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bioRxiv · 10.1101/2020.10.29.360735

Nonsense mediated decay and a novel protein Period-2 regulate casein kinase I in an opposing manner to control circadian period in Neurospora crassa

Kelliher, C. M.·Lambreghts, R.·Xiang, Q.·Baker, C. L.·Loros, J. J.·Dunlap, J.
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Abstract

Circadian clocks in fungi and animals are driven by a functionally conserved transcription-translation feedback loop. In Neurospora crassa, negative feedback is executed by a complex of Frequency (FRQ), FRQ-interacting RNA helicase (FRH), and Casein Kinase I (CKI), which inhibits the activity of the clocks positive arm, the White Collar Complex (WCC). Here, we show that the period-2 gene, whose mutation is characterized by recessive inheritance of a long 26-hour period phenotype, encodes an RNA-binding protein that stabilizes the ck-1a transcript, resulting in CKI protein levels sufficient for normal rhythmicity. Moreover, by examining the molecular basis for the short circadian period of period-6 mutants, we uncovered a strong influence of the Nonsense Mediated Decay pathway on CKI levels. The finding that circadian period defects in two classically-derived Neurospora clock mutants each arise from disruption of ck-1a regulation is consistent with circadian period being exquisitely sensitive to levels of casein kinase I.

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Kelliher, C. M., Lambreghts, R., Xiang, Q., Baker, C. L., Loros, J. J., Dunlap, J.. 2020-10-29. Nonsense mediated decay and a novel protein Period-2 regulate casein kinase I in an opposing manner to control circadian period in Neurospora crassa. https://doi.org/10.1101/2020.10.29.360735

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