In situ structural analysis of Golgi intracisternal protein arrays

Proc Natl Acad Sci U S A. 2015 Sep 8;112(36):11264-9. doi: 10.1073/pnas.1515337112. Epub 2015 Aug 26.


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.

Keywords: Chlamydomonas; Golgi; cryo-electron tomography; focused ion beam; glycosyltransferase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algal Proteins / metabolism*
  • Algal Proteins / ultrastructure
  • Chlamydomonas reinhardtii / metabolism*
  • Chlamydomonas reinhardtii / ultrastructure
  • Cryoelectron Microscopy / methods
  • Electron Microscope Tomography / methods
  • Golgi Apparatus / metabolism*
  • Golgi Apparatus / ultrastructure
  • Membrane Proteins / metabolism*
  • Membrane Proteins / ultrastructure
  • Models, Anatomic
  • Models, Biological
  • Protein Transport
  • trans-Golgi Network / metabolism
  • trans-Golgi Network / ultrastructure


  • Algal Proteins
  • Membrane Proteins