Intergenic transcripts originating from a subclass of ribosomal DNA repeats silence ribosomal RNA genes in trans.
Epigenetic silencing of a fraction of ribosomal DNA (rDNA) requires association of the nucleolar chromatin-remodelling complex NoRC to 150-250 nucleotide RNAs (pRNA) that originate from an RNA polymerase I promoter located in the intergenic spacer separating rDNA repeats. Here, we show that NoRC-associated pRNA is transcribed from a sub-fraction of hypomethylated rRNA genes during mid S phase, acting in trans to inherit DNA methylation and transcriptional repression of late-replicating silent rDNA copies. The results reveal variability between individual rDNA clusters with distinct functional consequences.
Santoro
Raffaella
R
Division of Molecular Biology of the Cell II, German Cancer Research Center, DKFZ-ZMBH-Alliance, INF 581, 69120 Heidelberg, Germany.
Schmitz
Kerstin-Maike
KM
Sandoval
Juan
J
Grummt
Ingrid
I
D000818:Animals; D042002:Chromatin Assembly and Disassembly / Q000235:genetics / Q000502:physiology; D019175:DNA Methylation / Q000235:genetics / Q000502:physiology; D021901:DNA, Intergenic / Q000235:genetics*; D004275:DNA, Ribosomal / Q000235:genetics*; D012321:DNA-Directed RNA Polymerases / Q000235:genetics / Q000378:metabolism; D044127:Epigenesis, Genetic / Q000235:genetics*; D020868:Gene Silencing; D051379:Mice; D041681:NIH 3T3 Cells; D011401:Promoter Regions, Genetic; D012335:RNA, Ribosomal / Q000235:genetics*; D022661:RNA, Untranslated / Q000235:genetics / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016196:S Phase; D014158:Transcription, Genetic
D021901:DNA, Intergenic; D004275:DNA, Ribosomal; D012335:RNA, Ribosomal; D022661:RNA, Untranslated; D012321:DNA-Directed RNA Polymerases