Mitochondria-endoplasmic reticulum (ER) contact sites in mammals provide platforms for various reactions, such as calcium signaling, lipid metabolism, organelle dynamics and autophagy. To fulfill these tasks, a number of proteins assemble at the contact sites including MITOL/MARCHF5, a critical mitochondrial ubiquitin ligase. How MITOL regulates mitochondrial function from the contact site, however, has been largely unresolved. Recently, a new role for MITOL in the active transport of phosphatidic acid from the ER to mitochondria was reported. In this commentary, we briefly summarize our current understanding of mitochondria-ER contact sites and discuss the recently elucidated mechanism of MITOL fine-tuning phospholipid transfer activity through ubiquitination.
Keywords: contact site; mitochondria; phospholipid; ubiquitin; ubiquitin ligase.
© The Author(s) 2023. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.