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Ajore R, Mattsson J, Pertesi M, Ekdahl L, Ali Z, Hansson M, Nilsson B. Genome-wide CRISPR/Cas9 screen identifies regulators of BCMA expression on multiple myeloma cells. Blood Cancer J 2024; 14:21. [PMID: 38272874 PMCID: PMC10811322 DOI: 10.1038/s41408-024-00986-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 01/06/2024] [Accepted: 01/09/2024] [Indexed: 01/27/2024] Open
Affiliation(s)
- Ram Ajore
- Division of Hematology and Transfusion Medicine, Department of Laboratory Medicine, Lund University, 221 84, Lund, Sweden
- Lund Stem Cell Center, Lund University, 221 84, Lund, Sweden
| | - Jenny Mattsson
- Division of Hematology and Transfusion Medicine, Department of Laboratory Medicine, Lund University, 221 84, Lund, Sweden
- Lund Stem Cell Center, Lund University, 221 84, Lund, Sweden
- BioInvent International AB, Ideongatan 1, 223 70, Lund, Sweden
| | - Maroulio Pertesi
- Division of Hematology and Transfusion Medicine, Department of Laboratory Medicine, Lund University, 221 84, Lund, Sweden
- Lund Stem Cell Center, Lund University, 221 84, Lund, Sweden
| | - Ludvig Ekdahl
- Division of Hematology and Transfusion Medicine, Department of Laboratory Medicine, Lund University, 221 84, Lund, Sweden
- Lund Stem Cell Center, Lund University, 221 84, Lund, Sweden
| | - Zain Ali
- Division of Hematology and Transfusion Medicine, Department of Laboratory Medicine, Lund University, 221 84, Lund, Sweden
- Lund Stem Cell Center, Lund University, 221 84, Lund, Sweden
| | - Markus Hansson
- Division of Hematology and Transfusion Medicine, Department of Laboratory Medicine, Lund University, 221 84, Lund, Sweden
- Department of Internal Medicine and Clinical Nutrition, Sahlgrenska Academy, Göteborg University, 41346, Göteborg, Sweden
| | - Björn Nilsson
- Division of Hematology and Transfusion Medicine, Department of Laboratory Medicine, Lund University, 221 84, Lund, Sweden.
- Lund Stem Cell Center, Lund University, 221 84, Lund, Sweden.
- Broad Institute, Cambridge, MA, 02142, USA.
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2
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Serneels L, Bammens L, Zwijsen A, Tolia A, Chávez-Gutiérrez L, De Strooper B. Functional and topological analysis of PSENEN, the fourth subunit of the γ-secretase complex. J Biol Chem 2024; 300:105533. [PMID: 38072061 PMCID: PMC10790097 DOI: 10.1016/j.jbc.2023.105533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 11/20/2023] [Accepted: 11/26/2023] [Indexed: 01/01/2024] Open
Abstract
The γ-secretase complexes are intramembrane cleaving proteases involved in the generation of the Aβ peptides in Alzheimer's disease. The complex consists of four subunits, with Presenilin harboring the catalytic site. Here, we study the role of the smallest subunit, PSENEN or Presenilin enhancer 2, encoded by the gene Psenen, in vivo and in vitro. We find a profound Notch deficiency phenotype in Psenen-/- embryos confirming the essential role of PSENEN in the γ-secretase complex. We used Psenen-/- fibroblasts to explore the structure-function of PSENEN by the scanning cysteine accessibility method. Glycine 22 and proline 27, which border the membrane domains 1 and 2 of PSENEN, are involved in complex formation and stabilization of γ-secretase. The hairpin structured hydrophobic membrane domains 1 and 2 are exposed to a water-containing cavity in the complex, while transmembrane domain 3 is not water exposed. We finally demonstrate the essential role of PSENEN for the cleavage activity of the complex. PSENEN is more than a structural component of the γ-secretase complex and might contribute to the catalytic mechanism of the enzyme.
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Affiliation(s)
- Lutgarde Serneels
- Laboratory for the Research of Neurodegenerative Diseases, VIB Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurosciences and Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Leen Bammens
- Laboratory for the Research of Neurodegenerative Diseases, VIB Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurosciences and Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - An Zwijsen
- Laboratory of Developmental Signaling, Center for Human Genetics, KU Leuven, Leuven, Belgium
| | - Alexandra Tolia
- Laboratory for the Research of Neurodegenerative Diseases, VIB Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurosciences and Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Lucía Chávez-Gutiérrez
- Laboratory for the Research of Neurodegenerative Diseases, VIB Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurosciences and Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Bart De Strooper
- Laboratory for the Research of Neurodegenerative Diseases, VIB Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurosciences and Leuven Brain Institute, KU Leuven, Leuven, Belgium.
