Mitochondria-ER contacts are an organelle exchange site for lipids and ions, but their regulation is not well understood. Here, Isshin et al. find that RMDN3 transfers lipid radicals, generated by mtROS, from mitochondria to the ER at contact sites to reduce toxicity to the cell.
- Isshin Shiiba
- Naoki Ito
- Shigeru Yanagi
