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Odorčić I, Hamed MB, Lismont S, Chávez-Gutiérrez L, Efremov RG. Apo and Aβ46-bound γ-secretase structures provide insights into amyloid-β processing by the APH-1B isoform. Nat Commun 2024; 15:4479. [PMID: 38802343 PMCID: PMC11130327 DOI: 10.1038/s41467-024-48776-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 05/07/2024] [Indexed: 05/29/2024] Open
Abstract
Deposition of amyloid-β (Aβ) peptides in the brain is a hallmark of Alzheimer's disease. Aβs are generated through sequential proteolysis of the amyloid precursor protein by the γ-secretase complexes (GSECs). Aβ peptide length, modulated by the Presenilin (PSEN) and APH-1 subunits of GSEC, is critical for Alzheimer's pathogenesis. Despite high relevance, mechanistic understanding of the proteolysis of Aβ, and its modulation by APH-1, remain incomplete. Here, we report cryo-EM structures of human GSEC (PSEN1/APH-1B) reconstituted into lipid nanodiscs in apo form and in complex with the intermediate Aβ46 substrate without cross-linking. We find that three non-conserved and structurally divergent APH-1 regions establish contacts with PSEN1, and that substrate-binding induces concerted rearrangements in one of the identified PSEN1/APH-1 interfaces, providing structural basis for APH-1 allosteric-like effects. In addition, the GSEC-Aβ46 structure reveals an interaction between Aβ46 and loop 1PSEN1, and identifies three other H-bonding interactions that, according to functional validation, are required for substrate recognition and efficient sequential catalysis.
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Affiliation(s)
- Ivica Odorčić
- Center for Structural Biology, VIB, Brussels, Belgium
- Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
- VIB-KU Leuven Center for Brain & Disease Research, Herestraat 49 box 602, 3000, Leuven, Belgium
- Department of Neurosciences, Leuven Brain Institute, KU Leuven, Herestraat 49 box 602, 3000, Leuven, Belgium
| | - Mohamed Belal Hamed
- VIB-KU Leuven Center for Brain & Disease Research, Herestraat 49 box 602, 3000, Leuven, Belgium
- Department of Neurosciences, Leuven Brain Institute, KU Leuven, Herestraat 49 box 602, 3000, Leuven, Belgium
| | - Sam Lismont
- VIB-KU Leuven Center for Brain & Disease Research, Herestraat 49 box 602, 3000, Leuven, Belgium
- Department of Neurosciences, Leuven Brain Institute, KU Leuven, Herestraat 49 box 602, 3000, Leuven, Belgium
| | - Lucía Chávez-Gutiérrez
- VIB-KU Leuven Center for Brain & Disease Research, Herestraat 49 box 602, 3000, Leuven, Belgium.
- Department of Neurosciences, Leuven Brain Institute, KU Leuven, Herestraat 49 box 602, 3000, Leuven, Belgium.
| | - Rouslan G Efremov
- Center for Structural Biology, VIB, Brussels, Belgium.
- Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium.
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O’Day DH. Alzheimer's Disease beyond Calcium Dysregulation: The Complex Interplay between Calmodulin, Calmodulin-Binding Proteins and Amyloid Beta from Disease Onset through Progression. Curr Issues Mol Biol 2023; 45:6246-6261. [PMID: 37623212 PMCID: PMC10453589 DOI: 10.3390/cimb45080393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 07/12/2023] [Accepted: 07/25/2023] [Indexed: 08/26/2023] Open
Abstract
A multifactorial syndrome, Alzheimer's disease is the main cause of dementia, but there is no existing therapy to prevent it or stop its progression. One of the earliest events of Alzheimer's disease is the disruption of calcium homeostasis but that is just a prelude to the disease's devastating impact. Calcium does not work alone but must interact with downstream cellular components of which the small regulatory protein calmodulin is central, if not primary. This review supports the idea that, due to calcium dyshomeostasis, calmodulin is a dominant regulatory protein that functions in all stages of Alzheimer's disease, and these regulatory events are impacted by amyloid beta. Amyloid beta not only binds to and regulates calmodulin but also multiple calmodulin-binding proteins involved in Alzheimer's. Together, they act on the regulation of calcium dyshomeostasis, neuroinflammation, amyloidogenesis, memory formation, neuronal plasticity and more. The complex interactions between calmodulin, its binding proteins and amyloid beta may explain why many therapies have failed or are doomed to failure unless they are considered.
