FIGURE 4.

Dephosphorylation of SNAP-25 was modulated in PC12 cells expressing PRIP-1. PC12 cells expressing GFP (A), GFP-PRIP-1 (WT) (B), GFP-RPIP-1 (F97A) (C), or GFP-PRIP-1 (T94A) (D) were labeled with [³²P]orthophosphate, followed by stimulation with 50 μm FSK for 5 min. After removal of the stimulus, cells were left for the time period indicated. Cell extracts were subjected to immunoprecipitation by anti-SNAP-25 antibody overnight at 4 °C, and the precipitates were examined by SDS-PAGE for autoradiography and Western blotting using anti-SNAP-25 antibody. The panels show a typical autoradiogram and immunoblot. Results are expressed as the mean ± S.E. (error bars) of five (A–C) or four (D) separate experiments.