Figure 5.

Competing models of mitochondrial morphogenesis machinery and apoptosis progression. (A) Mitochondrial foci model. From left to right, Bax (orange) translocates to mitochondria and coalesces into foci with Drp1, mitofusins, and Bak (see key), leading to mitochondrial division and release of cytochrome c (small red circles) from mitochondrial stores. (B) Cristae model of apoptosis. Drp1 (yellow) forms constriction sites on the OMM (left), then small amounts of cytochrome c from the intermembrane space are released through Bax/Bak pores (middle). (Right) Finally, cristae undergo remodeling, opening the junctions to release the larger amount of cytochrome c stored within the matrix.