Fig. 2. Effect of Chat overexpression on Ras family small GTPase activities. Activation levels of the small GTPases in Chat-overexpressing 293T cells were examined by a pull down assay as in Fig. 1. (A) Overexpression of Chat or Myr-Chat induced Rap1 activation. The activation level was low compared with a positive control Rap1 GEF, C3G. Neither Chat nor Myr-Chat increased the amount of GTP-bound H-Ras (B), R-Ras (C) and RalA (D) in similar experiments to A. mSos-F, a membrane-targeted form of mSos, C3G or RalGDL was used as a positive control for H-Ras, R-Ras or RalA activation.