Autophagosomes forming from mitochondria is a novel form of parkin-associated mitophagy. A. Distribution of parkin and PINK1 in mitochondrial and cytoplasmic fractions of control and fulvestrant treated LCC9 cells as determined by western blot hybridization. B. Effect of mitophagy inhibition by PINK1 knockdown on antiestrogen sensitivity in LCC9 cells. C. Confocal microscopy of PINK1, parkin, LC3, and mitochondria in LCC9 cells treated with 100 nM ICI for 72 hours. D. Quantification of parkin-immunogold EM parkin distribution within LCC9 cells. n = 5. E. EM image of parkin-immunogold stained LCC9 cells. Mitochondria forming vesicles stain positive for parkin. M indicates mitochondria; Av indicates an autophagic vesicle; * indicates mitochondria-autophagosome interaction; arrows indicate parkin-immunogold particles.