TABLE 1.

Comparison of protein phosphorylation changes

Spot no.	Mol mass (kDa)	pI	Relative phosphorylation change (1 min/0 min)a		P
			HS176 (ERK2 WT)	HS174 (erk2−)
1	50	6.3	1.63 ± 0.45	1.54 ± 0.35	0.44
2	44	6.5	2.72 ± 0.95	1.95 ± 0.86	0.29
3	45	5.9	2.95 ± 0.29	1.22 ± 0.06	<0.01
4	46	5.7	2.00 ± 0.39	0.70 ± 0.23	0.02
5	42	5.9	1.59 ± 0.40	2.01 ± 0.78	0.32
6	40	4.8	3.52 ± 1.43	0.91 ± 0.22	0.07
7	40	4.2	0.98 ± 0.37	1.48 ± 0.67	0.28
8	38	4.9	1.94 ± 0.74	1.07 ± 0.43	0.18
9	38	4.7	2.52 ± 0.55	1.22 ± 0.66	0.10
10	36	4.7	3.94 ± 0.71	0.94 ± 0.29	0.01
11	37	4.4	3.61 ± 2.20	0.88 ± 0.22	0.14
12	36	6.6	1.49 ± 0.43	0.96 ± 0.36	0.20
13	38	5.9	0.98 ± 0.34	1.29 ± 0.60	0.34
14	34	4.7	3.82 ± 1.12	1.35 ± 0.57	0.06
15	34	4.5	3.45 ± 1.56	1.43 ± 0.25	0.14
16	30	5.7	1.78 ± 0.41	1.94 ± 0.88	0.44
17	28	5.3	0.78 ± 0.16	1.77 ± 0.74	0.13
18	29	5.0	2.62 ± 0.37	1.33 ± 0.39	0.04
19	27	6.6	0.68 ± 0.40	0.93 ± 0.38	0.34
20	26	4.8	1.89 ± 0.45	1.07 ± 0.11	0.08
21	25	6.5	2.07 ± 0.76	1.11 ± 0.32	0.15
22	24	5.1	2.18 ± 0.75	0.91 ± 0.16	0.09
23	24	4.5	2.85 ± 1.31	2.96 ± 1.86	0.48
24	22	6.5	1.46 ± 0.22	1.02 ± 0.42	0.20
25	22	6.4	1.29 ± 0.23	1.11 ± 0.38	0.35
26	20	5.7	2.06 ± 1.21	1.87 ± 0.84	0.45
27	22	5.3	1.73 ± 0.66	1.16 ± 0.54	0.27
28	22	5.2	2.14 ± 0.98	1.51 ± 0.74	0.32
29	20	4.8	3.20 ± 1.19	1.13 ± 0.23	0.08
30	20	4.7	4.75 ± 1.94	1.45 ± 0.48	0.09
31	18	5.3	2.79 ± 0.45	1.09 ± 0.51	0.03
32	14	6.0	2.43 ± 0.61	1.48 ± 0.90	0.22
33	17	4.9	1.49 ± 0.50	1.25 ± 0.53	0.38
34	17	4.8	1.86 ± 0.69	0.90 ± 0.23	0.13
35	17	4.4	2.65 ± 1.00	0.98 ± 0.20	0.09

^a32P incorporation into spots of 2-D gels was quantified by PhosphorImager and normalized to the protein amount of actin in each gel. Phosphorylation changes of proteins are expressed as the fold change in ³²P incorporation after cAMP stimulation versus before stimulation. Values are means ± standard errors from three experiments. Only proteins that were phosphorylated in three independent experiments were quantified.