FIG. 4.

RasGRF proteins synergize with Vav1 in a Ras-dependent manner for NF-AT activation. (A) Jurkat cells expressing the indicated proteins and the pNF-ATluc reporter plasmid were stimulated with anti-CD3 antibodies as indicated and subjected to NF-AT assays (upper panel). Aliquots of total cellular lysates were subjected to immunoblot analysis with the indicated antibodies (right) to monitor the level of expression of the proteins used in this experiment (lower panel). (B) Jurkat cells expressing HA-H-Ras, either alone or in combination with the indicated molecules, were subjected to GST-RBD pulldown experiments as indicated in the legend to Fig. 1. WB, Western blot.