Figure 2. Effects of halothane on the phosphorylation of MARCKS in rat synaptosomal membranes. The washed membrane fraction from lysed rat cerebrocortical synaptosomes was treated as described in the legend to figure 1 and subjected to immunoprecipitation with an antibody to MARCKS, a specific substrate for PKC, as described in methods and materials. Protein phosphorylation was analyzed by sodium dodecyl sulfate/polyacrylamide gel electrophoresis followed by autoradiography. The phosphorylation of MARCKS (Mr= 83,000; arrow) was stimulated by 2.4 vol% halothane (lanes 3, 4) compared to control (lanes 1, 2; plus 10 micro Meter [Ala286]CaMKII281-302), and was inhibited by 10 micro Meter PKC19-36 (lanes 5, 6).