Table 2.

RBPs expressed in the medulloblastoma Daoy and the glioblastoma U251 cell line

Sample	Daoy cytosol	U251, replicate 1, cytosol	U251, replicate 2, cytosol	U251, replicate 1, pellet	U251, replicate 2, pellet
Total number of proteins	1025	1160	813	1210	702
Average expression level across all proteins	9.79	11.02	11.46	11.28	11.47
Standard deviation	3.03	2.50	2.42	2.45	2.36
Number of RBPs detected in dataset (out of 36)	12	15	13	11	10
Average expression level	13.58	12.47	12.52	12.40	13.11
Standard deviation	2.53	2.32	2.66	2.77	2.00
p-value (t-test)	0.0002	0.0329	0.1843	0.2141	0.0241
Name	Daoy cytosol	U251, replicate 1, cytosol	U251, replicate 2, cytosol	U251, replicate 1, pellet	U251, replicate 2, pellet
CPSF6	11.10	13.16	12.98	13.29	13.46
DHX9	12.89	9.51	10.60	11.00	11.00
HNRPK	15.45	13.26	14.01	15.46	14.98
HNRPUL1	11.29	11.61	10.24	11.65	11.26
NONO	12.89	12.81	13.48	14.25	14.32
NPM1	18.39	16.29	16.66	17.09	17.11
RPL12	14.33	15.79	15.24	10.56	13.75
RPS17	15.24	15.00	13.83	13.99	12.51
DKC1		8.81	10.82	12.23	11.49
RPS5	16.87	14.50	15.98
RPS9	10.79	12.01	11.49
EIF3S9		8.80	7.85
PAIP1		11.49	9.56
RBM39				9.15	11.21
RPL18A	10.50	12.32
NXF1				7.72
RPL13	13.22
RPL34		11.71

We analyzed quantitative proteomics data from Daoy and U251 cell lines to test for over-expression of RBPs involved in brain tumor formation. The Daoy sample derives from a cytosolic fraction.25 The U251 sample derives from two biological replicates, fractionated into cytosol and pellet. Of the 36 RBPs, we identified 18 proteins across the five samples, and these proteins had higher expression levels than average in the dataset (p-value <0.05). The raw LC-MS/MS data and experimental methods are published at http://www.marcottelab.org/MSdata/. Expression levels were estimated using APEX,26 and are provided in (log base 2) molecules/cell.