title: The Broad-Complex directly controls a tissue-specific response to the steroid hormone ecdysone at the onset of Drosophila metamorphosis.
abstract: In Drosophila, all of the major metamorphic transitions are regulated by changes in the titer of the steroid hormone ecdysone. Here we examine how a key regulator of metamorphosis and primary ecdysone response gene, the Broad-Complex, transmits the hormonal signal to one of its targets, the Sgs-4 glue gene. We show that Broad-Complex RNAs accumulate in mid third instar larval salivary glands prior to Sgs-4 induction, as expected for the products of a gene that regulates the timing of Sgs-4 activation. The Broad-Complex codes for a family of zinc finger transcriptional regulators. We have identified a number of binding sites for these proteins in sequences known to regulate the timing of Sgs-4 induction, and have used these sites to derive a binding consensus for each protein. Some of these binding sites are required in vivo for Sgs-4 activity. In addition, rbp+, a genetically defined Broad-Complex function that is required for Sgs-4 induction, acts through these Broad-Complex binding sites. Thus, the Broad-Complex directly mediates a temporal and tissue-specific response to ecdysone as larvae become committed to metamorphosis.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley 94720.
authors.forename: L
authors.initials: L
authors.lastname: von Kalm
authors.forename: K
authors.initials: K
authors.lastname: Crossgrove
authors.forename: D
authors.initials: D
authors.lastname: Von Seggern
authors.forename: G M
authors.initials: GM
authors.lastname: Guild
authors.forename: S K
authors.initials: SK
authors.lastname: Beckendorf
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D016384:Consensus Sequence; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D004330:Drosophila / Q000235:genetics / Q000254:growth & development*; D004440:Ecdysone / Q000502:physiology*; D005260:Female; D005786:Gene Expression Regulation / Q000235:genetics*; D017344:Genes, Insect / Q000235:genetics*; D005967:Glue Proteins, Drosophila / Q000235:genetics; D008297:Male; D008675:Metamorphosis, Biological / Q000235:genetics*; D008957:Models, Genetic; D008969:Molecular Sequence Data; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D014158:Transcription, Genetic / Q000235:genetics; D016335:Zinc Fingers / Q000235:genetics
chemical_list: D004268:DNA-Binding Proteins; D005967:Glue Proteins, Drosophila; D004440:Ecdysone; D004247:DNA