Pen2 and presenilin-1 modulate the dynamic equilibrium of presenilin-1 and presenilin-2 gamma-secretase complexes.

Published

Journal Article

gamma-Secretase is known to play a pivotal role in the pathogenesis of Alzheimer disease through production of amyloidogenic Abeta42 peptides. Early onset familial Alzheimer disease mutations in presenilin (PS), the catalytic core of gamma-secretase, invariably increase the Abeta42:Abeta40 ratio. However, the mechanism by which these mutations affect gamma-secretase complex formation and cleavage specificity is poorly understood. We show that our in vitro assay system recapitulates the effect of PS1 mutations on the Abeta42:Abeta40 ratio observed in cell and animal models. We have developed a series of small molecule affinity probes that allow us to characterize active gamma-secretase complexes. Furthermore we reveal that the equilibrium of PS1- and PS2-containing active complexes is dynamic and altered by overexpression of Pen2 or PS1 mutants and that formation of PS2 complexes is positively correlated with increased Abeta42:Abeta40 ratios. These data suggest that perturbations to gamma-secretase complex equilibrium can have a profound effect on enzyme activity and that increased PS2 complexes along with mutated PS1 complexes contribute to an increased Abeta42:Abeta40 ratio.

Full Text

Duke Authors

Cited Authors

  • Placanica, L; Tarassishin, L; Yang, G; Peethumnongsin, E; Kim, S-H; Zheng, H; Sisodia, SS; Li, Y-M

Published Date

  • January 30, 2009

Published In

Volume / Issue

  • 284 / 5

Start / End Page

  • 2967 - 2977

PubMed ID

  • 19036728

Pubmed Central ID

  • 19036728

International Standard Serial Number (ISSN)

  • 0021-9258

Digital Object Identifier (DOI)

  • 10.1074/jbc.M807269200

Language

  • eng

Conference Location

  • United States