The circadian (~24 h) clock has an enormous influence on the biology of plants and controls a plethora of processes including growth, photosynthesis, photoperiodic flowering and transcription of more than 30% of the genome. The oscillator mechanism that generates these circadian rhythms consists of interlocking feedback loops. CIR CADIAN CLOCK ASSOCIAT ED 1 (CCA1) is a single MYB-transcription factor with a key role in the main feedback loop. CCA1 regulation is important for correct oscillator function and may be an important integration point for environmental signals such as temperature and light that entrain the oscillator. Here we show that CCA1 protein stability is controlled by the proteasome and discuss our findings in the context of the different levels of CCA1 regulation.
Bibliographical noteFunding Information:
This work was supported by American Friends of Hebrew University grant 0367445, ISF grant 0398636 and DFG grant 0308300.