Abraham KJ, Khosraviani N, Chan JNY, Gorthi A, Samman A, Zhao DY, Wang M, Bokros M, Vidya E, Ostrowski LA, Oshidari R, Pietrobon V, Patel PS, Algouneh A, Singhania R, Liu Y, Yerlici VT, De Carvalho DD, Ohh M, Dickson BC, Hakem R, Greenblatt JF, Lee S, Bishop AJR, Mekhail K.

Nature. 2020 Sep;585(7824):298-302. doi: 10.1038/s41586-020-2497-0

Nucleolar RNA polymerase II drives ribosome biogenesis.

Active (S2p) Pol II is enriched at InterGenic Spacer (IGS) regions. Pol II inhibition with α-amanitin (AMN) or flavopiridol for 30 min was sufficient to disrupt rRNA processing. IGS noncoding RNAs (ncRNAs) decreased in abundance following Pol I inhibition and increased with Pol II inhibition. Double inhibition decreased their abundance. Pol I transcribed sense intergenic ncRNAs (sincRNAs) and Pol II antisense intergenic ncRNAs (asincRNAs).