title: The period E-box is sufficient to drive circadian oscillation of transcription in vivo.
abstract: The minimum element from the Drosophila period promoter capable of driving in vivo cycling mRNA is the 69 bp circadian regulatory sequence (CRS). In cell culture, an 18 bp E-box element from the period promoter is regulated by five genes that are involved in the regulation of circadian expression in flies. This E-box is a target for transcriptional activation by bHLH-PAS proteins dCLOCK (dCLK) and CYCLE (CYC), this activation is inhibited by PERIOD (PER) and TIMELESS (TIM) together, and inhibition of dCLK/CYC by PER and TIM is blocked by CRYPTOCHROME (CRY) in the presence of light. Here, the same 18 bp E-box region generated rhythmic expression of luciferase in flies under both light-dark cycling and constant conditions. Flies heterozygous for the Clke(jrk) mutation maintained rhythmic expression from the E-box although at a lower level than wild type. Homozygous mutant Clk(jrk) animals had drastically lowered and arrhythmic expression. In a per01 background, expression from the E-box was high and not rhythmic. Transcription mediated by the per E-box was restricted to the same spatial pattern as the CRS. The per E-box DNA element and cognate binding proteins can confer per-like temporal and spatial expression. This demonstrates in vivo that the known circadian genes that form the core of the circadian oscillator in Drosophila integrate their activities at a single DNA element.
authors: Department of Cell Biology and NSF Center for Biological Timing, The Scripps Research Institute, La Jolla, CA 92037, USA.
authors: T K
authors: TK
authors: Darlington
authors: L C
authors: LC
authors: Lyons
authors: P E
authors: PE
authors: Hardin
authors: S A
authors: SA
authors: Kay
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D051792:Basic Helix-Loop-Helix Proteins; D002940:Circadian Rhythm / Q000502:physiology*; D004330:Drosophila / Q000235:genetics / Q000502:physiology*; D029721:Drosophila Proteins; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D018257:Helix-Loop-Helix Motifs; D008156:Luciferases / Q000235:genetics; D008163:Luminescent Measurements; D008297:Male; D009687:Nuclear Proteins / Q000502:physiology*; D056950:Period Circadian Proteins; D011401:Promoter Regions, Genetic; D015534:Trans-Activators / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D001616:beta-Galactosidase / Q000235:genetics; D000099162:Endothelial PAS Domain-Containing Protein 1
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D029721:Drosophila Proteins; D008156:Luciferases; D009687:Nuclear Proteins; D056950:Period Circadian Proteins; D015534:Trans-Activators; D001616:beta-Galactosidase; D000099162:Endothelial PAS Domain-Containing Protein 1; C539040:PER protein, Drosophila