trehalose (a-d-glucosyl-[1,1]-a-d-glucopyranoside) is involved in mechanisms that coordinate metabolism with plant growth adaptation and development. the main objective of the current work was to find out whether trehalose feeding affects the expression of two genes involved in photosynthesis: one gene coding for photosystem1 subunit h (ps1-h) and the other for the light harvesting complex b1 (...

Trehalose (a-D-glucosyl-[1,1]-a-D-glucopyranoside) is involved in mechanisms that coordinate metabolism with plant growth adaptation and development. The main objective of the current work was to find out whether trehalose feeding affects the expression of two genes involved in photosynthesis: one gene coding for photosystem1 subunit H (PS1-H) and the other for the light harvesting complex B1 (...

Presenilin 1 (PS1) plays a pivotal role in Notch signaling and the intracellular metabolism of the amyloid beta-protein. To understand intracellular signaling events downstream of PS1, we investigated in this study the action of PS1 on mitogen-activated protein kinase pathways. Overexpressed PS1 suppressed the stress-induced stimulation of stress-activated protein kinase (SAPK)/c-Jun NH(2)-term...

beta-Catenin has previously been shown to interact with presenilin 1 (PS1) in transfected cells. Here we report that beta-catenin co-immunoprecipitates with the endogenous C-terminal fragment of presenilin 1 (PS1-CTF) but not with the endogenous CTF of presenilin 2 (PS2-CTF) in H4 human neuroglioma cells. During staurosporine (STS)-induced cell death, beta-catenin and PS1-CTF undergo a caspase-...

Mutations in genes for presenilins (PS1 and PS2) lead to early-onset familial Alzheimer’s disease (FAD). It was recently shown that PS1 is required for macroautophagy in mouse blastocysts, and lysosomal proteolysis was proposed as a potential therapeutic target in FAD. Zhang et al. have meticulously tested that hypothesis and found it flawed. The previous work asserted that in cells lacking PS1...

Disruption of iron homeostasis and increased glial response are known to occur in brains afflicted by Alzheimer's disease (AD). While the APP/PS1 transgenic mouse model recapitulates the hallmark amyloid-beta plaque pathology of AD, it does so in a different neuronal mileu than humans. Understanding the iron characteristics and glial response of the APP/PS1 model is important when testing new t...

Amyloid beta-peptide (Abeta) is generated by the consecutive cleavages of beta- and gamma-secretase. The intramembraneous gamma-secretase cleavage critically depends on the activity of presenilins (PS1 and PS2). Although there is evidence that PSs are aspartyl proteases with gamma-secretase activity, it remains controversial whether their subcellular localization overlaps with the cellular site...

In Photosystem 1 (PS1), phylloquinone (PhQ) acts as a secondary electron acceptor from chlorophyll ec(3) and also as an electron donor to the iron-sulfur cluster F(X). PS1 possesses two virtually equivalent branches of electron transfer (ET) cofactors from P(700) to F(X), and the lifetime of the semiquinone intermediate displays biphasic kinetics, reflecting ET along the two different branches....

Presenilin 1 (PS1) forms the -secretase complex with at least three components: nicastrin, APH-1, and PEN-2. This complex mediates intramembrane cleavage of amyloid precursor protein (APP) to generate -amyloid protein (A ) as well as other type 1 transmembrane proteins. Although PS1 mutations linked to familial Alzheimer’s disease influence these cleavages, their biological consequences have no...

Curcumin has been reported to inhibit the generation of Aβ, but the underlying mechanisms by which this occurs remain unknown. Aβ is thought to play an important role in the pathogenesis of Alzheimer's disease (AD). The amyloid hypothesis argues that aggregates of Aβ trigger a complex pathological cascade that leads to neurodegeneration. Aβ is generated by the processing of APP (amyloid precurs...