Fig. 8
From: The a subunit isoforms of V-ATPase are involved in glucose-dependent trafficking of insulin granules
Localization of Rab27A to insulin granules and insulin secretion in control and a3KD MIN6 cells. (A) Effect of a3 on the localization of Rab27A to insulin granules. Control and a3KD cells expressing V5-Rab27A were incubated with 2.2 mM glucose for 60 min and stained with antibodies specific for insulin (magenta) and V5 (green). Merged images are also shown. (B) Co-localization was quantified as the percentage of insulin-positive pixels that were also Rab27A-positive. Open and closed bars indicate control and a3KD cells, respectively. More than 30 cells were randomly selected from three experiments using WT and a3KD cells. Data are means ± S.E. (C) Total insulin content in control (open bars) and a3KD (closed bars) cells. (D) Insulin secretion from control (open bars) and a3KD (closed bars) cells. Cells were treated with KRH buffer containing 2 or 20 mM glucose for 2 h, and then the insulin content in the recovered medium and acid ethanol extracts was determined using an ELISA kit. Insulin secretion from control cells treated with 2 mM glucose was set to 1. Data are means ± S.E. from four independent experiments. *p < 0.05, unpaired two-tailed Student’s t-test.
