Figure 1.

PhosphorImager record of in situ phosphorylation of PRBPs isolated from hippocampal slices of 12-day-old rats, labeled with ³³P. (A) Stimulation with 0.1 mM DHPG for 10 min increased endogenous phosphorylation of proteins with molecular masses of 90, 85, 48, 33, 22, and 19 kDa (arrows). A comparable effect could be observed after addition of a PKC activator, 1 μM PDBu, but not after stimulation with 50 μM forskolin. This enhanced phosphorylation elicited by DHPG was not detectable if 10 μM calphostin C, an inhibitor of PKC, or 10 μM GF109203X, an inhibitor of both PKC and p90rsk, was present during stimulation. (B) Scanning profiles obtained from the shown autoradiographs. Black line: unstimulated samples; gray line: stimulated samples (DHPG, PDBu, and forskolin). Arrows indicate peaks corresponding to the indicated bands in the autoradiography.