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3
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Xia Y, Zhang Y, Xu M, Zou X, Gao J, Ji MH, Chen G. Presenilin enhancer 2 is crucial for the transition of apical progenitors into neurons but into not basal progenitors in the developing hippocampus. Development 2022; 149:275418. [PMID: 35575074 DOI: 10.1242/dev.200272] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 05/04/2022] [Indexed: 12/23/2022]
Abstract
Recent evidence has shown that presenilin enhancer 2 (Pen2; Psenen) plays an essential role in corticogenesis by regulating the switch of apical progenitors (APs) to basal progenitors (BPs). The hippocampus is a brain structure required for advanced functions, including spatial navigation, learning and memory. However, it remains unknown whether Pen2 is important for hippocampal morphogenesis. To address this question, we generated Pen2 conditional knockout (cKO) mice, in which Pen2 is inactivated in neural progenitor cells (NPCs) in the hippocampal primordium. We showed that Pen2 cKO mice exhibited hippocampal malformation and decreased population of NPCs in the neuroepithelium of the hippocampus. We found that deletion of Pen2 neither affected the proliferative capability of APs nor the switch of APs to BPs in the hippocampus, and that it caused enhanced transition of APs to neurons. We demonstrated that expression of the Notch1 intracellular domain (N1ICD) significantly increased the population of NPCs in the Pen2 cKO hippocampus. Collectively, this study uncovers a crucial role for Pen2 in the maintenance of NPCs during hippocampal development.
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Affiliation(s)
- Yingqian Xia
- Ministry of Education (MOE) Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Jiangsu Key Laboratory of Molecular Medicine, Medical School, Nanjing University, 12 Xuefu Avenue, Nanjing, Jiangsu, China, 210061
| | - Yizhi Zhang
- Ministry of Education (MOE) Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Jiangsu Key Laboratory of Molecular Medicine, Medical School, Nanjing University, 12 Xuefu Avenue, Nanjing, Jiangsu, China, 210061
| | - Min Xu
- Department of Neurobiology, Key Laboratory of Human Functional Genomics of Jiangsu, Nanjing Medical University, Nanjing, Jiangsu, China, 211166
| | - Xiaochuan Zou
- Ministry of Education (MOE) Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Jiangsu Key Laboratory of Molecular Medicine, Medical School, Nanjing University, 12 Xuefu Avenue, Nanjing, Jiangsu, China, 210061
| | - Jun Gao
- Department of Neurobiology, Key Laboratory of Human Functional Genomics of Jiangsu, Nanjing Medical University, Nanjing, Jiangsu, China, 211166
| | - Mu-Huo Ji
- Department of Anesthesiology, The Second Affiliated Hospital, Nanjing Medical University, Nanjing, China, 210003
| | - Guiquan Chen
- Ministry of Education (MOE) Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Jiangsu Key Laboratory of Molecular Medicine, Medical School, Nanjing University, 12 Xuefu Avenue, Nanjing, Jiangsu, China, 210061.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China, 226001
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4
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Klein M, Kaleem A, Oetjen S, Wünkhaus D, Binkle L, Schilling S, Gjorgjieva M, Scholz R, Gruber-Schoffnegger D, Storch S, Kins S, Drewes G, Hoffmeister-Ullerich S, Kuhl D, Hermey G. Converging roles of PSENEN/PEN2 and CLN3 in the autophagy-lysosome system. Autophagy 2021; 18:2068-2085. [PMID: 34964690 PMCID: PMC9397472 DOI: 10.1080/15548627.2021.2016232] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
PSENEN/PEN2 is the smallest subunit of the γ-secretase complex, an intramembrane protease that cleaves proteins within their transmembrane domains. Mutations in components of the γ-secretase underlie familial Alzheimer disease. In addition to its proteolytic activity, supplementary, γ-secretase independent, functions in the macroautophagy/autophagy-lysosome system have been proposed. Here, we screened for PSENEN-interacting proteins and identified CLN3. Mutations in CLN3 are causative for juvenile neuronal ceroid lipofuscinosis, a rare lysosomal storage disorder considered the most common neurodegenerative disease in children. As mutations in the PSENEN and CLN3 genes cause different neurodegenerative diseases, understanding shared cellular functions of both proteins might be pertinent for understanding general cellular mechanisms underlying neurodegeneration. We hypothesized that CLN3 modulates γ-secretase activity and that PSENEN and CLN3 play associated roles in the autophagy-lysosome system. We applied CRISPR gene-editing and obtained independent isogenic HeLa knockout cell lines for PSENEN and CLN3. Following previous studies, we demonstrate that PSENEN is essential for forming a functional γ-secretase complex and is indispensable for γ-secretase activity. In contrast, CLN3 does not modulate γ-secretase activity to a significant degree. We observed in PSENEN- and CLN3-knockout cells corresponding alterations in the autophagy-lysosome system. These include reduced activity of lysosomal enzymes and lysosome number, an increased number of autophagosomes, increased lysosome-autophagosome fusion, and elevated levels of TFEB (transcription factor EB). Our study strongly suggests converging roles of PSENEN and CLN3 in the autophagy-lysosome system in a γ-secretase activity-independent manner, supporting the idea of common cytopathological processes underlying different neurodegenerative diseases. Abbreviations: Aβ, amyloid-beta; AD, Alzheimer disease; APP, amyloid precursor protein; ATP5MC, ATP synthase membrane subunit c; DQ-BSA, dye-quenched bovine serum albumin; ER, endoplasmic reticulum; GFP, green fluorescent protein; ICC, immunocytochemistry; ICD, intracellular domain; JNCL, juvenile neuronal ceroid lipofuscinosis; KO, knockout; LC3, microtubule associated protein 1 light chain 3; NCL, neuronal ceroid lipofuscinoses; PSEN, presenilin; PSENEN/PEN2: presenilin enhancer, gamma-secretase subunit; TAP, tandem affinity purification; TEV, tobacco etch virus; TF, transferrin; WB, Western blot; WT, wild type.
