Figure 4.

SPL Ser94 variants affect complex formation and dissociation. (A) CHO cells were transfected with Myc-tagged WT or variant SPL plus HA-tagged RGS18. After 48 hours, the CHO cells were incubated with 20 µM forskolin and 1 µM okadaic acid as indicated. Proteins were precipitated with anti-Myc or nonimmune immunoglobulin (Ig) and then probed with anti-HA before reprobing with anti-Myc. Note that a marker lane was excised as indicated by the vertical line. The graph summarizes 3 experiments (mean ± SEM). The data are expressed relative to normal (WT) SPL. P values are relative to WT SPL. (B) Identical to panel A except the cells were transfected with SHP-1 instead of HA-RGS18 and probed with anti-SHP-1 before reprobing with anti-Myc. NS, nonsignificant.