NOL11 is required for pre-rRNA processing in HeLa cells.

<p>(A) Diagram of pre-rRNA processing in human cells. Cleavage sites are indicated with labeled arrows. The positions of oligonucleotide probes used for Northern blotting are indicated with lettered lines. (B) hUTP4/Cirhin and NOL11 were successfully knocked down by siRNAs. After siRNA treatment, total protein was extracted from HeLa cells, separated by SDS-PAGE, and transferred to a PVDF membrane. Western blotting was used to check for the presence of hUTP4/Cirhin (left) or NOL11 (right). (C) Northern blot analysis of pre-rRNA processing. After siRNA treatment, total RNA was extracted from HeLa cells, separated on an agarose/formaldehyde gel, and transferred to a Hybond XL nylon membrane. RNA was detected with the indicated oligonucleotide probe or with methylene blue.