Table I. LC-MS/MS identifies many known and several novel Numb interacting proteins. A list of proteins identified by LC-MS/MS as co-immunoprecipitating with the Numb isoforms. Shown here are proteins that were not identified in FLAG controls, and appeared in at least five of seven biological replicates with either the p66 or p72 isoform. Protein identification probability for each identified protein was 100%. * indicates previously identified Numb interacting proteins.

Identified Proteins	Gene Symbol	Accession Number	Molecular Weight	p66		p72
				Spectral Count	Sequence Coverage	Spectral Count	Sequence Coverage
Isoform 1 of Protein numb homolog	NUMB	IPI00137943	71 kDa	253	32%	1060	41%
*Adaptor-related protein complex 2, alpha 2	AP2A2	IPI00016621	104 kDa	187	34%	671	36%
Isoform 1 of AP-2 complex subunit beta-1	AP2B1	IPI00784156	105 kDa	178	35%	643	38%
Isoform 1 of AP-2 complex subunit mu-1	AP2M1	IPI00022256	50 kDa	107	35%	375	55%
*Isoform B of AP-2 complex subunit alpha-1	AP2A1	IPI00256684	105 kDa	127	21%	359	25%
*Epidermal growth factor receptor substrate 15	EPS15	IPI00292134	99 kDa	38	24%	294	41%
RALBP1 associated Eps domain containing 1 isoform a	REPS1	IPI00337532	87 kDa	75	18%	151	31%
*cDNA FLJ60624, highly similar to Epidermal growth factor receptor substrate 15-like 1	EPS15L1	IPI00163849	100 kDa	7	7%	124	23%
25 kDa protein		IPI00872430	25 kDa	30	28%	79	37%
Isoform 2 of AP-2 complex subunit sigma-1	AP2S1	IPI00183781	12 kDa	0	0%	87	44%
Isoform A of AP-1 complex subunit beta-1	AP1B1	IPI00328257	105 kDa	16	10%	77	17%
*RalA-binding protein 1	RALBP1	IPI00009544	76 kDa	9	9%	70	27%
Trifunctional enzyme subunit alpha, mitochondrial	HADHA	IPI00031522	83 kDa	7	5%	74	22%
Isoform 1 of Serine/arginine repetitive matrix protein 2	SRRM2	IPI00782992	300 kDa	37	8%	34	4%
Isoform 1 of BMP-2-inducible protein kinase	BMP2K	IPI00337426	129 kDa	22	6%	40	12%
*14–3-3 protein epsilon	YWHAE	IPI00000816	29 kDa	13	22%	31	28%
Isoform 1 of Fragile X mental retardation syndrome-related protein 1	FXR1	IPI00016249	70 kDa	6	7%	32	12%
Isoform 1 of Breakpoint cluster region protein	BCR	IPI00004497	143 kDa	0	0%	27	8%
Isoform 1 of Bcl-2-associated transcription factor 1	BCLAF1	IPI00006079	106 kDa	9	5%	12	5%