When the plasma membrane is disrupted, lethal consequences can ensue. However, some cells can mount a plasma membrane repair response specifically targeted to the wound site. Horn et al. studied the role of mitochondria in plasma membrane repair in cultured mammalian cells. Mitochondria form a distributed interconnected network throughout the cytoplasm. When the plasma membrane is breached, a local influx of calcium promotes a localized wave of rapid mitochondrial fission. The fission process is mediated by the mitochondrial fission protein Drp1. At the injury site, the locally fragmented mitochondria help to clear the influx of calcium from the cytosol and generate a localized redox signal that promotes membrane repair. In cells lacking Drp1 or its adaptor protein, the mitochondria do not fragment and fail to repair plasma membrane damage.
J. Cell Biol. 219, e201909154 (2020).