FIG. 8.

Mitochondrial events controlled by RAF signaling. Apoptosis of 32D cells induced through the removal of the essential growth and survival factor IL-3 is preceded by an increase in mitochondrial ROS production. This in turn translates into significantly elevated mitochondrial Ca²⁺ levels, which may directly trigger cell death. An increase in mitochondrial Ca²⁺ also may function as a stimulator of ROS production. Changes in mitochondrial Ca²⁺ and ROS levels are prevented by IL-3, antioxidants, or vRAF. mito, mitochondrion. C-RAF*, activated C-RAF.