Juvenile hormone regulates Aedes aegypti Kr??ppel homolog 1 through a conserved E box motif.

Autor(es): Cui Yingjun; Sui Yipeng; Xu Jingjing; Zhu Fang; Palli Subba Reddy

Resumo: 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 Kr??ppel 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-h1Î? and AaKr-h1β, the expression of both isoforms is induced by JH III, but AaKr-h1Î? is the predominant isoform in both Aag-2 cells and Ae. aegypti larvae.

Palavras-Chave: Juvenile hormone; Methoprene-tolerant; Krüppel homolog 1; bHLH | JH response element

Imprenta: Insect Biochemistry and Molecular Biology, v. 52, p. 23-32, 2014

Identificador do objeto digital: 10.1016/j.ibmb.2014.05.009

Descritores: Aedes aegypti - Pathogenesis ; Aedes aegypti - Cell ; Aedes aegypti - Genome ; Aedes aegypti - Molecular Structure ; Aedes aegypti - Proteins ; Aedes aegypti - RNA

Data de publicação: 2014