Macromolecular architecture in eukaryotic cells visualized by cryoelectron tomography.
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.
Medalia
Ohad
O
Max Planck Institute for Biochemistry, D-82152 Martinsried, Germany.
Weber
Igor
I
Frangakis
Achilleas S
AS
Nicastro
Daniela
D
Gerisch
Gunther
G
Baumeister
Wolfgang
W
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*
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