Figure 5

Btk:ER-induced ERK and JNK activation, and apoptosis, are dependent on PLCγ2. A, Btk:ER-induced ERK MAPK activation is dependent on PLCγ2. Parental and PLCγ2-deficient cells expressing Btk:ER were treated for 60-min with vehicle control (0.1% ethanol), 4-HT (1 μM) and/or anti-μ mAb M4 (4 μg/ml), or for 15-min with PMA (100 ng/ml) as a positive control. ERK activation was measured by immune complex kinase assay as described in the legend for Fig 3A. B, Btk:ER-induced JNK phosphorylation is dependent on PLCγ2. Parental and PLCγ2-deficient cells expressing Btk:ER were treated for 30-min with vehicle control (0.1% ethanol), 4-HT (1 μM) and/or anti-μ mAb M4 (4 μg/ml), or for 10-min with PMA (100 ng/ml) and ionomycin (250 ng/ml) as a positive control. JNK phosphorylation was measured by immunblotting with anti-active JNK phosphospecific antiserum as described in the legend for Fig 3B. C, Btk:ER-induced apoptosis is dependent on PLCγ2. Apoptosis of parental and PLCγ2-deficient cells expressing Btk:ER was measured by TUNEL assay as described in the legend for Fig 3C. PMA (100 ng/ml) and ionomycin (250 ng/ml) were used as a positive control. These data are representative of three independent stable clones.