Processing of Notch and amyloid precursor protein by γ-secretase is spatially distinct Journal Article

Authors: Tarassishin, L.; Yin, Y. I.; Bassit, B.; Li, Y. M.
Article Title: Processing of Notch and amyloid precursor protein by γ-secretase is spatially distinct
Abstract: γ-Secretase activity is associated with a presenilin (PS)-containing macromolecular complex. Whether PS contains the active site of γ-secretase has been controversial. One challenge is to find PS that is engaged in the active γ-secretase complex at the cell surface, where some substrates appear to be processed. In this study, we developed an intact cell photolabeling technique that allows the direct visualization of active γ-secretase at the cell surface. We demonstrated that active γ-secretase is present in the plasma membrane. Moreover, the PS1 heterodimer is specifically photolabeled at the cell surface by a potent inhibitor that binds to only the active γ-secretase. We also explored the cellular processing sites of γ-secretase for amyloid precursor protein (APP) and Notch by using small molecular probes. MRL631, a γ-secretase inhibitor that is unable to penetrate the cell membrane, significantly blocks γ-secretase-mediated Notch cleavage but has little effect on APP processing. These results indicate that Notch is processed at the cell surface and that the majority of APP is processed by intracellular γ-secretase. Furthermore, the fact that inhibitors first target γ-secretase in the plasma membrane for Notch processing, and not for APP, will have important implications for drug development to treat Alzheimer's disease and cancer.
Keywords: controlled study; unclassified drug; human cell; protease inhibitors; cell line; membrane proteins; enzyme activity; transfection; protein processing, post-translational; receptors, notch; cell membrane; protein transport; molecular probe; membrane binding; gamma secretase inhibitor; notch1 receptor; amyloid precursor protein secretases; cell labeling; macromolecule; presenilin; gamma secretase; photoaffinity labeling; photoaffinity labels; endopeptidases; cell surface; amyloid; intramembrane protease; amyloid protein; aspartic endopeptidases; humans; human; priority journal; article; intact cell photolabeling; mrl 631
Journal Title: Proceedings of the National Academy of Sciences of the United States of America
Volume: 101
Issue: 49
ISSN: 0027-8424
Publisher: National Academy of Sciences  
Date Published: 2004-12-01
Start Page: 17050
End Page: 17055
Language: English
DOI: 10.1073/pnas.0408007101
PROVIDER: scopus
PMCID: PMC535399
PUBMED: 15563588
Notes: Proc. Natl. Acad. Sci. U. S. A. -- Cited By (since 1996):65 -- Export Date: 16 June 2014 -- CODEN: PNASA -- Source: Scopus
Citation Impact
MSK Authors
  1. Ye Yin
    11 Yin
  2. Yueming Li
    109 Li
  3. Bhramdeo Bassit
    7 Bassit