Novel mechanism of elimination of malfunctioning mitochondria (mitoptosis):
Formation of mitoptotic bodies and extrusion of mitochondrial material from the cell
When mitochondria are faulty, what is often observed is mitochondrial autophagy or mitophagy, where a subset of the mitochondrial population are digested by autophagosomes. In this paper, another pathway is observed after damage to the whole mitochondrial population. As a model, highly glycolytic HeLa cells are studied. Respiratory chain inhibitors and uncouplers (which induce ROS production and hydrolyse ATP in mitochondria) were applied. This was observed to cause fission of the mitochondrial network, migration of mitochondria to the perinuclear space, accumulation of mitochondria into a vesicle and then its subsequent expulsion by fusing to the plasma membrane.