Iron and the translation of the amyloid precursor protein (APP) and ferritin mRNAs: riboregulation against neural oxidative damage in Alzheimer's disease

The essential metals iron, zinc and copper deposit near the Aβ (amyloid β-peptide) plaques in the brain cortex of AD (Alzheimer's disease) patients. Plaque-associated iron and zinc are in neurotoxic excess at 1 mM concentrations. APP (amyloid precursor protein) is a single transmembrane metalloprotein cleaved to generate the 40–42-amino-acid Aβs, which exhibit metal-catalysed neurotoxicity. In health, ubiquitous APP is cleaved in a non-amyloidogenic pathway within its Aβ domain to release the neuroprotective APP ectodomain, APP(s). To adapt and counteract metal-catalysed oxidative stress, as during reperfusion from stroke, iron and cytokines induce the translation of both APP and ferritin (an iron storage protein) by similar mechanisms. We reported that APP was regulated at the translational level by active IL (interleukin)-1 (IL-1-responsive acute box) and IRE (iron-responsive element) RNA stem–loops in the 5′ untranslated region of APP mRNA. The APP IRE is homologous with the canonical IRE RNA stem–loop that binds the iron regulatory proteins (IRP1 and IRP2) to control intracellular iron homoeostasis by modulating ferritin mRNA translation and transferrin receptor mRNA stability. The APP IRE interacts with IRP1 (cytoplasmic cis-aconitase), whereas the canonical H-ferritin IRE RNA stem–loop binds to IRP2 in neural cell lines, and in human brain cortex tissue and in human blood lysates. The same constellation of RNA-binding proteins [IRP1/IRP2/poly(C) binding protein] control ferritin and APP translation with implications for the biology of metals in AD.

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Processing of Alzheimer Aβ-Amyloid Precursor Protein: Cell Biology, Regulation, and Role in Alzheimer’s Disease

Amyloid Protein Precursor in Development, Aging and Alzheimer’s Disease ◽

10.1007/978-3-662-01135-5_10 ◽

1994 ◽

pp. 100-120

Author(s):

S. Gandy ◽

P. Greengard

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Amyloid Precursor Protein ◽

Cell Biology ◽

Precursor Protein ◽

Aβ Amyloid ◽

Protein Cell

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Protein–protein interactions in the assembly and subcellular trafficking of the BACE (β-site amyloid precursor protein-cleaving enzyme) complex of Alzheimer's disease

Biochemical Society Transactions ◽

10.1042/bst0350974 ◽

2007 ◽

Vol 35 (5) ◽

pp. 974-979 ◽

Cited By ~ 12

Author(s):

R.B. Parsons ◽

B.M. Austen

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Amyloid Precursor Protein ◽

Protein Interactions ◽

Senile Plaques ◽

Amyloid Β ◽

Precursor Protein ◽

Amyloid Β Peptide ◽

Aβ Amyloid ◽

Ad Alzheimer’S Disease

The correct assembly of the BACE (β-site amyloid precursor protein-cleaving enzyme or β-secretase) complex and its subsequent trafficking to cellular compartments where it associates with the APP (amyloid precursor protein) is essential for the production of Aβ (amyloid β-peptide), the protein whose aggregation into senile plaques is thought to be responsible for the pathogenesis of AD (Alzheimer's disease). These processes rely upon both transient and permanent BACE–protein interactions. This review will discuss what is currently known about these BACE–protein interactions and how they may reveal novel therapeutic targets for the treatment of AD.

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Syntaxin 5 interacts with presenilin holoproteins, but not with their N- or C-terminal fragments, and affects β-amyloid peptide production

Biochemical Journal ◽

10.1042/bj20040618 ◽

2004 ◽

Vol 381 (3) ◽

pp. 619-628 ◽

Cited By ~ 28

Author(s):

