Cryo-electron tomography reveals how COPII assembles on cargo-containing membranes

Euan Pyle; Elizabeth A Miller; Giulia Zanetti

doi:10.1038/s41594-024-01413-4

Cryo-electron tomography reveals how COPII assembles on cargo-containing membranes

Nat Struct Mol Biol. 2024 Nov 7. doi: 10.1038/s41594-024-01413-4. Online ahead of print.

Authors

Euan Pyle^{1

2

3

4}, Elizabeth A Miller^{5

6}, Giulia Zanetti^{7

8

9}

Affiliations

¹ Institute of Structural and Molecular Biology, Birkbeck College, London, UK.
² Institute of Structural and Molecular Biology, UCL, London, UK.
³ The Francis Crick Institute, London, UK.
⁴ EMBL, Heidelberg, Germany.
⁵ MRC Laboratory of Molecular Biology, Cambridge, UK.
⁶ School of Life Sciences, University of Dundee, Dundee, UK.
⁷ Institute of Structural and Molecular Biology, Birkbeck College, London, UK. [email protected].
⁸ Institute of Structural and Molecular Biology, UCL, London, UK. [email protected].
⁹ The Francis Crick Institute, London, UK. [email protected].

PMID: 39511455
DOI: 10.1038/s41594-024-01413-4

Abstract

Proteins traverse the eukaryotic secretory pathway through membrane trafficking between organelles. The coat protein complex II (COPII) mediates the anterograde transport of newly synthesized proteins from the endoplasmic reticulum, engaging cargoes with a wide range of size and biophysical properties. The native architecture of the COPII coat and how cargo might influence COPII carrier morphology remain poorly understood. Here we reconstituted COPII-coated membrane carriers using purified Saccharomyces cerevisiae proteins and cell-derived microsomes as a native membrane source. Using cryo-electron tomography with subtomogram averaging, we demonstrate that the COPII coat binds cargo and forms largely spherical vesicles from native membranes. We reveal the architecture of the inner and outer coat layers and shed light on how spherical carriers are formed. Our results provide insights into the architecture and regulation of the COPII coat and advance our current understanding of how membrane curvature is generated.