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Affiliation(s)
- Marcel Klein
- Institute for Molecular and Cellular Cognition, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Abuzar Kaleem
- Institute for Molecular and Cellular Cognition, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sandra Oetjen
- Institute for Molecular and Cellular Cognition, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Lars Binkle
- Institute of Neuroimmunology and Multiple Sclerosis, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sandra Schilling
- Division of Human Biology and Human Genetics, University of Kaiserslautern, Kaiserslautern, Germany
| | - Milena Gjorgjieva
- Institute for Molecular and Cellular Cognition, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ralf Scholz
- Institute for Molecular and Cellular Cognition, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Stephan Storch
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Stefan Kins
- Division of Human Biology and Human Genetics, University of Kaiserslautern, Kaiserslautern, Germany
| | - Gerard Drewes
- Cellzome, Functional Genomics Research and Development, Heidelberg, Germany
| | - Sabine Hoffmeister-Ullerich
- Bioanalytics, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Dietmar Kuhl
- Institute for Molecular and Cellular Cognition, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Guido Hermey
- Institute for Molecular and Cellular Cognition, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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5
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Sen S, Hallee L, Lam CK. The Potential of Gamma Secretase as a Therapeutic Target for Cardiac Diseases. J Pers Med 2021; 11:jpm11121294. [PMID: 34945766 PMCID: PMC8703931 DOI: 10.3390/jpm11121294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 11/24/2021] [Accepted: 12/01/2021] [Indexed: 11/16/2022] Open
Abstract
Heart diseases are some of the most common and pressing threats to human health worldwide. The American Heart Association and the National Institute of Health jointly work to annually update data on cardiac diseases. In 2018, 126.9 million Americans were reported as having some form of cardiac disorder, with an estimated direct and indirect total cost of USD 363.4 billion. This necessitates developing therapeutic interventions for heart diseases to improve human life expectancy and economic relief. In this review, we look into gamma-secretase as a potential therapeutic target for cardiac diseases. Gamma-secretase, an aspartyl protease enzyme, is responsible for the cleavage and activation of a number of substrates that are relevant to normal cardiac development and function as found in mutation studies. Some of these substrates are involved in downstream signaling processes and crosstalk with pathways relevant to heart diseases. Most of the substrates and signaling events we explored were found to be potentially beneficial to maintain cardiac function in diseased conditions. This review presents an updated overview of the current knowledge on gamma-secretase processing of cardiac-relevant substrates and seeks to understand if the modulation of gamma-secretase activity would be beneficial to combat cardiac diseases.
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Affiliation(s)
- Sujoita Sen
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA;
| | - Logan Hallee
- Department of Mathematical Sciences, University of Delaware, Newark, DE 19716, USA;
| | - Chi Keung Lam
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA;
- Correspondence: ; Tel.: +1-302-831-3165
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6
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Wouters R, Michiels C, Sannerud R, Kleizen B, Dillen K, Vermeire W, Ayala AE, Demedts D, Schekman R, Annaert W. Assembly of γ-secretase occurs through stable dimers after exit from the endoplasmic reticulum. J Cell Biol 2021; 220:212501. [PMID: 34292306 PMCID: PMC8302450 DOI: 10.1083/jcb.201911104] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 12/29/2020] [Accepted: 06/07/2021] [Indexed: 01/22/2023] Open
Abstract
γ-Secretase affects many physiological processes through targeting >100 substrates; malfunctioning links γ-secretase to cancer and Alzheimer’s disease. The spatiotemporal regulation of its stoichiometric assembly remains unresolved. Fractionation, biochemical assays, and imaging support prior formation of stable dimers in the ER, which, after ER exit, assemble into full complexes. In vitro ER budding shows that none of the subunits is required for the exit of others. However, knockout of any subunit leads to the accumulation of incomplete subcomplexes in COPII vesicles. Mutating a DPE motif in presenilin 1 (PSEN1) abrogates ER exit of PSEN1 and PEN-2 but not nicastrin. We explain this by the preferential sorting of PSEN1 and nicastrin through Sec24A and Sec24C/D, respectively, arguing against full assembly before ER exit. Thus, dimeric subcomplexes aided by Sec24 paralog selectivity support a stepwise assembly of γ-secretase, controlling final levels in post-Golgi compartments.
