FIGURE 2.

Overexpression of mortalin reduces the amount of bound C5b-9 on the cell surface. K562 cells, 48 h after transfection with a mortalin-EGFP plasmid, were treated with anti-K562 antibodies and then with C9D-NHS supplemented with C9-AF555 for 10 min at 37 °C. Next, the cells were washed and observed under a confocal microscope, and 30 randomly selected cell images were taken. A, a representative image is shown. Levels of C9-AF555 bound to the cell surface (representing C5b-9) and of mortalin-EGFP in the cell images were quantified by densitometry and analyzed with ImageJ. B, regression analysis for estimating the relationship between C9 deposition and the level of mortalin is shown. A.U., arbitrary units. C, levels of C9 deposition in cells having low (0–5 A.U.) or high (>5 A.U.) mortalin-EGFP level are shown. *, p < 0.005. Error bars, S.D.