Fig. 8. Second messengers involved in HA signaling to GRC. GRC-transfected COS-7 cells were treated with various inhibitors for 20 minutes at 37°C, before HA was added. Blockage of Ca²⁺ channels by SK&F 93625 (SKF), of inhibitory G proteins by pertussis toxin (PTX), of Ca²⁺/calmodulin-dependent kinases by KN-93 (KN), and of PI(3)-kinase by wortmannin (WORT) inhibited the HA-induced translocation of GRC, whereas roscovitine (ROS), which blocks cyclin-dependent kinases, had no effect.