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Affiliation(s)
- Rosanne Wouters
- Laboratory for Membrane Trafficking, Vlaams Instituut voor Biotechnologie Center for Brain and Disease Research, Katholieke Universiteit Leuven, Leuven, Belgium.,Department of Neurosciences, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Christine Michiels
- Laboratory for Membrane Trafficking, Vlaams Instituut voor Biotechnologie Center for Brain and Disease Research, Katholieke Universiteit Leuven, Leuven, Belgium.,Department of Neurosciences, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Ragna Sannerud
- Laboratory for Membrane Trafficking, Vlaams Instituut voor Biotechnologie Center for Brain and Disease Research, Katholieke Universiteit Leuven, Leuven, Belgium.,Department of Neurosciences, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Bertrand Kleizen
- Cellular Protein Chemistry, Bijvoet Center for Biomolecular Research, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Katleen Dillen
- Laboratory for Membrane Trafficking, Vlaams Instituut voor Biotechnologie Center for Brain and Disease Research, Katholieke Universiteit Leuven, Leuven, Belgium.,Department of Neurosciences, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Wendy Vermeire
- Laboratory for Membrane Trafficking, Vlaams Instituut voor Biotechnologie Center for Brain and Disease Research, Katholieke Universiteit Leuven, Leuven, Belgium.,Department of Neurosciences, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Abril Escamilla Ayala
- Vlaams Instituut voor Biotechnologie BioImaging Core, Vlaams Instituut voor Biotechnologie Center for Brain and Disease Research, Leuven, Belgium
| | - David Demedts
- Laboratory for Membrane Trafficking, Vlaams Instituut voor Biotechnologie Center for Brain and Disease Research, Katholieke Universiteit Leuven, Leuven, Belgium.,Department of Neurosciences, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Randy Schekman
- Department of Molecular and Cell Biology and Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA
| | - Wim Annaert
- Laboratory for Membrane Trafficking, Vlaams Instituut voor Biotechnologie Center for Brain and Disease Research, Katholieke Universiteit Leuven, Leuven, Belgium.,Department of Neurosciences, Katholieke Universiteit Leuven, Leuven, Belgium
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7
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Chelban V, Breza M, Szaruga M, Vandrovcova J, Murphy D, Lee C, Alikhwan S, Bourinaris T, Vavougios G, Ilyas M, Halim SA, Al‐Harrasi A, Kartanou C, Ronald C, Blumcke I, Alexoudi A, Gatzonis S, Stefanis L, Karadima G, Wood NW, Chávez‐Gutiérrez L, Hardy J, Houlden H, Koutsis G. Spastic paraplegia preceding PSEN1-related familial Alzheimer's disease. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2021; 13:e12186. [PMID: 33969176 PMCID: PMC8088589 DOI: 10.1002/dad2.12186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 03/02/2021] [Accepted: 03/09/2021] [Indexed: 11/08/2022]
Abstract
INTRODUCTION We investigated the frequency, neuropathology, and phenotypic characteristics of spastic paraplegia (SP) that precedes dementia in presenilin 1 (PSEN1) related familial Alzheimer's disease (AD). METHODS We performed whole exome sequencing (WES) in 60 probands with hereditary spastic paraplegia (HSP) phenotype that was negative for variants in known HSP-related genes. Where PSEN1 mutation was identified, brain biopsy was performed. We investigated the link between HSP and AD with PSEN1 in silico pathway analysis and measured in vivo the stability of PSEN1 mutant γ-secretase. RESULTS We identified a PSEN1 variant (p.Thr291Pro) in an individual presenting with pure SP at 30 years of age. Three years later, SP was associated with severe, fast cognitive decline and amyloid deposition with diffuse cortical plaques on brain biopsy. Biochemical analysis of p.Thr291Pro PSEN1 revealed that although the mutation does not alter active γ-secretase reconstitution, it destabilizes γ-secretase-amyloid precursor protein (APP)/amyloid beta (Aβn) interactions during proteolysis, enhancing the production of longer Aβ peptides. We then extended our analysis to all 226 PSEN1 pathogenic variants reported and show that 7.5% were associated with pure SP onset followed by cognitive decline later in the disease. We found that PSEN1 cases manifesting initially as SP have a later age of onset, are associated with mutations located beyond codon 200, and showed larger diffuse, cored plaques, amyloid-ring arteries, and severe CAA. DISCUSSION We show that pure SP can precede dementia onset in PSEN1-related familial AD. We recommend PSEN1 genetic testing in patients presenting with SP with no variants in known HSP-related genes, particularly when associated with a family history of cognitive decline.
