Model of Nix-Mediated Autophagic Clearance of Mitochondria From Reticulocytes. Nix interacts with mitochondria in reticulocytes that have completed heme synthesis. Nix induces depolarization of the inner mitochondrial membrane, and the depolarized mitochondrion is sequestrated in a double membrane structure termed the autophagosome. The autophagosome subsequently fuses with a lysosome forming the autolysosome. Proteolytic enzymes from the lysosome degrade the inner membrane of the autolysosome and partially degrade the sequestered depolarized mitochondrion. The non-degraded contents of the autolysosome are extruded from the reticulocyte.