Nix, a receptor protein for mitophagy in mammals.

Mitochondria are important organelles that supply energy to the cell. However, these organelles are also the major source of cellular reactive oxygen species (ROS). Thus, the elimination of damaged or excess mitochondria is essential for maintaining cellular homeostasis. Selective autophagy of mitochondria (mitophagy) plays an important role in the quality control of mitochondria. However, little is known about the molecular mechanism of mitophagy in mammalian cells. Nix is a mitochondrial outer membrane protein that is required for mitochondrial clearance during erythrocyte maturation. Recently, it was reported that Nix is a mitochondrial receptor that can directly connect to one of the autophagic machinery components, the Atg8 homologs LC3 and GABARAP.