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Affiliation(s)
- Viorica Chelban
- Department of Neuromuscular Disease, Queen Square Institute of NeurologyUniversity College LondonLondonUK
- Department of Neurology and NeurosurgeryInstitute of Emergency MedicineToma Ciorbă 1ChisinauRepublic of Moldova
| | - Marianthi Breza
- Neurogenetics Unit1st Department of NeurologyEginition HospitalSchool of MedicineNational and Kapodistrian University of AthensAthensGreece
| | - Maria Szaruga
- KU Leuven‐VIB Center for Brain & Disease ResearchLeuvenBelgium
- Department of NeurosciencesLeuven Institute for Neuroscience and Disease (LIND)KU LeuvenLeuvenBelgium
- Neurobiology DivisionMRC Laboratory of Molecular BiologyFrancis Crick AvenueCambridgeCB2 0QHUK
| | - Jana Vandrovcova
- Department of Neuromuscular Disease, Queen Square Institute of NeurologyUniversity College LondonLondonUK
| | - David Murphy
- Department of Clinical and Movement NeurosciencesQueen Square Institute of NeurologyUniversity College LondonLondonUK
| | - Chia‐Ju Lee
- Department of Neuromuscular Disease, Queen Square Institute of NeurologyUniversity College LondonLondonUK
| | - Sondos Alikhwan
- Department of Neuromuscular Disease, Queen Square Institute of NeurologyUniversity College LondonLondonUK
| | - Thomas Bourinaris
- Department of Neuromuscular Disease, Queen Square Institute of NeurologyUniversity College LondonLondonUK
| | | | - Muhammad Ilyas
- Centre for Omic ScienceIslamia College PeshawarPeshawarPakistan
| | - Sobia Ahsan Halim
- Natural and Medical Sciences Research CenterUniversity of NizwaPakistan
| | - Ahmed Al‐Harrasi
- Natural and Medical Sciences Research CenterUniversity of NizwaPakistan
| | - Chrisoula Kartanou
- Neurogenetics Unit1st Department of NeurologyEginition HospitalSchool of MedicineNational and Kapodistrian University of AthensAthensGreece
| | - Coras Ronald
- Institute of NeuropathologyUniversitätsklinikum ErlangenErlangenGermany
| | - Ingmar Blumcke
- Institute of NeuropathologyUniversitätsklinikum ErlangenErlangenGermany
| | - Athanasia Alexoudi
- Department of NeurosurgeryEvangelismos HospitalUniversity of AthensGreece
| | - Stylianos Gatzonis
- Department of NeurosurgeryEvangelismos HospitalUniversity of AthensGreece
| | - Leonidas Stefanis
- 1st Department of NeurologySchool of MedicineEginition HospitalNational and Kapodistrian University of AthensAthensGreece
| | - Georgia Karadima
- Neurogenetics Unit1st Department of NeurologyEginition HospitalSchool of MedicineNational and Kapodistrian University of AthensAthensGreece
| | - Nicholas W. Wood
- Department of Neuromuscular Disease, Queen Square Institute of NeurologyUniversity College LondonLondonUK
- Neurogenetics LaboratoryNational Hospital for Neurology and NeurosurgeryQueen SquareLondonUK
| | - Lucía Chávez‐Gutiérrez
- KU Leuven‐VIB Center for Brain & Disease ResearchLeuvenBelgium
- Department of NeurosciencesLeuven Institute for Neuroscience and Disease (LIND)KU LeuvenLeuvenBelgium
| | - John Hardy
- Department of Neurodegenerative DiseaseReta Lila Weston LaboratoriesQueen Square GenomicsUCL Dementia Research InstituteLondonUK
| | - Henry Houlden
- Department of Neuromuscular Disease, Queen Square Institute of NeurologyUniversity College LondonLondonUK
- Neurogenetics LaboratoryNational Hospital for Neurology and NeurosurgeryQueen SquareLondonUK
| | - Georgios Koutsis
- Neurogenetics Unit1st Department of NeurologyEginition HospitalSchool of MedicineNational and Kapodistrian University of AthensAthensGreece
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Flexible and Accurate Substrate Processing with Distinct Presenilin/γ-Secretases in Human Cortical Neurons. eNeuro 2021; 8:ENEURO.0500-20.2021. [PMID: 33608391 PMCID: PMC7932187 DOI: 10.1523/eneuro.0500-20.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 01/27/2021] [Accepted: 01/30/2021] [Indexed: 01/10/2023] Open
Abstract
Mutations in the presenilin genes (PS1, PS2) have been linked to the majority of familial Alzheimer’s disease (AD). Although great efforts have been made to investigate pathogenic PS mutations, which ultimately cause an increase in the toxic form of β-amyloid (Aβ), the intrinsic physiological functions of PS in human neurons remain to be determined. In this study, to investigate the physiological roles of PS in human neurons, we generated PS1 conditional knock-out (KO) induced pluripotent stem cells (iPSCs), in which PS1 can be selectively abrogated under Cre transduction with or without additional PS2 KO. We showed that iPSC-derived neural progenitor cells (NPCs) do not confer a maintenance ability in the absence of both PS1 and PS2, showing the essential role of PS in Notch signaling. We then generated PS-null human cortical neurons, where PS1 was intact until full neuronal differentiation occurred. Aβ40 production was reduced exclusively in human PS1/PS2-null neurons along with a concomitant accumulation of amyloid β precursor protein (APP)-C-terminal fragments CTFs, whereas Aβ42 was decreased in neurons devoid of PS2. Unlike previous studies in mice, in which APP cleavage is largely attributable to PS1, γ-secretase activity seemed to be comparable between PS1 and PS2. In contrast, cleavage of another substrate, N-cadherin, was impaired only in neurons devoid of PS1. Moreover, PS2/γ-secretase exists largely in late endosomes/lysosomes, as measured by specific antibody against the γ-secretase complex, in which Aβ42 species are supposedly produced. Using this novel stem cell-based platform, we assessed important physiological PS1/PS2 functions in mature human neurons, the dysfunction of which could underlie AD pathogenesis.
