title: Characterization of estrogen receptor betab in sea bream (Sparus auratus): phylogeny, ligand-binding, and comparative analysis of expression.
abstract: Estrogens control many physiological processes in both female and male vertebrates, mostly mediated by specific nuclear estrogen receptors (ER). Two ER subtypes (ERalpha and ERbeta) are present in most vertebrates, including the sea bream (Sparus auratus) a hermaphrodite teleost fish. In the present study several variant cDNAs encoding a second sea bream ERbeta (sbERbetab) is reported. Phylogenetic and Southern blot analysis indicate that sbERbetab and the previously cloned sbERbetaa (formerly sbERbeta) are encoded by different genes, which may have arisen by duplication of an ancestral ERbeta gene. Competitive binding assays show that sbERbetab has high affinity for 17beta-estradiol (K(d) = 1 nM) and specifically binds estrogen agonists (diethylstilbestrol and ethynylestradiol) and antagonists (ICI 182,780). In Northern blot sbERalpha, sbERbetaa, sbERbetab produce several different transcripts in a variety of tissues. RT-PCR showed a partially overlapping but differential tissue distribution in both male and female sea bream.
authors.affiliation: Centro de Ciências do Mar, CIMAR-Laboratório Associado, University of Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
authors.forename: Patrícia I S
authors.initials: PI
authors.lastname: Pinto
authors.forename: Ana Lúcia
authors.initials: AL
authors.lastname: Passos
authors.forename: Rute S
authors.initials: RS
authors.lastname: Martins Deborah M Power
authors.forename: Adelino V M
authors.initials: AV
authors.lastname: Canário
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D047629:Estrogen Receptor beta / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D005260:Female; D029941:Fish Proteins / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D008024:Ligands; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D011993:Recombinant Fusion Proteins / Q000032:analysis; D021541:Sea Bream / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D012737:Sex Factors; D014018:Tissue Distribution
chemical_list: D018076:DNA, Complementary; D047629:Estrogen Receptor beta; D029941:Fish Proteins; D008024:Ligands; D011993:Recombinant Fusion Proteins