Abstract
To investigate a possible association between G-proteins and presenilin-1 (PS-1), a series of glutathione S-transferase-fusion proteins containing portions of PS-1 were prepared and used in vitro in binding experiments with tissue and recombinant G-proteins. The results demonstrate that the 39 C-terminal amino acids of PS-1 selectively bind the brain G-protein, Go. Addition of guanosine 5'-3-O-(thio)triphosphate promoted Go dissociation from PS-1, indicating that this domain mimics the function of G-protein-coupling domains found in receptors. The 39-amino acid synthetic polypeptide activated Go in a magnesium ion-dependent manner. Physical interaction of full-length PS-1 and Go was also demonstrated. Following transfection of Goalpha and N-terminally FLAG-tagged PS-1 in COS-7 cells, Go was immunoprecipitated by FLAG antibodies. In addition, endogenous PS-1 and Goalpha were colocalized immunocytochemically in human glioma cell lines. The results indicate that PS-1 regulates Go activities in living cells.
Publication types
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Research Support, Non-U.S. Gov't
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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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Amino Acid Sequence
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Animals
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Brain / metabolism*
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COS Cells
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Cells, Cultured
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Conserved Sequence
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Epitopes / metabolism
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GTP Phosphohydrolases / metabolism
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GTP-Binding Protein alpha Subunits, Gi-Go / metabolism
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GTP-Binding Proteins / genetics*
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GTP-Binding Proteins / metabolism
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Gene Expression Regulation*
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Guanosine 5'-O-(3-Thiotriphosphate) / metabolism
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Humans
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Intercellular Signaling Peptides and Proteins
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Membrane Proteins / genetics*
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Membrane Proteins / metabolism
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Molecular Sequence Data
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Oligopeptides
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Peptides / metabolism
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Presenilin-1
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Rats
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Recombinant Proteins / genetics
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Recombinant Proteins / metabolism
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Wasp Venoms / chemistry
Substances
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Epitopes
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Intercellular Signaling Peptides and Proteins
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Membrane Proteins
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Oligopeptides
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PSEN1 protein, human
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Peptides
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Presenilin-1
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Recombinant Proteins
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Wasp Venoms
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Guanosine 5'-O-(3-Thiotriphosphate)
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mastoparan
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FLAG peptide
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GTP Phosphohydrolases
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GTP-Binding Proteins
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GTP-Binding Protein alpha Subunits, Gi-Go