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Affiliation(s)
- Danton H. O’Day
- Department of Biology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada;
- Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
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3
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O’Day DH. Calmodulin and Amyloid Beta as Coregulators of Critical Events during the Onset and Progression of Alzheimer's Disease. Int J Mol Sci 2023; 24:ijms24021393. [PMID: 36674908 PMCID: PMC9863087 DOI: 10.3390/ijms24021393] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 01/03/2023] [Accepted: 01/05/2023] [Indexed: 01/12/2023] Open
Abstract
Calmodulin (CaM) and a diversity of CaM-binding proteins (CaMBPs) are involved in the onset and progression of Alzheimer's disease (AD). In the amyloidogenic pathway, AβPP1, BACE1 and PSEN-1 are all calcium-dependent CaMBPs as are the risk factor proteins BIN1 and TREM2. Ca2+/CaM-dependent protein kinase II (CaMKII) and calcineurin (CaN) are classic CaMBPs involved in memory and plasticity, two events impacted by AD. Coupled with these events is the production of amyloid beta monomers (Aβ) and oligomers (Aβo). The recent revelations that Aβ and Aβo each bind to both CaM and to a host of Aβ receptors that are also CaMBPs adds a new level of complexity to our understanding of the onset and progression of AD. Multiple Aβ receptors that are proven CaMBPs (e.g., NMDAR, PMCA) are involved in calcium homeostasis an early event in AD and other neurodegenerative diseases. Other CaMBPs that are Aβ receptors are AD risk factors while still others are involved in the amyloidogenic pathway. Aβ binding to receptors not only serves to control CaM's ability to regulate critical proteins, but it is also implicated in Aβ turnover. The complexity of the Aβ/CaM/CaMBP interactions is analyzed using two events: Aβ generation and NMDAR function. The interactions between Aβ, CaM and CaMBPs reveals a new level of complexity to critical events associated with the onset and progression of AD and may help to explain the failure to develop successful therapeutic treatments for the disease.
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Affiliation(s)
- Danton H. O’Day
- Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada;
- Department of Biology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
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Cai T, Tomita T. Sequential conformational changes in transmembrane domains of presenilin 1 in Aβ42 downregulation. J Biochem 2021; 170:215-227. [PMID: 33739423 DOI: 10.1093/jb/mvab033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 03/18/2021] [Indexed: 01/01/2023] Open
Abstract
Alzheimer disease (AD) is the most common neurodegenerative disease worldwide. AD is pathologically characterized by the deposition of senile plaques in the brain, which are composed of an amyloid-β peptide (Aβ) that is produced through the multistep cleavage of amyloid precursor protein (APP) by γ-secretase. γ-Secretase is a membrane protein complex, which includes its catalytic subunit presenilin 1 (PS1). However, much about the structural dynamics of this enzyme remain unclear. We have previously demonstrated that movements of the transmembrane domain (TMD) 1 and TMD3 of PS1 are strongly associated with decreased production of the Aβ peptide ending at the 42nd residue (i.e., Aβ42), which is the aggregation-prone, toxic species. However, the association between these movements as well as the sequence of these TMDs remains unclear. In this study, we raised the possibility that the vertical movement of TMD1 is a prerequisite for expansion of the catalytic cavity around TMD3 of PS1, resulting in reduced Aβ42 production. Our results shed light on the association between the conformational changes of TMDs and the regulation of γ-secretase activity.
