Hormonal regulation and functional role of Drosophila E75A orphan nuclear receptor in the juvenile hormone signaling pathway

Dubrovsky, Edward B.; Dubrovskaya, Veronica A.; Berger, Edward M.

doi:10.1016/j.ydbio.2004.01.009

Cited by 77 publications

(61 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Many JH-inducible genes, such as jhp21 (27), JH esterase (28,29), calmodulin (30), vitellogenin (31), Epac (32), E75 (33), and others (34-37), have been reported. However, induction of BmKr-h1 occurred at considerably lower (subnanomolar) concentrations of natural JHs (EC 50 = 1.2-2.6 × 10 −10 M), compared with those of other JH-inducible genes (29,32,33). The JH titer in the hemolymph of third-and fourth-instar B. mori larvae is maintained between 1.45-11.6 ng/mL (4.9-39.4 × 10 −9 M) (21).…”

Section: Discussionmentioning

confidence: 94%

Transcriptional regulation of juvenile hormone-mediated induction of Krüppel homolog 1, a repressor of insect metamorphosis

Kayukawa

Minakuchi²,

Namiki³

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

289

310

View full text Add to dashboard Cite

The Krüppel homolog 1 gene (Kr-h1) has been proposed to play a key role in the repression of insect metamorphosis. Kr-h1 is assumed to be induced by juvenile hormone (JH) via a JH receptor, methoprene-tolerant (Met), but the mechanism of induction is unclear. To elucidate the molecular mechanism of Kr-h1 induction, we first cloned cDNAs encoding Kr-h1 (BmKr-h1) and Met (BmMet1 and BmMet2) homologs from Bombyx mori. In a B. mori cell line, BmKrh1 was rapidly induced by subnanomolar levels of natural JHs. Reporter assays identified a JH response element (kJHRE), comprising 141 nucleotides, located ∼2 kb upstream from the BmKr-h1 transcription start site. The core region of kJHRE (GGCCTCCACGTG) contains a canonical E-box sequence to which Met, a basic helix-loophelix Per-ARNT-Sim (bHLH-PAS) transcription factor, is likely to bind. In mammalian HEK293 cells, which lack an intrinsic JH receptor, ectopic expression of BmMet2 fused with Gal4DBD induced JHdependent activity of an upstream activation sequence reporter. Meanwhile, the kJHRE reporter was activated JH-dependently in HEK293 cells only when cotransfected with BmMet2 and BmSRC, another bHLH-PAS family member, suggesting that BmMet2 and BmSRC jointly interact with kJHRE. We also found that the interaction between BmMet2 and BmSRC is dependent on JH. Therefore, we propose the following hypothesis for the mechanism of JHmediated induction of BmKr-h1: BmMet2 accepts JH as a ligand, JH-liganded BmMet2 interacts with BmSRC, and the JH/BmMet2/ BmSRC complex activates BmKr-h1 by interacting with kJHRE. development | insecticide | steroid receptor coactivator

show abstract

Section: Discussionmentioning

confidence: 94%

Transcriptional regulation of juvenile hormone-mediated induction of Krüppel homolog 1, a repressor of insect metamorphosis

Kayukawa

Minakuchi²,

Namiki³

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

289

310

View full text Add to dashboard Cite

show abstract

“…59) The signaling pathway of JH is unknown yet, but the expression of some ecdysone-regulated early genes such as broad and E75 is modulated by JH in both D. melanogaster and M. sexta. [60][61][62][63][64][65][66] Further studies are necessary to elucidate the role of these genes in the JH signaling pathway.…”

Section: Biosynthesis Transport and Metabolism Of Juvenile Hormonementioning

confidence: 99%

Insect juvenile hormone action as a potential target of pest management

Minakuchi

Riddiford

2006

J. Pestic. Sci.

View full text Add to dashboard Cite

Juvenile hormone (JH) is a sesquiterpenoid hormone that regulates growth and development in insects. Since JH is a hormone specific to insects and other arthropods, compounds disrupting JH action in insects are expected to be ideal insecticides with low toxicity to non-target organisms. Many natural or synthetic analogs with JH-like or anti-JH activity have been identified, and some potent JH mimics have been used as insecticides. Recent studies on the enzymes in JH biosynthetic and metabolic pathways should be helpful for the discovery of more potent analogs and for the establishment of new means of pest management using recombinant DNA technology. © Pesticide Science Society of Japan Keywords: juvenile hormone (JH), insect metamorphosis, insect growth regulators, biosynthesis and metabolism of JH. Review* To whom correspondence should be addressed. E-mail: chieka_minakuchi@yahoo.com © Pesticide Science Society of Japan doptera. 17,18) Higher Diptera such as D. melanogaster and the blowfly Calliphora vomitoria produce JH III bisepoxide. 19,20) A small amount of methyl farnesoate, a precursor of JH III, was found in cockroach embryos and larvae. [20][21][22] Methyl farnesoate has also been identified in crustaceans 23) and is thought to have a JH-like action in female reproduction. 24)12Ј-OH JH III identified from the corpora allata of the African locust Locusta migratoria migratorioides was reported to exhibit JH activity when a high dose of this compound was topically applied to Tenebrio pupae. 25,26) Biosynthesis, Transport and Metabolism of Juvenile HormoneIn insects, JH is synthesized in the corpora allata via the mevalonate pathway (Fig. 2).27) The mevalonate pathway also exists in mammals and plants, and the early steps from acetylCoA to farnesyl diphosphate are conserved among these organisms. Importantly, insects and other arthropods do not synthesize cholesterol de novo but have to acquire it from dietary sources because they lack the genes encoding squalene synthase and other subsequent enzymes of the sterol branch. 28,29) Another peculiarity of the mevalonate pathway in insects is the capacity to synthesize JH via the isoprenoid branch.The genes encoding the enzymes in the mevalonate pathway from acetyl-CoA to farnesyl diphosphate have been identified in the genome of D. melanogaster and the malaria mosquito Anopheles gambiae, and in an EST library of the pine engraver Ips pini.27) However, it has been difficult to identify the genes encoding enzymes from farnesyl diphosphate to JH

