keyword
MENU ▼
Read by QxMD icon Read
search

Presenilin

keyword
https://www.readbyqxmd.com/read/28193235/dynamic-presenilin-1-and-synaptotagmin-1-interaction-modulates-exocytosis-and-amyloid-%C3%AE-production
#1
Katarzyna Marta Zoltowska, Masato Maesako, Iryna Lushnikova, Shuko Takeda, Laura J Keller, Galina Skibo, Bradley T Hyman, Oksana Berezovska
BACKGROUND: Alzheimer's disease (AD)-linked protein, presenilin 1 (PS1), is present at the synapse, and the knock-out of presenilin in mice leads to synaptic dysfunction. On the other hand, synaptic activity was shown to influence PS1-dependent generation of distinct amyloid β (Aβ) species. However, the precise nature of these regulations remains unclear. The current study reveals novel role of PS1 at the synapse, and deciphers how PS1 and synaptic vesicle-associated protein, synaptotagmin 1 (Syt1) modulate each other functions in neurons via direct activity-triggered interaction...
February 13, 2017: Molecular Neurodegeneration
https://www.readbyqxmd.com/read/28181072/interactions-of-mitochondria-metabolism-and-calcium-regulation-in-alzheimer-s-disease-a-calcinist-point-of-view
#2
Gary E Gibson, Ankita Thakkar
Decades of research suggest that alterations in calcium are central to the pathophysiology of Alzheimer's Disease (AD). Highly reproducible changes in calcium dynamics occur in cells from patients with both genetic and non-genetic forms of AD relative to controls. The most robust change is an exaggerated release of calcium from internal stores. Detailed analysis of these changes in animal and cell models of the AD-causing presenilin mutations reveal robust changes in ryanodine receptors, inositol tris-phosphate receptors, calcium leak channels and store activated calcium entry...
February 8, 2017: Neurochemical Research
https://www.readbyqxmd.com/read/28165225/initial-substrate-binding-of-%C3%AE-secretase-the-role-of-substrate-flexibility
#3
Shu Li, Wan Zhang, Wei Han
γ-Secretase cleaves transmembrane domains (TMD) of amyloid precursor protein (APP), producing pathologically relevant amyloid-β proteins. Initial substrate binding represents a key step of the γ-secretase cleavage whose mechanism remains elusive. Through long timescale coarse-grained and atomic simulations, we have found that the APP TMD can bind to the catalytic subunit presenilin 1 (PS1) on an extended surface covering PS1's TMD2/6/9 and PAL motif that are all known to be essential for enzymatic activity...
February 6, 2017: ACS Chemical Neuroscience
https://www.readbyqxmd.com/read/28152299/development-of-a-reporter-system-for-in-vivo-monitoring-of-%C3%AE-secretase-activity-in-drosophila
#4
Young Gi Hong, Seyun Roh, Donggi Paik, Sangyun Jeong
The γ-secretase complex represents an evolutionarily conserved family of transmembrane aspartyl proteases that cleave numerous type-I membrane proteins, including the β-amyloid precursor protein (APP) and the receptor Notch. All known rare mutations in APP and the γ-secretase catalytic component, presenilin, which lead to increased amyloid βpeptide production, are responsible for early-onset familial Alzheimer's disease. β-amyloid protein precursor-like (APPL) is the Drosophila ortholog of human APP. Here, we created Notch- and APPL-based Drosophila reporter systems for in vivo monitoring of γ-secretase activity...
January 2017: Molecules and Cells
https://www.readbyqxmd.com/read/28132667/pathogenic-ps1-phosphorylation-at-ser367
#5
Masato Maesako, Jana Horlacher, Katarzyna M Zoltowska, Ksenia V Kastanenka, Eleanna Kara, Sarah Svirsky, Laura J Keller, Xuejing Li, Bradley T Hyman, Brian J Bacskai, Oksana Berezovska
The high levels of serine (S) and threonine (T) residues within the Presenilin 1 (PS1) N-terminus and in the large hydrophilic loop region suggest that the enzymatic function of PS1/γ-secretase can be modulated by its 'phosphorylated' and 'dephosphorylated' states. However, the functional outcome of PS1 phosphorylation and its significance for Alzheimer's disease (AD) pathogenesis is poorly understood. Here, comprehensive analysis using FRET-based imaging reveals that activity-driven and Protein Kinase A-mediated PS1 phosphorylation at three domains (domain 1: T74, domain 2: S310 and S313, domain 3: S365, S366, and S367), with S367 being critical, is responsible for the PS1 pathogenic 'closed' conformation, and resulting increase in the Aβ42/40 ratio...