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Affiliation(s)
- Tetsuo Cai
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Taisuke Tomita
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
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A computer-simulated mechanism of familial Alzheimer’s disease: Mutations enhance thermal dynamics and favor looser substrate-binding to γ-secretase. J Struct Biol 2020; 212:107648. [DOI: 10.1016/j.jsb.2020.107648] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 09/22/2020] [Accepted: 10/09/2020] [Indexed: 11/22/2022]
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Chávez-Gutiérrez L, Szaruga M. Mechanisms of neurodegeneration - Insights from familial Alzheimer's disease. Semin Cell Dev Biol 2020; 105:75-85. [PMID: 32418657 DOI: 10.1016/j.semcdb.2020.03.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 03/13/2020] [Accepted: 03/16/2020] [Indexed: 12/18/2022]
Abstract
The rising prevalence of Alzheimer's disease (AD), together with the lack of effective treatments, portray it as one of the major health challenges of our times. Untangling AD implies advancing the knowledge of the biology that gets disrupted during the disease while deciphering the molecular and cellular mechanisms leading to AD-related neurodegeneration. In fact, a solid mechanistic understanding of the disease processes stands as an essential prerequisite for the development of safe and effective treatments. Genetics has provided invaluable clues to the genesis of the disease by revealing deterministic genes - Presenilins (PSENs) and the Amyloid Precursor Protein (APP) - that, when affected, lead in an autosomal dominant manner to early-onset, familial AD (FAD). PSEN is the catalytic subunit of the membrane-embedded γ-secretase complexes, which act as proteolytic switches regulating key cell signalling cascades. Importantly, these intramembrane proteases are responsible for the production of Amyloid β (Aβ) peptides from APP. The convergence of pathogenic mutations on one functional pathway, the amyloidogenic cleavage of APP, strongly supports the significance of this process in AD pathogenesis. Here, we review and discuss the state-of-the-art knowledge of the molecular mechanisms underlying FAD, their implications for the sporadic form of the disease and for the development of safe AD therapeutics.
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Affiliation(s)
- Lucía Chávez-Gutiérrez
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium; Department of Neurosciences, Leuven Research Institute for Neuroscience and Disease (LIND), KU Leuven, Leuven, Belgium.
| | - Maria Szaruga
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium; Department of Neurosciences, Leuven Research Institute for Neuroscience and Disease (LIND), KU Leuven, Leuven, Belgium
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7
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Cai T, Tomita T. Structure-activity relationship of presenilin in γ-secretase-mediated intramembrane cleavage. Semin Cell Dev Biol 2020; 105:102-109. [PMID: 32171519 DOI: 10.1016/j.semcdb.2020.02.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 02/18/2020] [Accepted: 02/19/2020] [Indexed: 01/12/2023]
Abstract
Genetic research on familial cases of Alzheimer disease have identified presenilin (PS) as an important membrane protein in the pathomechanism of this disease. PS is the catalytic subunit of γ-secretase, which is responsible for the generation of amyloid-β peptide deposited in the brains of Alzheimer disease patients. γ-Secretase is an atypical protease composed of four membrane proteins (i.e., presenilin, nicastrin, anterior pharynx defective-1 (Aph-1), and presenilin enhancer-2 (Pen-2)) and mediates intramembrane proteolysis. Numerous investigations have been conducted toward understanding the structural features of γ-secretase components as well as the cleavage mechanism of γ-secretase. In this review, we summarize our current understanding of the structure and activity relationship of the γ-secretase complex.
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Affiliation(s)
- Tetsuo Cai
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Taisuke Tomita
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 113-0033, Japan.
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Cai T, Hatano A, Kanatsu K, Tomita T. Histidine 131 in presenilin 1 is the pH-sensitive residue that causes the increase in Aβ42 level in acidic pH. J Biochem 2019; 167:463-471. [DOI: 10.1093/jb/mvz110] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Accepted: 11/30/2019] [Indexed: 12/22/2022] Open
Abstract
AbstractAlzheimer disease (AD) is the most common neurodegenerative disease worldwide. The pathological hallmark of AD is the presence of senile plaques in the brain, which are accumulations of amyloid-β peptide (Aβ) ending at the 42nd residue (i.e. Aβ42), which is produced through multistep cleavage by γ-secretase. Thus, methods to regulate γ-secretase activity to attenuate the production of Aβ42 are in urgent demand towards the development of treatments for AD. We and others have demonstrated that γ-secretase activity is affected by its localization and ambient environment. In particular, an increase in Aβ42 production is correlated with the intracellular transport of γ-secretase and endosomal maturation-dependent luminal acidification. In this study, we focused on the mechanism by which γ-secretase affects Aβ42 production together with alterations in pH. Histidine is known to function as a pH sensor in many proteins, to regulate their activities through the protonation state of the imidazole side chain. Among the histidines facing the luminal side of presenilin (PS) 1, which is the catalytic subunit of γ-secretase, point mutations at H131 had no effect on the Aβ42 production ratio in an acidic environment. We also observed an increase in Aβ42 ratio when histidine was introduced into N137 of PS2, which is the corresponding residue of H131 in PS1. These results indicated that H131 serves as the pH sensor in PS1, which contains γ-secretase, to regulate Aβ42 production depending on the luminal pH. Our findings provide new insights into therapeutic strategies for AD targeting endosomes or the intracellular transport of γ-secretase.
