Visualizing membrane trafficking through the electron microscope: cryo-tomography of coat complexes

Acta Crystallogr D Struct Biol. 2019 May 1;75(Pt 5):467-474. doi: 10.1107/S2059798319005011. Epub 2019 Apr 30.

Abstract

Coat proteins mediate vesicular transport between intracellular compartments, which is essential for the distribution of molecules within the eukaryotic cell. The global arrangement of coat proteins on the membrane is key to their function, and cryo-electron tomography and subtomogram averaging have been used to study membrane-bound coat proteins, providing crucial structural insight. This review outlines a workflow for the structural elucidation of coat proteins, incorporating recent developments in the collection and processing of cryo-electron tomography data. Recent work on coat protein I, coat protein II and retromer performed on in vitro reconstitutions or in situ is summarized. These studies have answered long-standing questions regarding the mechanisms of membrane binding, polymerization and assembly regulation of coat proteins.

Keywords: COPII; coat proteins; cryo-electron tomography; subtomogram averaging; three-dimensional reconstruction; vesicular transport.

MeSH terms

  • Biological Transport
  • Cell Membrane / metabolism*
  • Cell Membrane / ultrastructure
  • Cryoelectron Microscopy / methods*
  • Electron Microscope Tomography / methods*
  • Humans
  • Models, Molecular
  • Multiprotein Complexes / metabolism*
  • Multiprotein Complexes / ultrastructure
  • Vesicular Transport Proteins / metabolism*
  • Vesicular Transport Proteins / ultrastructure

Substances

  • Multiprotein Complexes
  • Vesicular Transport Proteins