January 30, 2017: ELife
https://www.readbyqxmd.com/read/28131463/very-early-onset-sporadic-alzheimer-s-disease-with-a-de-novo-mutation-in-the-psen1-gene
#6
Fan Lou, Xiaoguang Luo, Ming Li, Yan Ren, Zhiyi He
We report a 22-year onset age man diagnosed with rapidly progressing early-onset Alzheimer's disease with predominant extrapyramidal symptoms as the initial presenting symptoms and V391G mutation in presenilin 1 gene (PSEN1) was founded. The unaffected parents of the proband are not carriers of the mutation but have histories of extrapyramidal diseases, suggesting de novo origin of V391G mutation. The Val391Gly variation widens the number of PSEN1 mutations responsible for early-onset Alzheimer's disease with extrapyramidal phenotype and would help to establish a functional map of presenilin 1 protein architecture...
January 6, 2017: Neurobiology of Aging
https://www.readbyqxmd.com/read/28120269/presenilin-2-deficiency-facilitates-a%C3%AE-induced-neuroinflammation-and-injury-by-upregulating-p2x7-expression
#7
Juliang Qin, Xiaoyu Zhang, Ziqiang Wang, Jinju Li, Zhen Zhang, Liangcai Gao, Hua Ren, Min Qian, Bing Du
Accumulating evidence suggests that β-amyloid (Aβ)-induced neuroinflammation plays a prominent and early role in Alzheimer's disease (AD). In this study, we demonstrated that Presenilin 2 (PS2) deficiency facilitates Aβ-induced neuroinflammation and injury by upregulating P2X7 expression both in vitro and in vivo. PS2 knockout mice demonstrated increased cognitive impairments and cerebral injury. PS2 deficiency increased the expression of P2X7 both in neurons and microglial cells. Furthermore, extracellular ATP also increased in both Aβ-treated and untreated PS2 knockout microglial cells...
January 23, 2017: Science China. Life Sciences
https://www.readbyqxmd.com/read/28120208/huannao-yicong-formula-regulates-%C3%AE-secretase-activity-through-aph-1-and-pen-2-gene-ragulation-pathways-in-hippocampus-of-app-ps1-double-transgenic-mice
#8
Zhi-Yong Wang, Jian-Gang Liu, Yun Wei, Mei-Xia Liu, Qi Wang, Lin Liang, Hui-Min Yang, Hao Li
OBJECTIVE: To observe the effects of Huannao Yicong Formula (, HYF) on learning and memory and it's regulating effect on γ-secretase related anterior pharynx defective 1 (APH-1), presenilin enhancer-2 (PEN-2) signaling pathway, so as to discuss and further clarify the mechanism of HYF on Alzheimer's disease. METHODS: Sixty APP/PS1 transgenic mice, randomly allocated into 4 groups, the model group, the donepezil group (0.65 mg/kg), HYF low-dose group (HYF-L, 5.46 g/kg) and HYF high-dose group (HYF-H, 10...
January 24, 2017: Chinese Journal of Integrative Medicine
https://www.readbyqxmd.com/read/28096459/zinc-and-copper-differentially-modulate-amyloid-precursor-protein-processing-by-%C3%AE-secretase-and-amyloid-%C3%AE-peptide-production
#9
Hermeto Gerber, Fang Wu, Mitko Dimitrov, Guillermo M Garcia Osuna, Patrick C Fraering
Recent evidence suggests involvement of biometal homeostasis in the pathological mechanisms in Alzheimer's disease (AD). For example, increased intracellular copper or zinc has been linked to a reduction in secreted levels of the AD-causing amyloid-β peptide (Aβ). However, little is known about whether these biometals modulate the generation of Aβ. In the present study, we demonstrate in both cell-free and cell-based assays that zinc and copper regulate Aβ production by distinct molecular mechanisms affecting the processing by γ-secretase of its Aβ precursor protein substrate APP-C99...
January 17, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28068334/two-paralogous-tetraspanins-tsp-12-and-tsp-14-function-with-the-adam10-metalloprotease-sup-17-to-promote-bmp-signaling-in-caenorhabditis-elegans
#10
Lin Wang, Zhiyu Liu, Herong Shi, Jun Liu
The highly conserved bone morphogenetic protein (BMP) signaling pathway regulates many developmental and homeostatic processes. While the core components of the BMP pathway have been well studied, much research is needed for understanding the mechanisms involved in the precise spatiotemporal control of BMP signaling in vivo. Here, we provide evidence that two paralogous and evolutionarily conserved tetraspanins, TSP-12 and TSP-14, function redundantly to promote BMP signaling in C. elegans. We further show that the ADAM10 (a disintegrin and metalloprotease 10) ortholog SUP-17 also functions to promote BMP signaling, and that TSP-12 can bind to and promote the cell surface localization of SUP-17...