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Affiliation(s)
- Tetsuo Cai
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Aki Hatano
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Kunihiko Kanatsu
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Taisuke Tomita
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
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9
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Activation of γ-Secretase Trimming Activity by Topological Changes of Transmembrane Domain 1 of Presenilin 1. J Neurosci 2017; 37:12272-12280. [PMID: 29118109 DOI: 10.1523/jneurosci.1628-17.2017] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Revised: 10/10/2017] [Accepted: 11/03/2017] [Indexed: 11/21/2022] Open
Abstract
γ-Secretase is an intramembrane cleaving protease that is responsible for the generation of amyloid-β peptides, which are linked to the pathogenesis of Alzheimer disease. Recently, γ-secretase modulators (GSMs) have been shown to specifically decrease production of the aggregation-prone and toxic longer Aβ species, and concomitantly increase the levels of shorter Aβ. We previously found that phenylimidazole-type GSMs bind to presenilin 1 (PS1), the catalytic subunit of the γ-secretase, and allosterically modulate γ-secretase activity. However, the precise conformational alterations in PS1 remained unclear. Here we mapped the amino acid residues in PS1 that is crucial for the binding and pharmacological actions of E2012, a phenylimidazole-type GSM, using photoaffinity labeling and the substituted cysteine accessibility method. We also demonstrated that a piston-like vertical motion of transmembrane domain (TMD) 1 occurs during modulation of Aβ production. Taking these results together, we propose a model for the molecular mechanism of phenylimidazole-type GSMs, in which the trimming activity of γ-secretase is modulated by the position of the TMD1 of PS1 in the lipid bilayer.SIGNIFICANCE STATEMENT Reduction of the toxic longer amyloid-β peptide is one of the therapeutic approaches for Alzheimer disease. A subset of small compounds called γ-secretase modulators specifically decreases the longer amyloid-β production, although its mechanistic action remains unclear. Here we found that the modulator compound E2012 targets to the hydrophilic loop 1 of presenilin 1, which is a catalytic subunit of the γ-secretase. Moreover, E2012 triggers the piston movement of the transmembrane domain 1 of presenilin 1, which impacts on the γ-secretase activity. These results illuminate how γ-secretase modulators allosterically affect the proteolytic activity, and highlight the importance of the structural dynamics of presenilin 1 in the complexed process of the intramembrane cleavage.
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Alzheimer’s-Causing Mutations Shift Aβ Length by Destabilizing γ-Secretase-Aβn Interactions. Cell 2017; 170:443-456.e14. [DOI: 10.1016/j.cell.2017.07.004] [Citation(s) in RCA: 146] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 04/06/2017] [Accepted: 07/06/2017] [Indexed: 11/20/2022]
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Liu CY, Ohki Y, Tomita T, Osawa S, Reed BR, Jagust W, Van Berlo V, Jin LW, Chui HC, Coppola G, Ringman JM. Two Novel Mutations in the First Transmembrane Domain of Presenilin1 Cause Young-Onset Alzheimer’s Disease. J Alzheimers Dis 2017; 58:1035-1041. [DOI: 10.3233/jad-161203] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Collin Y. Liu
- Alzheimer’s Disease Research Center, Keck School of Medicine at the University of Southern California, Los Angeles, CA, USA
| | - Yu Ohki
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Taisuke Tomita
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Satoko Osawa
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Bruce R. Reed
- Alzheimer’s Disease Research Center, UC Davis, Davis, CA, USA
- Center for Scientific Review, National Institutes of Health, Bethesda, MD, USA
| | - William Jagust
- Alzheimer’s Disease Research Center, UC Davis, Davis, CA, USA
| | | | - Lee-Way Jin
- Alzheimer’s Disease Research Center, UC Davis, Davis, CA, USA
| | - Helena C. Chui
- Alzheimer’s Disease Research Center, Keck School of Medicine at the University of Southern California, Los Angeles, CA, USA
| | - Giovanni Coppola
- Semel Institute at UCLA, Los Angeles, CA, USA
- Easton Center for Alzheimer’s Disease Research, UCLA, Los Angeles, CA, USA
| | - John M. Ringman
- Alzheimer’s Disease Research Center, Keck School of Medicine at the University of Southern California, Los Angeles, CA, USA
- Easton Center for Alzheimer’s Disease Research, UCLA, Los Angeles, CA, USA
