Making and breaking contacts

Abstract

Cell Biology\nWithin our cells, mitochondria frequently make contact and undergo fission and fusion events to regulate the mitochondrial network. Mitochondrial contact is important for normal cellular metabolism. Wong et al. used super-resolution live-cell imaging to examine intermitochondrial contacts sites in human cell lines. They found that intermitochondrial contact restricts the motility of individual mitochondria within the cell but can be modulated. Lysosome contact promotes mitochondrial untethering by RAB7 guanosine triphosphate (GTP) hydrolysis. By contrast, contact with endoplasmic reticulum (ER) does not prompt decoupling, although ER tubules marked intermitochondrial untethering events. Multiple lysosomal and mitochondrial GTPases appear to coordinate to regulate mitochondrial contact dynamics. If these dynamics are disrupted by mutation, for example, in cells from patients with the hereditary neuropathy Charcot-Marie-Tooth disease, mitochondrial contacts are slower to disassemble. This results in dysfunctional mitochondrial dynamics, which culminates in axonal degradation.\n\nDev. Cell 50 , 339 (2019).