title: Histone modifications in Arabidopsis- high methylation of H3 lysine 9 is dispensable for constitutive heterochromatin.
abstract: N-terminal modifications of nucleosomal core histones are involved in gene regulation, DNA repair and recombination as well as in chromatin modeling. The degree of individual histone modifications may vary between specific chromatin domains and throughout the cell cycle. We have studied the nuclear patterns of histone H3 and H4 acetylation and of H3 methylation in Arabidopsis. A replication-linked increase of acetylation only occurred at H4 lysine 16 (not for lysines 5 and 12) and at H3 lysine 18. The last was not observed in other plants. Strong methylation at H3 lysine 4 was restricted to euchromatin, while strong methylation at H3 lysine 9 occurred preferentially in heterochromatic chromocenters of Arabidopsis nuclei. Chromocenter appearance, DNA methylation and histone modification patterns were similar in nuclei of wild-type and kryptonite mutant (which lacks H3 lysine 9-specific histone methyltransferase), except that methylation at H3 lysine 9 in heterochromatic chromocenters was reduced to the same low level as in euchromatin. Thus, a high level of H3methylK9 is apparently not necessary to maintain chromocenter structure and does not prevent methylation of H3 lysine 4 within Arabidopsis chromocenters.
authors.affiliation: Institut für Pflanzengenetik und Kulturpflanzenforschung (IPK), D-06466 Gatersleben, Germany.
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Jasencakova
authors.forename: Wim J J
authors.initials: WJ
authors.lastname: Soppe
authors.forename: Armin
authors.initials: A
authors.lastname: Meister
authors.forename: Dorota
authors.initials: D
authors.lastname: Gernand
authors.forename: Bryan M
authors.initials: BM
authors.lastname: Turner
authors.forename: Ingo
authors.initials: I
authors.lastname: Schubert
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D002453:Cell Cycle / Q000235:genetics / Q000502:physiology; D002466:Cell Nucleolus / Q000235:genetics / Q000378:metabolism; D022004:Chromosome Structures / Q000235:genetics / Q000378:metabolism; D019175:DNA Methylation; D022041:Euchromatin / Q000235:genetics / Q000378:metabolism; D006570:Heterochromatin / Q000235:genetics* / Q000378:metabolism; D000076983:Histone Methyltransferases; D011495:Histone-Lysine N-Methyltransferase; D006657:Histones / Q000235:genetics* / Q000378:metabolism; D008239:Lysine / Q000235:genetics* / Q000378:metabolism; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D011496:Protein Methyltransferases
chemical_list: D029681:Arabidopsis Proteins; D022041:Euchromatin; D006570:Heterochromatin; D006657:Histones; D000076983:Histone Methyltransferases; D008780:Methyltransferases; D011496:Protein Methyltransferases; D011495:Histone-Lysine N-Methyltransferase; C471228:SUVH4 protein, Arabidopsis; D008239:Lysine