ORP150-CHIP chaperone antagonism control BACE1-mediated amyloid processing

J Cell Biochem. 2018 Jun;119(6):4615-4626. doi: 10.1002/jcb.26630. Epub 2018 Feb 27.

Abstract

BACE1, a key protein involved in Alzheimer's progression, initiates Aβ42 generation that induce senile plaques in brain. However, the role of chaperone synergy or antagonism on BACE1-mediated amyloid processing is unknown. We have discovered that BACE1 as well as Aβ42 are antagonistically controlled by ER chaperone ORP150 and cellular chaperone CHIP. We have shown ORP150 as a chaperone interacts with and stabilizes BACE1 at post-translational level. Furthermore, ORP150 enhances BACE1-mediated amyloid processing thus masking CHIP-mediated BACE1 degradation. Conversely, siORP150 reversed the chaperone function of ORP150 resulting in BACE1 degradation. ORP150 and CHIP demonstrate antagonism under normal and stress conditions wherein they inversely regulate each other thus affecting BACE1 level. In conclusion, we have uncovered for the first time a phenomenon of chaperone antagonism on BACE1-mediated Aβ42 generation. Future strategy would require both suppression of ORP150 as well as activation of E3-ligase activity of CHIP that might prevent Aβ42 in Alzheimer's disease.

Keywords: Aβ42; BACE1; CHIP; ORP150; chaperones.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyloid Precursor Protein Secretases / genetics
  • Amyloid Precursor Protein Secretases / metabolism*
  • Amyloid beta-Peptides / genetics
  • Amyloid beta-Peptides / metabolism*
  • Aspartic Acid Endopeptidases / genetics
  • Aspartic Acid Endopeptidases / metabolism*
  • Cell Line, Tumor
  • HEK293 Cells
  • HSP70 Heat-Shock Proteins / genetics
  • HSP70 Heat-Shock Proteins / metabolism*
  • Humans
  • Peptide Fragments / genetics
  • Peptide Fragments / metabolism*
  • Proteolysis*
  • Ubiquitin-Protein Ligases / genetics
  • Ubiquitin-Protein Ligases / metabolism*

Substances

  • Amyloid beta-Peptides
  • HSP70 Heat-Shock Proteins
  • Peptide Fragments
  • amyloid beta-protein (1-42)
  • oxygen-regulated proteins
  • STUB1 protein, human
  • Ubiquitin-Protein Ligases
  • Amyloid Precursor Protein Secretases
  • Aspartic Acid Endopeptidases
  • BACE1 protein, human