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

The period-2 (prd-2) mutant of Neurospora crassa is characterized by recessive inheritance of a 26-hour long period phenotype of the circadian clock. PRD-2 encodes a putative RNA-binding protein. To identify PRD-2 target genes and its role in the clock, we performed transcript profiling in delta prd-2 compared to control samples using RNA-Sequencing. Hundreds of genes are affected by loss of prd-2, including decreased levels of Casein Kinase I (ck-1a, NCU00685). The circadian period length in Neurospora is exquisitely sensitive to ck-1a levels, and we attribute the long period length defect in the prd-2 mutant to low levels of ck-1a transcript, decreased ck-1a transcript stability, and lower levels of CKI protein. Thus, Casein Kinase I gene expression is subject to complex regulation in the circadian clock. To identify the role of the period-2 mutant in the circadian clock, transcript profiling was performed and compared to control samples. RNA-Sequencing was performed by Novogene. Hundreds of genes are affected by loss of the period-2 gene, and the clock-relevant target is downregulation of ck-1a (NCU00685). RNA-Seq was performed on biological triplicate samples from 25C, Bird 1.8% glucose medium, constant light cultures.