◽  
Early Puff

The DHR3 orphan receptor gene is induced directly by the steroid hormone ecdysone at the onset of Drosophila metamorphosis. DHR3 expression peaks in early prepupae, as the early puff genes are repressed and betaFTZ-F1 is induced. Here we provide evidence that DHR3 directly contributes to both of these regulatory responses. DHR3 protein is bound to many ecdysone-induced puffs in the polytene chromosomes, including the early puffs that encode the BR-C and E74 regulatory genes, as well as the E75, E78 and betaFTZ-F1 orphan receptor loci. Three DHR3 binding sites were identified downstream from the start site of betaFTZ-F1 transcription, further indicating that this gene is a direct target of DHR3 regulation. Ectopic expression of DHR3 revealed that the polytene chromosome binding pattern is of functional significance. DHR3 is sufficient to repress BR-C, E74A, E75A and E78B transcription as well as induce betaFTZ-F1. DHR3 thus appears to function as a switch that defines the larval-prepupal transition by arresting the early regulatory response to ecdysone at puparium formation and facilitating the induction of the betaFTZ-F1 competence factor in mid-prepupae. This study also provides evidence for direct cross-regulation among orphan members of the nuclear receptor superfamily and further implicates these genes as critical transducers of the hormonal signal during the onset of Drosophila metamorphosis.

The Drosophila E74 gene is required for metamorphosis and plays a role in the polytene chromosome puffing response to ecdysone

Development ◽  
1995 ◽  
Vol 121 (5) ◽  
pp. 1455-1465 ◽  
Author(s):  
J.C. Fletcher ◽  
K.C. Burtis ◽  
D.S. Hogness ◽  
C.S. Thummel
Keyword(s):  
Gene Expression ◽  
Salivary Gland ◽  
Critical Role ◽  
Polytene Chromosomes ◽  
Transcription Unit ◽  
Loss Of Function ◽  
Phenotypic Analysis ◽  
Pupal Development ◽  
Puparium Formation ◽  
Early Puff

The steroid hormone ecdysone initiates Drosophila metamorphosis by reprogramming gene expression during late larval and prepupal development. The ecdysone-inducible gene E74, a member of the ets proto-oncogene family, has been proposed to play a key role in this process. E74 is encoded within the 74EF early puff and consists of two overlapping transcription units, E74A and E74B. To assess the function(s) of E74 during metamorphosis, we have isolated and characterized recessive loss-of-function mutations specific to each transcription unit. We find that mutations in E74A and E74B are predominantly lethal during prepupal and pupal development, consistent with a critical role for their gene products in metamorphosis. Phenotypic analysis reveals that E74 function is required for both pupariation and pupation, and for the metamorphosis of both larval and imaginal tissues. E74B mutants are defective in puparium formation and head eversion and die as prepupae or cryptocephalic pupae, while E74A mutants pupariate normally and die either as prepupae or pharate adults. We have also investigated the effects of the E74 mutations on gene expression by examining the puffing pattern of the salivary gland polytene chromosomes in newly formed mutant prepupae. Most puffs are only modestly affected by the E74B mutation, whereas a subset of late puffs are sub-maximally induced in E74A mutant prepupae. These observations are consistent with Ashburner's proposal that early puff proteins induce the formation of late puffs, and define E74A as a regulator of late puff activity. They also demonstrate that E74 plays a wide role in reshaping the insect during metamorphosis, affecting tissues other than the salivary gland in which it was originally identified.

