Coiled-coil domain-mediated FRQ-FRQ interaction is essential for its circadian clock function in Neurospora.
The frequency (frq) gene, the central component of the frq-based circadian negative feedback loop, regulates various aspects of the circadian clock in NEUROSPORA: However, the biochemical function of its protein products, FRQ, is poorly understood. In this study, we demonstrated that the most conserved region of FRQ forms a coiled-coil domain. FRQ interacts with itself in vivo, and the deletion of the coiled-coil region results in loss of the interaction. Point mutations, which are designed to disrupt the coiled-coil structure, weaken or completely abolish the FRQ self-association and lead to the arrhythmicity of the overt rhythm. Mutations of the FRQ coiled-coil that inhibit self-association also prevent its interaction with two other key components of the NEUROSPORA: circadian clock, namely WC-1 and WC-2, the two PAS domain-containing transcription factors. Taken together, these data strongly suggest that the formation of the FRQ-FRQ and FRQ-WC complexes is essential for the function of the NEUROSPORA: clock.
Cheng
P
P
Department of Physiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9040, USA.
Yang
Y
Y
Heintzen
C
C
Liu
Y
Y
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001665:Binding Sites; D001683:Biological Clocks; D002940:Circadian Rhythm; D003198:Computer Simulation; D005656:Fungal Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009491:Neurospora / Q000235:genetics / Q000502:physiology*; D016366:Open Reading Frames; D017354:Point Mutation; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
C087405:FRQ protein, Neurospora crassa; D005656:Fungal Proteins; D011994:Recombinant Proteins