Tetraspanin 6: a pivotal protein of the multiple vesicular body determining exosome release and lysosomal degradation of amyloid precursor protein fragments

Research output: Contribution to journalArticlepeer-review

Authors

  • Francesc X. Guix
  • Ragna Sannerud
  • Amaia M. Arranz
  • Katrien Horré
  • An Snellinx
  • Amantha Thathiah
  • Takaomi Saido
  • Takashi Saito
  • Samir Kumar-Singh
  • Enrico Radaelli
  • Nikky Corthout
  • Julien Colombelli
  • Sébastien Tosi
  • Sebastian Munck
  • Isabel H. Salas
  • Wim Annaert
  • Bart De Strooper

Colleges, School and Institutes

Abstract

Background
The mechanisms behind Aβ-peptide accumulation in non-familial Alzheimer’s disease (AD) remain elusive. Proteins of the tetraspanin family modulate Aβ production by interacting to γ-secretase.

Methods
We searched for tetraspanins with altered expression in AD brains. The function of the selected tetraspanin was studied in vitro and the physiological relevance of our findings was confirmed in vivo.

Results
Tetraspanin-6 (TSPAN6) is increased in AD brains and overexpression in cells exerts paradoxical effects on Amyloid Precursor Protein (APP) metabolism, increasing APP-C-terminal fragments (APP-CTF) and Aβ levels at the same time. TSPAN6 affects autophagosome-lysosomal fusion slowing down the degradation of APP-CTF. TSPAN6 recruits also the cytosolic, exosome-forming adaptor syntenin which increases secretion of exosomes that contain APP-CTF.

Conclusions
TSPAN6 is a key player in the bifurcation between lysosomal-dependent degradation and exosome mediated secretion of APP-CTF. This corroborates the central role of the autophagosomal/lysosomal pathway in APP metabolism and shows that TSPAN6 is a crucial player in APP-CTF turnover.

Details

Original languageEnglish
Article number25
Number of pages21
JournalMolecular Neurodegeneration
Volume12
Publication statusPublished - 10 Mar 2017