Fig. 1. Rap1 activation induced by overexpression of Chat. (A) A diagram of Chat
variants used in this study. We used an N-terminally myristoylated
membrane-targeted form of Chat (Myr-Chat) to evaluate the activation status of
Chat. C-terminal deletion mutants (Chat-
CT and Myr-
CT) lacked
the Cas association activity. (B) 293T cells were transiently transfected with
the indicated Chat-related expression plasmid together with small GTPase Rap1.
After 30 hours, the activation level of Rap1 was compared by a pull-down
assay. The amount of pulled-down GTP-bound Rap1 (GTP-Rap1), expression levels
of transfected Rap1 (Total Rap1) and Chat-derivatives (Anti-Chat) is shown.
Overexpression of Chat increased the GTP-bound Rap1 compared with the control
pCAX vector transfectant. Myr-Chat activated Rap1 more effectively than
wild-type Chat. Chat-
CT and Myr-
CT abolished the Rap1 activation
competence.