There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

gamma-Secretase is a membrane protein complex with an unusual aspartyl protease activity that catalyses the regulated intramembranous cleavage of the beta-amyloid precursor protein (APP) to release the Alzheimer's disease (AD)-associated amyloid beta-peptide (Abeta) and the APP intracellular domain (AICD). Here we show the reconstitution of gamma-secretase activity in the yeast Saccharomyces cerevisiae, which lacks endogenous gamma-secretase activity. Reconstituted gamma-secretase activity depends on the presence of four complex components including presenilin (PS), nicastrin (Nct), APH-1 (refs 3-6) and PEN-2 (refs 4, 7), is associated with endoproteolysis of PS, and produces Abeta and AICD in vitro. Thus, the biological activity of gamma-secretase is reconstituted by the co-expression of human PS, Nct, APH-1 and PEN-2 in yeast.

Related collections

Most cited references 14

Record: found
Abstract: found
Article: not found

Two transmembrane aspartates in presenilin-1 required for presenilin endoproteolysis and gamma-secretase activity.

M S Wolfe, W. Xia, B Ostaszewski … (1999)

Accumulation of the amyloid-beta protein (Abeta) in the cerebral cortex is an early and invariant event in the pathogenesis of Alzheimer's disease. The final step in the generation of Abeta from the beta-amyloid precursor protein is an apparently intramembranous proteolysis by the elusive gamma-secretase(s). The most common cause of familial Alzheimer's disease is mutation of the genes encoding presenilins 1 and 2, which alters gamma-secretase activity to increase the production of the highly amyloidogenic Abeta42 isoform. Moreover, deletion of presenilin-1 in mice greatly reduces gamma-secretase activity, indicating that presenilin-1 mediates most of this proteolytic event. Here we report that mutation of either of two conserved transmembrane (TM) aspartate residues in presenilin-1, Asp 257 (in TM6) and Asp 385 (in TM7), substantially reduces Abeta production and increases the amounts of the carboxy-terminal fragments of beta-amyloid precursor protein that are the substrates of gamma-secretase. We observed these effects in three different cell lines as well as in cell-free microsomes. Either of the Asp --> Ala mutations also prevented the normal endoproteolysis of presenilin-1 in the TM6 --> TM7 cytoplasmic loop. In a functional presenilin-1 variant (carrying a deletion in exon 9) that is associated with familial Alzheimer's disease and which does not require this cleavage, the Asp 385 --> Ala mutation still inhibited gamma-secretase activity. Our results indicate that the two transmembrane aspartate residues are critical for both presenilin-1 endoproteolysis and gamma-secretase activity, and suggest that presenilin 1 is either a unique diaspartyl cofactor for gamma-secretase or is itself gamma-secretase, an autoactivated intramembranous aspartyl protease.

0 comments Cited 311 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Endoproteolysis of presenilin 1 and accumulation of processed derivatives in vivo.

Gopal Thinakaran, David Borchelt, Michael Lee … (1996)

The majority of early-onset cases of familial Alzheimer's disease (FAD) are linked to mutations in two related genes, PS1 and PS2, located on chromosome 14 and 1, respectively. Using two highly specific antibodies against nonoverlapping epitopes of the PS1-encoded polypeptide, termed presenilin 1 (PS1), we document that the preponderant PS1-related species that accumulate in cultured mammalian cells, and in the brains of rodents, primates, and humans are approximately 27-28 kDa N-terminal and approximately 16-17 kDa C-terminal derivatives. Notably, a FAD-linked PS1 variant that lacks exon 9 is not subject to endoproteolytic cleavage. In brains of transgenic mice expressing human PS1, approximately 17 kDa and approximately 27 kDa PS1 derivatives accumulate to saturable levels, and at approximately 1:1 stoichiometry, independent of transgene-derived mRNA. We conclude that PS1 is subject to endoproteolytic processing in vivo.

0 comments Cited 158 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Photoactivated gamma-secretase inhibitors directed to the active site covalently label presenilin 1.

Y. M. Li, M XU, M Lai … (2000)

Cleavage of amyloid precursor protein (APP) by the beta- and gamma-secretases generates the amino and carboxy termini, respectively, of the A beta amyloidogenic peptides A beta40 and A beta42--the major constituents of the amyloid plaques in the brain parenchyma of Alzheimer's disease patients. There is evidence that the polytopic membrane-spanning proteins, presenilin 1 and 2 (PS1 and PS2), are important determinants of gamma-secretase activity: mutations in PS1 and PS2 that are associated with early-onset familial Alzheimer's disease increase the production of A beta42 (refs 4-6), the more amyloidogenic peptide; gamma-secretase activity is reduced in neuronal cultures derived from PS1-deficient mouse embryos; and directed mutagenesis of two conserved aspartates in transmembrane segments of PS1 inactivates the ability of gamma-secretase to catalyse processing of APP within its transmembrane domain. It is unknown, however, whether PS1 (which has little or no homology to any known aspartyl protease) is itself a transmembrane aspartyl protease or a gamma-secretase cofactor, or helps to colocalize gamma-secretase and APP. Here we report photoaffinity labelling of PS1 (and PS2) by potent gamma-secretase inhibitors that were designed to function as transition state analogue inhibitors directed to the active site of an aspartyl protease. This observation indicates that PS1 (and PS2) may contain the active site of gamma-secretase. Interestingly, the intact, single-chain form of wild-type PS1 is not labelled by an active-site-directed photoaffinity probe, suggesting that intact wild-type PS1 may be an aspartyl protease zymogen.

0 comments Cited 129 times – based on 0 reviews      Review now

Bookmark

All references

Author and article information

Journal

PubMed ID:: 12679784

DOI:: 10.1038/ncb960

ScienceOpen disciplines: Chemistry

Keywords: Alzheimer Disease,genetics,metabolism,Amyloid Precursor Protein Secretases,Amyloid beta-Peptides,biosynthesis,Amyloid beta-Protein Precursor,Aspartic Acid Endopeptidases,Cell Membrane,enzymology,Cells, Cultured,Endopeptidases,Eukaryotic Cells,Gene Expression Regulation, Enzymologic,Gene Expression Regulation, Fungal,Genes, Reporter,Humans,Macromolecular Substances,Membrane Glycoproteins,Membrane Proteins,Peptide Hydrolases,Presenilin-1,Recombinant Fusion Proteins,diagnostic use,Saccharomyces cerevisiae

Reconstitution of gamma-secretase activity.

Read this article at

Abstract

Related collections

Journal of Circulating Biomarkers

Most cited references 14

Two transmembrane aspartates in presenilin-1 required for presenilin endoproteolysis and gamma-secretase activity.

Endoproteolysis of presenilin 1 and accumulation of processed derivatives in vivo.

Photoactivated gamma-secretase inhibitors directed to the active site covalently label presenilin 1.

Author and article information

Journal

Comments

Comment on this article

Similar content 350

Cited by 144

Most referenced authors 625