Reciprocal regulation between TOC1 and LHY/CCA1 within the Arabidopsis circadian clock.
The interactive regulation between clock genes is central for oscillator function. Here, we show interactions between the Arabidopsis clock genes LATE ELONGATED HYPOCOTYL (LHY), CIRCADIAN CLOCK ASSOCIATED 1 (CCA1), and TIMING OF CAB EXPRESSION 1 (TOC1). The MYB transcription factors LHY and CCA1 negatively regulate TOC1 expression. We show that both proteins bind to a region in the TOC1 promoter that is critical for its clock regulation. Conversely, TOC1 appears to participate in the positive regulation of LHY and CCA1 expression. Our results indicate that these interactions form a loop critical for clock function in Arabidopsis.
Alabadí
D
D
Department of Cell Biology and Institute for Childhood and Neglected Diseases, The Scripps Research Institute, La Jolla, CA 92037, USA.
Oyama
T
T
Yanovsky
M J
MJ
Harmon
F G
FG
Más
P
P
Kay
S A
SA
D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology; D029681:Arabidopsis Proteins; D001683:Biological Clocks / Q000235:genetics; D002940:Circadian Rhythm / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008957:Models, Genetic; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
D029681:Arabidopsis Proteins; C114425:CCA1 protein, Arabidopsis; D004268:DNA-Binding Proteins; C113192:LHY protein, Arabidopsis; D010940:Plant Proteins; D012333:RNA, Messenger; D018749:RNA, Plant; C411822:TOC1 protein, Arabidopsis; D014157:Transcription Factors