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Gallo M, Frangipane F, Cupidi C, De Bartolo M, Turone S, Ferrari C, Nacmias B, Grimaldi G, Laganà V, Colao R, Bernardi L, Anfossi M, Conidi ME, Vasso F, Curcio SAM, Mirabelli M, Smirne N, Torchia G, Muraca MG, Puccio G, Di Lorenzo R, Piccininni M, Tedde A, Maletta RG, Sorbi S, Bruni AC. The novel PSEN1 M84V mutation associated to frontal dysexecutive syndrome, spastic paraparesis, and cerebellar atrophy in a dominant Alzheimer's disease family. Neurobiol Aging 2017; 56:213.e7-213.e12. [PMID: 28532646 DOI: 10.1016/j.neurobiolaging.2017.04.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 04/18/2017] [Accepted: 04/19/2017] [Indexed: 12/30/2022]
Abstract
We identified the novel PSEN1 pathogenic mutation M84V in 3 patients belonging to a large kindred affected by autosomal dominant Alzheimer's disease (AD). The clinical phenotype was characterized by early onset dementia in 14 affected subjects over 3 generations. Detailed clinical, imaging and genetic assessment was performed. We highlighted the presence of unusual symptoms such as frontal executive syndrome, psychosis and spastic paraparesis in these patients. Spastic paraparesis has been reported in other PSEN1 mutations in adjacent codons, suggesting that the position of the genetic defect may affect the clinical expression, although this phenotype can occur in mutations throughout the whole PSEN1 gene. Brain magnetic resonance imaging showed diffuse cortical atrophy, but also atrophy of cerebellar lobules, mainly involving Crus I, in 2 patients without cerebellar motor deficits. These neuroimaging results were consistent with recent findings about the association between sporadic AD and distinct and circumscribed cerebellar atrophy. The present work acknowledged the novel PSEN1 pathogenic mutation M84V and might contribute to the ongoing debate about the involvement of cerebellum in AD.
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Affiliation(s)
- Maura Gallo
- Regional Neurogenetic Centre (CRN), ASP Catanzaro, Lamezia Terme, Italy
| | | | - Chiara Cupidi
- Regional Neurogenetic Centre (CRN), ASP Catanzaro, Lamezia Terme, Italy
| | - Matteo De Bartolo
- Neurofisiopatologia, Distretto Ionio Sud, ASP CS, Rossano (CS), Italy
| | - Sabina Turone
- Neurofisiopatologia, Distretto Ionio Sud, ASP CS, Rossano (CS), Italy
| | - Camilla Ferrari
- IRCCS Don Gnocchi, Florence, Italy; Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Benedetta Nacmias
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Giuliana Grimaldi
- Groupe de Recherche Interdisciplinaire du Mouvement, ULB, Erasme, Brussels, Belgium
| | - Valentina Laganà
- Regional Neurogenetic Centre (CRN), ASP Catanzaro, Lamezia Terme, Italy
| | - Rosanna Colao
- Regional Neurogenetic Centre (CRN), ASP Catanzaro, Lamezia Terme, Italy
| | - Livia Bernardi
- Regional Neurogenetic Centre (CRN), ASP Catanzaro, Lamezia Terme, Italy
| | - Maria Anfossi
- Regional Neurogenetic Centre (CRN), ASP Catanzaro, Lamezia Terme, Italy
| | | | - Franca Vasso
- Regional Neurogenetic Centre (CRN), ASP Catanzaro, Lamezia Terme, Italy
| | | | - Maria Mirabelli
- Regional Neurogenetic Centre (CRN), ASP Catanzaro, Lamezia Terme, Italy
| | - Nicoletta Smirne
- Regional Neurogenetic Centre (CRN), ASP Catanzaro, Lamezia Terme, Italy
| | - Giusi Torchia
- Regional Neurogenetic Centre (CRN), ASP Catanzaro, Lamezia Terme, Italy
| | | | - Gianfranco Puccio
- Regional Neurogenetic Centre (CRN), ASP Catanzaro, Lamezia Terme, Italy
| | | | - Maristella Piccininni
- Department of Neurology, San Giovanni di Dio Hospital, USL Toscana Centro-Florence, Florence, Italy
| | - Andrea Tedde
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | | | - Sandro Sorbi
- IRCCS Don Gnocchi, Florence, Italy; Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
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13
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Probing the Structure and Function Relationships of Presenilin by Substituted-Cysteine Accessibility Method. Methods Enzymol 2017; 584:185-205. [DOI: 10.1016/bs.mie.2016.10.033] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
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Li Y, Sun H, Chen Z, Xu H, Bu G, Zheng H. Implications of GABAergic Neurotransmission in Alzheimer's Disease. Front Aging Neurosci 2016; 8:31. [PMID: 26941642 PMCID: PMC4763334 DOI: 10.3389/fnagi.2016.00031] [Citation(s) in RCA: 161] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 02/08/2016] [Indexed: 01/02/2023] Open
Abstract
