title: Juvenile hormone regulates Aedes aegypti Krüppel homolog 1 through a conserved E box motif.
abstract: Juvenile hormone (JH) plays important roles in regulation of many physiological processes including development, reproduction and metabolism in insects. However, the molecular mechanisms of JH signaling pathway are not completely understood. To elucidate the molecular mechanisms of JH regulation of Krüppel homolog 1 gene (Kr-h1) in Aedes aegypti, we employed JH-sensitive Aag-2 cells developed from the embryos of this insect. In Aag-2 cells, AaKr-h1 gene is induced by nanomolar concentration of JH III, its expression peaked at 1.5 h after treatment with JH III. RNAi studies showed that JH induction of this gene requires the presence of Ae. aegypti methoprene-tolerant (AaMet). A conserved 13 nucleotide JH response element (JHRE, TGCCTCCACGTGC) containing canonical E box motif (underlined) identified in the promoter of AaKr-h1 is required for JH induction of this gene. Critical nucleotides in the JHRE required for JH action were identified by employing mutagenesis and reporter assays. Reporter assays also showed that basic helix loop helix (bHLH) domain of AaMet is required for JH induction of AaKr-h1. 5' rapid amplification of cDNA ends method identified two isoforms of AaKr-h1, AaKr-h1α and AaKr-h1β, the expression of both isoforms is induced by JH III, but AaKr-h1α is the predominant isoform in both Aag-2 cells and Ae. aegypti larvae.
authors.affiliation: Department of Entomology, College of Agriculture, University of Kentucky, Lexington, KY 40546, United States.
authors.forename: Yingjun
authors.initials: Y
authors.lastname: Cui
authors.affiliation: Department of Entomology, College of Agriculture, University of Kentucky, Lexington, KY 40546, United States.
authors.forename: Yipeng
authors.initials: Y
authors.lastname: Sui
authors.affiliation: Department of Entomology, College of Agriculture, University of Kentucky, Lexington, KY 40546, United States.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Xu
authors.affiliation: Department of Entomology, College of Agriculture, University of Kentucky, Lexington, KY 40546, United States.
authors.forename: Fang
authors.initials: F
authors.lastname: Zhu
authors.affiliation: Department of Entomology, College of Agriculture, University of Kentucky, Lexington, KY 40546, United States. Electronic address: rpalli@email.uky.edu.
authors.forename: Subba Reddy
authors.initials: SR
authors.lastname: Palli
mesh_terms: D000330:Aedes / Q000235:genetics* / Q000254:growth & development; D000818:Animals; D002460:Cell Line; D024721:E-Box Elements; D018507:Gene Expression Regulation, Developmental; D007605:Juvenile Hormones / Q000235:genetics* / Q000378:metabolism*; D051741:Kruppel-Like Transcription Factors / Q000235:genetics / Q000378:metabolism*; D007814:Larva / Q000235:genetics* / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D017434:Protein Structure, Tertiary; D034622:RNA Interference; D015398:Signal Transduction
chemical_list: D007605:Juvenile Hormones; D051741:Kruppel-Like Transcription Factors
keywords: Juvenile hormone; Krüppel homolog 1; Methoprene-tolerant; bHLH | JH response element