Geometric instability catalyzes mitochondrial fission.
Ehsan Irajizad1, Rajesh Ramachandran2, Ashutosh Agrawal1
1Department of Mechanical Engineering, University of Houston, Houston, TX 77204.
Molecular Biology of the Cell
|November 1, 2018
Summary
This study reveals how conical lipids and proteins synergistically remodel mitochondrial membranes during fission. Their cooperation creates robust, stable constrictions, essential for cellular membrane dynamics.
Area of Science:
- Cell Biology
- Biophysics
- Membrane Dynamics
Background:
- Mitochondrial fission involves membrane remodeling.
- Proteins are known drivers, but conical lipids' role is increasingly recognized.
- The synergistic mechanisms between proteins and lipids remain unquantified.
Purpose of the Study:
- To quantitatively investigate the cooperative mechanisms of proteins and conical lipids in mitochondrial fission.
- To model how these components interact to remodel the mitochondrial membrane.
Main Methods:
- Computational modeling of membrane squeezing during mitochondrial fission.
- In vitro validation of protein-lipid cooperativity in membrane tubule constriction.
Main Results:
- Proteins and conical lipids act synergistically to induce buckling instability and extreme membrane constriction.
- Conical lipids facilitate hierarchical instabilities with various fission proteins, creating stable, narrow constrictions.
- This geometric plasticity enhances the robustness of the fission process against membrane rebound.
Conclusions:
- A general mechanism for drastic topological remodeling in cellular membranes is presented.
- Protein-lipid cooperation is crucial for regulating mitochondrial morphology and fission.
- The findings provide quantitative insights into the biophysical processes underlying membrane dynamics.
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