RRC ID 37890
著者 Kayukawa T, Nagamine K, Ito Y, Nishita Y, Ishikawa Y, Shinoda T.
タイトル Krüppel Homolog 1 Inhibits Insect Metamorphosis via Direct Transcriptional Repression of Broad-Complex, a Pupal Specifier Gene.
ジャーナル J Biol Chem
Abstract The Broad-Complex gene (BR-C) encodes transcription factors that dictate larval-pupal metamorphosis in insects. The expression of BR-C is induced by molting hormone (20-hydroxyecdysone (20E)), and this induction is repressed by juvenile hormone (JH), which exists during the premature larval stage. Krüppel homolog 1 gene (Kr-h1) has been known as a JH-early inducible gene responsible for repression of metamorphosis; however, the functional relationship between Kr-h1 and repression of BR-C has remained unclear. To elucidate this relationship, we analyzed cis- and trans elements involved in the repression of BR-C using a Bombyx mori cell line. In the cells, as observed in larvae, JH induced the expression of Kr-h1 and concurrently suppressed 20E-induced expression of BR-C. Forced expression of Kr-h1 repressed the 20E-dependent activation of the BR-C promoter in the absence of JH, and Kr-h1 RNAi inhibited the JH-mediated repression, suggesting that Kr-h1 controlled the repression of BR-C. A survey of the upstream sequence of BR-C gene revealed a Kr-h1 binding site (KBS) in the BR-C promoter. When KBS was deleted from the promoter, the repression of BR-C was abolished. Electrophoresis mobility shift demonstrated that two Kr-h1 molecules bound to KBS in the BR-C promoter. Based on these results, we conclude that Kr-h1 protein molecules directly bind to the KBS sequence in the BR-C promoter and thereby repress 20E-dependent activation of the pupal specifier, BR-C. This study has revealed a considerable portion of the picture of JH signaling pathways from the reception of JH to the repression of metamorphosis.
巻・号 291(4)
ページ 1751-1762
公開日 2016-1-22
DOI 10.1074/jbc.M115.686121
PII S0021-9258(20)36111-1
PMID 26518872
PMC PMC4722455
MeSH Animals Bombyx / genetics Bombyx / growth & development Bombyx / metabolism* Down-Regulation Ecdysterone / metabolism Gene Expression Regulation, Developmental Insect Proteins / genetics Insect Proteins / metabolism* Juvenile Hormones / metabolism Kruppel-Like Transcription Factors / genetics Kruppel-Like Transcription Factors / metabolism* Larva / genetics Larva / growth & development Larva / metabolism Metamorphosis, Biological Promoter Regions, Genetic Protein Binding Pupa / genetics Pupa / growth & development* Pupa / metabolism Signal Transduction Species Specificity Transcription Factors / genetics* Transcription Factors / metabolism
IF 4.238
引用数 47
WOS 分野 BIOCHEMISTRY & MOLECULAR BIOLOGY
リソース情報
ヒト・動物細胞 BM-N(RCB0457)