title: Presenilin-1 differentially facilitates endoproteolysis of the beta-amyloid precursor protein and Notch.
abstract: Mutations in the presenilin-1 (PS1) gene are associated with Alzheimer's disease and cause increased secretion of the neurotoxic amyloid-beta peptide (Abeta). Critical intramembraneous aspartates at residues 257 and 385 are required for the function of PS1 protein. Here we investigate the biological function of a naturally occurring PS1 splice variant (PS1 Deltaexon 8), which lacks the critical aspartate 257. Cell lines that stably express PS1 Deltaexon 8 or a PS1 protein in which aspartate residue 257 is mutated secrete significant levels of Abeta, whereas Abeta generation is severely reduced in cells transfected with PS1 containing a mutation of aspartate 385. In contrast, endoproteolytic processing of Notch is almost completely inhibited in cell lines expressing any of the PS1 variants that lack one of the critical aspartates. These data indicate that PS1 may differentially facilitate gamma-secretase-mediated generation of Abeta and endoproteolysis of Notch.
authors.affiliation: Adolf Butenandt-Institute, Department of Biochemistry, Laboratory for Alzheimer's Disease Research, Ludwig-Maximilians-University, 80336 Munich, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Capell
authors.forename: H
authors.initials: H
authors.lastname: Steiner
authors.forename: H
authors.initials: H
authors.lastname: Romig
authors.forename: S
authors.initials: S
authors.lastname: Keck
authors.forename: M
authors.initials: M
authors.lastname: Baader
authors.forename: M G
authors.initials: MG
authors.lastname: Grim
authors.forename: R
authors.initials: R
authors.lastname: Baumeister
authors.forename: C
authors.initials: C
authors.lastname: Haass
mesh_terms: D017398:Alternative Splicing / Q000502:physiology; D016564:Amyloid beta-Protein Precursor / Q000378:metabolism*; D000911:Antibodies, Monoclonal; D001224:Aspartic Acid; D002460:Cell Line; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D000939:Epitopes / Q000235:genetics; D005091:Exons; D015870:Gene Expression / Q000502:physiology; D006801:Humans; D007668:Kidney / Q000166:cytology; D008565:Membrane Proteins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D017354:Point Mutation; D053764:Presenilin-1; D051880:Receptors, Notch; D015398:Signal Transduction / Q000502:physiology
chemical_list: D016564:Amyloid beta-Protein Precursor; D000911:Antibodies, Monoclonal; D000939:Epitopes; D008565:Membrane Proteins; C508853:PSEN1 protein, human; D053764:Presenilin-1; D051880:Receptors, Notch; D001224:Aspartic Acid