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Abstract Mitochondria play a crucial role in the regulation of cellular metabolism and signalling. Mitochondrial activity is modulated by the processes of mitochondrial fission and fusion, which are required to properly balance respiratory and metabolic functions, transfer material between mitochondria, and remove defective mitochondria. Mitochondrial fission occurs at sites of contact between the endoplasmic reticulum (ER) and mitochondria, and is dependent on the formation of actin filaments that drive mitochondrial constriction and the recruitment and activation of the dynamin-related GTPase fission protein DRP1. The requirement for mitochondria- and ER-associated actin filaments in mitochondrial fission remains unclear, and the role of actin in mitochondrial fusion remains entirely unexplored. Here we show that preventing the formation of actin filaments on either mitochondria or the ER disrupts both mitochondrial fission and fusion. We show that fusion but not fission is dependent on Arp2/3, whereas both fission and fusion are dependent on INF2 formin-dependent actin polymerization. We also show that mitochondria-associated actin marks fusion sites prior to the dynamin family GTPase fusion protein MFN2. Together, our work introduces a novel method for perturbing organelle-associated actin filaments, and demonstrates a previously unknown role for actin in mitochondrial fusion.
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Filamin A interacting protein 1-like (FILIP1L) has mitochondrial localization
Filamin A interacting protein 1-like (FILIP1L) is a multifunctional protein that plays a role in cancer progression, apoptosis, and angiogenesis. However, FILIP1L remains a relatively underexplored protein, and many of FILIP1L’s key mechanisms and interacting partners are still unknown. Using immunofluorescence staining for endogenous FILIP1L and high-resolution confocal microscopy, we show that FILIP1L colocalizes with the mitochondrial marker, TOM20, suggesting a novel connection between FILIP1L and mitochondria. Further exploring the relationship between FILIP1L and mitochondria might provide a deeper understanding of the emerging function of FILIP1L in health and disease.
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- Award ID(s):
- 2022048
- PAR ID:
- 10646194
- Publisher / Repository:
- microPublication Biology
- Date Published:
- Journal Name:
- microPublication biology
- Volume:
- 2025
- ISSN:
- 2578-9430
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.17912/micropub.biology.001572
