title: Genomic structure and ecdysone regulation of the prophenoloxidase 1 gene in the malaria vector Anopheles gambiae.
abstract: Prophenoloxidase, a melanin-synthesizing enzyme, is considered to be an important arthropod immune protein. In mosquitoes, prophenoloxidase has been shown to be involved in refractory mechanisms against malaria parasites. In our study we used Anopheles gambiae, the most important human malaria vector, to characterize the first arthropod prophenoloxidase gene at the genomic level. The complete nucleotide sequence, including the immediate 5' flanking sequence (-855 bp) of the prophenoloxidase 1 gene, was determined. The gene spans 10 kb and is composed of five exons and four introns coding for a 2.5-kb mRNA. In the 5' flanking sequence, we found several putative regulatory motifs, two of which were identified as ecdysteroid regulatory elements. Electrophoretic mobility gel-shift assays and supershift assays demonstrated that the Aedes aegypti ecdysone receptor/Ultraspiracle nuclear receptor complex, and, seemingly, the endogenous Anopheles gambiae nuclear receptor complex, was able to bind one of the ecdysteroid response elements. Furthermore, 20-hydroxyecdysone stimulation was shown to up-regulate the transcription of the prophenoloxidase 1 gene in an A. gambiae cell line.
authors.affiliation: Laboratoire de Biochimie et Biologie Moléculaire des Insectes, Institut Pasteur, 25 rue du Dr. Roux, 75724 Paris Cedex 15, France.
authors.forename: A
authors.initials: A
authors.lastname: Ahmed
authors.forename: D
authors.initials: D
authors.lastname: Martín
authors.forename: A G
authors.initials: AG
authors.lastname: Manetti
authors.forename: S J
authors.initials: SJ
authors.lastname: Han
authors.forename: W J
authors.initials: WJ
authors.lastname: Lee
authors.forename: K D
authors.initials: KD
authors.lastname: Mathiopoulos
authors.forename: H M
authors.initials: HM
authors.lastname: Müller
authors.forename: F C
authors.initials: FC
authors.lastname: Kafatos
authors.forename: A
authors.initials: A
authors.lastname: Raikhel
authors.forename: P T
authors.initials: PT
authors.lastname: Brey
mesh_terms: D000818:Animals; D000852:Anopheles / Q000201:enzymology / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites; D004156:Catechol Oxidase / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000378:metabolism; D004199:Disease Vectors; D029721:Drosophila Proteins; D004440:Ecdysone / Q000494:pharmacology*; D004792:Enzyme Precursors / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic; D017344:Genes, Insect; D008288:Malaria / Q000635:transmission; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011987:Receptors, Steroid / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D004792:Enzyme Precursors; D011987:Receptors, Steroid; D014157:Transcription Factors; C066030:USP protein, Drosophila; C034808:ecdysteroid receptor; D004440:Ecdysone; C038451:pro-phenoloxidase; D004156:Catechol Oxidase