title: Suppression of WHITE COLLAR-independent frequency Transcription by Histone H3 Lysine 36 Methyltransferase SET-2 Is Necessary for Clock Function in Neurospora.
abstract: The circadian system in Neurospora is based on the transcriptional/translational feedback loops and rhythmic frequency (frq) transcription requires the WHITE COLLAR (WC) complex. Our previous paper has shown that frq could be transcribed in a WC-independent pathway in a strain lacking the histone H3K36 methyltransferase, SET-2 (su(var)3-9-enhancer-of-zeste-trithorax-2) (1), but the mechanism was unclear. Here we disclose that loss of histone H3K36 methylation, due to either deletion of SET-2 or H3K36R mutation, results in arrhythmic frq transcription and loss of overt rhythmicity. Histone acetylation at frq locus increases in set-2(KO) mutant. Consistent with these results, loss of H3K36 methylation readers, histone deacetylase RPD-3 (reduced potassium dependence 3) or EAF-3 (essential SAS-related acetyltransferase-associated factor 3), also leads to hyperacetylation of histone at frq locus and WC-independent frq expression, suggesting that proper chromatin modification at frq locus is required for circadian clock operation. Furthermore, a mutant strain with three amino acid substitutions (histone H3 lysine 9, 14, and 18 to glutamine) was generated to mimic the strain with hyperacetylation state of histone H3. H3K9QK14QK18Q mutant exhibits the same defective clock phenotype as rpd-3(KO) mutant. Our results support a scenario in which H3K36 methylation is required to establish a permissive chromatin state for circadian frq transcription by maintaining proper acetylation status at frq locus.
authors.affiliation: From the State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Guangyan
authors.initials: G
authors.lastname: Sun
authors.affiliation: From the State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China, College of Agriculture and Biotechnology, China Agricultural University, Beijing 100193, China, and.
authors.forename: Zhipeng
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: From the State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Liu
authors.affiliation: From the State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Kexin
authors.initials: K
authors.lastname: Gai
authors.affiliation: From the State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Qingqing
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390.
authors.forename: Joonseok
authors.initials: J
authors.lastname: Cha
authors.affiliation: From the State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Farah Naz
authors.initials: FN
authors.lastname: Kaleri
authors.affiliation: From the State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.affiliation: From the State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China, qunhe@cau.edu.cn.
authors.forename: Qun
authors.initials: Q
authors.lastname: He
mesh_terms: D057906:Circadian Clocks / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D055786:Gene Knockout Techniques; D005800:Genes, Fungal; D006655:Histone Deacetylases / Q000235:genetics / Q000378:metabolism; D011495:Histone-Lysine N-Methyltransferase / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D009492:Neurospora crassa / Q000235:genetics* / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; C087405:FRQ protein, Neurospora crassa; D005656:Fungal Proteins; D050505:Mutant Proteins; D011994:Recombinant Proteins; D014157:Transcription Factors; C105589:wc-1 protein, Neurospora crassa; C103772:white collar 2 protein, Neurospora; D011495:Histone-Lysine N-Methyltransferase; D006655:Histone Deacetylases
keywords: Neurospora; SET-2 pathway; WC-independent frq; circadian rhythm; clock gene; gene transcription; histone modification