Alzheimer's disease (AD) is characterized pathologically by the deposition of β-amyloid peptides (Aβ) and the accumulation of neurofibrillary tangles (NFTs) composed of hyper-phosphorylated tau. Regardless of the pathological hallmarks, synaptic dysfunction is widely accepted as a causal event in AD. Of the two major types of synapses in the central nervous system (CNS): glutamatergic and GABAergic, which provide excitatory and inhibitory outputs respectively, abundant data implicate an impaired glutamatergic system during disease progression. However, emerging evidence supports the notion that disrupted default neuronal network underlies impaired memory, and that alterations of GABAergic circuits, either plays a primary role or as a compensatory response to excitotoxicity, may also contribute to AD by disrupting the overall network function. The goal of this review is to provide an overview of the involvement of Aβ, tau and apolipoprotein E4 (apoE4), the major genetic risk factor in late-onset AD (LOAD), in GABAergic neurotransmission and the potential of modulating the GABAergic function as AD therapy.
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Affiliation(s)
- Yanfang Li
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University Xiamen, China
| | - Hao Sun
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University Xiamen, China
| | - Zhicai Chen
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University Xiamen, China
| | - Huaxi Xu
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen UniversityXiamen, China; Neurodegenerative Disease Research Program, Sanford-Burnham Medical Research InstituteLa Jolla, CA, USA
| | - Guojun Bu
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen UniversityXiamen, China; Department of Neuroscience, Mayo ClinicJacksonville, FL, USA
| | - Hui Zheng
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen UniversityXiamen, China; The Interdepartmental Program of Translational Biology and Molecular Medicine, Huffington Center on Aging, Baylor College of MedicineHouston, TX, USA
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15
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Roher AE, Maarouf CL, Kokjohn TA. Familial Presenilin Mutations and Sporadic Alzheimer’s Disease Pathology: Is the Assumption of Biochemical Equivalence Justified? J Alzheimers Dis 2016; 50:645-58. [DOI: 10.3233/jad-150757] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Alex E. Roher
- Longtine Center for Neurodegenerative Biochemistry, Banner Sun Health Research Institute, Sun City, AZ, USA
| | - Chera L. Maarouf
- Longtine Center for Neurodegenerative Biochemistry, Banner Sun Health Research Institute, Sun City, AZ, USA
| | - Tyler A. Kokjohn
- Department of Microbiology, Midwestern University School of Medicine, Glendale, AZ, USA
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Oestereich F, Bittner HJ, Weise C, Grohmann L, Janke LK, Hildebrand PW, Multhaup G, Munter LM. Impact of amyloid precursor protein hydrophilic transmembrane residues on amyloid-beta generation. Biochemistry 2015; 54:2777-84. [PMID: 25875527 DOI: 10.1021/acs.biochem.5b00217] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Amyloid-β (Aβ) peptides are likely the molecular cause of neurodegeneration observed in Alzheimer's disease. In the brain, Aβ42 and Aβ40 are toxic and the most important proteolytic fragments generated through sequential processing of the amyloid precursor protein (APP) by β- and γ-secretases. Impeding the generation of Aβ42 and Aβ40 is thus considered as a promising strategy to prevent Alzheimer's disease. We therefore wanted to determine key parameters of the APP transmembrane sequence enabling production of these Aβ species. Here we show that the hydrophilicity of amino acid residues G33, T43, and T48 critically determines the generation of Aβ42 and Aβ40 peptides (amino acid numbering according to Aβ nomenclature starting with aspartic acid 1). First, we performed a comprehensive mutational analysis of glycine residue G33 positioned within the N-terminal half of the APP transmembrane sequence by exchanging it against the 19 other amino acids. We found that hydrophilicity of the residue at position 33 positively correlated with Aβ42 and Aβ40 generation. Second, we analyzed two threonine residues at positions T43 and T48 in the C-terminal half of the APP-transmembrane sequence. Replacement of single threonine residues by hydrophobic valines inversely affected Aβ42 and Aβ40 generation. We observed that threonine mutants affected the initial γ-secretase cut, which is associated with levels of Aβ42 or Aβ40. Overall, hydrophilic residues of the APP transmembrane sequence decide on the exact initial γ-cut and the amounts of Aβ42 and Aβ40.
