Characterization of genes encoding members of the nuclear hormone receptor superfamily from Onchocerca volvulus.
Several lines of evidence suggest that molting in parasitic nematodes is controlled through the action of steroid molting hormones, or ecdysones. In other organisms, the central mediator of steroid hormone action is the hormone receptor. These receptor molecules are members of a superfamily of proteins called the nuclear hormone receptor family. Using an oligonucleotide derived from the amino-acid sequence of the Drosophila melanogaster ecdysone receptor, genes encoding homologues of the nuclear hormone receptor family were identified in the genome of the human filarial parasite Onchocerca volvulus. The O. volvulus genome contains at least three genes that encode putative members of the nuclear hormone receptor superfamily. A complete cDNA for one of these genes, designated OvNHR-1, has been isolated and characterized. The OvNHR-1 cDNA was 2378 bp in length, and contained a single open reading frame of 1104 bp. The open reading frame encoded a peptide with all of the features characteristic of a member of the nuclear hormone receptor superfamily of proteins. OVNHR-1 appeared to be encoded by a single-copy gene. Expression of the mRNA corresponding to OvNHR-1 was developmentally regulated, with maximal expression occurring during early embryogenesis. The polypeptide encoded by the OvNHR-1 open reading frame is antigenic in a minority of individuals exposed to O. volvulus.
Yates
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Division of Geographic Medicine, University of Alabama at Birmingham 35294, USA.
Tuan
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Shepley
K J
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Unnasch
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D000595:Amino Acid Sequence; D000818:Animals; D000947:Antigens, Helminth / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology; D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004440:Ecdysone / Q000378:metabolism; D004926:Escherichia coli; D005260:Female; D018507:Gene Expression Regulation, Developmental; D017238:Genes, Helminth; D015801:Helminth Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D005810:Multigene Family; D017181:Onchocerca volvulus / Q000196:embryology / Q000235:genetics* / Q000254:growth & development / Q000276:immunology; D016366:Open Reading Frames; D010802:Phylogeny; D018160:Receptors, Cytoplasmic and Nuclear / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology; D011987:Receptors, Steroid / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis
D000947:Antigens, Helminth; D018076:DNA, Complementary; D015801:Helminth Proteins; C095044:NHR-1 protein, Onchocerca volvulus; D018160:Receptors, Cytoplasmic and Nuclear; D011987:Receptors, Steroid; D011993:Recombinant Fusion Proteins; C055469:ecdysone receptor; D004440:Ecdysone