Proton myo-inositol cotransporter is a novel γ-secretase associated protein that regulates Aβ production without affecting Notch cleavage

FEBS J. 2015 Sep;282(17):3438-51. doi: 10.1111/febs.13353. Epub 2015 Jul 14.


γ-Secretase is a transmembrane protease complex that is responsible for the processing of a multitude of type 1 transmembrane proteins, including the amyloid precursor protein and Notch. γ-Secretase processing of amyloid precursor protein results in the release of the amyloid β-peptide (Aβ), which is involved in the pathogenesis in Alzheimer's disease. Processing of Notch leads to the release of its intracellular domain, which is important for cell development. γ-Secretase associated proteins (GSAPs) could be of importance for substrate selection, and we have previously shown that affinity purification of γ-secretase in combination with mass spectrometry can be used for finding such proteins. In the present study, we used this methodology to screen for novel GSAPs from human brain, and studied their effect on Aβ production in a comprehensive gene knockdown approach. Silencing of probable phospholipid-transporting ATPase IIA, brain-derived neurotrophic factor/neurotrophin-3 growth factor receptor precursor and proton myo-inositol cotransporter (SLC2A13) showed a clear reduction of Aβ and these proteins were selected for further studies on Aβ production and Notch cleavage using small interfering RNA-mediated gene silencing, as well as an overexpression approach. Silencing of these reduced Aβ secretion in a small interfering RNA dose-dependent manner. Interestingly, SLC2A13 had a lower effect on Notch processing. Furthermore, overexpression of SLC2A13 increased Aβ40 generation. Finally, the interaction between γ-secretase and SLC2A13 was confirmed using immunoprecipitation and a proximity ligation assay. In summary, SLC2A13 was identified as a novel GSAP that regulates Aβ production without affecting Notch cleavage. We suggest that SLC2A13 could be a target for Aβ lowering therapy aimed at treating Alzheimer's disease.

Keywords: Alzheimer's disease; Notch; amyloid β-peptide; proton myo-inositol cotransporter; γ-secretase.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Adenosine Triphosphatases / antagonists & inhibitors
  • Adenosine Triphosphatases / genetics
  • Adenosine Triphosphatases / metabolism
  • Amyloid Precursor Protein Secretases / genetics*
  • Amyloid Precursor Protein Secretases / metabolism
  • Amyloid beta-Peptides / antagonists & inhibitors
  • Amyloid beta-Peptides / biosynthesis
  • Amyloid beta-Peptides / genetics*
  • Animals
  • Brain Chemistry
  • Brain-Derived Neurotrophic Factor / antagonists & inhibitors
  • Brain-Derived Neurotrophic Factor / genetics
  • Brain-Derived Neurotrophic Factor / metabolism
  • Carbamates / pharmacology
  • Dipeptides / pharmacology
  • Enzyme Inhibitors / pharmacology
  • Gene Expression Regulation
  • Gene Knockdown Techniques
  • Glucose Transport Proteins, Facilitative / antagonists & inhibitors
  • Glucose Transport Proteins, Facilitative / genetics*
  • Glucose Transport Proteins, Facilitative / metabolism
  • Hippocampus / cytology
  • Hippocampus / drug effects
  • Hippocampus / metabolism
  • Humans
  • Inositol / metabolism
  • Mice
  • Microsomes / chemistry
  • Microsomes / drug effects
  • Microsomes / metabolism
  • Molecular Sequence Annotation
  • Neurons / cytology
  • Neurons / drug effects
  • Neurons / metabolism
  • Peptide Fragments / antagonists & inhibitors
  • Peptide Fragments / biosynthesis
  • Peptide Fragments / genetics*
  • Phospholipid Transfer Proteins / antagonists & inhibitors
  • Phospholipid Transfer Proteins / genetics
  • Phospholipid Transfer Proteins / metabolism
  • Primary Cell Culture
  • Protein Binding
  • Protein Stability
  • Proteolysis
  • Protons*
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / metabolism
  • Receptors, Notch / genetics*
  • Receptors, Notch / metabolism
  • Signal Transduction


  • Amyloid beta-Peptides
  • Brain-Derived Neurotrophic Factor
  • Carbamates
  • Dipeptides
  • Enzyme Inhibitors
  • Glucose Transport Proteins, Facilitative
  • L 685458
  • Peptide Fragments
  • Phospholipid Transfer Proteins
  • Protons
  • RNA, Small Interfering
  • Receptors, Notch
  • SLC2A13 protein, human
  • amyloid beta-protein (1-40)
  • Inositol
  • Amyloid Precursor Protein Secretases
  • Adenosine Triphosphatases
  • Atp8a1 protein, mouse