Interlocked molecular feedback loops of
. White-collar complex (WCC) acts as the transcriptional activator (positive element) of Frequency gene (Frq). The protein product of Frq undergoes phosphorylation in the cytoplasm under the influence of specific kinases, and subsequently acts as inhibitor of its own transcription (negative element). WCC levels are regulated by another gene called Vivid (Vvd), which in turn is regulated by WCC complex. Thus, WCC acts as one of the key components of Neurospora clock that connects the two loops, and hence appear to be important for the persistence of molecular oscillations. In addition, WCC is light sensitive, and appears to be crucial for light entrainment for the Neurospora molecular clock.