Overexpression of a wildtype Syk transgene does not result in constitutive Syk kinase activity (A) Expression levels of a wildtype Syk transgene (T) were evaluated as described in Figure 3C, using RNA isolated from BCL1.3B3 (lane 1), a control vector-infected cell line (lane 2), and wildtype Syk-infected clones (lanes 3 and 4). (B). An ICKA for Syk immunoprecipitated from unstimulated (-) and stimulated (+; 15 μg anti-IgM for 0.5 minutes) BCL1.3B3 and wildtype Syk-infected clones (2.4.1 and 2.4.3). The arrow marks the migration position of Syk. Anti-ova was used as an immunoprecipitation control (C; lanes 3, 6, and 9).