Mitochondria-anchored receptor Atg32 mediates degradation of mitochondria via selective autophagy.
Mitochondria are essential organelles that produce most of the energy for a cell, but concomitantly accumulate oxidative damage. Degradation of damaged mitochondria is critical for cell homeostasis, and this process is thought to be mediated by mitophagy, an autophagy-related pathway specific for mitochondria. However, whether mitochondria are selectively degraded, and how the autophagic machinery is targeted to mitochondria, remain largely unknown. Here we demonstrate that, in post-log phase cells under respiratory conditions, a substantial fraction of mitochondria are exclusively sequestered as cargoes and transported to the vacuole, a lytic compartment in yeast, in an autophagy-dependent manner. Interestingly, we found Atg32, a mitochondria-anchored protein essential for mitophagy that is induced during respiratory growth. In addition, our data suggest that Atg32 interacts with Atg8 and Atg11, autophagy-related proteins critical for recognition of cargo receptors. We propose that Atg32 acts as a mitophagy-specific receptor and regulates selective degradation of mitochondria.
Okamoto
Koji
K
Division of Molecular Cell Biology, National Institute for Basic Biology, Okazaki, Japan. kokamoto@iri.titech.ac.jp
Kondo-Okamoto
Noriko
N
Ohsumi
Yoshinori
Y
D000595:Amino Acid Sequence; D001343:Autophagy / Q000502:physiology*; D000071190:Autophagy-Related Protein 8 Family; D000071183:Autophagy-Related Proteins; D019069:Cell Respiration / Q000502:physiology; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism* / Q000648:ultrastructure; D051336:Mitochondrial Membranes / Q000378:metabolism / Q000648:ultrastructure; D008969:Molecular Sequence Data; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D020798:Two-Hybrid System Techniques; D033921:Vesicular Transport Proteins / Q000235:genetics / Q000378:metabolism; D000097573:Red Fluorescent Protein
D000071190:Autophagy-Related Protein 8 Family; D000071183:Autophagy-Related Proteins; D008164:Luminescent Proteins; D008869:Microtubule-Associated Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins; D000097573:Red Fluorescent Protein; C113757:ATG8 protein, S cerevisiae; C502923:Atg11 protein, S cerevisiae; C543183:Atg32 protein, S cerevisiae