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bioRxiv · 10.1101/2022.10.25.513744

The N-terminal GTPase of Miro1 regulates oligomer formation

Eberhardt, E. L.·Mohamed, A. A.·Vos, S.·Cianfrocco, M. A.
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Abstract

The outer-mitochondrial membrane protein Miro1 is critical for the regulation of mitochondrial trafficking. Miro1 contains two GTPase domains, where changes in the N-terminal GTPase nucleotide state strongly affects mitochondrial trafficking. Previous work showed that the GTP-locked mutation Miro1P13V decreases trafficking and affects mitochondrial dynamics. Despite showing a clear role in Miro1 function, the molecular basis for this activity remains unknown. Using in vitro reconstitution, we demonstrate that Miro1 self-associates to form dimers and higher-ordered species. Structural characterization of Miro1P13V suggests that the oligomers adopt a range of conformations in vitro. Additionally, Miro1P13V has diminished interaction with its downstream cargo adapter TRAK1. These results indicate that the NGTPase of Miro1 facilitates the formation of higher-ordered species and suggests that changes in the oligomeric state may regulate mitochondrial trafficking through reduced association with TRAK1.

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Eberhardt, E. L., Mohamed, A. A., Vos, S., Cianfrocco, M. A.. 2022-10-25. The N-terminal GTPase of Miro1 regulates oligomer formation. https://doi.org/10.1101/2022.10.25.513744

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