DRP1 and MID49 co-diffusion scans mitochondria for fission

Area of Science:

• Cell Biology
• Molecular Biology
• Biophysics

Background:

• Mitochondrial fission is vital for cellular health, regulated by dynamin-related protein 1 (DRP1).
• The precise mechanism and dynamic regulation of DRP1 during mitochondrial division remain unclear.

Purpose of the Study:

• To elucidate the dynamic behavior of DRP1 on mitochondria during fission.
• To understand how DRP1 motility is regulated and its functional significance.

Main Methods:

• Observation of DRP1 oligomer movement using advanced microscopy.
• Molecular dynamics simulations to model DRP1 diffusion.
• Perturbation studies to assess the impact of DRP1 motility changes.

Main Results:

• DRP1 oligomers exhibit a novel "mito-scanner" motion, diffusing helically along mitochondria and stalling at fission sites.
• Molecular dynamics simulations confirm a geometry-mediated diffusion mechanism.
• Disrupting DRP1 motility leads to elongated mitochondria, highlighting the importance of its scanning dynamics.
• Interactions with adaptors like MID49/MID51 differentially regulate DRP1 motility, with co-diffusion enhancing it.

Conclusions:

• DRP1's "mito-scanner" motion is a key mechanism for mitochondrial surveillance and division.
• Receptor-mediated regulation of DRP1 dynamics is essential for balanced mitochondrial division.
• Understanding DRP1 dynamics offers potential therapeutic targets for diseases involving mitochondrial dysfunction.