Kei SUGA ◽

Takami TOMIYAMA ◽

Hiroshi MORI ◽

Kimio AKAGAWA

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Amyloid Precursor Protein ◽

Full Length ◽

Precursor Protein ◽

Amyloid Peptide ◽

Familial Alzheimer’S Disease ◽

Aβ Amyloid ◽

Β Amyloid ◽

Familial Alzheimer's Disease

Mutations in presenilins 1 and 2 (PS1 and PS2) account for the majority of cases of early-onset familial Alzheimer's disease. However, the trafficking and interaction of PSs with other proteins in the early secretory pathways are poorly understood. Using co-immunoprecipitation, we found that PS bound to Syx5 (syntaxin 5), which is a target-soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptor involved in endoplasmic reticulum (ER)–Golgi vesicular transport in vivo. Syx5 interacted only with the full-length PS holoproteins and not with the naturally occurring N- or C-terminal fragments. The PS holoproteins co-immunoprecipitated with the mutant Syx5, which localized to the ER and Golgi compartments, despite the substitution of the transmembrane region with that of syntaxin 1A. In contrast, the transmembrane deletion mutant that localized to the cytosol, but not to the ER or Golgi compartments, did not co-immunoprecipitate the PS holoproteins. The PS1 variant linked to familial Alzheimer's disease (PS1ΔE9), lacking the region that contains the endoproteolytic cleavage site in the cytoplasmic loop, showed markedly decreased binding to Syx5. Immunofluorescence and sucrose-density-gradient fractionation analyses showed that the full-length PS holoproteins co-localized with Syx5 to the ER and cis-Golgi compartments. Furthermore, Syx5 overexpression resulted in the accumulation of PS holoproteins and the β-amyloid precursor protein, and reduced the secretion of the Aβ (amyloid β) peptide in COS-7 cells. In summary, these results indicate that Syx5 binds to full-length PSs and affects the processing and trafficking of β-amyloid precursor protein in the early secretory compartments.

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Clioquinol Mediates Copper Uptake and Counteracts Copper Efflux Activities of the Amyloid Precursor Protein of Alzheimer's Disease

Journal of Biological Chemistry ◽

10.1074/jbc.m407410200 ◽

2004 ◽

Vol 279 (50) ◽

pp. 51958-51964 ◽

Cited By ~ 97

Author(s):

Carina Treiber ◽

Andreas Simons ◽

Markus Strauss ◽

Mathias Hafner ◽

Roberto Cappai ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Amyloid Precursor Protein ◽

Precursor Protein ◽

Amyloid Peptide ◽

Yeast Culture ◽

Copper Binding ◽

Copper Uptake ◽

Aβ Amyloid ◽

Intracellular Copper

The key protein in Alzheimer's disease, the amyloid precursor protein (APP), is a ubiquitously expressed copper-binding glycoprotein that gives rise to the Aβ amyloid peptide. Whereas overexpression of APP results in significantly reduced brain copper levels in three different lines of transgenic mice, knock-out animals revealed increased copper levels. A provoked rise in peripheral levels of copper reduced concentrations of soluble amyloid peptides and resulted in fewer pathogenic Aβ plaques. Contradictory evidence has been provided by the efficacy of copper chelation treatment with the drug clioquinol. Using a yeast model system, we show that adding clioquinol to the yeast culture medium drastically increased the intracellular copper concentration but there was no significant effect observed on zinc levels. This finding suggests that clioquinol can act therapeutically by changing the distribution of copper or facilitating copper uptake rather than by decreasing copper levels. The overexpression of the human APP or APLP2 extracellular domains but not the extracellular domain of APLP1 decreased intracellular copper levels. The expression of a mutant APP deficient for copper binding increased intracellular copper levels several-fold. These data uncover a novel biological function for APP and APLP2 in copper efflux and provide a new conceptual framework for the formerly diverging theories of copper supplementation and chelation in the treatment of Alzheimer's disease.

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Alzheimer’s Disease: Physiological and Pathogenetic Role of the Amyloid Precursor Protein (APP), its Aβ-Amyloid Domain and Free Aβ-Amyloid Peptide

Neurodegenerative Disorders: Loss of Function Through Gain of Function - Research and Perspectives in Alzheimer’s Disease ◽

10.1007/978-3-662-04399-8_7 ◽

2001 ◽

pp. 97-117 ◽

Cited By ~ 3

Author(s):

K. Beyreuther ◽

C. L. Masters

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Amyloid Precursor Protein ◽

Precursor Protein ◽

Amyloid Peptide ◽

Pathogenetic Role ◽

Aβ Amyloid

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Memapsin 2, a drug target for Alzheimer's disease

Biochemical Society Symposium ◽

10.1042/bss0700213 ◽

2003 ◽

Vol 70 ◽

pp. 213-220 ◽

Cited By ~ 1

Author(s):

Gerald Koelsch ◽

Robert T. Turner ◽

Lin Hong ◽

Arun K. Ghosh ◽

Jordan Tang

Keyword(s):

Crystal Structure ◽

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Transition State ◽

Amyloid Precursor Protein ◽

Therapeutic Target ◽

Drug Target ◽

Aspartic Protease ◽

Precursor Protein ◽

Memapsin 2

Mempasin 2, a ϐ-secretase, is the membrane-anchored aspartic protease that initiates the cleavage of amyloid precursor protein leading to the production of ϐ-amyloid and the onset of Alzheimer's disease. Thus memapsin 2 is a major therapeutic target for the development of inhibitor drugs for the disease. Many biochemical tools, such as the specificity and crystal structure, have been established and have led to the design of potent and relatively small transition-state inhibitors. Although developing a clinically viable mempasin 2 inhibitor remains challenging, progress to date renders hope that memapsin 2 inhibitors may ultimately be useful for therapeutic reduction of ϐ-amyloid.