Genetic Analysis of the Drosophila 63F Early Puff: Characterization of Mutations in E63-1 and maggie, a Putative Tom22

Genetics ◽  
2000 ◽  
Vol 156 (1) ◽  
pp. 229-244
Author(s):  
Martina Vaskova ◽  
A M Bentley ◽  
Samantha Marshall ◽  
Pamela Reid ◽  
Carl S Thummel ◽  
...  
Keyword(s):  
Salivary Gland ◽  
Genetic Analysis ◽  
Polytene Chromosomes ◽  
Reading Frame ◽  
Protein Levels ◽  
Ef Hand ◽  
Larval Salivary Gland ◽  
Complementation Groups ◽  
Inducible Genes ◽  
Early Puff

Abstract The 63F early puff in the larval salivary gland polytene chromosomes contains the divergently transcribed E63-1 and E63-2 ecdysone-inducible genes. E63-1 encodes a member of the EF-hand family of Ca2+-binding proteins, while E63-2 has no apparent open reading frame. To understand the functions of the E63 genes, we have determined the temporal and spatial patterns of E63-1 protein expression, as well as undertaken a genetic analysis of the 63F puff. We show that E63-1 is expressed in many embryonic and larval tissues, but the third-instar larval salivary gland is the only tissue where increases in protein levels correlate with increases in ecdysone titer. Furthermore, the subcellular distribution of E63-1 protein changes dynamically in the salivary glands at the onset of metamorphosis. E63-1 and E63-2 null mutations, however, have no effect on development or fertility. We have characterized 40 kb of the 63F region, defined as the interval between Ubi-p and E63-2, and have identified three lethal complementation groups that correspond to the dSc-2, ida, and mge genes. We show that mge mutations lead to first-instar larval lethality and that Mge protein is similar to the Tom22 mitochondrial import proteins of fungi, suggesting that it has a role in mitochondrial function.

scholarly journals Drosophila Mi-2 Negatively Regulates dDREF by Inhibiting Its DNA-Binding Activity

2002 ◽  
Vol 22 (14) ◽  
pp. 5182-5193 ◽  
Author(s):  
Fumiko Hirose ◽  
Nobuko Ohshima ◽  
Eun-Jeong Kwon ◽  
Hideki Yoshida ◽  
Masamitsu Yamaguchi
Keyword(s):  
Dna Binding ◽  
Polytene Chromosomes ◽  
Ectopic Expression ◽  
Binding Activity ◽  
Mobility Shift ◽  
Interacting Protein ◽  
Reciprocal Regulation ◽  
Dna Binding Activity ◽  
Expression Of Genes ◽  
Biochemical Analyses

ABSTRACT Drosophila melanogaster DNA replication-related element (DRE) factor (dDREF) is a transcriptional regulatory factor required for the expression of genes carrying the 5′-TATCGATA DRE. dDREF has been reported to bind to a sequence in the chromatin boundary element, and thus, dDREF may play a part in regulating insulator activity. To generate further insights into dDREF function, we carried out a Saccharomyces cerevisiae two-hybrid screening with DREF polypeptide as bait and identified Mi-2 as a DREF-interacting protein. Biochemical analyses revealed that the C-terminal region of Drosophila Mi-2 (dMi-2) specifically binds to the DNA-binding domain of dDREF. Electrophoretic mobility shift assays showed that dMi-2 thereby inhibits the DNA-binding activity of dDREF. Ectopic expression of dDREF and dMi-2 in eye imaginal discs resulted in severe and mild rough-eye phenotypes, respectively, whereas flies simultaneously expressing both proteins exhibited almost-normal eye phenotypes. Half-dose reduction of the dMi-2 gene enhanced the DREF-induced rough-eye phenotype. Immunostaining of polytene chromosomes of salivary glands showed that dDREF and dMi-2 bind in mutually exclusive ways. These lines of evidence define a novel function of dMi-2 in the negative regulation of dDREF by its DNA-binding activity. Finally, we postulated that dDREF and dMi-2 may demonstrate reciprocal regulation of their functions.

scholarly journals The Sp transcription factors are involved in the cellular expression of the human glucose-dependent insulinotropic polypeptide receptor gene and overexpressed in adrenals of patients with Cushing’s syndrome

2005 ◽  
Vol 35 (1) ◽  
pp. 61-71 ◽  
Author(s):  
Valérie Baldacchino ◽  
Sylvie Oble ◽  
Patrick-Olivier Décarie ◽  
Isabelle Bourdeau ◽  
Pavel Hamet ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Cushing’S Syndrome ◽  
Receptor Gene ◽  
Gene Array ◽  
Ectopic Expression ◽  
Cushing's Syndrome ◽  
Tissue Array ◽  
R Gene ◽  
Consensus Sequences ◽  
Cellular Expression

