Table 1.

HPLC-ESI-MS/MS analysis of endogenous PI 3-K subunits association with IRS-1 in L6 myotubes upon insulin stimulation. Data shown are mean ± SEM, n=5

(A) Spectrum count and number of MS/MS spectra assigned to IRS-1 and PI 3-K subunits in the basal (BAS) and insulin (INS) stimulated samples
Gene symbola	Molecular weight (AMU)	Spectrum count BAS	Spectrum count INS	Exp.1 BAS	Exp.1 INS	Exp.2 BAS	Exp.2 INS	Exp.3 BAS	Exp.3 INS	Exp.4 BAS	Exp.4 INS	Exp.5 BAS	Exp.5 INS
IRS-1	131160	105±10	100±8	93	108	85	85	105	126	145	91	99	88
PIK3R1	83516	0±0	8±1	0	4	0	10	0	19	0	6	0	2
PIK3R2	81251	11±2	74±15	12	88	16	83	12	100	2	71	11	29
PIK3CA	124233	1±1	20±4	0	17	0	17	0	26	0	28	3	12
PIK3CB	122595	0 ±0	6±1	0	6	0	7	0	6	0	6	0	3
(B) Normalized spectrum count (NormSC) of PI 3-K subunits in the basal (BAS) and insulin (INS) stimulated samples
Gene Symbol a	NormSC BAS	NormSC INS		Exp.1 BAS	Exp.1 INS	Exp.2 BAS	Exp.2 INS	Exp.3 BAS	Exp.3 INS	Exp.4 BAS	Exp.4 INS	Exp.5 BAS	Exp.5 INS
PIK3R1*	0.000±0.000	0.079±0.024		0.000	0.037	0.000	0.118	0.000	0.151	0.000	0.066	0.000	0.023
PIK3R2*	0.111±0.028	0.739±0.108		0.129	0.815	0.188	0.976	0.114	0.794	0.014	0.780	0.111	0.330
PIK3CA*	0.006±0.006	0.202±0.030		0.000	0.157	0.000	0.200	0.000	0.206	0.000	0.308	0.030	0.136
PIK3CB*	0.000±0.000	0.057±0.008		0.000	0.056	0.000	0.082	0.000	0.048	0.000	0.066	0.000	0.034

^aIRS-1 = insulin receptor substrate-1; PIK3R1 = PI 3-K p85 regulatory subunit ↦; PIK3R2 = PI 3-K p85 regulatory subunit β; PIK3CA = PI 3-K p110 catalytic subunit ↦; PIK3CB = PI 3-K p110 catalytic subunit β

^*P<0.05 by the sign test