title: OTX5 regulates pineal expression of the zebrafish REV-ERB alpha through a new DNA binding site.
abstract: The pineal gland plays a central role in the photoneuroendocrine system and acts as a photosensory organ in lower vertebrates. The orphan nuclear receptor Rev-erbalpha (NR1D1) has previously been shown to be expressed in the pineal and to be regulated with a robust circadian rhythm during zebrafish embryogenesis. This early pineal expression is under the control of the transcription factor Orthodenticle homeobox 5 (Otx5). In this paper, we show that Otx5 regulates the second zfRev-erbalpha promoter, ZfP2. Despite the absence of a classical Otx-binding site within ZfP2, this regulation depends on the integrity of the Otx5 homeodomain. Mapping experiments as well as EMSAs show that this interaction between Otx5 and ZfP2 depends on a noncanonical bipartite Otx-binding site (GANNCTTA and TAAA) that we called pineal expression related element (PERE). We showed that PERE is necessary for pineal expression in vivo by injecting zebrafish embryos with wild type and mutated versions of zfRev-erbalpha promoter fused to green fluorescent protein. Interestingly, PERE is found upstream of other genes expressed in the pineal gland, suggesting that it may play an important role in governing pineal expression. Our data establish that PERE is a novel cis-acting element contributing to pineal-specific gene expression and to Otx target gene regulation.
authors.affiliation: Université de Lyon, Institut de Génomique Fonctionnelle de Lyon, Unité Mixte de Recherche 5242 du Centre National de la Recherche Scientifique, 69364 Lyon Cedex 07, France.
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Nishio
authors.forename: Tomoko
authors.initials: T
authors.lastname: Kakizawa
authors.forename: Gilles
authors.initials: G
authors.lastname: Chatelain
authors.forename: Gérard
authors.initials: G
authors.lastname: Triqueneaux
authors.forename: Frédéric
authors.initials: F
authors.lastname: Brunet
authors.forename: Juliette
authors.initials: J
authors.lastname: Rambaud
authors.forename: Thomas
authors.initials: T
authors.lastname: Lamonerie
authors.forename: Vincent
authors.initials: V
authors.lastname: Laudet
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D019556:COS Cells; D002522:Chlorocebus aethiops; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D017403:In Situ Hybridization; D008856:Microscopy, Fluorescence; D008957:Models, Genetic; D008969:Molecular Sequence Data; D056953:Nuclear Receptor Subfamily 1, Group D, Member 1; D051857:Otx Transcription Factors / Q000235:genetics / Q000378:metabolism*; D010870:Pineal Gland / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*; D012689:Sequence Homology, Nucleic Acid; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C520948:Nr1d1 protein, zebrafish; D056953:Nuclear Receptor Subfamily 1, Group D, Member 1; D051857:Otx Transcription Factors; C413467:Otx5 protein, zebrafish; D018160:Receptors, Cytoplasmic and Nuclear; D029961:Zebrafish Proteins; D004247:DNA