Control of Neurospora’s daily biological clock by an RNA unwinding protein

Down-regulation of FRH by inducible expression of a hairpin RNA leads to low levels of FRQ but high levels of frq RNA.

• FRQ interacts with the WC-1/WC-2 complex to repress its own transcription.
• FRH, an essential RNA helicase, associates with FRQ and the WC complex.
• Disruption of the FRQ-FRH complex eliminates the interaction between FRQ and the WC complex.
• The interaction between FRH and the WC complex is maintained even in a frq null strain.
• Loss of FRH disrupts circadian rhythmicities, indicating its role in the circadian negative-feedback loop.

Simplified