An abundant and ubiquitous homo-oligomeric ring-shaped ATPase particle related to the putative vesicle fusion proteins Sec18p and NSF

EMBO J. 1990 Jun;9(6):1757-67. doi: 10.1002/j.1460-2075.1990.tb08300.x.


We have discovered a ring-shaped particle of 12.5 nm diameter, 14.5S and apparent molecular weight of approximately 570,000 that displays 6-fold radial symmetry and is composed of a single kind of an acidic (pI approximately 5.5) polypeptide of Mr 97,000 (p97). Using antibodies to this protein we have detected its occurrence in a wide range of cells and tissues of diverse species from frog to man, including highly specialized cells such as mammalian erythrocytes and spermatozoa. In Xenopus laevis oocytes, the particle is found in both isolated nuclei and in manually enucleated ooplasms, which corresponds to immunofluorescence staining dispersed over both nucleoplasm and cytoplasm. The particle has a N-ethylmaleimide (NEM)-inhibitable Mg2(+)-ATPase activity, and its amino acid sequence, as deduced from cDNA clones, displays considerable homology to the mammalian NEM-sensitive fusion protein (NSF) and yeast Sec18p believed to be essential for vesicle fusion in secretory processes, indicating that these three proteins belong to the same multigene family.

MeSH terms

  • Adenosine Triphosphatases / genetics*
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Carrier Proteins / genetics*
  • Carrier Proteins / ultrastructure
  • Cells, Cultured
  • Cloning, Molecular
  • DNA / analysis
  • Epithelium / ultrastructure
  • Female
  • Fungal Proteins / genetics*
  • Fungal Proteins / ultrastructure
  • Humans
  • Male
  • Microscopy, Fluorescence
  • Molecular Sequence Data
  • Molecular Weight
  • N-Ethylmaleimide-Sensitive Proteins
  • Organ Specificity
  • Protein Conformation
  • Saccharomyces cerevisiae Proteins*
  • Vesicular Transport Proteins*
  • Xenopus laevis / genetics*
  • Xenopus laevis / metabolism


  • Carrier Proteins
  • Fungal Proteins
  • Saccharomyces cerevisiae Proteins
  • Vesicular Transport Proteins
  • DNA
  • Adenosine Triphosphatases
  • SEC18 protein, S cerevisiae
  • N-Ethylmaleimide-Sensitive Proteins