Mechanism of the cleavage specificity of Alzheimer’s disease γ-secretase identified by phenylalanine-scanning mutagenesis of the transmembrane domain of the amyloid precursor protein

• Stefan F. Lichtenthaler

  Center for Molecular Biology, University of Heidelberg, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany; Laboratory for Mass Spectrometry, The Rockefeller University, New York, NY 10021; and Department of Pathology, University of Melbourne, Parkville, Victoria 3052, Australia

• Rong Wang

  Center for Molecular Biology, University of Heidelberg, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany; Laboratory for Mass Spectrometry, The Rockefeller University, New York, NY 10021; and Department of Pathology, University of Melbourne, Parkville, Victoria 3052, Australia

• Heike Grimm

  Center for Molecular Biology, University of Heidelberg, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany; Laboratory for Mass Spectrometry, The Rockefeller University, New York, NY 10021; and Department of Pathology, University of Melbourne, Parkville, Victoria 3052, Australia

• Sacha N. Uljon

  Center for Molecular Biology, University of Heidelberg, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany; Laboratory for Mass Spectrometry, The Rockefeller University, New York, NY 10021; and Department of Pathology, University of Melbourne, Parkville, Victoria 3052, Australia

• Colin L. Masters

  Center for Molecular Biology, University of Heidelberg, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany; Laboratory for Mass Spectrometry, The Rockefeller University, New York, NY 10021; and Department of Pathology, University of Melbourne, Parkville, Victoria 3052, Australia

• Konrad Beyreuther

  Center for Molecular Biology, University of Heidelberg, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany; Laboratory for Mass Spectrometry, The Rockefeller University, New York, NY 10021; and Department of Pathology, University of Melbourne, Parkville, Victoria 3052, Australia

抄録

Proteolytic processing of the amyloid precursor protein by β-secretase yields A4CT (C99), which is cleaved further by the as yet unknown γ-secretase, yielding the β-amyloid (Aβ) peptide with 40 (Aβ 40 ) or 42 residues (Aβ 42 ). Because the position of γ-secretase cleavage is crucial for the pathogenesis of Alzheimer’s disease, we individually replaced all membrane-domain residues of A4CT outside the Aβ domain with phenylalanine, stably transfected the constructs in COS7 cells, and determined the effect of these mutations on the cleavage specificity of γ-secretase (Aβ 42 /Aβ 40 ratio). Compared with wild-type A4CT, mutations at Val-44, Ile-47, and Val-50 led to decreased Aβ 42 /Aβ 40 ratios, whereas mutations at Thr-43, Ile-45, Val-46, Leu-49, and Met-51 led to increased Aβ 42 /Aβ 40 ratios. A massive effect was observed for I45F (34-fold increase) making this construct important for the generation of animal models for Alzheimer’s disease. Unlike the other mutations, A4CT-V44F was processed mainly to Aβ 38 , as determined by mass spectrometry. Our data provide a detailed model for the active site of γ-secretase: γ-secretase interacts with A4CT by binding to one side of the α-helical transmembrane domain of A4CT. Mutations in the transmembrane domain of A4CT interfere with the interaction between γ-secretase and A4CT and, thus, alter the cleavage specificity of γ-secretase.

収録刊行物

• Proceedings of the National Academy of Sciences

  Proceedings of the National Academy of Sciences 96 (6), 3053-3058, 1999-03-16

  Proceedings of the National Academy of Sciences

キーワード

• Multidisciplinary

詳細情報

• CRID: 1362544419991579264
• NII論文ID: 30016222557
• NII書誌ID: AA10808769
• DOI: 10.1073/pnas.96.6.3053
• ISSN: 10916490
• ISSN: 00278424
• Web Site: https://pnas.org/doi/pdf/10.1073/pnas.96.6.3053
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