Fig. 4. Suppression of Syt III expression. Whole cell lysates derived from control (empty-vector-transfected) RBL or RBL-Syt III^- cells were resolved by SDS-PAGE, immunoblotted and probed (A) with antibodies directed against Syt III (1:1000 dilution), Syt II (1: 1000 dilution) or anti G_i2 (affinity-purified AS10 antibodies, 1 µg/ml) as indicated. Sucrose gradient fractions derived from control RBL and RBL-Syt III^- cells were resolved by SDS-PAGE, immunoblotted and probed with anti Syt III antibodies (B) or anti Syt II antibodies (C). The first 14 fractions are presented, as indicated. Data represent one of three separate experiments (A) or one of two separate experiments (B,C).