TbGPI16 is an essential component of GPI transamidase in Trypanosoma brucei

FEBS Lett. 2006 Jan 23;580(2):603-6. doi: 10.1016/j.febslet.2005.12.075. Epub 2006 Jan 4.


Glycosylphosphatidylinositol (GPI) is widely used by eukaryotic cell surface proteins for membrane attachment. De novo synthesized GPI precursors are attached to proteins post-translationally by the enzyme complex, GPI transamidase. TbGPI16, a component of the trypanosome transamidase, shares similarity with human PIG-T. Here, we show that TbGPI16 is the orthologue of PIG-T and an essential component of GPI transamidase by creating a TbGPI16 knockout. TbGPI16 forms a disulfide-linked complex with TbGPI8. A cysteine to serine mutant of TbGPI16 was unable to fully restore the surface expression of GPI-anchored proteins upon transfection into the knockout cells, indicating that its disulfide linkage with TbGPI8 is important for the full transamidase activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acyltransferases / genetics
  • Acyltransferases / metabolism*
  • Animals
  • Disulfides / metabolism
  • Gene Targeting
  • Humans
  • Membrane Glycoproteins / metabolism
  • Multiprotein Complexes
  • Mutation
  • Protein Subunits / genetics
  • Protein Subunits / metabolism*
  • Protozoan Proteins / metabolism
  • Trypanosoma brucei brucei / enzymology*
  • Trypanosoma brucei brucei / genetics


  • Disulfides
  • Membrane Glycoproteins
  • Multiprotein Complexes
  • Protein Subunits
  • Protozoan Proteins
  • procyclic acidic repetitive protein, Trypanosoma
  • Acyltransferases
  • COOH-terminal signal transamidase