title: Macromolecular architecture in eukaryotic cells visualized by cryoelectron tomography.
abstract: Electron tomography of vitrified cells is a noninvasive three-dimensional imaging technique that opens up new vistas for exploring the supramolecular organization of the cytoplasm. We applied this technique to Dictyostelium cells, focusing on the actin cytoskeleton. In actin networks reconstructed without prior removal of membranes or extraction of soluble proteins, the cross-linking of individual microfilaments, their branching angles, and membrane attachment sites can be analyzed. At a resolution of 5 to 6 nanometers, single macromolecules with distinct shapes, such as the 26S proteasome, can be identified in an unperturbed cellular environment.
authors.affiliation: Max Planck Institute for Biochemistry, D-82152 Martinsried, Germany.
authors.forename: Ohad
authors.initials: O
authors.lastname: Medalia
authors.forename: Igor
authors.initials: I
authors.lastname: Weber
authors.forename: Achilleas S
authors.initials: AS
authors.lastname: Frangakis
authors.forename: Daniela
authors.initials: D
authors.lastname: Nicastro
authors.forename: Gunther
authors.initials: G
authors.lastname: Gerisch
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Baumeister
mesh_terms: D008841:Actin Cytoskeleton / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure*; D000199:Actins / Q000648:ultrastructure; D000818:Animals; D001665:Binding Sites; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D002465:Cell Movement; D004023:Dictyostelium / Q000737:chemistry / Q000502:physiology / Q000648:ultrastructure*; D018870:Endoplasmic Reticulum, Rough / Q000648:ultrastructure; D005615:Freezing; D007091:Image Processing, Computer-Assisted; D046911:Macromolecular Substances; D008840:Microfilament Proteins / Q000648:ultrastructure*; D015388:Organelles / Q000648:ultrastructure*; D010447:Peptide Hydrolases / Q000648:ultrastructure; D046988:Proteasome Endopeptidase Complex; D020543:Proteome; D015800:Protozoan Proteins / Q000648:ultrastructure; D012270:Ribosomes / Q000648:ultrastructure; D014054:Tomography / Q000379:methods*
chemical_list: D000199:Actins; D046911:Macromolecular Substances; D008840:Microfilament Proteins; D020543:Proteome; D015800:Protozoan Proteins; C052523:actin filament bundling proteins; D010447:Peptide Hydrolases; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease