Developmental variation of glycosylphosphatidylinositol membrane anchors in Trypanosoma brucei. In vitro biosynthesis of intermediates in the construction of the GPI anchor of the major procyclic surface glycoprotein. Academic Article uri icon

Overview

MeSH

  • Aging
  • Animals
  • Cell Membrane
  • Chromatography, Thin Layer
  • Glycosylphosphatidylinositols
  • Guanosine Diphosphate Mannose
  • Kinetics
  • Mannose
  • Models, Biological
  • Time Factors
  • Tritium
  • Uridine Diphosphate N-Acetylglucosamine

MeSH Major

  • Glycolipids
  • Phosphatidylinositols
  • Trypanosoma brucei brucei

abstract

  • The African trypanosome, Trypanosoma brucei, expresses two abundant stage-specific glycosylphosphatidylinositol (GPI)-anchored glycoproteins, the procyclic acidic repetitive protein (PARP or procyclin) in the procyclic form, and the variant surface glycoprotein (VSG) in the mammalian bloodstream form. The GPI anchor of VSG can be readily cleaved by phosphatidylinositol (PI)-specific phospholipase C (PI-PLC), whereas that of PARP cannot, due to the presence of a fatty acid esterified to the inositol. In the bloodstream form trypanosome, a number of GPIs which are structurally related to the VSG GPI anchor have been identified. In addition, several structurally homologous GPIs have been described, both in vivo and in vitro, that contain acyl-inositol. In vivo the procyclic stage trypanosome synthesizes a GPI that is structurally homologous to the PARP GPI anchor, i.e. contains acyl-inositol. No PI-PLC-sensitive GPIs have been detected in the procyclic form. Using a membrane preparation from procyclic trypanosomes which is capable of synthesizing GPI lipids upon the addition of nucleotide sugars we find that intermediate glycolipids are predominantly of the acyl-inositol type, and the mature ethanolamine-phosphate-containing precursors are exclusively acylated. We suggest that the differences between the bloodstream and procyclic form GPI biosynthetic intermediates can be accounted for by the developmental regulation of an inositol acylhydrolase, which is active only in the bloodstream form, and a glyceride fatty acid remodeling system, which is only partially functional in the procyclic form.

publication date

  • March 15, 1992

has subject area

  • Aging
  • Animals
  • Cell Membrane
  • Chromatography, Thin Layer
  • Glycolipids
  • Glycosylphosphatidylinositols
  • Guanosine Diphosphate Mannose
  • Kinetics
  • Mannose
  • Models, Biological
  • Phosphatidylinositols
  • Time Factors
  • Tritium
  • Trypanosoma brucei brucei
  • Uridine Diphosphate N-Acetylglucosamine

Research

keywords

  • Journal Article

Identity

Language

  • eng

PubMed ID

  • 1371998

Additional Document Info

start page

  • 5324

end page

  • 5329

volume

  • 267

number

  • 8