<p>Jurkat cells were electroporated with GFP-RasGRP1 or GFP-RasGRP1Δtail plasmids. Live cell imaging was performed on a Zeiss Observer D1 station equipped with a CoolSNAP<sub>HQ</sub> charge-coupled device camera (Roper Scientific) and a high-speed automatic objective stage for multiple Z stack recording. The images were collected with a 40x objective lens and 2.5x camera zoom at 45 second intervals at 37°C. For each cell at each time point, GFP data were collected over 21 continuous vertical Z positions. After the first time frame, OKT3 or PMA were added to the samples. Images were processed by 3D deconvolution using AutoQuant X software (Media Cybernetics). All imaging manipulation and analysis were done using the MetaMorph software suite (Molecular Probes). Data are representative of at least six independent experiments analyzing at least five cells per experiment.</p
