Mitophagy in yeast occurs through a selective mechanism.
The regulation of mitochondrial degradation through autophagy is expected to be a tightly controlled process, considering the significant role of this organelle in many processes ranging from energy production to cell death. However, very little is known about the specific nature of the degradation process. We developed a new method to detect mitochondrial autophagy (mitophagy) by fusing the green fluorescent protein at the C terminus of two endogenous mitochondrial proteins and monitored vacuolar release of green fluorescent protein. Using this method, we screened several atg mutants and found that ATG11, a gene that is essential only for selective autophagy, is also essential for mitophagy. In addition, we found that mitophagy is blocked even under severe starvation conditions, if the carbon source makes mitochondria essential for metabolism. These findings suggest that the degradation of mitochondria is a tightly regulated process and that these organelles are largely protected from nonspecific autophagic degradation.
Kanki
Tomotake
T
Life Sciences Institute and Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109-2216, USA.
Klionsky
Daniel J
DJ
D001343:Autophagy; D000071183:Autophagy-Related Proteins; D002244:Carbon / Q000737:chemistry; D016923:Cell Death; D005838:Genotype; D049452:Green Fluorescent Proteins / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial; D008856:Microscopy, Fluorescence; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000378:metabolism; D008954:Models, Biological; D009154:Mutation; D010587:Phagocytosis; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D033921:Vesicular Transport Proteins / Q000378:metabolism
C502923:Atg11 protein, S cerevisiae; D000071183:Autophagy-Related Proteins; D024101:Mitochondrial Proteins; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins; D049452:Green Fluorescent Proteins; D002244:Carbon