SNAPs, a family of NSF attachment proteins involved in intracellular membrane fusion in animals and yeast

Cell. 1990 May 18;61(4):709-21. doi: 10.1016/0092-8674(90)90482-t.


Three new and likely related components of the cellular fusion machinery have been purified from bovine brain cytosol, termed alpha-SNAP (35 kd), beta-SNAP (36 kd), and gamma-SNAP (39 kd). Transport between cisternae of the Golgi complex measured in vitro requires SNAP activity during the membrane fusion stage, and each SNAP is capable of binding the general cellular fusion protein NSF to Golgi membranes. The SNAP-NSF-membrane complex may be an early stage in the assembly of a proposed multisubunit "fusion machine" on the target membrane. SNAP transport factor activity is also found in yeast. Yeast cytosol prepared from a secretion mutant defective in export from the endoplasmic reticulum (sec17) lacks SNAP activity, which can be restored in vitro by the addition of pure alpha-SNAP, but not beta- or gamma-SNAPs. These data suggest that the mechanism of action of SNAPs in membrane fusion is conserved in evolution.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Biological Transport / physiology
  • Brain / metabolism
  • Carrier Proteins / metabolism*
  • Carrier Proteins / physiology
  • Cattle
  • Coated Pits, Cell-Membrane / physiology
  • Cytosol / metabolism
  • Endoplasmic Reticulum / metabolism
  • Golgi Apparatus / metabolism
  • Intracellular Membranes / metabolism
  • Membrane Fusion / physiology*
  • Membrane Proteins / isolation & purification
  • Membrane Proteins / metabolism
  • Membrane Proteins / physiology*
  • Molecular Weight
  • N-Ethylmaleimide-Sensitive Proteins
  • Protein Binding
  • Saccharomyces cerevisiae / physiology
  • Vesicular Transport Proteins*


  • Carrier Proteins
  • Membrane Proteins
  • Vesicular Transport Proteins
  • N-Ethylmaleimide-Sensitive Proteins