FIG. 3.

BNIP3, NIX, and FUNDC1 are direct receptors for mitophagy. BNIP3 and NIX promote mitochondrial autophagy in response to cell stress or during erythrocyte maturation. Phosphorylation of FUNDC1 by CK2 and SRC kinases maintains FUNDC1 inhibition. In response to hypoxia or mitochondrial damage resulting in loss of membrane potential (ΔΨm), FUNDC1 is activated by dephosphorylation through the phosphatase PGAM5. LC3-interacting region (LIR) motifs bind directly to LC3II on the autophagosome to enable mitophagy. To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/ars