Nucleolar Chromatin Remodeling Complex (NoRC) binds intergenic spacer of rRNA gene

Stable Identifier
Reaction [binding]
Mus musculus
SVG |   | PPTX  | SBGN
Nucleolar Chromatin Remodeling Complex (NoRC) binds intergenic spacer of rRNA gene

The Nucleolar Remodeling Complex (NoRC) comprises Tip5 (Baz2a) and the chromatin remodeller SNF2h (Smarca5) (Strohner et al. 2001). Promoter-associated RNA (pRNA) transcribed from the intergenic spacer region is bound by Tip5 and is required to direct the complex to the main promoter of the rRNA gene, possibly by triple helix formation by pRNA and the rDNA (Mayer et al. 2006, Santoro et al. 2010). The PHD domain of Tip5 binds histone H4 acetylated at lysine-16 (Zhou and Grummt 2005). Transcription Termination Factor-I (Ttf-I) binds to a promoter-proximal terminator (T0 site) in the rDNA and interacts with the Tip5 subunit of NoRC (Nemeth et al. 2004, Strohner et al. 2004, Santoro and Grummt 2005). NoRC also interacts with the SIN3-HDAC complex, Hdac1, Hdac2, Dnmt1, and Dnmt3b (Santoro et al. 2002, Zhou and Grummt 2005, Santoro and Grummt 2005). Dnmt3b binds to the triple helix formed by pRNA and the rDNA (Schmitz et al. 2010). Hdac1, Dnmt1, and Dnmt3b have been shown to be required for proper DNA methylation of silenced rRNA gene copies. Binding of pRNA to the rDNA causes displacement of TTF-I (Schmitz et al. 2010).

Literature References
PubMed ID Title Journal Year
11532953 NoRC--a novel member of mammalian ISWI-containing chromatin remodeling machines

Längst, G, Hofmann-Rohrer, U, Strohner, R, Santoro, R, Grummt, I, Jansa, P, Németh, A

EMBO J 2001
20010804 Intergenic transcripts originating from a subclass of ribosomal DNA repeats silence ribosomal RNA genes in trans

Schmitz, KM, Sandoval, J, Santoro, R, Grummt, I

EMBO Rep. 2010
20952535 Interaction of noncoding RNA with the rDNA promoter mediates recruitment of DNMT3b and silencing of rRNA genes

Schmitz, KM, Mayer, C, Postepska, A, Grummt, I

Genes Dev. 2010
16085498 The PHD finger/bromodomain of NoRC interacts with acetylated histone H4K16 and is sufficient for rDNA silencing

Zhou, Y, Grummt, I

Curr Biol 2005
15767661 Epigenetic mechanism of rRNA gene silencing: temporal order of NoRC-mediated histone modification, chromatin remodeling, and DNA methylation

Santoro, R, Grummt, I

Mol Cell Biol 2005
14749393 Recruitment of the nucleolar remodeling complex NoRC establishes ribosomal DNA silencing in chromatin

Németh, A, Strohner, R, Längst, G, Becker, PB, Nightingale, KP, Grummt, I

Mol. Cell. Biol. 2004
15292447 The chromatin remodeling complex NoRC and TTF-I cooperate in the regulation of the mammalian rRNA genes in vivo

Németh, A, Strohner, R, Längst, G, Grummt, I

Nucleic Acids Res. 2004
16678107 Intergenic transcripts regulate the epigenetic state of rRNA genes

Mayer, C, Santoro, R, Grummt, I, Li, J, Schmitz, KM

Mol Cell 2006
12368916 The nucleolar remodeling complex NoRC mediates heterochromatin formation and silencing of ribosomal gene transcription

Santoro, R, Grummt, I, Li, J

Nat Genet 2002
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