title: An Interaction between RRP6 and SU(VAR)3-9 Targets RRP6 to Heterochromatin and Contributes to Heterochromatin Maintenance in Drosophila melanogaster.
abstract: RNA surveillance factors are involved in heterochromatin regulation in yeast and plants, but less is known about the possible roles of ribonucleases in the heterochromatin of animal cells. Here we show that RRP6, one of the catalytic subunits of the exosome, is necessary for silencing heterochromatic repeats in the genome of Drosophila melanogaster. We show that a fraction of RRP6 is associated with heterochromatin, and the analysis of the RRP6 interaction network revealed physical links between RRP6 and the heterochromatin factors HP1a, SU(VAR)3-9 and RPD3. Moreover, genome-wide studies of RRP6 occupancy in cells depleted of SU(VAR)3-9 demonstrated that SU(VAR)3-9 contributes to the tethering of RRP6 to a subset of heterochromatic loci. Depletion of the exosome ribonucleases RRP6 and DIS3 stabilizes heterochromatic transcripts derived from transposons and repetitive sequences, and renders the heterochromatin less compact, as shown by micrococcal nuclease and proximity-ligation assays. Such depletion also increases the amount of HP1a bound to heterochromatic transcripts. Taken together, our results suggest that SU(VAR)3-9 targets RRP6 to a subset of heterochromatic loci where RRP6 degrades chromatin-associated non-coding RNAs in a process that is necessary to maintain the packaging of the heterochromatin.
authors.affiliation: Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.
authors.forename: Andrea B
authors.initials: AB
authors.lastname: Eberle
authors.affiliation: Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.
authors.forename: Antonio
authors.initials: A
authors.lastname: Jordán-Pla
authors.affiliation: Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.
authors.forename: Antoni
authors.initials: A
authors.lastname: Gañez-Zapater
authors.affiliation: Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.
authors.forename: Viktoria
authors.initials: V
authors.lastname: Hessle
authors.affiliation: Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.
authors.forename: Gilad
authors.initials: G
authors.lastname: Silberberg
authors.affiliation: Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.
authors.forename: Anne
authors.initials: A
authors.lastname: von Euler
authors.affiliation: Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Silverstein
authors.affiliation: Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.
authors.forename: Neus
authors.initials: N
authors.lastname: Visa
mesh_terms: D000818:Animals; D004251:DNA Transposable Elements; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism*; D063326:Exosome Multienzyme Ribonuclease Complex / Q000378:metabolism*; D020868:Gene Silencing; D016678:Genome; D006570:Heterochromatin / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics; D012097:Repressor Proteins / Q000378:metabolism*
chemical_list: D004251:DNA Transposable Elements; D029721:Drosophila Proteins; D006570:Heterochromatin; D012333:RNA, Messenger; D012097:Repressor Proteins; C545895:Rrp6 protein, Drosophila; C089148:Su(var)3-9 protein, Drosophila; D063326:Exosome Multienzyme Ribonuclease Complex