Additional file 5: Figure S5. of A T-type channel-calmodulin complex triggers αCaMKII activation

Activation of αCaMKII depends on Cav3.1 calcium influx and an increase in [Ca]i. The distribution of GFP-αCaMKII tested in tsA-201 cells in low [K]o (1 mM) or high [K]o (50 mM) and indicated reagents. All cells are cotransfected with CaM and Kir2.1. Plots indicate mean pixel variance of fluorescence in ROIs in cytoplasm and nuclear regions. a, b. A diffuse distribution of αCaMKII-GFP is stable in low [K]o over time. c-h. The aggregation of αCaMKII-GFP depends on Cav3.1-mediated calcium influx, as shown when a Cav3.1 pore mutant (Cav3.1 PM) that does not conduct calcium is expressed (c, d), the ability for high [K]o to promote aggregation in the presence of 30 μM Cd2+(e, f) but not in the presence of mibefradil (1 μM) and Ni2+ (300 μM) (g, h). i, j. The dependence of αCaMKII-GFP aggregation induced by high [K]o exposure also depends on an increase in [Ca]i in being blocked by pre-expossure to BAPTA-AM (0.1 mM). Values are mean ± SD at 250 s derived from 3 to 4 plates with 14–19 ROIs. Scale bars 10 μm. (PDF 5411 kb)