title: Chromocentre integrity and epigenetic marks.
abstract: The epigenetic modification of histones dictates the formation of euchromatin and heterochromatin domains. We studied the effects of a deficiency of histone methyltransferase, SUV39h, and trichostatin A-dependent hyperacetylation on the structural stability of centromeric clusters, called chromocentres. We did not observe the expected disintegration of chromocentres, but both SUV39h deficiency and hyperacetylation in SUV39h+/+ cells induced the re-positioning of chromocentres closer to the nuclear periphery. Conversely, TSA treatment of SUV39h-/- cells re-established normal nuclear radial positioning of chromocentres. This structural re-arrangement was likely caused by several epigenetic events at centromeric heterochromatin. In particular, reciprocal exchanges between H3K9me1, H3K9me2, H3K9me3, DNA methylation, and HP1 protein levels influenced chromocentre nuclear composition. For example, H3K9me1 likely substituted for the function of H3K9me3 in chromocentre nuclear arrangement and compaction. Our results illustrate the important and interchangeable roles of epigenetic marks for chromocentre integrity. Therefore, we propose a model for epigenetic regulation of nuclear stability of centromeric heterochromatin in the mouse genome.
authors.affiliation: Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Královopolská 135, CZ-612 65 Brno, Czech Republic.
authors.forename: Andrea
authors.initials: A
authors.lastname: Harnicarová Horáková
authors.forename: Gabriela
authors.initials: G
authors.lastname: Galiová
authors.forename: Sona
authors.initials: S
authors.lastname: Legartová
authors.forename: Stanislav
authors.initials: S
authors.lastname: Kozubek
authors.forename: Pavel
authors.initials: P
authors.lastname: Matula
authors.forename: Eva
authors.initials: E
authors.lastname: Bártová
mesh_terms: D000818:Animals; D002460:Cell Line; D044127:Epigenesis, Genetic / Q000235:genetics*; D006570:Heterochromatin / Q000378:metabolism; D000076983:Histone Methyltransferases; D011495:Histone-Lysine N-Methyltransferase / Q000235:genetics / Q000502:physiology; D006657:Histones / Q000378:metabolism; D008745:Methylation; D051379:Mice
chemical_list: D006570:Heterochromatin; D006657:Histones; D000076983:Histone Methyltransferases; D011495:Histone-Lysine N-Methyltransferase