title: JMJ24 targets CHROMOMETHYLASE3 for proteasomal degradation in Arabidopsis.
abstract: H3K9 methylation is usually associated with DNA methylation, and together they symbolize transcriptionally silenced heterochromatin. A number of proteins involved in epigenetic processes have been characterized. However, how the stability of these proteins is regulated at the post-translational level is largely unknown. Here, we show that an Arabidopsis JmjC domain protein, JMJ24, possesses ubiquitin E3 ligase activity. JMJ24 directly targets a DNA methyltransferase, CHROMOMETHYLASE 3 (CMT3), for proteasomal degradation to initiate destabilization of the heterochromatic state of endogenous silenced loci. Our results uncover an additional connection between two conserved epigenetic modifications: histone modification and DNA methylation.
authors.affiliation: Laboratory of Plant Molecular Biology, Rockefeller University, New York, New York 10065, USA;
authors.forename: Shulin
authors.initials: S
authors.lastname: Deng
authors.affiliation: Laboratory of Plant Molecular Biology, Rockefeller University, New York, New York 10065, USA; Temasek Life Sciences Laboratory, National University of Singapore, 117604 Singapore.
authors.forename: In-Cheol
authors.initials: IC
authors.lastname: Jang
authors.affiliation: Laboratory of Plant Molecular Biology, Rockefeller University, New York, New York 10065, USA;
authors.forename: Linlin
authors.initials: L
authors.lastname: Su
authors.affiliation: Laboratory of Plant Molecular Biology, Rockefeller University, New York, New York 10065, USA;
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.affiliation: Laboratory of Plant Molecular Biology, Rockefeller University, New York, New York 10065, USA;
authors.forename: Nam-Hai
authors.initials: NH
authors.lastname: Chua
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D015257:DNA-Cytosine Methylases / Q000235:genetics / Q000378:metabolism; D044127:Epigenesis, Genetic; D056484:Jumonji Domain-Containing Histone Demethylases / Q000378:metabolism*; D008745:Methylation; D046988:Proteasome Endopeptidase Complex / Q000235:genetics / Q000378:metabolism*; D055550:Protein Stability; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism; D054875:Ubiquitination
chemical_list: D029681:Arabidopsis Proteins; C000608068:JMJ24 protein, Arabidopsis; D056484:Jumonji Domain-Containing Histone Demethylases; D015257:DNA-Cytosine Methylases; C429766:CMT3 protein, Arabidopsis; D044767:Ubiquitin-Protein Ligases; D046988:Proteasome Endopeptidase Complex
keywords: CMT3; E3 ligase; JmjC protein; histone demethylation; protein stability; transcriptional gene silencing