RRP8 (Nucleomethylin, NML) recruits SIRT1 to the nucleolus to form the energy-dependent Nucleolar Silencing Complex (eNoSC), which induces chromatin changes that inhibit rRNA transcription. RRP8 can bind 5S RNA (transcribed by RNA ploymerase III), 5.8S rRNA, and 28S rRNA and the bound RNA prevents RRP8 from binding SIRT1 (Yang et al. 2013). Thus the level of 5S RNA, 5.8S rRNA, and 28S rRNA in the nucleus negatively regulates the assembly of eNoSC, coupling transcriptional regulation of rRNA to epigenetic silencing of rRNA genes.
Zheng, H, Chen, L, Chen, J, Seto, E, Song, T, Yang, L, Kabra, N, Koomen, J
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