title: Identification and characterization of a nuclear receptor subfamily I member in the Platyhelminth Schistosoma mansoni (SmNR1).
abstract: A cDNA encoding a nuclear receptor subfamily I member in the platyhelminth Schistosoma mansoni (SmNR1) was identified and characterized. SmNR1 cDNA is 2406 bp long and contains an open reading frame encoding a 715 residue protein. Phylogenetic analysis demonstrates that SmNR1 is a divergent member of nuclear receptor subfamily I with no known orthologue. SmNR1 was localized to S. mansoni chromosome 1 by fluorescent in situ hybridization. Gene structure of SmNR1 was determined showing it to consist of eight exons spanning more than 14 kb. Quantitative real-time RT-PCR showed that SmNR1 was expressed throughout schistosome development with a higher expression in eggs, sporocysts and 21-day worms. SmNR1 contains an autonomous transactivation function (AF1) in the A/B domain as demonstrated in a yeast one-hybrid assay; it interacts with SmRXR1 in a yeast two-hybrid assay and in a glutathione S-transferase pull-down assay. Electrophoretic mobility shift assay showed that SmNR1 could form a heterodimer with SmRXR1 to bind to DNA elements containing the half-site AGGTCA, a direct repeat of the half-site separated by 0-5 nucleotides (DR1-DR5) and a palindrome repeat of the half-site not separated by nucleic acids (Pal0). Transient transfection in mammalian COS-7 cells showed that SmNR1/SmRXR1 could enhance the transcriptional activation of a DR2-dependent reporter gene. Our results demonstrate that SmNR1 is a partner of SmRXR1.
authors.affiliation: Department of Microbiology and Immunology, School of Medicine and Biomedical Science, State University of New York, Buffalo, NY, USA.
authors.forename: Wenjie
authors.initials: W
authors.lastname: Wu
authors.forename: Edward G
authors.initials: EG
authors.lastname: Niles
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Hirai
authors.forename: Philip T
authors.initials: PT
authors.lastname: LoVerde
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002522:Chlorocebus aethiops; D002874:Chromosome Mapping; D005091:Exons; D017930:Genes, Reporter; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010802:Phylogeny; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry / Q000235:genetics* / Q000502:physiology*; D012550:Schistosoma mansoni / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013997:Time Factors
chemical_list: D018160:Receptors, Cytoplasmic and Nuclear