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9
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Gadhave K, Gehi BR, Kumar P, Xue B, Uversky VN, Giri R. The dark side of Alzheimer's disease: unstructured biology of proteins from the amyloid cascade signaling pathway. Cell Mol Life Sci 2020; 77:4163-4208. [PMID: 31894361 PMCID: PMC11104979 DOI: 10.1007/s00018-019-03414-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Revised: 11/17/2019] [Accepted: 12/04/2019] [Indexed: 12/21/2022]
Abstract
Alzheimer's disease (AD) is a leading cause of age-related dementia worldwide. Despite more than a century of intensive research, we are not anywhere near the discovery of a cure for this disease or a way to prevent its progression. Among the various molecular mechanisms proposed for the description of the pathogenesis and progression of AD, the amyloid cascade hypothesis, according to which accumulation of a product of amyloid precursor protein (APP) cleavage, amyloid β (Aβ) peptide, induces pathological changes in the brain observed in AD, occupies a unique niche. Although multiple proteins have been implicated in this amyloid cascade signaling pathway, their structure-function relationships are mostly unexplored. However, it is known that two major proteins related to AD pathology, Aβ peptide, and microtubule-associated protein tau belong to the category of intrinsically disordered proteins (IDPs), which are the functionally important proteins characterized by a lack of fixed, ordered three-dimensional structure. IDPs and intrinsically disordered protein regions (IDPRs) play numerous vital roles in various cellular processes, such as signaling, cell cycle regulation, macromolecular recognition, and promiscuous binding. However, the deregulation and misfolding of IDPs may lead to disturbed signaling, interactions, and disease pathogenesis. Often, molecular recognition-related IDPs/IDPRs undergo disorder-to-order transition upon binding to their biological partners and contain specific disorder-based binding motifs, known as molecular recognition features (MoRFs). Knowing the intrinsic disorder status and disorder-based functionality of proteins associated with amyloid cascade signaling pathway may help to untangle the mechanisms of AD pathogenesis and help identify therapeutic targets. In this paper, we have used multiple computational tools to evaluate the presence of intrinsic disorder and MoRFs in 27 proteins potentially relevant to the amyloid cascade signaling pathway. Among these, BIN1, APP, APOE, PICALM, PSEN1 and CD33 were found to be highly disordered. Furthermore, their disorder-based binding regions and associated short linear motifs have also been identified. These findings represent important foundation for the future research, and experimental characterization of disordered regions in these proteins is required to better understand their roles in AD pathogenesis.
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Affiliation(s)
- Kundlik Gadhave
- School of Basic Sciences, Indian Institute of Technology Mandi, Mandi, India
| | | | - Prateek Kumar
- School of Basic Sciences, Indian Institute of Technology Mandi, Mandi, India
| | - Bin Xue
- Department of Cell Biology, Microbiology and Molecular Biology, School of Natural Sciences and Mathematics, College of Arts and Sciences, University of South Florida, Tampa, FL, 33620, USA
| | - Vladimir N Uversky
- Department of Molecular Medicine and Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, 33620, USA.
- Laboratory of New Methods in Biology, Institute for Biological Instrumentation, Russian Academy of Sciences, 142290, Pushchino, Moscow Region, Russia.
| | - Rajanish Giri
- School of Basic Sciences, Indian Institute of Technology Mandi, Mandi, India.
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Bi HR, Zhou CH, Zhang YZ, Cai XD, Ji MH, Yang JJ, Chen GQ, Hu YM. Neuron-specific deletion of presenilin enhancer2 causes progressive astrogliosis and age-related neurodegeneration in the cortex independent of the Notch signaling. CNS Neurosci Ther 2020; 27:174-185. [PMID: 32961023 PMCID: PMC7816208 DOI: 10.1111/cns.13454] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 08/19/2020] [Accepted: 08/24/2020] [Indexed: 12/18/2022] Open
Abstract
Introduction Presenilin enhancer2 (Pen‐2) is an essential subunit of γ‐secretase, which is a key protease responsible for the cleavage of amyloid precursor protein (APP) and Notch. Mutations on Pen‐2 cause familial Alzheimer disease (AD). However, it remains unknown whether Pen‐2 regulates neuronal survival and neuroinflammation in the adult brain. Methods Forebrain neuron‐specific Pen‐2 conditional knockout (Pen‐2 cKO) mice were generated for this study. Pen‐2 cKO mice expressing Notch1 intracellular domain (NICD) conditionally in cortical neurons were also generated. Results Loss of Pen‐2 causes astrogliosis followed by age‐dependent cortical atrophy and neuronal loss. Loss of Pen‐2 results in microgliosis and enhanced inflammatory responses in the cortex. Expression of NICD in Pen‐2 cKO cortices ameliorates neither neurodegeneration nor neuroinflammation. Conclusions Pen‐2 is required for neuronal survival in the adult cerebral cortex. The Notch signaling may not be involved in neurodegeneration caused by loss of Pen‐2.
