Endoplasmic reticulum and trans-Golgi network generate distinct populations of Alzheimer β-amyloid peptides
Greenfield, Jeffrey P. ; Tsai, Julia ; Gouras, Gunnar K. LU
; Hai, Bing
; Thinakaran, Gopal
; Checler, Frederic
; Sisodia, Sangram S.
; Greengard, Paul
and Xu, Huaxi
(1999)
In Proceedings of the National Academy of Sciences of the United States of America
96(2).
p.742-747
- Abstract
The excessive generation and accumulation of 40- and 42-aa β-amyloid peptides (Aβ40/Aβ42) in selectively vulnerable brain regions is a major neuropathological feature of Alzheimer's disease. Aβ, derived by proteolytic cleavage from the β-amyloid precursor protein (βAPP), is normally secreted. However, recent evidence suggests that significant levels of Aβ also may remain inside cells. Here, we have investigated the subcellular compartments within which distinct amyloid species are generated and the compartments from which they are secreted. Three experimental approaches were used: (i) immunofluorescence performed in intact cortical neurons; (ii) sucrose gradient fractionation performed with mouse neuroblastoma... (More)
The excessive generation and accumulation of 40- and 42-aa β-amyloid peptides (Aβ40/Aβ42) in selectively vulnerable brain regions is a major neuropathological feature of Alzheimer's disease. Aβ, derived by proteolytic cleavage from the β-amyloid precursor protein (βAPP), is normally secreted. However, recent evidence suggests that significant levels of Aβ also may remain inside cells. Here, we have investigated the subcellular compartments within which distinct amyloid species are generated and the compartments from which they are secreted. Three experimental approaches were used: (i) immunofluorescence performed in intact cortical neurons; (ii) sucrose gradient fractionation performed with mouse neuroblastoma cells stably expressing wild-type βAPP695 (N2a695); and (iii) cell-free reconstitution of Aβ generation and trafficking from N2a695 cells. These studies demonstrate that: (i) Aβ40 (Aβ1-40 plus Aβ(x-40), where x is an NH2-terminal truncation) is generated exclusively within the trans-Golgi Network (TGN) and packaged into post-TGN secretory vesicles; (ii) Aβ(x-42) is made and retained within the endoplasmic reticulum in an insoluble state; (iii) Aβ42 (Aβ1-42 plus Aβ(x-42)) is made in the TGN and packaged into secretory vesicles; and (iv) the amyloid peptides formed in the TGN consist of two pools (a soluble population extractable with detergents and a detergent-insoluble form). The identification of the organelles in which distinct forms of Aβ are generated and from which they are secreted should facilitate the identification of the proteolytic enzymes responsible for their formation.
(Less)
- author
- Greenfield, Jeffrey P.
; Tsai, Julia
; Gouras, Gunnar K.
LU
; Hai, Bing
; Thinakaran, Gopal
; Checler, Frederic
; Sisodia, Sangram S.
; Greengard, Paul
and Xu, Huaxi
- publishing date
- 1999-01-19
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Proceedings of the National Academy of Sciences of the United States of America
- volume
- 96
- issue
- 2
- pages
- 742 - 747
- publisher
- National Academy of Sciences
- external identifiers
-
- pmid:9892704
- scopus:0033582159
- ISSN
- 0027-8424
- DOI
- 10.1073/pnas.96.2.742
- language
- English
- LU publication?
- no
- id
- 7ac2832b-95ce-4cee-981c-2aec1b3533ac
- date added to LUP
- 2020-02-20 14:34:32
- date last changed
- 2024-04-17 04:52:52
@article{7ac2832b-95ce-4cee-981c-2aec1b3533ac,
abstract = {{<p>The excessive generation and accumulation of 40- and 42-aa β-amyloid peptides (Aβ<sub>40</sub>/Aβ<sub>42</sub>) in selectively vulnerable brain regions is a major neuropathological feature of Alzheimer's disease. Aβ, derived by proteolytic cleavage from the β-amyloid precursor protein (βAPP), is normally secreted. However, recent evidence suggests that significant levels of Aβ also may remain inside cells. Here, we have investigated the subcellular compartments within which distinct amyloid species are generated and the compartments from which they are secreted. Three experimental approaches were used: (i) immunofluorescence performed in intact cortical neurons; (ii) sucrose gradient fractionation performed with mouse neuroblastoma cells stably expressing wild-type βAPP<sub>695</sub> (N2a<sub>695</sub>); and (iii) cell-free reconstitution of Aβ generation and trafficking from N2a<sub>695</sub> cells. These studies demonstrate that: (i) Aβ<sub>40</sub> (Aβ<sub>1-40</sub> plus Aβ(x-40), where x is an NH<sub>2</sub>-terminal truncation) is generated exclusively within the trans-Golgi Network (TGN) and packaged into post-TGN secretory vesicles; (ii) Aβ(x-42) is made and retained within the endoplasmic reticulum in an insoluble state; (iii) Aβ<sub>42</sub> (Aβ<sub>1-42</sub> plus Aβ(x-42)) is made in the TGN and packaged into secretory vesicles; and (iv) the amyloid peptides formed in the TGN consist of two pools (a soluble population extractable with detergents and a detergent-insoluble form). The identification of the organelles in which distinct forms of Aβ are generated and from which they are secreted should facilitate the identification of the proteolytic enzymes responsible for their formation.</p>}},
author = {{Greenfield, Jeffrey P. and Tsai, Julia and Gouras, Gunnar K. and Hai, Bing and Thinakaran, Gopal and Checler, Frederic and Sisodia, Sangram S. and Greengard, Paul and Xu, Huaxi}},
issn = {{0027-8424}},
language = {{eng}},
month = {{01}},
number = {{2}},
pages = {{742--747}},
publisher = {{National Academy of Sciences}},
series = {{Proceedings of the National Academy of Sciences of the United States of America}},
title = {{Endoplasmic reticulum and trans-Golgi network generate distinct populations of Alzheimer β-amyloid peptides}},
url = {{http://dx.doi.org/10.1073/pnas.96.2.742}},
doi = {{10.1073/pnas.96.2.742}},
volume = {{96}},
year = {{1999}},
}