FIG. 3.

Cloning and analysis of the RasGRP3 cDNA. (A) Full-length RasGRP3 was cloned from the mouse endothelial cell line Py-4-1 by RT-PCR and sequenced. Underlined sequences represent conserved domains. (B) Schematic of RasGRP3 protein. REM, RasGEF N-terminal domain; CDC25, catalytic RasGEF domain; EF, atypical EF hand domain; C1, PKC region 1 domain that binds DAG. (C) Model of RasGRP3 activation and signaling. Upon ligand-receptor engagement, PLC-γ is activated, which leads to the production of DAG from PIP₂. DAG is localized to the plasma membrane. C1 domain binding of DAG recruits RasGRP3 to the membrane where Ras activation occurs.