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Affiliation(s)
- Hui-Ru Bi
- Model Animal Research Center, MOE Key Laboratory of Model Animal for Disease Study, Medical School, Nanjing University, Nanjing, China
| | - Cui-Hua Zhou
- Department of Anesthesiology, The Second Affiliated Changzhou People's Hospital of Nanjing Medical University, Changzhou, China
| | - Yi-Zhi Zhang
- Model Animal Research Center, MOE Key Laboratory of Model Animal for Disease Study, Medical School, Nanjing University, Nanjing, China
| | - Xu-Dong Cai
- Model Animal Research Center, MOE Key Laboratory of Model Animal for Disease Study, Medical School, Nanjing University, Nanjing, China
| | - Mu-Huo Ji
- Department of Anesthesiology, Pain and Perioperative Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Jian-Jun Yang
- Department of Anesthesiology, Pain and Perioperative Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Gui-Quan Chen
- Model Animal Research Center, MOE Key Laboratory of Model Animal for Disease Study, Medical School, Nanjing University, Nanjing, China
| | - Yi-Min Hu
- Department of Anesthesiology, The Second Affiliated Changzhou People's Hospital of Nanjing Medical University, Changzhou, China
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11
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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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12
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Dehury B, Tang N, Blundell TL, Kepp KP. Structure and dynamics of γ-secretase with presenilin 2 compared to presenilin 1. RSC Adv 2019; 9:20901-20916. [PMID: 35515530 PMCID: PMC9065803 DOI: 10.1039/c9ra02623a] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 06/27/2019] [Indexed: 12/12/2022] Open
Abstract
Severe early-onset familial Alzheimer's disease (FAD) is caused by more than 200 different mutations in the genes coding for presenilin, the catalytic subunit of the 4-subunit protease complex γ-secretase, which cleaves the C99 fragment of the amyloid precursor protein (APP) to produce Aβ peptides. γ-Secretase exists with either of two homologues, PS1 and PS2. All cryo-electron microscopic structures and computational work has so far focused on γ-secretase with PS1, yet PS2 mutations also cause FAD. A central question is thus whether there are structural and dynamic differences between PS1 and PS2. To address this question, we use the cryo-electron microscopic data for PS1 to develop the first structural and dynamic model of PS2-γ-secretase in the catalytically relevant mature membrane-bound state at ambient temperature, equilibrated by three independent 500 ns molecular dynamics simulations. We find that the characteristic nicastrin extra-cellular domain breathing mode and major movements in the cytosolic loop between TM6 and TM7 occur in both PS2- and PS1-γ-secretase. The overall structures and conformational states are similar, suggesting similar catalytic activities. However, at the sequence level, charge-controlled membrane-anchoring is extracellular for PS1 and intracellular for PS2, which suggests different subcellular locations. The tilt angles of the TM2, TM6, TM7 and TM9 helices differ in the two forms of γ-secretase, suggesting that the two proteins have somewhat different substrate processing and channel sizes. Our MD simulations consistently indicated that PS2 retains several water molecules near the catalytic site at the bilayer, as required for catalysis. The possible reasons for the differences of PS1 and PS2 are discussed in relation to their location and function.
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Affiliation(s)
- Budheswar Dehury
- Department of Chemistry, Technical University of Denmark DK-2800 Kongens Lyngby Denmark +045 45252409
| | - Ning Tang
- Department of Chemistry, Technical University of Denmark DK-2800 Kongens Lyngby Denmark +045 45252409
| | - Tom L Blundell
- Department of Biochemistry, University of Cambridge Cambridge CB2 1GA UK
| | - Kasper P Kepp
- Department of Chemistry, Technical University of Denmark DK-2800 Kongens Lyngby Denmark +045 45252409
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Conditional Inactivation of Pen-2 in the Developing Neocortex Leads to Rapid Switch of Apical Progenitors to Basal Progenitors. J Neurosci 2019; 39:2195-2207. [PMID: 30692224 DOI: 10.1523/jneurosci.2523-18.2019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Revised: 01/08/2019] [Accepted: 01/11/2019] [Indexed: 12/16/2022] Open
Abstract
The transition of apical progenitors (APs) to basal progenitors (BPs) is an important neurogenic process during cortical expansion. Presenilin enhancer 2 (Pen-2, also named as Psenen) is a key subunit of γ-secretase and has been implicated in neurodevelopmental disease. However, it remains unknown how Pen-2 may regulate the maintenance of APs. To address this question, we generated a conditional KO (cKO) mouse in which Pen-2 is specifically inactivated in neural progenitor cells in the telencephalon. Both male and female embryos were used. We show that Pen-2 cKO cortices display remarkable depletion of Aps, but transient increase on BPs, compared with controls. We demonstrate that the proliferation rate of APs or BPs is not changed, but the switch of APs to BPs is dramatically accelerated in Pen-2 cKO cortices. Molecular analyses reveal decreased levels of Hes1 and Hes5 but increased levels of Ngn2 and NeuroD1 in Pen-2 KO cells. We report that expression of Notch1 intracellular domain in Pen-2 cKO cortices restores the population of APs and BPs. In summary, these findings highlight a central role of the Notch signaling in Pen-2-dependent maintenance of neural stem cells in the developing neocortex.SIGNIFICANCE STATEMENT Presenilin enhancer 2 (Pen-2) has been implicated in neurodevelopmental disease. However, mechanisms by which Pen-2 regulates cortical development are not understood. In this study, we generated neural progenitor cell-specific Pen-2 conditional KO mice. We observe depletion of apical progenitors and transiently increased the number of basal progenitors in the developing neocortex of Pen-2 mutant mice. Mechanistic analyses reveal decreased levels of Hes1 and Hes5, but increased levels of neurogenic transcription factors in Pen-2 mutant cortices, compared with controls. We demonstrate that reintroduction of Notch intracellular domain into mutant mice restores the population of apical progenitors to basal progenitors. The above findings strongly suggest that the Pen-2-Notch pathway plays an essential role in the maintenance of neural stem cells during cortical development.
