Co-localization of receptor and transducer proteins in the glycosphingolipid-enriched, low density, detergent-insoluble membrane fraction of sea urchin sperm

Glycoconj J. Mar-Apr 2000;17(3 -4):205-14. doi: 10.1023/a:1026589223811.


The low density, detergent-insoluble membrane fraction (LD-DIM), where gangliosides are likely to be highly enriched, was prepared from sperm of two sea urchin species, Hemicentrotus pulcherrimus and Strongylocentrotus purpuratus. Immunoblotting showed the presence in the LD-DIM of two receptors for egg ligands, a glycosylphosphatidylinositol (GPI)-anchored protein, and four proteins which may be involved in signal transduction. Co-immunoprecipitation revealed that at least three proteins, the speract receptor, the 63kDa GPI-anchored protein and the alpha subunit of a heterotrimeric Gs protein, are localized in the LD-DIM. This suggests that the LD-DIM fraction may be a membrane microdomain for speract-speract receptor interaction, as well as the subsequent signal transduction pathway involved in induction of sperm respiration, motility and possibly the acrosome reaction.

Publication types

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

MeSH terms

  • Animals
  • Blotting, Western
  • Carbohydrate Sequence
  • Cell Membrane / chemistry
  • Cell Membrane / metabolism
  • Detergents / chemistry*
  • Fluorescent Antibody Technique
  • GTP-Binding Protein alpha Subunits, Gs / metabolism*
  • Gangliosides / immunology
  • Gangliosides / metabolism
  • Glycosphingolipids / chemistry
  • Glycosphingolipids / metabolism*
  • Male
  • Molecular Sequence Data
  • Precipitin Tests
  • Receptors, Cell Surface / metabolism*
  • Sea Urchins
  • Solubility
  • Spermatozoa / chemistry*
  • Spermatozoa / metabolism


  • Detergents
  • Gangliosides
  • Glycosphingolipids
  • Receptors, Cell Surface
  • egg surface sperm receptor
  • GTP-Binding Protein alpha Subunits, Gs