title: Regulation of per and cry genes reveals a central role for the D-box enhancer in light-dependent gene expression.
abstract: Light serves as a key environmental signal for synchronizing the circadian clock with the day night cycle. The zebrafish represents an attractive model for exploring how light influences the vertebrate clock mechanism. Direct illumination of most fish tissues and cell lines induces expression of a broad range of genes including DNA repair, stress response and key clock genes. We have previously identified D- and E-box elements within the promoter of the zebrafish per2 gene that together direct light-induced gene expression. However, is the combined regulation by E- and D-boxes a general feature for all light-induced gene expression? We have tackled this question by examining the regulation of additional light-inducible genes. Our results demonstrate that with the exception of per2, all other genes tested are not induced by light upon blocking of de novo protein synthesis. We reveal that a single D-box serves as the principal light responsive element within the cry1a promoter. Furthermore, upon inhibition of protein synthesis D-box mediated gene expression is abolished while the E-box confers light driven activation as observed in the per2 gene. Given the existence of different photoreceptors in fish cells, our results implicate the D-box enhancer as a general convergence point for light driven signaling.
authors.affiliation: Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Mracek
authors.forename: Cristina
authors.initials: C
authors.lastname: Santoriello
authors.forename: M Laura
authors.initials: ML
authors.lastname: Idda
authors.forename: Cristina
authors.initials: C
authors.lastname: Pagano
authors.forename: Zohar
authors.initials: Z
authors.lastname: Ben-Moshe
authors.forename: Yoav
authors.initials: Y
authors.lastname: Gothilf
authors.forename: Daniela
authors.initials: D
authors.lastname: Vallone
authors.forename: Nicholas S
authors.initials: NS
authors.lastname: Foulkes
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D002940:Circadian Rhythm / Q000502:physiology / Q000528:radiation effects*; D056931:Cryptochromes / Q000235:genetics / Q000378:metabolism*; D003513:Cycloheximide / Q000494:pharmacology; D017931:DNA Primers / Q000235:genetics; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects*; D008027:Light; D008156:Luciferases; D016297:Mutagenesis, Site-Directed; D056950:Period Circadian Proteins / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D014176:Protein Biosynthesis / Q000502:physiology; D060888:Real-Time Polymerase Chain Reaction; D018808:Transcription Factor AP-1 / Q000378:metabolism; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D056931:Cryptochromes; D017931:DNA Primers; D005136:Eye Proteins; D056950:Period Circadian Proteins; D018808:Transcription Factor AP-1; D029961:Zebrafish Proteins; C466244:cry1a protein, zebrafish; C498846:per2 protein, zebrafish; D003513:Cycloheximide; D008156:Luciferases