Enhanced production of A|342is believed to be the pathogenic molecular alteration in PS1-linked autosomal dominant FAD. The overall goal of the studies proposed in this application is to examine APP-y-secretase interactions, in order to better understand the regulation of A|342/4o production by y-secretase. The underlying hypothesis is that y-secretase, a complex of four membrane associated proteins, can adopt different conformations which differentially favor Ap40 or Ap42 production. We postulate that these conformations become preferred either through structural changes in core y-components or allosteric modifications of the complex. For example, using FRET based assay we have demonstrated that FAD associated PS1 mutations that increase A(342 (Berezovska et al., 2005) lead to a specific alteration in PS1 conformation. Iwatsubo and colleagues recently demonstrated that extension of the N terminus of Pen-2 (Isoo et al., 2007) similarly leads to structural change in y-complex and enhances the Ap42/40 ratio. Presumed allosteric modulators, such as some nonsteroidal anti-inflammatory drugs, which lower A|342/4o ratio (Lleo et al., 2004), or fenofibrate, which increases A|342/4o ratio, alter PS1 conformation in opposite directions. We therefore postulate that the conformational profile of the y- secretase complex measured by FRET reflects functional changes in the y-complex that lead to alterations in A(342/40 ratios. A second, related hypothesis is that the amount of Ap and A|342/40 ratio may also depend on how and where APP is presented to y-secretase. FAD mutations near the y-cleavage site in APP, and interactors that modify either APP or PS1 trafficking, and the cellular site of cleavage, may act in this fashion. The advanced imaging methodologies developed in these experiments, designed to monitor protein conformation and protein - protein interactions in living cells, are based on FRET, bimolecular complementation, and total internal reflection microscopy. Together with biochemical assays, sensitive ELISA, and interactions with other members of the PPG team, the proposed experiments will allow us to explore the effects of subcellular compartments and Pen2 alterations (Aim1), APP and substrate manipulations (Aim2), and pharmacological interventions (Aim3). Importantly, the development of these assays will allow us to examine the consequences on y-secretase of interacting molecules, mutations, and novel substrates as they emerge from the PPG effort.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Program Projects (P01)
Project #
5P01AG015379-15
Application #
8381461
Study Section
Special Emphasis Panel (ZAG1-ZIJ-3)
Project Start
Project End
2013-08-31
Budget Start
2012-09-01
Budget End
2013-08-31
Support Year
15
Fiscal Year
2012
Total Cost
$166,476
Indirect Cost
Name
Brigham and Women's Hospital
Department
Type
DUNS #
030811269
City
Boston
State
MA
Country
United States
Zip Code
02115
Zoltowska, Katarzyna Marta; Berezovska, Oksana (2017) Dynamic Nature of presenilin1/?-Secretase: Implication for Alzheimer's Disease Pathogenesis. Mol Neurobiol :
Gong, Yi; Sasidharan, Nikhil; Laheji, Fiza et al. (2017) Microglial dysfunction as a key pathological change in adrenomyeloneuropathy. Ann Neurol 82:813-827
Kara, Eleanna; Marks, Jordan D; Fan, Zhanyun et al. (2017) Isoform- and cell type-specific structure of apolipoprotein E lipoparticles as revealed by a novel Forster resonance energy transfer assay. J Biol Chem 292:14720-14729
Raven, Frank; Ward, Joseph F; Zoltowska, Katarzyna M et al. (2017) Soluble Gamma-secretase Modulators Attenuate Alzheimer's ?-amyloid Pathology and Induce Conformational Changes in Presenilin 1. EBioMedicine 24:93-101
Wagner, Steven L; Rynearson, Kevin D; Duddy, Steven K et al. (2017) Pharmacological and Toxicological Properties of the Potent Oral ?-Secretase Modulator BPN-15606. J Pharmacol Exp Ther 362:31-44
Yang, Ting; Li, Shaomin; Xu, Huixin et al. (2017) Large Soluble Oligomers of Amyloid ?-Protein from Alzheimer Brain Are Far Less Neuroactive Than the Smaller Oligomers to Which They Dissociate. J Neurosci 37:152-163
Ward, Joseph; Wang, Haizhi; Saunders, Aleister J et al. (2017) Mechanisms that synergistically regulate ?-secretase processing of APP and A?-? protein levels: relevance to pathogenesis and treatment of Alzheimer's disease. Discov Med 23:121-128
Zoltowska, Katarzyna Marta; Maesako, Masato; Lushnikova, Iryna et al. (2017) Dynamic presenilin 1 and synaptotagmin 1 interaction modulates exocytosis and amyloid ? production. Mol Neurodegener 12:15
Bolduc, D M; Selkoe, D J; Wolfe, M S (2017) Enzymatic Assays for Studying Intramembrane Proteolysis. Methods Enzymol 584:295-308
Williamson, Rebecca L; Laulagnier, Karine; Miranda, André M et al. (2017) Disruption of amyloid precursor protein ubiquitination selectively increases amyloid ? (A?) 40 levels via presenilin 2-mediated cleavage. J Biol Chem 292:19873-19889

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