title: RNase P protein subunit Rpp29 represses histone H3.3 nucleosome deposition.
abstract: In mammals, histone H3.3 is a critical regulator of transcription state change and heritability at both euchromatin and heterochromatin. The H3.3-specific chaperone, DAXX, together with the chromatin-remodeling factor, ATRX, regulates H3.3 deposition and transcriptional silencing at repetitive DNA, including pericentromeres and telomeres. However, the events that precede H3.3 nucleosome incorporation have not been fully elucidated. We previously showed that the DAXX-ATRX-H3.3 pathway regulates a multi-copy array of an inducible transgene that can be visualized in single living cells. When this pathway is impaired, the array can be robustly activated. H3.3 is strongly recruited to the site during activation where it accumulates in a complex with transcribed sense and antisense RNA, which is distinct from the DNA/chromatin. This suggests that transcriptional events regulate H3.3 recruited to its incorporation sites. Here we report that the nucleolar RNA proteins Rpp29, fibrillarin, and RPL23a are also components of this H3.3/RNA complex. Rpp29 is a protein subunit of RNase P. Of the other subunits, POP1 and Rpp21 are similarly recruited suggesting that a variant of RNase P regulates H3.3 chromatin assembly. Rpp29 knockdown increases H3.3 chromatin incorporation, which suggests that Rpp29 represses H3.3 nucleosome deposition, a finding with implications for epigenetic regulation.
authors: Molecular and Cellular Oncogenesis Program, Wistar Institute, Philadelphia, PA 19104.
authors: Alyshia
authors: A
authors: Newhart
authors: Molecular and Cellular Oncogenesis Program, Wistar Institute, Philadelphia, PA 19104.
authors: Sara Lawrence
authors: SL
authors: Powers
authors: Molecular and Cellular Oncogenesis Program, Wistar Institute, Philadelphia, PA 19104 Department of Biological Sciences, University of the Sciences in Philadelphia, Philadelphia, PA 19104.
authors: Prashanth Krishna
authors: PK
authors: Shastrula
authors: Molecular and Cellular Oncogenesis Program, Wistar Institute, Philadelphia, PA 19104.
authors: Isabel
authors: I
authors: Sierra
authors: Molecular and Cellular Oncogenesis Program, Wistar Institute, Philadelphia, PA 19104.
authors: Lucy M
authors: LM
authors: Joo
authors: Molecular and Cellular Oncogenesis Program, Wistar Institute, Philadelphia, PA 19104.
authors: James E
authors: JE
authors: Hayden
authors: Electrical and Computer Engineering Department, Drexel University, Philadelphia, PA 19104.
authors: Andrew R
authors: AR
authors: Cohen
authors: Molecular and Cellular Oncogenesis Program, Wistar Institute, Philadelphia, PA 19104 sjanicki@wistar.org.
authors: Susan M
authors: SM
authors: Janicki
mesh_terms: D042002:Chromatin Assembly and Disassembly; D002868:Chromosomal Proteins, Non-Histone; D044127:Epigenesis, Genetic; D006657:Histones; D006801:Humans; D009707:Nucleosomes / Q000378:metabolism*; D012260:Ribonucleases; D012261:Ribonucleoproteins
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D006657:Histones; D009707:Nucleosomes; D012261:Ribonucleoproteins; C047458:fibrillarin; D012260:Ribonucleases; C105253:POP4 protein, human