title: Suppression of WC-independent frequency transcription by RCO-1 is essential for Neurospora circadian clock.
abstract: Rhythmic activation and repression of clock gene transcription is essential for the functions of eukaryotic circadian clocks. In the Neurospora circadian oscillator, frequency (frq) transcription requires the WHITE COLLAR (WC) complex. Here, we show that the transcriptional corepressor regulation of conidiation-1 (RCO-1) is essential for clock function by regulating frq transcription. In rco-1 mutants, both overt and molecular rhythms are abolished, frq mRNA levels are constantly high, and WC binding to the frq promoter is dramatically reduced. Surprisingly, frq mRNA levels were constantly high in the rco-1 wc double mutants, indicating that RCO-1 suppresses WC-independent transcription and promotes WC complex binding to the frq promoter. Furthermore, RCO-1 is required for maintaining normal chromatin structure at the frq locus. Deletion of H3K36 methyltransferase su(var)3-9-enhancer-of-zeste-trithorax-2 (SET-2) or the chromatin remodeling factor CHD-1 leads to WC-independent frq transcription and loss of overt rhythms. Together, our results uncover a previously unexpected regulatory mechanism for clock gene transcription.
authors.affiliation: State Key Laboratory of Agrobiotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Zhipeng
authors.initials: Z
authors.lastname: Zhou
authors.forename: Xiao
authors.initials: X
authors.lastname: Liu
authors.forename: Qiwen
authors.initials: Q
authors.lastname: Hu
authors.forename: Ning
authors.initials: N
authors.lastname: Zhang
authors.forename: Guangyan
authors.initials: G
authors.lastname: Sun
authors.forename: Joonseok
authors.initials: J
authors.lastname: Cha
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.forename: Qun
authors.initials: Q
authors.lastname: He
mesh_terms: D015152:Blotting, Northern; D015153:Blotting, Western; D002843:Chromatin / Q000378:metabolism; D047369:Chromatin Immunoprecipitation; D057906:Circadian Clocks / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology*; D017931:DNA Primers / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism*; D017353:Gene Deletion; D005786:Gene Expression Regulation / Q000502:physiology*; D008156:Luciferases; D046912:Multiprotein Complexes / Q000378:metabolism; D009491:Neurospora / Q000502:physiology*; D060888:Real-Time Polymerase Chain Reaction; D012097:Repressor Proteins / Q000172:deficiency*; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D002843:Chromatin; D017931:DNA Primers; D004268:DNA-Binding Proteins; C087405:FRQ protein, Neurospora crassa; D005656:Fungal Proteins; D046912:Multiprotein Complexes; C102112:RCO-1 protein, Neurospora crassa; D012097:Repressor Proteins; D014157:Transcription Factors; C103772:white collar 2 protein, Neurospora; D008156:Luciferases
keywords: H3K36me3; RCO-1/Tup1; clock gene frq; transcriptional repression