Regulation of the Neurospora circadian clock by casein kinase II

Yuhong Yang, Ping Cheng, Yi Liu

Research output: Contribution to journalArticlepeer-review

122 Scopus citations


Phosphorylation of clock proteins represents an important mechanism regulating circadian clocks. In Neurospora, clock protein FREQUENCY (FRQ) is progressively phosphorylated over time, and its level decreases when it is extensively phosphorylated. To identify the kinase phosphorylating FRQ and to understand the function of FRQ phosphorylation, a FRQ-phosphorylating kinase was purified and identified as casein kinase II (CKII). Disruption of the catalytic subunit gene of CKII in Neurospora resulted in hypophosphorylation and increased levels of FRQ protein. In addition, the circadian rhythms of frq RNA, FRQ protein, and clock-controlled genes are abolished in the CKII mutant. Our data suggest that the phosphorylation of FRQ by CKII may have at least three functions; it decreases the stability of FRQ, reduces the protein complex formation between FRQ and the WHITE COLLAR proteins, and is important for the closing of the Neurospora circadian negative feedback loop. Taken together, our results suggest that CKII is an important component of the Neurospora circadian clock.

Original languageEnglish (US)
Pages (from-to)994-1006
Number of pages13
JournalGenes and Development
Issue number8
StatePublished - Apr 15 2002


  • Circadian
  • Frequency
  • Neurospora
  • Phosphorylation
  • White collar-1

ASJC Scopus subject areas

  • Genetics
  • Developmental Biology


Dive into the research topics of 'Regulation of the Neurospora circadian clock by casein kinase II'. Together they form a unique fingerprint.

Cite this