FIGURE 5.
Knockdown of Syt11 and its effect on insulin secretion and exocytosis in INS‐1 832/13 cells. (A) Expression of Syt11 after silencing with siRNA (siSYT11; blue bar) relative to its expression using scramble control (siSCR; white bar). (B) Relative expression of Syt4, Syt7, and Syt13 in siSYT11 (blue bars) and siSCR (white bars) cells. (C) Insulin secretion in siSYT11 (blue bars) and siSCR (white bars) cells after stimulation for 1 h in 2.8 mM glucose (2.8G), 16.7 mM glucose (16.7G), or 16.7 mM glucose + 2.5 μM forskolin (16.7G + forsk) as indicated. (D) Insulin secretion in siSYT11 (blue bars) and siSCR (white bars) cells after stimulation with 50 mM K+ in 2.8 mM glucose for 15 min. (E) Representative traces of depolarization‐induced increases in membrane capacitance in siSYT11 (black trace) and siSCR (gray trace) cells. (F) Summed capacitance changes (sum) and the total capacitance change (total) for siSyt11 (blue bar) and siSCR (white bar) after a train of ten 500 ms long depolarisations. (G) The capacitance change for siSYT11 (blue bar) and siSCR (white bar) after each individual pulse in (F). (H) Charge–voltage relationships in siSYT11 cells (black circles) compared to their scramble control (black squares). Data are given as mean ± SEM from three to five experiments in (A–D) and 15 cells in (E–G). *p ≤ 0.05, † p ≤ 0.01, ‡ p < 0.001.