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Dnm1 forms spirals that are structurally tailored to fit mitochondria

Elena Ingerman1, Edward M Perkins, Michael Marino

  • 1Department of Molecular and Cellular Biology, Center for Genetics and Development, University of California, Davis, Davis, CA 95616, USA.

The Journal of Cell Biology
|September 28, 2005
PubMed

Insights

Dynamin-related protein 1 (Dnm1) self-assembly drives mitochondrial division by forming spirals that constrict membranes. Its nucleotide hydrolysis and nucleation steps regulate this essential cellular process.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Biochemistry

Background:

  • Dynamin-related proteins (DRPs) are crucial GTPases regulating membrane dynamics in cellular processes.
  • Dnm1, a yeast DRP, is essential for mitochondrial division, but its precise mechanism remains unclear.

Purpose of the Study:

  • To elucidate the mechanism by which Dnm1 mediates mitochondrial division.
  • To identify regulatory features governing Dnm1 self-assembly and function.

Main Methods:

  • Investigated Dnm1 self-assembly in vitro.
  • Analyzed Dnm1's interaction with GTP and its hydrolysis.
  • Characterized the structure of assembled Dnm1 using electron microscopy.

Main Results:

  • Dnm1 self-assembly drives membrane constriction during mitochondrial division.
  • Dnm1 self-assembly involves a rate-limiting nucleation step.
  • Nucleotide hydrolysis by assembled Dnm1 is highly cooperative with GTP.
  • Assembled Dnm1 forms spirals with diameters matching mitochondrial constriction sites.

Conclusions:

  • Dnm1 functions through self-assembly to constrict mitochondrial membranes.
  • The structure of Dnm1 assemblies is adapted to the dimensions of mitochondrial division sites.
  • Understanding Dnm1 regulation provides insights into mitochondrial dynamics and cellular membrane remodeling.

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