January 2017: PLoS Genetics
https://www.readbyqxmd.com/read/28065657/mapping-the-binding-site-of-bms-708163-on-%C3%AE-secretase-with-cleavable-photoprobes
#11
Natalya Gertsik, Christopher W Am Ende, Kieran F Geoghegan, Chuong Nguyen, Paramita Mukherjee, Scot Mente, Uthpala Seneviratne, Douglas S Johnson, Yue-Ming Li
γ-Secretase, a four-subunit transmembrane aspartic proteinase, is a highly valued drug target in Alzheimer's disease and cancer. Despite significant progress in structural studies, the respective molecular mechanisms and binding modes of γ-secretase inhibitors (GSIs) and modulators (GSMs) remain uncertain. Here, we developed biotinylated cleavable-linker photoprobes based on the BMS-708163 GSI to study its interaction with γ-secretase. Comparison of four cleavable linkers indicated that the hydrazine-labile N-1-(4,4-dimethyl-2,6-dioxocyclohexylidene)ethyl (Dde) linker was cleaved most efficiently to release photolabeled and affinity-captured presenilin-1 (PS1), the catalytic subunit of γ-secretase...
January 19, 2017: Cell Chemical Biology
https://www.readbyqxmd.com/read/28065273/screening-and-characterization-strategies-for-nanobodies-targeting-membrane-proteins
#12
S Veugelen, M Dewilde, B De Strooper, L Chávez-Gutiérrez
The study of membrane protein function and structure requires their successful detection, expression, solubilization, and/or reconstitution, which poses a challenging task and relies on the availability of suitable tools. Several research groups have successfully applied Nanobodies in the purification, as well as the functional and structural characterization of membrane proteins. Nanobodies are small, single-chain antibody fragments originating from camelids presenting on average a longer CDR3 which enables them to bind in cavities and clefts (such as active and allosteric sites)...
2017: Methods in Enzymology
https://www.readbyqxmd.com/read/28065263/probing-the-structure-and-function-relationships-of-presenilin-by-substituted-cysteine-accessibility-method
#13
T Tomita
Presenilin is a catalytic subunit of γ-secretase, which hydrolyzes several transmembrane proteins within the lipid bilayer, together with binding cofactors such as nicastrin, Aph-1, and Pen-2. However, the structural basis as well as molecular mechanism of this unusual proteolytic process remains unknown. We have analyzed the structure and function relationships of presenilin using the substituted-cysteine accessibility method (SCAM), which enables identification of the hydrophilic environment by the accessibility of sulfhydryl reagents to cysteine residues introduced at a desired position...
2017: Methods in Enzymology
https://www.readbyqxmd.com/read/28065261/expression-purification-and-enzymatic-characterization-of-intramembrane-proteases
#14
R Zhou, Y Shi, G Yang
Intramembrane proteases catalyze peptide bond hydrolysis in the lipid bilayer and play a key role in numerous cellular processes. These integral membrane enzymes consist of four classes: site-2 protease (S2P), rhomboid serine protease, Rce1-type glutamyl protease, and aspartyl protease exemplified by presenilin and signal peptide peptidase (SPP). Structural elucidation of these enzymes is important for mechanistic understanding of their functions, particularly their roles in cell signaling and debilitating diseases such as Parkinson's disease and Alzheimer's disease...
2017: Methods in Enzymology
https://www.readbyqxmd.com/read/28061464/met-receptor-variant-r970c-favors-calpain-dependent-generation-of-a-fragment-promoting-epithelial-cell-scattering
#15
Rémi Montagne, Anne Baranzelli, Ghaffar Muharram, Leroy Catherine, Marie Lesaffre, Audrey Vinchent, Zoulika Kherrouche, Elisabeth Werkmeister, Alexis B Cortot, David Tulasne
The receptor tyrosine kinase MET and its ligand, the hepatocyte growth factor, are essential to embryonic development, whereas deregulation of MET signaling is associated with tumorigenesis leading to various cancers, including lung carcinoma. Mutations in the MET kinase domain lead to constitutive kinase activity and are associated with tumorigenesis. In lung cancer, however, some mutations are found in the juxtamembrane domain, and their functional consequences are unknown. Because the juxtamembrane domain of MET is targeted by several proteolytic cleavages, involved in its degradation during cell death or under steady-state conditions, we evaluated the influence of these mutations on the MET proteolytic cleavages...
