COPII-coated vesicle formation reconstituted with purified coat proteins and chemically defined liposomes

Cell. 1998 Apr 17;93(2):263-75. doi: 10.1016/s0092-8674(00)81577-9.


COPII vesicle formation requires only three coat assembly subunits: Sar1p, Sec13/31p, and Sec23/24p. PI 4-phosphate or PI 4,5-bisphosphate is required for the binding of these proteins to liposomes. The GTP-bound form of Sar1p recruits Sec23/24p to the liposomes as well as to the ER membranes, and this Sar1p-Sec23/24p complex is required for the binding of Sec13/31p. Ultrastructural analysis shows that the binding of COPII coat proteins to liposomes results in coated patches, coated buds, and coated vesicles of 50-90 nm in diameter. Budding proceeds without rupture of the donor liposome or vesicle product. These observations suggest that the assembly of the COPII coat on the ER occurs by a sequential binding of coat proteins to specific lipids and that this assembly promotes the budding of COPII-coated vesicles.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • COP-Coated Vesicles
  • Coated Vesicles / metabolism*
  • Coated Vesicles / ultrastructure
  • Endoplasmic Reticulum / metabolism
  • Fungal Proteins / isolation & purification
  • Fungal Proteins / metabolism*
  • GTP-Binding Proteins / isolation & purification
  • GTP-Binding Proteins / metabolism*
  • GTPase-Activating Proteins
  • Guanosine Monophosphate / analogs & derivatives
  • Lipid Bilayers
  • Liposomes / chemistry
  • Liposomes / metabolism*
  • Membrane Proteins / isolation & purification
  • Membrane Proteins / metabolism*
  • Microsomes / metabolism
  • Monomeric GTP-Binding Proteins*
  • Nuclear Pore Complex Proteins
  • Phosphatidic Acids
  • Phospholipids
  • Proteolipids / metabolism
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins*
  • Vesicular Transport Proteins


  • Fungal Proteins
  • GTPase-Activating Proteins
  • Lipid Bilayers
  • Liposomes
  • Membrane Proteins
  • Nuclear Pore Complex Proteins
  • Phosphatidic Acids
  • Phospholipids
  • Proteolipids
  • SEC13 protein, S cerevisiae
  • SEC23 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Vesicular Transport Proteins
  • proteoliposomes
  • Guanosine Monophosphate
  • GTP-Binding Proteins
  • Monomeric GTP-Binding Proteins
  • SAR1 protein, S cerevisiae