Translocalization of RCK1 after cAMP stimulation. (A) Localization of wild-type RCK1 and mutants C551A, E510G, and EN510-511GA before (0") and after cAMP stimulation. Cells expressing myc-tagged RCK1 or its mutants were pulsed for 4.5 h, stimulated with 20 μM cAMP, fixed at the time indicated, and stained for myc-RCK1 as described in MATERIALS AND METHODS. (B) Localization of the RCK1 kinase-dead mutant RCK1K867A before (0") and after cAMP stimulation.