Developmental variation of glycosylphosphatidylinositol membrane anchors in Trypanosoma brucei: Identification of a candidate biosynthetic precursor of the glycosylphosphatidylinositol anchor of the major procyclic stage surface glycoprotein Academic Article uri icon


MeSH Major

  • Glycolipids
  • Phosphatidylinositols
  • Protozoan Proteins
  • Trypanosoma brucei brucei
  • Variant Surface Glycoproteins, Trypanosoma


  • The major surface antigen of the mammalian bloodstream form of Trypanosoma brucei, the variant surface glycoprotein (VSG), is attached to the cell membrane by a glycosylphosphatidylinositol (GPI) anchor. The VSG anchor is susceptible to phosphatidylinositol-specific phospholipase C (PI-PLC). Candidate precursor glycolipids, P2 and P3, which are PI-PLC-sensitive and -resistant respectively, have been characterized in the bloodstream stage. In the insect midgut stage, the major surface glycoprotein, procyclic acidic repetitive glycoprotein, is also GPI-anchored but is resistant to PI-PLC. To determine how the structure of the GPI anchor is altered at different life stages, we characterized candidate GPI molecules in procyclic T. brucei. The structure of a major procyclic GPI, PP1, is ethanolamine-PO4-Man alpha 1-2Man alpha 1-6 Man alpha 1-GlcN-acylinositol, linked to lysophosphatidic acid. The inositol can be labeled with [3H]palmitic acid, and the glyceride with [3H]stearic acid. We have also found that all detectable ethanolamine-containing GPIs from procyclic cells contain acylinositol and are resistant to cleavage by PI-PLC. This suggests that the procyclic acidic repetitive glycoprotein GPI anchor structure differs from that of the VSG by virtue of the structures of the GPIs available for transfer.

publication date

  • May 5, 1991



  • Academic Article



  • eng

PubMed ID

  • 1850744

Additional Document Info

start page

  • 8392

end page

  • 400


  • 266


  • 13