title: In situ structural analysis of Golgi intracisternal protein arrays.
abstract: We acquired molecular-resolution structures of the Golgi within its native cellular environment. Vitreous Chlamydomonas cells were thinned by cryo-focused ion beam milling and then visualized by cryo-electron tomography. These tomograms revealed structures within the Golgi cisternae that have not been seen before. Narrow trans-Golgi lumina were spanned by asymmetric membrane-associated protein arrays that had ∼6-nm lateral periodicity. Subtomogram averaging showed that the arrays may determine the narrow central spacing of the trans-Golgi cisternae through zipper-like interactions, thereby forcing cargo to the trans-Golgi periphery. Additionally, we observed dense granular aggregates within cisternae and intracisternal filament bundles associated with trans-Golgi buds. These native in situ structures provide new molecular insights into Golgi architecture and function.
authors: Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, D-82152 Martinsried, Germany baumeist@biochem.mpg.de engelben@biochem.mpg.de.
authors: Benjamin D
authors: BD
authors: Engel
authors: Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, D-82152 Martinsried, Germany.
authors: Miroslava
authors: M
authors: Schaffer
authors: Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, D-82152 Martinsried, Germany.
authors: Sahradha
authors: S
authors: Albert
authors: Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, D-82152 Martinsried, Germany.
authors: Shoh
authors: S
authors: Asano
authors: Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, D-82152 Martinsried, Germany.
authors: Jürgen M
authors: JM
authors: Plitzko
authors: Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, D-82152 Martinsried, Germany baumeist@biochem.mpg.de engelben@biochem.mpg.de.
authors: Wolfgang
authors: W
authors: Baumeister
mesh_terms: D020418:Algal Proteins / Q000378:metabolism* / Q000648:ultrastructure; D016825:Chlamydomonas reinhardtii / Q000378:metabolism* / Q000648:ultrastructure; D020285:Cryoelectron Microscopy / Q000379:methods; D055032:Electron Microscope Tomography / Q000379:methods; D006056:Golgi Apparatus / Q000378:metabolism* / Q000648:ultrastructure; D008565:Membrane Proteins / Q000378:metabolism* / Q000648:ultrastructure; D008953:Models, Anatomic; D008954:Models, Biological; D021381:Protein Transport; D021601:trans-Golgi Network / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D020418:Algal Proteins; D008565:Membrane Proteins
keywords: Chlamydomonas; Golgi; cryo-electron tomography; focused ion beam; glycosyltransferase