The acquisition of competence to respond to ecdysone in Drosophila is transcript specific

Richards, Gareth; Lage, Jean-Luc Da; Huet, François; Ruiz, Claude

doi:10.1016/s0925-4773(99)00028-3

Cited by 20 publications

(11 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In Drosophila, HR3 is required for XFTZ-F1 expression, which is, in turn, thought to be a competency factor that is required for the ecdysone dependent induction of late genes (Broadus et al, 1999, Richards et al, 1999. We observe a similar pattern of expression during A. aegypti midgut remodeling, in which increased AHR3 and AaE75B expression precedes increased AaXFTZ-F1 expression.…”

Section: Article In Presssupporting

confidence: 52%

Expression of nuclear receptor-transcription factor genes during Aedes aegypti midgut metamorphosis and the effect of methoprene on expression

Nishiura

Ray

Murray

2005

Insect Biochemistry and Molecular Biology

View full text Add to dashboard Cite

Section: Article In Presssupporting

confidence: 52%

Expression of nuclear receptor-transcription factor genes during Aedes aegypti midgut metamorphosis and the effect of methoprene on expression

Nishiura

Ray

Murray

2005

Insect Biochemistry and Molecular Biology

View full text Add to dashboard Cite

“…This difference was less prominent for E75A mRNA. As cycloheximide is known to stabilize some mRNA species (15,19,39), these results suggest that the normal turnover rate of dBlimp-1 mRNA is much higher than that of E75A mRNA.…”

Section: Fig 3 Confirmation Of Factor I-4 As Dblimp-1 (A)mentioning

confidence: 81%

Drosophila Blimp-1 Is a Transient Transcriptional Repressor That Controls Timing of the Ecdysone-Induced Developmental Pathway

Agawa

Sarhan

Kageyama

et al. 2007

Molecular and Cellular Biology

View full text Add to dashboard Cite

Regulatory mechanisms controlling the timing of developmental events are crucial for proper development to occur. ftz-f1 is expressed in a temporally regulated manner following pulses of ecdysteroid and this precise expression is necessary for the development of Drosophila melanogaster. To understand how insect hormone ecdysteroids regulate the timing of FTZ-F1 expression, we purified a DNA binding regulator of ftz-f1. Mass spectroscopy analysis revealed this protein to be a fly homolog of mammalian B lymphocyte-induced maturation protein 1 (Blimp-1). Drosophila Blimp-1 (dBlimp-1) is induced directly by 20-hydroxyecdysone, and its product exists during high-ecdysteroid periods and turns over rapidly. Forced expression of dBlimp-1 and RNA interference analysis indicate that dBlimp-1 acts as a repressor and controls the timing of FTZ-F1 expression. Furthermore, its prolonged expression results in delay of pupation timing. These results suggest that the transient transcriptional repressor dBlimp-1 is important for determining developmental timing in the ecdysone-induced pathway.The steroid hormone ecdysone and its active metabolite 20-hydroxyecdysone (20E) (hereafter referred to collectively as ecdysone) are responsible for many essential developmental processes, including insect molting, metamorphosis, oogenesis, and embryogenesis (25,40). The insect ecdysone response provides an excellent model for studying hormone function, in which temporally regulated induction of multiple genes is required to control complex developmental events. For instance, at the onset of metamorphosis in Drosophila melanogaster, a large pulse of ecdysone causes the third-instar larval-to-prepupal transition. Based on the observation of puffs on polytene chromosomes in cultured salivary glands more than 30 years ago, it has long been known that there are at least four categories of ecdysone-inducible genes (1-4, 38). The early genes are induced directly by the ecdysone-receptor complex and are repressed by their products. The early-late genes are also induced directly by ecdysone but require an ecdysone-induced gene product(s) for maximal induction. The late genes are induced by the early gene products, and the mid-prepupal genes are induced only after ecdysone levels have declined. In the last two decades, many of the genes belonging to these four groups have been cloned, and their regulated expression profile has been confirmed. These include multiple transcription factors, which constitute an ecdysone-induced gene cascade.ftz-f1 is a mid-prepupal gene (29) that encodes a nuclear receptor-type transcription factor (30). The beta isoform of the ftz-f1 gene product is expressed not only during the mid-prepupal period at the onset of metamorphosis but also during late embryogenesis, just before larval ecdysis and eclosion (45,51,54,55). All of these periods closely follow declines in ecdysone levels. The importance of timing of ftz-f1 expression has been shown by rescue of ftz-f1 mutants by temporally specific expression of ␤FTZ-F1 as well...

show abstract

“…With the inception of the original model by Ashburner on hierarchical, steroid-driven genetic programs for invertebrate development [37], the sophistication of the models has progressively increased as more transcription factors have been discovered to participate in these complex developmental programs [38]. However, despite the inclusion of ultraspiracle in these conceptual models since its discovery over 10 years ago, there has been much angst over whether this receptor possesses a ligand-binding activity.…”

Section: Discussionmentioning

confidence: 99%

Activation of transcription through the ligand‐binding pocket of the orphan nuclear receptor ultraspiracle

Fang

Chu

et al. 2002

European Journal of Biochemistry

View full text Add to dashboard Cite

The invertebrate nuclear receptor, ultraspiracle (USP), an ortholog of the vertebrate RXR, is typically modelled as an orphan receptor that functions without a ligand-binding activity. The identification of a ligand that can transcriptionally activate USP would provide heuristic leads to the structure of potentially high affinity activating compounds, with which to detect unknown regulatory pathways in which this nuclear receptor participates. We show here that the application of the sesquiterpenoid methyl epoxyfarnesoate (juvenile hormone III) to Sf9 cells induces transcription from a transfected heterologous core promoter, through a 5¢-placed DR12 enhancer to which the receptor ultraspiracle (USP) binds. Isolated, recombinant USP from Drosophila melanogaster specifically binds methyl epoxyfarnesoate, whereupon the receptor homodimerizes and changes tertiary conformation, including the movement of the ligand-binding domain a-helix 12. Ligand-binding pocket point mutants of USP that do not bind methyl epoxyfarnesoate act as dominant negative suppressors of methyl epoxyfarnesoate-activation of the reporter promoter, and addition of wild-type USP rescues this activation. These data establish a paradigm in which the USP ligandbinding pocket can productively bind ligand with a functional outcome of enhanced promoter activity, the first such demonstration for an invertebrate orphan nuclear receptor. USP thus establishes the precedent that invertebrate orphan receptors are viable targets for development of agonists and antagonists with which to discern and manipulate transcriptional pathways dependent on USP or other orphan receptors. The demonstration here of these functional capacities of USP in a transcriptonal activation pathway has significant implications for current paradigms of USP action that do not include for USP a ligandbinding activity.

show abstract

The acquisition of competence to respond to ecdysone in Drosophila is transcript specific

Cited by 20 publications

References 38 publications

Expression of nuclear receptor-transcription factor genes during Aedes aegypti midgut metamorphosis and the effect of methoprene on expression

Expression of nuclear receptor-transcription factor genes during Aedes aegypti midgut metamorphosis and the effect of methoprene on expression

Drosophila Blimp-1 Is a Transient Transcriptional Repressor That Controls Timing of the Ecdysone-Induced Developmental Pathway

Activation of transcription through the ligand‐binding pocket of the orphan nuclear receptor ultraspiracle

Contact Info

Product

Resources

About