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Affiliation(s)
- Felix Oestereich
- †Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir William Osler, H3G 1Y6 Montréal, Canada.,‡Institut für Chemie und Biochemie, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany.,∥Integrated Program in Neuroscience, McGill University, Montréal, Canada
| | - Heiko J Bittner
- §Institut für Medizinische Physik und Biophysik, Charité, Charitéplatz 1, 10117 Berlin, Germany
| | - Christoph Weise
- ‡Institut für Chemie und Biochemie, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany
| | - Lisa Grohmann
- ‡Institut für Chemie und Biochemie, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany
| | - Lisa-Kristin Janke
- ‡Institut für Chemie und Biochemie, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany
| | - Peter W Hildebrand
- §Institut für Medizinische Physik und Biophysik, Charité, Charitéplatz 1, 10117 Berlin, Germany
| | - Gerhard Multhaup
- †Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir William Osler, H3G 1Y6 Montréal, Canada.,‡Institut für Chemie und Biochemie, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany
| | - Lisa-Marie Munter
- †Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir William Osler, H3G 1Y6 Montréal, Canada.,‡Institut für Chemie und Biochemie, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany
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Zhang X, Li Y, Xu H, Zhang YW. The γ-secretase complex: from structure to function. Front Cell Neurosci 2014; 8:427. [PMID: 25565961 PMCID: PMC4263104 DOI: 10.3389/fncel.2014.00427] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 11/27/2014] [Indexed: 12/21/2022] Open
Abstract
One of the most critical pathological features of Alzheimer’s disease (AD) is the accumulation of β-amyloid (Aβ) peptides that form extracellular senile plaques in the brain. Aβ is derived from β-amyloid precursor protein (APP) through sequential cleavage by β- and γ-secretases. γ-secretase is a high molecular weight complex minimally composed of four components: presenilins (PS), nicastrin, anterior pharynx defective 1 (APH-1), and presenilin enhancer 2 (PEN-2). In addition to APP, γ-secretase also cleaves many other type I transmembrane (TM) protein substrates. As a crucial enzyme for Aβ production, γ-secretase is an appealing therapeutic target for AD. Here, we summarize current knowledge on the structure and function of γ-secretase, as well as recent progress in developing γ-secretase targeting drugs for AD treatment.
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Affiliation(s)
- Xian Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University Xiamen, FJ, China
| | - Yanfang Li
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University Xiamen, FJ, China
| | - Huaxi Xu
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University Xiamen, FJ, China ; Degenerative Disease Research Program, Sanford-Burnham Medical Research Institute La Jolla, CA, USA
| | - Yun-Wu Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University Xiamen, FJ, China
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Allosteric regulation of γ-secretase activity by a phenylimidazole-type γ-secretase modulator. Proc Natl Acad Sci U S A 2014; 111:10544-9. [PMID: 25009180 DOI: 10.1073/pnas.1402171111] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
γ-Secretase is an intramembrane-cleaving protease responsible for the generation of amyloid-β (Aβ) peptides. Recently, a series of compounds called γ-secretase modulators (GSMs) has been shown to decrease the levels of long toxic Aβ species (i.e., Aβ42), with a concomitant elevation of the production of shorter Aβ species. In this study, we show that a phenylimidazole-type GSM allosterically induces conformational changes in the catalytic site of γ-secretase to augment the proteolytic activity. Analyses using the photoaffinity labeling technique and systematic mutational studies revealed that the phenylimidazole-type GSM targets a previously unidentified extracellular binding pocket within the N-terminal fragment of presenilin (PS). Collectively, we provide a model for the mechanism of action of the phenylimidazole-type GSM in which binding at the luminal side of PS induces a conformational change in the catalytic center of γ-secretase to modulate Aβ production.
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