Abstract |
Familial British dementia (FBD) is an early-onset non- amyloid-β (Aβ) cerebral amyloidosis that presents with severe cognitive decline and strikingly similar neuropathological features to those present in Alzheimer's disease (AD). FBD is associated with a T to A single nucleotide transition in the stop codon of a gene encoding BRI2, leading to the production of an elongated precursor protein. Furin-like proteolytic processing at its C-terminus releases a longer-than-normal 34 amino acid peptide, ABri, exhibiting amyloidogenic properties not seen in its 23 amino acid physiologic counterpart Bri1-23. Deposited ABri exhibits abundant post-translational pyroglutamate (pE) formation at the N-terminus, a feature seen in truncated forms of Aβ found in AD deposits, and co-exists with neurofibrillary tangles almost identical to those found in AD. We tested the impact of the FBD mutation alone and in conjunction with the pE post-translational modification on the structural properties and associated neurotoxicity of the ABri peptide. The presence of pE conferred to the ABri molecule enhanced hydrophobicity and accelerated aggregation/fibrillization properties. ABri pE was capable of triggering oxidative stress, loss of mitochondrial membrane potential and activation of caspase-mediated apoptotic mechanisms in neuronal cells, whereas homologous peptides lacking the elongated C-terminus and/or the N-terminal pE were unable to induce similar detrimental cellular pathways. The data indicate that the presence of N-terminal pE is not in itself sufficient to induce pathogenic changes in the physiologic Bri1-23 peptides but that its combination with the ABri mutation is critical for the molecular pathogenesis of FBD.
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Authors | Krysti Todd, Silvia Fossati, Jorge Ghiso, Agueda Rostagno |
Journal | Biochimica et biophysica acta
(Biochim Biophys Acta)
Vol. 1842
Issue 12 Pt A
Pg. 2457-67
(Dec 2014)
ISSN: 0006-3002 [Print] Netherlands |
PMID | 25261792
(Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
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Copyright | Copyright © 2014 Elsevier B.V. All rights reserved. |
Chemical References |
- Adaptor Proteins, Signal Transducing
- Amyloid
- Codon, Terminator
- ITM2B protein, human
- Membrane Glycoproteins
- Peptides
- Protein Isoforms
- Cytochromes c
- Pyrrolidonecarboxylic Acid
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Topics |
- Adaptor Proteins, Signal Transducing
- Amyloid
(chemistry, metabolism)
- Amyloid Neuropathies, Familial
- Apoptosis
(genetics)
- Blotting, Western
- Cell Line, Tumor
- Cerebral Amyloid Angiopathy, Familial
(genetics, metabolism)
- Circular Dichroism
- Codon, Terminator
(genetics)
- Cytochromes c
(metabolism)
- Humans
- Membrane Glycoproteins
(genetics, metabolism)
- Membrane Potential, Mitochondrial
- Microscopy, Confocal
- Mitochondria
(metabolism, physiology)
- Models, Neurological
- Mutation
- Neurodegenerative Diseases
(genetics, metabolism)
- Peptides
(chemistry, genetics, metabolism)
- Protein Isoforms
(chemistry, genetics, metabolism)
- Protein Processing, Post-Translational
- Pyrrolidonecarboxylic Acid
(chemistry, metabolism)
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