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Random mutagenesis of presenilin-1 identifies novel mutants exclusively generating long amyloid beta-peptides.
- Source :
-
The Journal of biological chemistry [J Biol Chem] 2005 May 13; Vol. 280 (19), pp. 19070-7. Date of Electronic Publication: 2005 Mar 10. - Publication Year :
- 2005
-
Abstract
- Familial Alzheimer disease-causing mutations in the presenilins increase production of longer pathogenic amyloid beta-peptides (A beta(42/43)) by altering gamma-secretase activity. The mechanism underlying this effect remains unknown, although it has been proposed that heteromeric macromolecular complexes containing presenilins mediate gamma-secretase cleavage of the amyloid beta-precursor protein. Using a random mutagenesis screen of presenilin-1 (PS1) for PS1 endoproteolysis-impairing mutations, we identified five unique mutants, including R278I-PS1 and L435H-PS1, that exclusively generated a high level of A beta43, but did not support physiological PS1 endoproteolysis or A beta40 generation. These mutants did not measurably alter the molecular size or subcellular localization of PS1 complexes. Pharmacological studies indicated that the up-regulation of activity for A beta43 generation by these mutations was not further enhanced by the difluoroketone inhibitor DFK167 and was refractory to inhibition by sulindac sulfide. These results suggest that PS1 mutations can lead to a wide spectrum of changes in the activity and specificity of gamma-secretase and that the effects of PS1 mutations and gamma-secretase inhibitors on the specificity are mediated through a common mechanism.
- Subjects :
- Allosteric Site
Amyloid beta-Protein Precursor chemistry
Animals
Binding Sites
Blotting, Western
Cell Line
Cell Membrane metabolism
Centrifugation, Density Gradient
DNA, Complementary metabolism
Dose-Response Relationship, Drug
Enzyme-Linked Immunosorbent Assay
Fibroblasts metabolism
Glycerol pharmacology
Humans
Immunoblotting
Immunohistochemistry
Immunoprecipitation
Mass Spectrometry
Membrane Proteins metabolism
Mice
Mutation
Mutation, Missense
Presenilin-1
Protein Isoforms
Protein Structure, Tertiary
Proteins chemistry
Receptors, Notch
Retroviridae genetics
Subcellular Fractions metabolism
Sulindac pharmacology
Transfection
Up-Regulation
Amyloid beta-Peptides chemistry
Membrane Proteins genetics
Membrane Proteins physiology
Mutagenesis
Sulindac analogs & derivatives
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9258
- Volume :
- 280
- Issue :
- 19
- Database :
- MEDLINE
- Journal :
- The Journal of biological chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 15764596
- Full Text :
- https://doi.org/10.1074/jbc.M501130200