Characterization of human presenilin 1 using N-terminal specific monoclonal antibodies: Evidence that Alzheimer mutations affect proteolytic processing

• Published in: FEBS letters 1996-07, Vol.389 (3), p.297-303
• Main Authors: Mercken, Marc, Takahashi, Hiroshi, Honda, Toshiyuki, Sato, Kazuki, Murayama, Miyuki, Nakazato, Yuko, Noguchi, Kaori, Imahori, Kasutomo, Takashima, Akihiko
• Format: Article
• Language: English
• Subjects: Alzheimer disease; Alzheimer Disease - genetics; Alzheimer Disease - metabolism; Amino Acid Sequence; Animals; Antibodies, Monoclonal; Blotting, Western; Brain - metabolism; Cells, Cultured; Chromosome 14; Electrophoresis, Polyacrylamide Gel; Epitopes; Escherichia coli - genetics; Glutathione Transferase - genetics; Glutathione Transferase - metabolism; Humans; Membrane Proteins - chemistry; Membrane Proteins - genetics; Membrane Proteins - immunology; Membrane Proteins - isolation & purification; Membrane Proteins - metabolism; Molecular Sequence Data; Molecular Weight; Monoclonal antibody; Mutation; PC12 Cells; Peptide Fragments - chemistry; Peptide Fragments - immunology; Presenilin; Presenilin-1; Protein Processing, Post-Translational; Proteolysis; Rats; Recombinant Fusion Proteins - metabolism; Transfection
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(96)00608-4

The majority of cases of early-onset familial Alzheimer disease are caused by mutations in the recently identified presenilin 1 (PS1) gene, located on chromosome 14. PS1, a 467 amino acid protein, is predicted to be an integral membrane protein containing seven putative transmembrane domains and a large hydrophilic loop between the sixth and seventh membrane-spanning domain. We produced 7 monoclonal antibodies that react with 3 non-overlapping epitopes on the N-terminal hydrophilic tail of PS1. The monoclonal antibodies can detect the full-size PS1 at M r 47 000 and a more abundant M r 28 000 product in membrane extracts from human brain and human cell lines. PC12 cells transiently transfected with PS1 constructs containing two different Alzheimer mutations fail to generate the 28 kDa degradation product in contrast to PC12 cells transfected with wild-type PS1. Our results indicate that missense mutations in this form of familial Alzheimer disease may act via a mechanism of impaired proteolytic processing of PS1.