The Drosophila Broad-Complex encodes a family of related proteins containing zinc fingers.

Abstract

The Broad-Complex (BR-C) is essential for metamorphosis in Drosophila melanogaster. This locus is coextensive with the 2B5 ecdysone-responsive early puff and is necessary for puffing and transcription of many subsequently activated late genes in the developing salivary gland. Mapping of 31 cDNA clones indicates that approximately 100 kb of the genome is devoted to the synthesis of many BR-C RNAs. Sequence analyses of these cDNA clones show that the BR-C encodes a family of related proteins characterized by a common core amino-terminal domain fused to alternate carboxy domains each containing a pair of zinc fingers. Most proteins also contain domains rich in distinctive amino acids located between the common core and zinc finger regions. BR-C mutant alleles resulting from chromosomal rearrangements at 2B5 are associated with deletions of 5'-untranslated sequences, separation of the core coding domain from the downstream zinc finger domains, or a P element insertional disruption of a zinc finger coding sequence. We infer that the BR-C directly regulates late gene expression by specifying the synthesis of a family of proteins with DNA binding potential.

Cross-talk of insulin-like peptides, juvenile hormone, and 20-hydroxyecdysone in regulation of metabolism in the mosquito Aedes aegypti

“…S11). Unlike the switch in two isoforms E74, the other ecdysone-inducible early gene, broad-complex (BR-C) and Eip75 (E75), have multiple protein isoforms and complex regulatory actions (34,35). Thus, we used the ChIP assay to examine a possible interaction of E74A and E74B to ilp gene promoters.…”

bantam miRNA Promotes Systemic Growth by Connecting Insulin Signaling and Ecdysone Production

“…In contrast, P0206>ban larvae showed lower circulating 20E levels than controls at both stages, and the amplitude of the peak was strongly reduced (Figure 2A). Ecdysone signaling in target tissues was also reduced in late larval development upon ban overexpression in the PG (in phm>banD animals; Figure 2B) as measured by the expression levels of E75A and Broad-Complex (BR-C), two targets of EcR [15,16]. Furthermore, the phantom (phm), disembodied (dib), and shade (sad) genes, which are specifically expressed in the PG and encode enzymes required for ecdysteroid biosynthesis (reviewed in [17]), showed reduced expression in phm>ban animals (Figure 2C).…”

Regulatory mechanisms underlying the specification of the pupal-homologous stage in a hemimetabolous insect

“…The subsequent repression of Br during the pupal stage allows proper pupal-adult transition [19][20][21][22]. In Drosophila melanogaster (Dm), Dm'Br is predominantly expressed during the larval-pupal transition when 20E is high and JH is absent [23,24]. In comparison, the milkweed bug Oncopeltus fasciatus (Of ) and cockroach Blattella germanica (Bg), which are hemimetabolous insects that lack pupal stages, Of'Br or Bg'Br are expressed during embryonic, pronymphal (first postembryonic form before hatching) and nymphal development, but then disappear at the moult to adult [25,26].…”