Abstract
Presenilin 1 (PS1), a polytopic membrane protein, is required for endoproteolytic processing at gamma-secretase site within the transmembrane domain of amyloid precursor proteins (APP). In addition, PS1 and its orthologues facilitate signaling of Notch family members, cell-surface receptors that specify cell fates during development. To clarify the mechanism(s) by which PS facilitates Notch signaling, we examined human Jagged-2-dependent metabolism and activity of a chimeric full-length Notchl-GFP molecule expressed in fibroblasts with heterozygous, or homozygous deletions of PS1. We demonstrate that PS1 is required for facilitating Jagged 2-mediated proteolysis and that translocation and accumulation of NICD in the nucleus correlates with signaling activity. Moreover, in a ligand-independent, Ca2+-depletion paradigm, we demonstrate that PS1 facilitates endoproteolysis of a plasma-membrane-associated, Notch1-GFP derivative. Finally, we report that NICD production is inhibited by L-685,458, a potent and selective inhibitor that blocks solubilized gamma-secretase activity and Abeta production in cultured cells. These findings strongly suggest that intramembranous processing of APP and Notch 1 are mediated by similar, if not identical, proteases that require PS1 for their activation.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Alzheimer Disease / genetics*
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Alzheimer Disease / metabolism
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Alzheimer Disease / physiopathology
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Amyloid Precursor Protein Secretases
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Amyloid beta-Protein Precursor / metabolism
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Animals
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Aspartic Acid Endopeptidases
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Carbamates
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Carrier Proteins / genetics
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Carrier Proteins / metabolism*
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Cell Line, Transformed / cytology
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Cell Line, Transformed / metabolism
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Cell Membrane / genetics
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Cell Membrane / metabolism*
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Cell Nucleus / genetics
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Cell Nucleus / metabolism
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Dipeptides
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Endopeptidases / drug effects
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Endopeptidases / metabolism
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Fetus
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Fibroblasts / cytology
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Fibroblasts / metabolism
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Green Fluorescent Proteins
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Indicators and Reagents / metabolism
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Intercellular Signaling Peptides and Proteins
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Jagged-2 Protein
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Luminescent Proteins / metabolism
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Membrane Proteins / genetics
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Membrane Proteins / metabolism*
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Mice
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Mice, Knockout
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Peptide Fragments / genetics
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Peptide Fragments / metabolism
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Peptide Hydrolases / genetics
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Peptide Hydrolases / metabolism*
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Presenilin-1
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Protease Inhibitors / pharmacology
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Receptor, Notch1
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Receptors, Cell Surface*
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Recombinant Fusion Proteins / genetics
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Recombinant Fusion Proteins / metabolism
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Signal Transduction / genetics*
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Transcription Factors*
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Translocation, Genetic / genetics
Substances
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Amyloid beta-Protein Precursor
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Carbamates
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Carrier Proteins
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Dipeptides
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Indicators and Reagents
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Intercellular Signaling Peptides and Proteins
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JAG2 protein, human
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Jag2 protein, mouse
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Jagged-2 Protein
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L 685458
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Luminescent Proteins
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Membrane Proteins
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Notch1 protein, mouse
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PSEN1 protein, human
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Peptide Fragments
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Presenilin-1
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Protease Inhibitors
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Receptor, Notch1
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Receptors, Cell Surface
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Recombinant Fusion Proteins
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Transcription Factors
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Green Fluorescent Proteins
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Amyloid Precursor Protein Secretases
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Endopeptidases
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Peptide Hydrolases
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Aspartic Acid Endopeptidases
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BACE1 protein, human
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Bace1 protein, mouse