A novel substrate for analyzing Alzheimer's disease gamma-secretase

FEBS Lett. 1999 Jun 25;453(3):288-92. doi: 10.1016/s0014-5793(99)00730-9.


Proteolytic processing of Alzheimer's disease amyloid precursor protein (APP) by beta-secretase leads to A4CT (C99), which is further cleaved by the as yet unknown protease called gamma-secretase. To study the enzymatic properties of gamma-secretase independently of beta-secretase, A4CT together with an N-terminal signal peptide (SPA4CT) may be expressed in eukaryotic cells. However, in all existing SPA4CT proteins the signal peptide is not correctly cleaved upon membrane insertion. Here, we report the generation of a mutated SPA4CT protein that is correctly cleaved by signal peptidase and, thus, identical to the APP-derived A4CT. This novel SPA4CT protein is processed by gamma-secretase in the same manner as APP-derived A4CT and might be valuable for the generation of transgenic animals showing amyloid pathology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Amyloid Precursor Protein Secretases
  • Amyloid beta-Protein Precursor / genetics
  • Amyloid beta-Protein Precursor / metabolism*
  • Endopeptidases / analysis*
  • Membrane Proteins / metabolism*
  • Molecular Sequence Data
  • Mutation*
  • Peptide Fragments / genetics
  • Peptide Fragments / metabolism*
  • Protein Processing, Post-Translational*
  • Recombinant Proteins / metabolism
  • Sequence Analysis
  • Serine Endopeptidases


  • Amyloid beta-Protein Precursor
  • Membrane Proteins
  • Peptide Fragments
  • Recombinant Proteins
  • SPA4CT protein, recombinant
  • Amyloid Precursor Protein Secretases
  • Endopeptidases
  • Serine Endopeptidases
  • type I signal peptidase