Table 1. Identification of Myc Cofactors in mESCs by Co-Immunoprecipitation and Tandem Mass Spectrometry.

mESCs were lysed and immunoprecipitated two times with N- or c-Myc antibody. Isolated protein complexes identified by tandem mass spectrometry are listed in order of highest total peptide number and total percent peptide coverage. Known Myc cofactors are designated by cell type in which the interaction was previously found.

Gene Symbol	Gene Name	Peptide # (N-N-c-c- Myc co-IP)	Peptide # Control (No Antibody)	Total Percent Peptide Coverage	Range of Percent Probability	Known Myc Cofactors (Cell Type)
Eef1a1	Eukaryotic translation elongation factor 1 alpha 1	0-0-6-5	0-0	16	60–95
Ddx20	DEAD box polypeptide 20	0-0-4-3	0-0	10	50–95	mESCs30
Hist1h2be	Histone cluster 1, H2be	0-0-4-2	0-0	37	77–95
Ruvbl2	Ruvb-like protein 2	0-0-4-2	0-0	7	75–95	mESCs31,32
H3f3b	H3 histone, family 3b	0-0-3-3	0-0	25	65–95
Npm1	Nucleophosmin 1	0-3-3-0	0-0	11	81–95	MEFs33
Ybx1	V box protein 1	1-1-1-2	0-1	17	70–95	mESCs30
hnrnpk	Heterogeneous nuclear ribonucleoprotein K	0-0-5-0	0-0	8	61–95
Hist1h1b	Histone cluster 1, H1b	0-0-3-2	1-0	20	95
Dppa4	Developmental pluripotency associated 4	0-2-0-0	0-0	11	52–69
Nono	Non-POU-domain- containing, octamer binding protein	1-0-1-0	0-0	7	95
Ctrnb1	Catenin, beta 1	0-2-0-0	0-0	6	95
Mycn	V-myc myelocytomatosis viral related oncogene, neuroblastoma derived	0-0-1-1	0-0	10	80–90	Control
Hist1h1a	Histone cluster 1, H1a	0-0-0-1	0-0	15	95
Hist4h4	Histone cluster 4, H4	0-0-1-0	0-0	12	94–95
Utf1	Undifferentiated embryonic cell transcription factor 1	0-0-0-1	0-0	5	95	95
Dnmt3a	DNA methyltransferase 3a	1-0-0-0	0-0	2	76	U2OS34