RT Journal Article SR Electronic T1 ER-Mitochondria Contact Sites expand during mitosis JF bioRxiv FD Cold Spring Harbor Laboratory SP 2023.06.22.546089 DO 10.1101/2023.06.22.546089 A1 Yu, Fang A1 Courjaret, Raphael A1 Elmi, Asha A1 Hammad, Ayat A1 Fisher, Melanie A1 Terasaki, Mark A1 Machaca, Khaled YR 2023 UL http://biorxiv.org/content/early/2023/06/22/2023.06.22.546089.abstract AB Membrane contact sites between various organelles define specialized spatially defined signaling hubs, they are of great interest to better understand inter-organelle communication and its implications on cellular physiology. ER-mitochondria contact sites (ERMCS) are one of the best studied and mediate Ca2+ signaling that regulates mitochondrial bioenergetics. However, little is known about ERMCS during mitosis. Here we show that ERMCS expand during mitosis using transmission electron microscopy, serial EM coupled to 3D reconstruction, and ERMCS markers. ERMCS expansion in mitosis is functionally significant as it is associated with enhanced Ca2+ coupling between the ER and mitochondria resulting in heightened activation of mitochondrial dehydrogenases. Our data suggest that ERMCS remodeling in mitosis is important to meet the increased energy needs during cell division.Competing Interest StatementThe authors have declared no competing interest.