title: Overexpression of a histone H3K4 demethylase, JMJ15, accelerates flowering time in Arabidopsis.
abstract: The methylation of histone 3 lysine 4 (H3K4) is essential for gene activation. Flowering Locus C (FLC), an important flowering repressor, quantitatively regulates flowering time in Arabidopsis and its expression level is coincident with H3K4 trimethylation (H3K4me3) dynamics. The methylation state of FLC chromatin is determined by the balance between methylation and demethylation, which is mediated by histone methyltransferases and demethylases, respectively. However, little is known about the role of histone demethylase(s) in FLC regulation. Here, we characterized the biochemical activity and biological function of a novel JmjC domain-containing H3K4 demethylase, JMJ15, in Arabidopsis. JMJ15, which is a member of the H3K4 demethylase JARID1 family, displayed H3K4me3 demethylase activity both in vitro and in vivo. The mutation of JMJ15 did not produce an obvious phenotype; however, overexpression JMJ15 resulted in an obvious early flowering phenotype, which was associated with the repression of FLC level and reduction in H3K4me3 at the FLC locus, resulting in increased FT expression. Our results suggest that JMJ15 is a novel H3K4 demethylase, involved in the control of flowering time by demethylating H3K4me3 at FLC chromatin when it was overexpressed in Arabidopsis.
  
  
  CONCLUSIONS
  Overexpression of a histone H3K4 demethylase, JMJ15, represses FLC expression by decreasing its chromatin H3K4me3 level, thereby controlling flowering time in Arabidopsis.
authors.affiliation: Hebei Key Laboratory of Molecular Cell Biology, College of Biological Sciences, Hebei Normal University, Shijiazhuang 050016, Hebei, China.
authors.forename: Hongchun
authors.initials: H
authors.lastname: Yang
authors.forename: Huixian
authors.initials: H
authors.lastname: Mo
authors.forename: Di
authors.initials: D
authors.lastname: Fan
authors.forename: Ying
authors.initials: Y
authors.lastname: Cao
authors.forename: Sujuan
authors.initials: S
authors.lastname: Cui
authors.forename: Ligeng
authors.initials: L
authors.lastname: Ma
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D035264:Flowers / Q000201:enzymology / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D006657:Histones / Q000378:metabolism; D056484:Jumonji Domain-Containing Histone Demethylases / Q000235:genetics / Q000378:metabolism*; D026161:MADS Domain Proteins / Q000378:metabolism; D008745:Methylation; D008969:Molecular Sequence Data; D009154:Mutation
chemical_list: D029681:Arabidopsis Proteins; C418902:At5g10140 protein, Arabidopsis; D006657:Histones; D026161:MADS Domain Proteins; D056484:Jumonji Domain-Containing Histone Demethylases