Prion protein paralog doppel protein interacts with alpha-2-macroglobulin: a plausible mechanism for doppel-mediated neurodegeneration.

Published online

Journal Article

Doppel protein (Dpl) is a paralog of the cellular form of the prion protein (PrP(C)), together sharing common structural and biochemical properties. Unlike PrP(C), which is abundantly expressed throughout the central nervous system (CNS), Dpl protein expression is not detectable in the CNS. Interestingly, its ectopic expression in the brain elicits neurodegeneration in transgenic mice. Here, by combining native isoelectric focusing plus non-denaturing polyacrylamide gel electrophoresis and mass spectrometry analysis, we identified two Dpl binding partners: rat alpha-1-inhibitor-3 (alpha(1)I(3)) and, by sequence homology, alpha-2-macroglobulin (alpha(2)M), two known plasma metalloproteinase inhibitors. Biochemical investigations excluded the direct interaction of PrP(C) with either alpha(1)I(3) or alpha(2)M. Nevertheless, enzyme-linked immunosorbent assays and surface plasmon resonance experiments revealed a high affinity binding occurring between PrP(C) and Dpl. In light of these findings, we suggest a mechanism for Dpl-induced neurodegeneration in mice expressing Dpl ectopically in the brain, linked to a withdrawal of natural inhibitors of metalloproteinase such as alpha(2)M. Interestingly, alpha(2)M has been proven to be a susceptibility factor in Alzheimer's disease, and as our findings imply, it may also play a relevant role in other neurodegenerative disorders, including prion diseases.

Full Text

Duke Authors

Cited Authors

  • Benvegnù, S; Franciotta, D; Sussman, J; Bachi, A; Zardini, E; Torreri, P; Govaerts, C; Pizzo, S; Legname, G

Published Date

  • June 18, 2009

Published In

Volume / Issue

  • 4 / 6

Start / End Page

  • e5968 -

PubMed ID

  • 19536284

Pubmed Central ID

  • 19536284

Electronic International Standard Serial Number (EISSN)

  • 1932-6203

Digital Object Identifier (DOI)

  • 10.1371/journal.pone.0005968

Language

  • eng

Conference Location

  • United States