title: Familial Alzheimer disease presenilin-1 mutations alter the active site conformation of γ-secretase.
abstract: Presenilin-1 (PS1) is the catalytic subunit of γ-secretase, and mutations in this protein cause familial Alzheimer Disease (FAD). However, little is known about how these mutations affect the active site of γ-secretase. Here, we show that PS1 mutations alter the S2 subsite within the active site of γ-secretase using a multiple photoaffinity probe approach called "photophore walking." Moreover, we developed a unique in vitro assay with a biotinylated recombinant Notch1 substrate and demonstrated that PS1 FAD mutations directly and significantly reduced γ-secretase activity for Notch1 cleavage. Substitution of the Notch Cys-1752 residue, which interacts with the S2 subsite, with Val, Met, or Ile has little effect on wild-type PS1 but leads to more efficient substrates for mutant PS1s. This study indicates that alteration of this S2 subsite plays an important role in determining the activity and specificity of γ-secretase for APP and Notch1 processing, which provides structural basis and insights on how certain PS1 FAD mutations lead to AD pathogenesis.
authors.affiliation: Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065 and the Department of Pharmacology, Weill Cornell Graduate School of Medical Sciences of Cornell University, New York, NY 10021.
authors.forename: De-Ming
authors.initials: DM
authors.lastname: Chau
authors.affiliation: Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065 and the Department of Pharmacology, Weill Cornell Graduate School of Medical Sciences of Cornell University, New York, NY 10021.
authors.forename: Christina J
authors.initials: CJ
authors.lastname: Crump
authors.affiliation: Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065 and the Department of Pharmacology, Weill Cornell Graduate School of Medical Sciences of Cornell University, New York, NY 10021.
authors.forename: Jennifer C
authors.initials: JC
authors.lastname: Villa
authors.affiliation: Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065 and the Department of Pharmacology, Weill Cornell Graduate School of Medical Sciences of Cornell University, New York, NY 10021.
authors.forename: David A
authors.initials: DA
authors.lastname: Scheinberg
authors.affiliation: Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065 and the Department of Pharmacology, Weill Cornell Graduate School of Medical Sciences of Cornell University, New York, NY 10021. Electronic address: liy2@mskcc.org.
authors.forename: Yue-Ming
authors.initials: YM
authors.lastname: Li
mesh_terms: D000544:Alzheimer Disease / Q000235:genetics / Q000378:metabolism*; D019943:Amino Acid Substitution; D053829:Amyloid Precursor Protein Secretases / Q000235:genetics / Q000378:metabolism*; D020134:Catalytic Domain; D030342:Genetic Diseases, Inborn / Q000235:genetics / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D020125:Mutation, Missense; D053764:Presenilin-1 / Q000235:genetics / Q000378:metabolism*; D051881:Receptor, Notch1 / Q000235:genetics / Q000378:metabolism
chemical_list: C497761:NOTCH1 protein, human; C508853:PSEN1 protein, human; D053764:Presenilin-1; D051881:Receptor, Notch1; D053829:Amyloid Precursor Protein Secretases