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Faculty Opinions recommendation of Sorting of the Alzheimer's disease amyloid precursor protein mediated by the AP-4 complex.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.2620989.2751058 ◽

2010 ◽

Author(s):

Gilbert Di Paolo ◽

Akhil Bhalla

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Amyloid Precursor Protein ◽

Precursor Protein

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Exploring the Role of Aggregated Proteomes in the Pathogenesis of Alzheimer’s Disease

Current Protein and Peptide Science ◽

10.2174/1389203721666200921152246 ◽

2020 ◽

Vol 21 (12) ◽

pp. 1164-1173

Author(s):

Siju Ellickal Narayanan ◽

Nikhila Sekhar ◽

Rajalakshmi Ganesan Rajamma ◽

Akash Marathakam ◽

Abdullah Al Mamun ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Amyloid Precursor Protein ◽

Early Onset ◽

Late Onset ◽

Precursor Protein ◽

Brain Disorder ◽

Amyloid Aβ ◽

T Tau

: Alzheimer’s disease (AD) is a progressive brain disorder and one of the most common causes of dementia and death. AD can be of two types; early-onset and late-onset, where late-onset AD occurs sporadically while early-onset AD results from a mutation in any of the three genes that include amyloid precursor protein (APP), presenilin 1 (PSEN 1) and presenilin 2 (PSEN 2). Biologically, AD is defined by the presence of the distinct neuropathological profile that consists of the extracellular β-amyloid (Aβ) deposition in the form of diffuse neuritic plaques, intraneuronal neurofibrillary tangles (NFTs) and neuropil threads; in dystrophic neuritis, consisting of aggregated hyperphosphorylated tau protein. Elevated levels of (Aβ), total tau (t-tau) and phosphorylated tau (ptau) in cerebrospinal fluid (CSF) have become an important biomarker for the identification of this neurodegenerative disease. The aggregation of Aβ peptide derived from amyloid precursor protein initiates a series of events that involve inflammation, tau hyperphosphorylation and its deposition, in addition to synaptic dysfunction and neurodegeneration, ultimately resulting in dementia. The current review focuses on the role of proteomes in the pathogenesis of AD.

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A clinical dose of angiotensin-converting enzyme (ACE) inhibitor and heterozygous ACE deletion exacerbate Alzheimer's disease pathology in mice

Journal of Biological Chemistry ◽

10.1074/jbc.ra118.006420 ◽

2019 ◽

Vol 294 (25) ◽

pp. 9760-9770 ◽

Cited By ~ 5

Author(s):

Shuyu Liu ◽

Fujiko Ando ◽

Yu Fujita ◽

Junjun Liu ◽

Tomoji Maeda ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Angiotensin Converting Enzyme ◽

Amyloid Precursor Protein ◽

Ace Inhibitors ◽

Ace Inhibitor ◽

Precursor Protein ◽

Causative Role ◽

Converting Enzyme ◽

Clinical Dose

Inhibition of angiotensin-converting enzyme (ACE) is a strategy used worldwide for managing hypertension. In addition to converting angiotensin I to angiotensin II, ACE also converts neurotoxic β-amyloid protein 42 (Aβ42) to Aβ40. Because of its neurotoxicity, Aβ42 is believed to play a causative role in the development of Alzheimer's disease (AD), whereas Aβ40 has neuroprotective effects against Aβ42 aggregation and also against metal-induced oxidative damage. Whether ACE inhibition enhances Aβ42 aggregation or impairs human cognitive ability are very important issues for preventing AD onset and for optimal hypertension management. In an 8-year longitudinal study, we found here that the mean intelligence quotient of male, but not female, hypertensive patients taking ACE inhibitors declined more rapidly than that of others taking no ACE inhibitors. Moreover, the sera of all AD patients exhibited a decrease in Aβ42-to-Aβ40–converting activity compared with sera from age-matched healthy individuals. Using human amyloid precursor protein transgenic mice, we found that a clinical dose of an ACE inhibitor was sufficient to increase brain amyloid deposition. We also generated human amyloid precursor protein/ACE+/− mice and found that a decrease in ACE levels promoted Aβ42 deposition and increased the number of apoptotic neurons. These results suggest that inhibition of ACE activity is a risk factor for impaired human cognition and for triggering AD onset.

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