January 4, 2017: Oncotarget
https://www.readbyqxmd.com/read/28053619/overexpression-of-n141i-ps2-increases-%C3%AE-secretase-activity-through-up-regulation-of-presenilin-and-pen-2-in-brain-mitochondria-of-nse-hps2m-transgenic-mice
#16
Woo Bin Yun, Jin Ju Park, Ji Eun Kim, Ji Eun Sung, Hyun Ah Lee, Jae Ho Lee, Chang Jun Bae, Dae Youn Hwang
Alzheimer's disease (AD) is known to induce alterations of mitochondrial function such as elevation of oxidative stress and activation of apopotosis. The aim of this study was to investigate the effects of human Presenilin 2 mutant (hPS2m) overexpression on the γ-secretase complex in the mitochondrial fraction. To achieve this, alterations of γ-secretase complex expression and activity were detected in the mitochondrial fraction derived from brains of NSE/hPS2m Tg mice and Non-Tg mice. Herein, the following were observed: i) overexpression of the hPS2m gene significantly up-regulated the deposition of Aβ-42 peptides in the hippocampus and cortex of brain, ii) overexpression of hPS2m protein induced alterations of γ-secretase components such as main component protein and activator protein but not stabilization-related proteins, iii) changes in γ-secretase components induced by overexpression of hPS2m protein up-regulated γ-secretase activity in the mitochondrial fraction, and iv) elevation of γ-secretase activity induced production of Aβ-42 peptides in the mitochondrial fraction...
December 2016: Laboratory Animal Research
https://www.readbyqxmd.com/read/28034848/regulated-intramembrane-proteolysis-of-the-axl-receptor-kinase-generates-an-intracellular-domain-that-localizes-in-the-nucleus-of-cancer-cells
#17
Yinzhong Lu, Jun Wan, Zhifeng Yang, Xiling Lei, Qi Niu, Lanxin Jiang, Willemijn M Passtoors, Aiping Zang, Patrick C Fraering, Fang Wu
Deregulation of the TAM (TYRO3, AXL, and MERTK) family of receptor tyrosine kinases (RTKs) has recently been demonstrated to predominately promote survival and chemoresistance of cancer cells. Intramembrane proteolysis mediated by presenilin/γ-secretase is known to regulate the homeostasis of some RTKs. In the present study, we demonstrate that AXL, but not TYRO3 or MERTK, is efficiently and sequentially cleaved by α- and γ-secretases in various types of cancer cell lines. Proteolytic processing of AXL redirected signaling toward a secretase-mediated pathway, away from the classic, well-known, ligand-dependent canonical RTK signaling pathway...
December 29, 2016: FASEB Journal: Official Publication of the Federation of American Societies for Experimental Biology
https://www.readbyqxmd.com/read/28025335/caspneurod-a-knowledgebase-of-predicted-caspase-cleavage-sites-in-human-proteins-related-to-neurodegenerative-diseases
#18
Sonu Kumar, Piotr Cieplak
BACKGROUND: A variety of neurodegenerative diseases (NDs) have been associated with deregulated caspase activation that leads to neuronal death. Caspases appear to be involved in the molecular pathology of NDs by directly cleaving important proteins. For instance, several proteins involved in Alzheimer's disease, including β-amyloid precursor protein (APP) and presenilins, are known to be cleaved by caspases. Therefore, cell death pathway may play a central role in many neurological diseases, and targeting the important proteins that control the cell survival and death may potentially represent a therapeutic approach for chronic neurodegenerative disorders...
2016: Database: the Journal of Biological Databases and Curation
https://www.readbyqxmd.com/read/27987381/hypoxia-ischemia-activate-processing-of-amyloid-precursor-protein-impact-of-vascular-dysfunction-in-the-pathogenesis-of-alzheimer-s-disease
#19
REVIEW
Antero Salminen, Anu Kauppinen, Kai Kaarniranta
Alzheimer's disease (AD) is associated with deficiencies in cerebrovascular functions, e.g. reduced cerebral blood flow and capillary amyloid angiopathy, both of which are evident during the early phase of AD, thus local hypoxia/ischemia could augment the pathogenesis of AD. There is abundant literature revealing that exposures to hypoxia/ischemia increase the amyloidogenic processing of amyloid-β precursor protein (APP) leading to the accumulation of amyloid-β peptides in brain. This hypoxia-induced response has been attributed to a significant increase in the activities of β- and γ-secretases, whereas α-secretase activity decreases in hypoxia...
December 17, 2016: Journal of Neurochemistry
https://www.readbyqxmd.com/read/27932977/human-neural-stem-cell-transplantation-rescues-cognitive-defects-in-app-ps1-model-of-alzheimer-s-disease-by-enhancing-neuronal-connectivity-and-metabolic-activity
#20
Xueyuan Li, Hua Zhu, Xicai Sun, Fuxing Zuo, Jianfeng Lei, Zhanjing Wang, Xinjie Bao, Renzhi Wang
Alzheimer's disease (AD), the most frequent type of dementia, is featured by Aβ pathology, neural degeneration and cognitive decline. To date, there is no cure for this disease. Neural stem cell (NSC) transplantation provides new promise for treating AD. Many studies report that intra-hippocampal transplantation of murine NSCs improved cognition in rodents with AD by alleviating neurodegeneration via neuronal complement or replacement. However, few reports examined the potential of human NSC transplantation for AD...
2016: Frontiers in Aging Neuroscience
keyword
keyword
14322
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"