A functional genomics approach reveals CHE as a component of the Arabidopsis circadian clock.
Transcriptional feedback loops constitute the molecular circuitry of the plant circadian clock. In Arabidopsis, a core loop is established between CCA1 and TOC1. Although CCA1 directly represses TOC1, the TOC1 protein has no DNA binding domains, which suggests that it cannot directly regulate CCA1. We established a functional genomic strategy that led to the identification of CHE, a TCP transcription factor that binds specifically to the CCA1 promoter. CHE is a clock component partially redundant with LHY in the repression of CCA1. The expression of CHE is regulated by CCA1, thus adding a CCA1/CHE feedback loop to the Arabidopsis circadian network. Because CHE and TOC1 interact, and CHE binds to the CCA1 promoter, a molecular linkage between TOC1 and CCA1 gene regulation is established.
Pruneda-Paz
Jose L
JL
Section of Cell and Developmental Biology, Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA.
Breton
Ghislain
G
Para
Alessia
A
Kay
Steve A
SA
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D001665:Binding Sites; D001683:Biological Clocks / Q000235:genetics*; D002467:Cell Nucleus / Q000378:metabolism; D002940:Circadian Rhythm / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D025461:Feedback, Physiological; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D023281:Genomics; D008969:Molecular Sequence Data; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
D029681:Arabidopsis Proteins; C114425:CCA1 protein, Arabidopsis; C539497:CHE protein, Arabidopsis; D004268:DNA-Binding Proteins; C113192:LHY protein, Arabidopsis; D012097:Repressor Proteins; C411822:TOC1 protein, Arabidopsis; D014157:Transcription Factors