Mapping the Core of the Arabidopsis Circadian Clock Defines the Network Structure of the Oscillator
Abstract
In many organisms, the circadian clock is composed of functionally coupled morning and evening oscillators. In Arabidopsis, oscillator coupling relies on a core loop in which the evening oscillator component TIMING OF CAB EXPRESSION 1 (TOC1) was proposed to activate a subset of morning-expressed oscillator genes. Here, we show that TOC1 does not function as an activator but rather as a general repressor of oscillator gene expression. Repression occurs through TOC1 rhythmic association to the promoters of the oscillator genes. Hormone-dependent induction of TOC1 and analysis of RNA interference plants show that TOC1 prevents the activation of morning-expressed genes at night. Our study overturns the prevailing model of the Arabidopsis circadian clock, showing that the morning and evening oscillator loops are connected through the repressing activity of TOC1.
Additional Information
© 2012 American Association for the Advancement of Science. Received 12 January 2012; accepted 27 February 2012. We thank E. Meyerowitz for comments on the manuscript, E. Centeno for help with ChIP-Seq analysis, O. Casagran for help with the microfluidic arrays, M. Perales for help with the ChIP, L. Rico for help with the inducible constructs, and L. Schaeffer and D. Trout (Jacobs Genetics and Genomics Laboratory at Caltech) for the primary sequence data processing. This work was supported by grants to P.M. from the Ramón Areces Foundation, the Spanish Ministry of Science and Innovation (MICINN), the European Molecular Biology Organization (EMBO) Young Investigators Program, and from the European Heads of Research Councils and the European Science Foundation through the European Young Investigator Award; to J.L.R. from the European Comission (EC) Marie Curie program and MICINN; and to A.J.M. and others from the EC FP7 Collaborative Project TiMet. The Centre for Systems Biology at Edinburgh is a Centre for Integrative and Systems Biology supported by the Biotechnology and Biological Sciences Research Council and the Engineering and Physical Sciences Research Council award D019621. W.H. is supported by a Juan de la Cierva contract (MICINN) and P.P.-G. by a Formación de Personal Investigador fellowship (MICINN). Sequencing data have been deposited with the National Center for Biotechnology Information Gene Expression Omnibus under accession number GSE35952.Additional details
- Eprint ID
- 31265
- DOI
- 10.1126/science.1219075
- Resolver ID
- CaltechAUTHORS:20120502-083719443
- Ramón Areces Foundation
- European Molecular Biology Organization (EMBO)
- European Heads of Research Councils
- European Science Foundation
- Marie Curie Fellowship
- Biotechnology and Biological Sciences Research Council (BBSRC)
- D019621
- Engineering and Physical Sciences Research Council (EPSRC)
- Ministerio de Ciencia e Innovación (MCINN)
- Created
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2012-05-02Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field