Figure 4.
Effect of Ras-GRF1 on JNK1 activation in response to m2 receptor stimulation. (A) Time course of JNK1 activation in response to m2 receptor stimulation. Activities of HA-tagged JNK1 immunoprecipitated from 293 cells expressing the m2 receptor alone (○) or the m2 receptor and Ras-GRF1 (●) after stimulation with carbachol (10 μM) for specified periods. Relative values compared with the activity from 293 cells expressing the m2 receptor alone without carbachol stimulation are shown as mean ± SE (n = 3). (B) Effect of Gαo1 on m2 receptor and Ras-GRF1-mediated JNK1 activation. Activities of HA-tagged JNK1 immunoprecipitated from 293 cells expressing the m2 receptor and indicated proteins with (+) or without (−) carbachol stimulation (10 μM, 10 min). Data are shown as described in A.