Phosphorylation of each protein was measured by immunoblotting method as described in Methods. The band intensity of anti-phospho-CPI-17 Thr38 (A), MYPT1-Thr696, and -Thr853 (B) was normalized with that of anti-pan CPI-17 (A), and MYPT1 (B), respectively. Data from SMA without and after a 10-min exposure to 30 μM PE and 2.5 mM CaCl2 are indicated as Ctl and PE, respectively. Y27632 (+Y) and GF109203x (+GF) were added as described in Figure 2. All samples were loaded on single gel for densitometry. The mean values ± SEM were obtained from 3 independent assays. *p < 0.01, **p < 0.05.