The best characterized effect of glucose-dependent insulinotropic polypeptide (GIP) is its stimulatory effect on insulin secretion by pancreatic β-cells. Recently, it was demonstrated that some cases of primary adrenal Cushing’s syndrome were secondary to the ectopic expression of non-mutated GIP receptor (GIP-R) in bilateral adrenal hyperplasias or unilateral adrenal adenomas, resulting in food-dependent steroidogenesis. Using a human multiple-expression tissue array, GIP-R was found to be expressed in a large number of human adult and fetal tissues, but not in the adrenal gland. The analysis of the promoter region of human (h) GIP-R gene revealed six consensus sequences important in regulating the reporter gene activity and capable of binding to Sp1 and Sp3 transcription factors. Data obtained by gene array and semi-quantitative RT-PCR showed an increase in the expression of Sp3 and CRSP9 (co-regulator of Sp1 transcription factor, subunit 9) in the adrenal adenomas or bilateral macronodular hyperplasias of patients with GIP-dependent Cushing’s syndrome; they were, however, also increased in some patients with non-GIP-dependent cortisol-secreting adenomas or with ACTH-dependent Cushing’s disease. This study represents the first step in our understanding of the mechanisms involved in the regulation of the expression of the hGIP-R gene.

scholarly journals MicroRNA-342 Prohibits Proliferation and Invasion of Melanoma Cells by Directly Targeting Zinc-Finger E-Box-Binding Homeobox 1

2018 ◽  
Vol 26 (9) ◽  
pp. 1447-1455 ◽  
Author(s):  
Quan Shi ◽  
Qi He ◽  
Jing Wei
Keyword(s):  
Cell Proliferation ◽  
Zinc Finger ◽  
Ectopic Expression ◽  
Melanoma Cells ◽  
Potential Candidate ◽  
E Box ◽  
Direct Target Gene ◽  
Direct Target ◽  
Proliferation And Invasion ◽  
Zeb1 Expression

As documented in numerous studies, microRNAs (miRNAs) play key roles in various biological processes associated with melanoma occurrence and development. In this study, we found that miRNA-342 (miR-342) was significantly downregulated in melanoma tissues and cell lines. Additionally, the ectopic expression of miR-342 prohibited the cell proliferation and invasion of melanoma. Moreover, zinc-finger E-box-binding homeobox 1 (ZEB1) was identified as a direct target gene of miR-342 in melanoma. Similar with the results induced by miR-342 overexpression, ZEB1 knockdown attenuated cell proliferation and invasion in melanoma. Furthermore, the restoration of ZEB1 expression reversed the suppressive effects of miR-342 on the proliferation and invasion of melanoma cells. These findings suggest that miR-342 may play tumor-suppressing roles in melanoma, at least partially, by directly inhibiting ZEB1 expression. Therefore, miR-342 may be developed as a potential candidate for the treatment of patients with this aggressive type of cancer.

scholarly journals Mitogenic Effect of Orphan Receptor TR3 and Its Regulation by MEKK1 in Lung Cancer Cells

2003 ◽  
Vol 23 (23) ◽  
pp. 8651-8667 ◽  
Author(s):  
Siva Kumar Kolluri ◽  
Nathalie Bruey-Sedano ◽  
Xihua Cao ◽  
Bingzhen Lin ◽  
Feng Lin ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Dna Binding ◽  
Cancer Cells ◽  
Cellular Localization ◽  
Ectopic Expression ◽  
Orphan Receptor ◽  
Lung Cancer Cells ◽  
Brdu Incorporation ◽  
Mitogenic Effect ◽  
Retinoid Receptor

