title: The structure of NoRC-associated RNA is crucial for targeting the chromatin remodelling complex NoRC to the nucleolus.
abstract: Silencing of ribosomal RNA genes (rDNA) requires binding of the chromatin remodelling complex NoRC to RNA that is complementary to the rDNA promoter. NoRC-associated RNA (pRNA) folds into a conserved stem-loop structure that is required for nucleolar localization and rDNA silencing. Mutations that disrupt the stem-loop structure impair binding of TIP5, the large subunit of NoRC, to pRNA and abolish targeting of NoRC to nucleoli. Binding to pRNA results in a conformational change of TIP5, as shown by enhanced sensitivity of TIP5 towards trypsin digestion. Our results indicate an RNA-dependent mechanism that targets NoRC to chromatin and facilitates the interaction with co-repressors that promote heterochromatin formation and rDNA silencing.
authors.affiliation: Division of Molecular Biology of the Cell II, German Cancer Research Center, DKFZ-ZMBH-Alliance, INF 581, D-69120 Heidelberg, Germany. christine.mayer@dkfz.de
authors.forename: Christine
authors.initials: C
authors.lastname: Mayer
authors.forename: Melanie
authors.initials: M
authors.lastname: Neubert
authors.forename: Ingrid
authors.initials: I
authors.lastname: Grummt
mesh_terms: D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002466:Cell Nucleolus / Q000378:metabolism*; D002843:Chromatin / Q000378:metabolism*; D042002:Chromatin Assembly and Disassembly; D002868:Chromosomal Proteins, Non-Histone / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D005455:Fluorescent Antibody Technique; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D041681:NIH 3T3 Cells; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D011487:Protein Conformation; D012313:RNA / Q000737:chemistry / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic; D014162:Transfection; D000092468:Bromodomain Containing Proteins
chemical_list: D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D012313:RNA; D011993:Recombinant Fusion Proteins; C499051:Baz2a protein, mouse; D000092468:Bromodomain Containing Proteins