| Autor: |
Loetscher, Hansruedi, Deuschle, Ulrich, Brockhaus, Manfred, Reinhardt, Dieter, Nelboeck, Peter, Mous, Jan, Grünberg, Jürgen, Haass, Christian, Jacobsen, Helmut |
| Zdroj: |
Journal of Biological Chemistry; August 1997, Vol. 272 Issue: 33 p20655-20659, 5p |
| Abstrakt: |
Presenilin 1 (PS1) and presenilin 2 (PS2) are endoproteolytically processed in vivoand in cell transfectants to yield 27–35-kDa N-terminal and 15–24-kDa C-terminal fragments. We have studied the cleavage of PS1 and PS2 in transiently and stably transfected hamster kidney and mouse and human neuroblastoma cells by immunoblot and pulse-chase experiments. C-terminal fragments were isolated by affinity chromatography and SDS-polyacrylamide gel electrophoresis and sequenced. The processing sites identified in PS1 and PS2 (Asp345/Ser346and Asp329/Ser330, respectively) are typical for caspase-type proteases. Specific caspase inhibitors and cleavage site mutations confirmed the involvement of caspase(s) in PS1 and PS2 processing in cell transfectants. Fluorescent peptide substrates carrying the PS-identified cleavage sites were hydrolyzed by proteolytic activity from mouse brain. The PS2-derived peptide substrate was also cleaved by recombinant human caspase-3. Additional processing of PS2 by non-caspase-type proteases was also observed. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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