Abstract
Recent findings suggest that Presenilin 1 (PS1) mutations play a major role in the development of Alzheimer's disease (AD) by increasing the production of the beta amyloid peptide (Aβ). The exact mechanism whereby mutations in PS1 lead to this effect is not clear. To examine the question of how PS1 might be involved in amyloid precursor protein (APP) processing, we constructed a chimera of human APP695 fused at the C-terminal to enhanced green fluorescent protein (EGFP). This construct was injected into Xenopus laevis oocytes in the presence of wild type PS1 or one of three PS1 mutations associated with AD. The cellular location of the APP695-EGFP construct was examined by fluorescent confocal microscopy. In addition, membrane fractions of oocytes expressing APP695-EGFP in the presence or absence of wild type or mutant forms of PS1 were evaluated by Western blot analysis. The results show that APP695-EGFP is primarily expressed on the cell surface and undergoes limited cleavage. Specifically, APP695 was cleaved in the Aβ domain to generate three distinct C-terminal fragments that correspond in length to stubs expected after cleavage with α-, β- and γ-secretase, respectively. The presence of wild type PS1 not only increased the production of proteolytic C-terminal fragments of APP, but the production of APP itself. These findings were even more pronounced in the presence of all three PS1 mutations, suggesting that PS1 mutations may lead to over-expression of APP not just increased γ-secretase activity.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 189-198 |
| Number of pages | 10 |
| Journal | Brain Research |
| Volume | 904 |
| Issue number | 2 |
| DOIs | |
| State | Published - Jun 22 2001 |
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Keywords
- Alzheimer
- Amyloid precursor protien
- Beta amyloid
- GFP
- Presenilin 1
- Xenopus laevis
ASJC Scopus subject areas
- Neuroscience(all)
Cite this
Presenilin 1 mutations increase amyloid precursor protein production and proteolysis in Xenopus laevis oocytes. / Heyn, Sietske N.; Vulliet, Philip R.
In: Brain Research, Vol. 904, No. 2, 22.06.2001, p. 189-198.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Presenilin 1 mutations increase amyloid precursor protein production and proteolysis in Xenopus laevis oocytes
AU - Heyn, Sietske N.
AU - Vulliet, Philip R
PY - 2001/6/22
Y1 - 2001/6/22
N2 - Recent findings suggest that Presenilin 1 (PS1) mutations play a major role in the development of Alzheimer's disease (AD) by increasing the production of the beta amyloid peptide (Aβ). The exact mechanism whereby mutations in PS1 lead to this effect is not clear. To examine the question of how PS1 might be involved in amyloid precursor protein (APP) processing, we constructed a chimera of human APP695 fused at the C-terminal to enhanced green fluorescent protein (EGFP). This construct was injected into Xenopus laevis oocytes in the presence of wild type PS1 or one of three PS1 mutations associated with AD. The cellular location of the APP695-EGFP construct was examined by fluorescent confocal microscopy. In addition, membrane fractions of oocytes expressing APP695-EGFP in the presence or absence of wild type or mutant forms of PS1 were evaluated by Western blot analysis. The results show that APP695-EGFP is primarily expressed on the cell surface and undergoes limited cleavage. Specifically, APP695 was cleaved in the Aβ domain to generate three distinct C-terminal fragments that correspond in length to stubs expected after cleavage with α-, β- and γ-secretase, respectively. The presence of wild type PS1 not only increased the production of proteolytic C-terminal fragments of APP, but the production of APP itself. These findings were even more pronounced in the presence of all three PS1 mutations, suggesting that PS1 mutations may lead to over-expression of APP not just increased γ-secretase activity.
AB - Recent findings suggest that Presenilin 1 (PS1) mutations play a major role in the development of Alzheimer's disease (AD) by increasing the production of the beta amyloid peptide (Aβ). The exact mechanism whereby mutations in PS1 lead to this effect is not clear. To examine the question of how PS1 might be involved in amyloid precursor protein (APP) processing, we constructed a chimera of human APP695 fused at the C-terminal to enhanced green fluorescent protein (EGFP). This construct was injected into Xenopus laevis oocytes in the presence of wild type PS1 or one of three PS1 mutations associated with AD. The cellular location of the APP695-EGFP construct was examined by fluorescent confocal microscopy. In addition, membrane fractions of oocytes expressing APP695-EGFP in the presence or absence of wild type or mutant forms of PS1 were evaluated by Western blot analysis. The results show that APP695-EGFP is primarily expressed on the cell surface and undergoes limited cleavage. Specifically, APP695 was cleaved in the Aβ domain to generate three distinct C-terminal fragments that correspond in length to stubs expected after cleavage with α-, β- and γ-secretase, respectively. The presence of wild type PS1 not only increased the production of proteolytic C-terminal fragments of APP, but the production of APP itself. These findings were even more pronounced in the presence of all three PS1 mutations, suggesting that PS1 mutations may lead to over-expression of APP not just increased γ-secretase activity.
KW - Alzheimer
KW - Amyloid precursor protien
KW - Beta amyloid
KW - GFP
KW - Presenilin 1
KW - Xenopus laevis
UR - http://www.scopus.com/inward/record.url?scp=0035933518&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0035933518&partnerID=8YFLogxK
U2 - 10.1016/S0006-8993(01)02312-5
DO - 10.1016/S0006-8993(01)02312-5
M3 - Article
C2 - 11406116
AN - SCOPUS:0035933518
VL - 904
SP - 189
EP - 198
JO - Brain Research
JF - Brain Research
SN - 0006-8993
IS - 2
ER -