Nature Structural & Molecular Biology

Negative feedback is a conserved element in the maintenance of circadian rhythms. In Neurospora crassa, rhythmic oscillation is under the control of a central system in which the White Collar transcription-factor complex (WCC) stimulates expression of the clock protein FREQUENCY (FRQ). FRQ associates with the FRQ-interacting RNA helicase (FRH), and together they recruit factors that inactivate the WCC and subsequently promote the destruction of FRQ, thus resetting the cycle.   Read more »