ABSTRACT TR3, also known as NGFI-B or nur77, is an immediate-early response gene and an orphan member of the steroid/thyroid/retinoid receptor superfamily. We previously reported that TR3 expression was induced by apoptotic stimuli and was required for their apoptotic effect in lung cancer cells. Here, we present evidence that TR3 was also induced by epidermal growth factor (EGF) and serum and was required for their mitogenic effect in lung cancer cells. Ectopic expression of TR3 in both H460 and Calu-6 lung cancer cell lines promoted their cell cycle progression and BrdU incorporation, while inhibition of TR3 expression by the small interfering RNA approach suppressed the mitogenic effect of EGF and serum. Analysis of TR3 mutants showed that both TR3 DNA binding and transactivation were required for its mitogenic effect. In contrast, they were dispensable for its apoptotic activity. Furthermore, confocal microscopy analysis demonstrated that TR3 functioned in the nucleus to induce cell proliferation, whereas it acted on mitochondria to induce apoptosis. In examining the signaling that regulates the mitogenic function of TR3, we observed that coexpression of constitutive-active MEKK1 inhibited TR3 transcriptional activity and TR3-induced proliferation. The inhibitory effect of MEKK1 was mediated through activation of Jun N-terminal kinase, which efficiently phosphorylated TR3, resulting in loss of its DNA binding. Together, our results demonstrate that TR3 is capable of inducing both proliferation and apoptosis in the same cells depending on the stimuli and its cellular localization.

Amplification and overexpression of oncogene Mdm2 and orphan receptor gene Nr1h4 in immortal PRKDC knockout cells

2004 ◽  
Vol 31 (2) ◽  
pp. 91-96 ◽  
Author(s):  
Rong Ai ◽  
Ana Sandoval ◽  
David J. Chen ◽  
Sandeep Burma ◽  
Paul Labhart
Keyword(s):  
Receptor Gene ◽  
Orphan Receptor

Suppression of HGF receptor gene expression by oxidative stress is mediated through the interplay between Sp1 and Egr-1

2003 ◽  
Vol 284 (6) ◽  
pp. F1216-F1225 ◽  
Author(s):  
Xianghong Zhang ◽  
Youhua Liu
Keyword(s):  
Oxidative Stress ◽  
Epithelial Cells ◽  
Collecting Duct ◽  
Receptor Gene ◽  
Ectopic Expression ◽  
Transcriptional Activator ◽  
Physical Interaction ◽  
Nucleotide Position ◽  
Renal Epithelial Cells ◽  
Cis Acting

Hepatocyte growth factor (HGF) receptor, the product of the c-metprotooncogene, is transcriptionally regulated by a wide variety of cytokines as well as extracellular environmental cues. In this report, we demonstrate that c-met expression was significantly suppressed by oxidative stress. Treatment of mouse renal inner medullary collecting duct epithelial cells with 0.5 mM H2O2inhibited c-met mRNA and protein expression, which was concomitant with induction of Egr-1 transcription factor. Ectopic expression of Egr-1 in renal epithelial cells markedly inhibited endogenous c-met expression in a dose-dependent fashion, suggesting a causative effect of Egr-1 in mediating c-met suppression. The cis-acting element responsible for H2O2-induced c-met inhibition was localized at nucleotide position −223 to −68 of c-met promoter, in which reside an imperfect Egr-1 and three Sp1-binding sites. Egr-1 markedly suppressed c-met promoter activity but did not directly bind to its cis-acting element in the c-met gene. Induction of Egr-1 by oxidative stress attenuated the binding of Sp1 to its cognate sites, but it did not affect Sp1 abundance in renal epithelial cells. Immunoprecipitation uncovered that Egr-1 physically interacted with Sp1 by forming the Sp1/Egr-1 complex, which presumably resulted in a decreased availability of unbound Sp1 as a transcriptional activator for the c-met gene. Thus it appears that inhibition of c-met expression by oxidative stress is mediated by the interplay between Sp1 and Egr-1 transcription factors. Our findings reveal a novel transcriptional regulatory mechanism by which Egr-1 sequesters Sp1 as a transcriptional activator of c-met via physical interaction.

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