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Updated: Jan 5, 2026

Author Spotlight: Regulation and Dysregulation of ER-Mitochondria Contacts — Implications for Neurodegenerative Disease Pathogenesis
Published on: October 11, 2024
ORP5/ORP8 localize to endoplasmic reticulum-mitochondria contacts and are involved in mitochondrial function
Romain Galmes1, Audrey Houcine1, Alexander R van Vliet2
1Institut Jacques Monod, CNRS, UMR7592, Sorbonne Paris Cité, Université Paris Diderot, Paris, France.
Abstract:
The oxysterol-binding protein (OSBP)-related proteins ORP5 and ORP8 have been shown recently to transport phosphatidylserine (PS) from the endoplasmic reticulum (ER) to the plasma membrane (PM) at ER-PM contact sites. PS is also transferred from the ER to mitochondria where it acts as precursor for mitochondrial PE synthesis. Here, we show that, in addition to ER-PM contact sites, ORP5 and ORP8 are also localized to ER-mitochondria contacts and interact with the outer mitochondrial membrane protein PTPIP51. A functional lipid transfer (ORD) domain was required for this localization. Interestingly, ORP5 and ORP8 depletion leads to defects in mitochondria morphology and respiratory function.
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