title: Control of transcriptional repression of the vitellogenin receptor gene in largemouth bass (Micropterus salmoides) by select estrogen receptors isotypes.
abstract: The vitellogenin receptor (Vtgr) plays an important role in fish reproduction. This receptor functions to incorporate vitellogenin (Vtg), a macromolecule synthesized and released from the liver in the bloodstream, into oocytes where it is processed into yolk. Although studies have focused on the functional role of Vtgr in fish, the mechanistic control of this gene is still unexplored. Here we report the identification and analysis of the first piscine 5' regulatory region of the vtgr gene which was cloned from largemouth bass (Micropterus salmoides). Using this putative promoter sequence, we investigated a role for hormones, including insulin and 17β-estradiol (E2), in transcriptional regulation through cell-based reporter assays. No effect of insulin was observed, however, E2 was able to repress transcriptional activity of the vtgr promoter through select estrogen receptor subtypes, Esr1 and Esr2a but not Esr2b. Electrophoretic mobility shift assay demonstrated that Esr1 likely interacts with the vtgr promoter region through half ERE and/or SP1 sites, in part. Finally we also show that ethinylestradiol (EE2), but not bisphenol-A (BPA), represses promoter activity similarly to E2. These results reveal for the first time that the Esr1 isoform may play an inhibitory role in the expression of LMB vtgr mRNA under the influence of E2, and potent estrogens such as EE2. In addition, this new evidence suggests that vtgr may be a target of select endocrine disrupting compounds through environmental exposures.
authors: Department of Environmental Health Sciences, University of South Carolina, Columbia, South Carolina 29208 Department of Environmental and Global Health, University of Florida, Gainesville, Florida 32610.
authors: Gustavo A
authors: GA
authors: Dominguez
authors: Department of Environmental Health Sciences, University of South Carolina, Columbia, South Carolina 29208 Department of Environmental and Global Health, University of Florida, Gainesville, Florida 32610 Department of Physiological Sciences, University of Florida, Gainesville, Florida 32611.
authors: Joseph H
authors: JH
authors: Bisesi
authors: Department of Physiological Sciences, University of Florida, Gainesville, Florida 32611.
authors: Kevin J
authors: KJ
authors: Kroll
authors: Department of Physiological Sciences, University of Florida, Gainesville, Florida 32611.
authors: Nancy D
authors: ND
authors: Denslow
authors: Department of Environmental Health Sciences, University of South Carolina, Columbia, South Carolina 29208 Department of Environmental and Global Health, University of Florida, Gainesville, Florida 32610 Department of Physiological Sciences, University of Florida, Gainesville, Florida 32611.
authors: Tara
authors: T
authors: Sabo-Attwood
mesh_terms: D000818:Animals; D001483:Base Sequence; D001492:Bass / Q000235:genetics / Q000378:metabolism*; D001559:Benzhydryl Compounds / Q000494:pharmacology; D001665:Binding Sites; D003001:Cloning, Molecular; D015536:Down-Regulation; D004527:Egg Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D004958:Estradiol / Q000494:pharmacology; D047628:Estrogen Receptor alpha / Q000819:agonists / Q000235:genetics / Q000378:metabolism*; D047629:Estrogen Receptor beta / Q000819:agonists / Q000235:genetics / Q000378:metabolism*; D004997:Ethinyl Estradiol / Q000494:pharmacology; D029941:Fish Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D017930:Genes, Reporter; D057809:HEK293 Cells; D006801:Humans; D007328:Insulin / Q000494:pharmacology; D008969:Molecular Sequence Data; D010636:Phenols / Q000494:pharmacology; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D016329:Sp1 Transcription Factor / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects; D014162:Transfection; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D004527:Egg Proteins; D004958:Estradiol; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D004997:Ethinyl Estradiol; D029941:Fish Proteins; D007328:Insulin; D010636:Phenols; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D016329:Sp1 Transcription Factor; C030474:vitellogenin receptor; C006780:bisphenol A; D000098826:Bisphenol A Compounds
keywords: bisphenol-A; estrogen; estrogen receptors; ethinylestradiol; insulin; largemouth bass; vitellogenin receptor