Supplementary Fig. 4: NPM1-depletion and snoRNA-inactivation in K562 cell line.

a, NPM1 KD efficiency in K562/shNPM1 cells compared to scramble transduced cells (Ctrl). αTUBULIN was used as a loading control. Blot is a representative of n=3 independent experiments. b, NPM1-depletion in K562 cells led to decreased 2′-O-Me of specific residues. Data are mean±SD of n=3 independent experiments. Ctrl 2′-O-Me is the 2′-O-Me at 1804 18S rRNA. c, SnoRNA abundance in K562/shNPM1 cells. Data are presented as mean±SD of n=4 independent experiments. d, Examples of indels in specific snoRNA genes generated by CRISPR/Cas9 genome editing in K562 cells. In blue is the specific snoRNA’s wild type sequence; in red are examples of mutations in the same snoRNA induced by CRISPR/Cas9 editing. e, Analysis of control 2′-O-Me 4506 in CRISPR/Cas9 snoRNA-inactivated K562 cells. Data are presented as mean±SD of n=3 independent experiments.. f, Levels of specific 2′-O-Me residues (x-axis) mediated by only C/D box snoRNAs identified to interact with NPM1 by HITS-CLIP. Data are presented as mean±SD, n=3 independent experiments, of fold change of 2′-O-Me in K562/shNPM1+FBL cells relative to K562 cells transduced with scramble vector. Ctrl residue is the U1804 2′-O-Me modification on the 18S rRNA that is mediated by snoRD20, which was not identified to interact with NPM1 by HITS-CLIP. For all relevant panels, and unless otherwise stated, statistical significance was determined by one-tailed student’s t-test.