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Molecular architecture of a dynamin adaptor: implications for assembly of mitochondrial fission complexes

Sajjan Koirala1, Huyen T Bui, Heidi L Schubert

  • 1Department of Biochemistry, University of Utah, Salt Lake City, UT 84112, USA.

The Journal of Cell Biology
|December 15, 2010
PubMed

Insights

The yeast Mdv1 adaptor protein uses a coiled coil structure to bind to mitochondrial Fis1 and Dnm1 proteins. This interaction is crucial for dynamin-related protein assembly and mitochondrial division.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Biochemistry

Background:

  • Dynamin-related proteins are essential for membrane dynamics and cellular compartmentalization.
  • Adaptor proteins mediate the recruitment and assembly of these proteins to specific cellular membranes.
  • In yeast, the Mdv1 adaptor protein is critical for mitochondrial division by interacting with Fis1 and Dnm1.

Purpose of the Study:

  • To elucidate the structural basis of Mdv1 function in mitochondrial division.
  • To understand how the Mdv1 adaptor protein scaffolds dynamin assembly on mitochondrial membranes.

Main Methods:

  • Structural modeling of the Fis1-Mdv1 complex.
  • Analysis of coiled coil structure and length.
  • Biochemical assays to assess protein interactions and function.

Main Results:

  • The Mdv1 adaptor protein forms a dimer mediated by a central 92-Å antiparallel coiled coil.
  • Structural modeling suggests the coiled coil orients Mdv1 for simultaneous binding to Fis1 and Dnm1.
  • Appropriate coiled coil length and sequence are vital for Mdv1's interaction with Fis1 and Dnm1, and for Dnm1 assembly.

Conclusions:

  • The Mdv1 coiled coil acts as a molecular scaffold, positioning Fis1 and Dnm1 for efficient dynamin assembly.
  • This mechanism provides a framework for understanding how adaptor proteins regulate membrane-associated protein complexes.
  • The findings are crucial for comprehending mitochondrial dynamics and division processes.

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