(A) RasGRP1 is dispensable for BCR-stimulated p-JNK. B1a cells were sorted from wild type (WT) and RasGRP1-deficient (KO) mice and were stimulated with anti-Ig (15 μg/ml) (αIg) for 5 and 10 min. p-JNK was evaluated by immunoblot. Membranes were stripped and reprobed with JNK-specific antibody as a loading control. (B) RasGRP1 is dispensable for BCR-stimulated p-p38. Peritoneal lymphocytes from wild type and RasGRP1-deficient mice were unstimulated (US) (WT: red line; KO: blue line) or stimulated (WT: green line; KO: orange line) with anti-Ig (αIg) (15 μg/ml) for 1 min. p-p38 in B1 cells (CD19+CD43+) was evaluated by intracellular immunofluorence staining and flow cytometry. (C) Constitutive expression of NFATc1 is intact in RasGRP1-deficient B1 cells. NFATc1 protein expression was evaluated in WT B1 cells, WT B2 cells, KO B1 cells, and KO B2 cells by immunoblot. Membranes were stripped and reprobed with actin-specific antibody as a loading control. (D) BCR-stimulated NFATc1 protein expression is intact in RasGRP1-deficient B1 cells. WT B1 cells (left upper panels), WT B2 cells (left lower panels), KO B1 cells (right upper panels), and KO B2 cells (right lower panels) were stimulated with anti-Ig (15 μg/ml) (αIg) for 0, 1, or 2 days. NFATc1 protein expression was evaluated by immunoblot. Membranes were stripped and reprobed with actin-specific antibody as a loading control. Results represent one of three comparable experiments.