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Item Type: | Article |
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Title: | Cryo-EM studies of Drp1 reveal cardiolipin interactions that activate the helical oligomer |
Creators Name: | Francy, C.A., Clinton, R.W., Froehlich, C., Murphy, C. and Mears, J.A. |
Abstract: | Dynamins are mechano-chemical GTPases involved in the remodeling of cellular membranes. In this study, we have investigated the mechanism of dynamin-related protein 1 (Drp1), a key mediator of mitochondrial fission. To date, it is unclear how Drp1 assembles on the mitochondrial outer membrane in response to different lipid signals to induce membrane fission. Here, we present cryo-EM structures of Drp1 helices on nanotubes with distinct lipid compositions to mimic membrane interactions with the fission machinery. These Drp1 polymers assemble exclusively through stalk and G-domain dimerizations, which generates an expanded helical symmetry when compared to other dynamins. Interestingly, we found the characteristic gap between Drp1 and the lipid bilayer was lost when the mitochondrial specific lipid cardiolipin was present, as Drp1 directly interacted with the membrane. Moreover, this interaction leads to a change in the helical structure, which alters G-domain interactions to enhance GTPase activity. These results demonstrate how lipid cues at the mitochondrial outer membrane (MOM) can alter Drp1 structure to activate the fission machinery. |
Keywords: | Cardiolipins, Cryoelectron Microscopy, GTP Phosphohydrolases, Microtubule-Associated Proteins, Mitochondrial Proteins, Molecular Models, Nanotubes, Protein Binding, Protein Interaction Domains and Motifs, Protein Multimerization, Protein Stability, Quantitative Structure-Activity Relationship, Secondary Protein Structure |
Source: | Scientific Reports |
ISSN: | 2045-2322 |
Publisher: | Nature Publishing Group |
Volume: | 7 |
Number: | 1 |
Page Range: | 10744 |
Date: | 6 September 2017 |
Official Publication: | https://doi.org/10.1038/s41598-017-11008-3 |
PubMed: | View item in PubMed |
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