show abstract

“…Some effects of JH are mediated via membrane receptors and the protein kinase C signaling pathway (4,6), whereas more evidence suggests that JH acts through intracellular receptors to modulate gene expression (7)(8)(9)(10). In some cases, JH seems to exert its functions by modulating the ecdysteroid signaling pathway (11)(12)(13)(14)(15)(16)(17).…”

mentioning

confidence: 99%

Heterodimer of two bHLH-PAS proteins mediates juvenile hormone-induced gene expression

Mead

Zhu

2010

Proc. Natl. Acad. Sci. U.S.A.

252

271

View full text Add to dashboard Cite

Juvenile hormone (JH) plays crucial roles in many aspects of insect life. The Methoprene-tolerant (Met) gene product, a member of the bHLH-PAS family of transcriptional regulators, has been demonstrated to be a key component of the JH signaling pathway. However, the molecular function of Met in JH-induced signal transduction and gene regulation remains to be fully elucidated.Here we show that a transcriptional coactivator of the ecdysteroid receptor complex, FISC, acts as a functional partner of Met in mediating JH-induced gene expression. Met and FISC appear to use their PAS domains to form a dimer only in the presence of JH or JH analogs. In newly emerged adult female mosquitoes, expression of some JH responsive genes is considerably dampened when Met or FISC is depleted by RNAi. Met and FISC are found to be associated with the promoter of the early trypsin gene (AaET) when transcription of this gene is activated by JH. A juvenile hormone response element (JHRE) has been identified in the AaET upstream regulatory region and is bound in vitro by the Met-FISC complex present in the nuclear protein extracts of previtellogenic adult female mosquitoes. In addition, the Drosophila homologs of Met and FISC can also use this mosquito JHRE to activate gene transcription in response to JH in a cell transfection assay. Together, the evidence indicates that Met and FISC form a functional complex on the JHRE in the presence of JH and directly activate transcription of JH target genes.development | endocrinology | chromatin immunoprecipitation J uvenile hormones (JHs) are sesquiterpenoid molecules synthesized and secreted by the corpora allata in insects. JHs are essential for development, reproduction, diapause, caste differentiation, migratory behavior, and longevity in many insect species (1-4). The prominent role of JH is maintaining the status quo in juvenile insects and preventing an insect from precociously turning into an adult. During larval development, ecdysone (the molting hormone) causes larval-larval molts in the presence of JH in the hemolymph. After the corpora allata stop secreting JH in the final larval instar, insect tissues change their commitment, and ecdysone triggers the larval-pupal and pupaladult molts (5).JH appears to harness a variety of signal transduction pathways to exert its function. Some effects of JH are mediated via membrane receptors and the protein kinase C signaling pathway (4, 6), whereas more evidence suggests that JH acts through intracellular receptors to modulate gene expression (7-10). In some cases, JH seems to exert its functions by modulating the ecdysteroid signaling pathway (11-17).A leading candidate for the JH receptor (or a component of the receptor) is the product of the Methoprene-tolerant (Met) gene, which was originally isolated in Drosophila melanogaster (18). Met belongs to the basic helix-loop-helix (bHLH)-PerArnt-Sim (PAS) family of transcription factors that also includes the hypoxia inducible factor 1α (HIF-1α), aryl hydrocarbon receptor (AhR), aryl hydrocarbon ...

show abstract

Hormonal regulation and functional role of Drosophila E75A orphan nuclear receptor in the juvenile hormone signaling pathway

Cited by 77 publications

References 56 publications

Transcriptional regulation of juvenile hormone-mediated induction of Krüppel homolog 1, a repressor of insect metamorphosis

Transcriptional regulation of juvenile hormone-mediated induction of Krüppel homolog 1, a repressor of insect metamorphosis

Insect juvenile hormone action as a potential target of pest management

Heterodimer of two bHLH-PAS proteins mediates juvenile hormone-induced gene expression

Contact Info

Product

Resources

About