Skip to main content
. 2009 Jun 1;284(31):20840–20847. doi: 10.1074/jbc.M109.017467

FIGURE 6.

FIGURE 6.

siRNA suppression of endogenous Munc18b levels in INS-1E cells abolishes the effects of Cab45b-mEF2 and -mEF3 on exocytosis. A, Western blot showing the effect of siRNA on Munc18b protein levels in INS-1E cells after a 48-h transfection with a scrambled siRNA or siRNA directed against Munc18b. Antibody against β-actin was used to verify equal loading of the lanes. B, representative capacitance traces recorded from INS-1E cells transfected with a scrambled siRNA (Bi) or Munc18b-siRNA (Bii–Bvi). Equal concentrations (1 μm) of GST, GST-Cab45b-WT, or mutant proteins (Cab45b-mEF1, -mEF2, and -mEF3) were dialyzed into the cells for 1 min, and the ΔCm was measured. C, summary of total ΔCm evoked by the 10 depolarization pulses (pulse1–10). The data shown represent the mean ± S.E. from four independent experiments; each experiment included 2–3 cells for each group (total n = 9 cells for all groups except n = 11 for Cab45b-mEF3). **, p < 0.01, compared with the GST treatment from cells transfected with scrambled siRNA.