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14
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Hu C, Xu J, Zeng L, Li T, Cui MZ, Xu X. Pen-2 and Presenilin are Sufficient to Catalyze Notch Processing. J Alzheimers Dis 2018; 56:1263-1269. [PMID: 28234257 DOI: 10.3233/jad-161094] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Presenilin-1 (PS1) or presenilin-2 (PS2), nicastrin (NCT), anterior pharynx-defective 1 (Aph-1), and presenilin enhancer-2 (Pen-2) have been considered the minimal essential subunits required to form an active γ-secretase complex. Besides PS, which has been widely believed to function as the catalytic subunit of the complex, the functional roles of the other subunits in the γ-secretase complex remain debatable. In the current study, we set out to determine the role of Pen-2 in γ-secretase activity. To this end, using knockout cells in combination with siRNA and immunoprecipitation approaches, our results revealed that Pen-2 together with presenilin are sufficient to form a functionally active enzyme to process Notch. Specifically, our data demonstrated that Pen-2 plays a crucial role in substrate binding, a mechanism by which Pen-2 contributes directly to the catalytic mechanism of γ-secretase activity. Our data also suggested that there may be different requirements for components to process AβPP and Notch. This information would be important for therapeutic strategy aimed at inhibition or modulation of γ-secretase activity.
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Affiliation(s)
- Chen Hu
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN, USA
| | - Junjie Xu
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN, USA.,Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Jilin Medical University, Jilin, China
| | - Linlin Zeng
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN, USA.,School of Life Sciences, Jilin University, Changchun, China
| | - Ting Li
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN, USA.,Department of Cell Biology, Tianjin Medical University, Tianjin, China
| | - Mei-Zhen Cui
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN, USA
| | - Xuemin Xu
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN, USA
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Effects and Mechanism of Huannao Yicong Decoction Extract on the Ethology of Transgenic APP/PS1 Mice. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2017; 2017:9502067. [PMID: 29422937 PMCID: PMC5750494 DOI: 10.1155/2017/9502067] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2017] [Accepted: 09/11/2017] [Indexed: 01/16/2023]
Abstract
To investigate the mechanism of Huannao Yicong Decoction (HYD) extract on improving of learning memory of transgenic amyloid precursor protein (APP)/presenilin 1 (PS1) mice, we randomly divided 60 transgenic APP/PS1 mice of 3 months old into 4 groups: the model group, the Donepezil group, the HYD-L group, and the HYD-H group, with 15 C57BL/6J mice of the same genetic background as the control group. These mice were gavaged for 6 months in a row. The results showed that the latency was significantly shortened and the number of passing through the original platform was increased. HYD extract can increase the amount of neurons and improve the morphological structure of Nissl body obviously. The γ-secretase activity and the expression of phosphorylated APP, Aβ1-40, and Aβ1-42 in hippocampal CA1 were significantly decreased. The expressions of protein and mRNA of PEN-2 and CREB in hippocampal were significantly downregulated. These results demonstrated that HYD extract can improve the memory ability of transgenic APP/PS1 mice, which was related to the protection of neurons and structure of Nissl body, reducing cleavage of APP and production of Aβ and inhibiting the activity of γ-secretase by decreasing CREB activity because of downregulated expression of PEN-2.
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Huannao Yicong Formula () regulates γ-secretase activity through APH-1 and PEN-2 gene ragulation pathways in hippocampus of APP/PS1 double transgenic mice. Chin J Integr Med 2017; 23:270-278. [PMID: 28120208 DOI: 10.1007/s11655-017-2402-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Indexed: 02/07/2023]
Abstract
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, 10.92 g/kg), 15 for each group. Another 15 C57BL/6J mice with the same age and same genetic background were allocated into the control group, proper dosage of drugs or distilled water were given by intragastric administration once daily for 12 weeks. After 12 weeks of administration, the learning and memory abilities of mice in each group was evaluated by the morris water maze test, amyloid precursor protein (APP), Aβ1-40 and Aβ1-42 levels in hippocampus were detected by enzyme-linked immunosorbent assay, γ-secretase was detected by dual luciferase assaying, the levels of APH-1a, hypoxia-inducible factor 1α (HIF-1α), cAMP response element-binding protein (CREB) and PEN-2 and their mRNA expression was measured by Western blot and real-time polymerase chain reaction. RESULTS HYF can ameliorate learning and memory deficits in APP/PS1 transgenic mice by decreasing the escape latency, improving the number of platform crossing and swimming speed (P<0.01, P<0.05). HYF can decrease the levels of APP, Aβ1-40, Aβ1-42 and the activity of γ-secretase in hippocampus of Alzheimer's disease model mice. HYF can down-regulate the levels of CREB and PEN-2 and the expression of their mRNA. CONCLUSION HYF can improve the learning and memory ability by inhibiting the activity of γ-secretase through the CREB/PEN-2 signaling pathway, and this may be one of the therapeutic mechanisms of HYF in Alzheimer's disease.
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Conformational Changes in Transmembrane Domain 4 of Presenilin 1 Are Associated with Altered Amyloid-β 42 Production. J Neurosci 2016; 36:1362-72. [PMID: 26818522 DOI: 10.1523/jneurosci.5090-14.2016] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
UNLABELLED γ-Secretase is an intramembrane-cleaving protease that produces amyloid-β peptide 42 (Aβ42), which is the toxic and aggregation-prone species of Aβ that causes Alzheimer's disease. Here, we used the substituted cysteine accessibility method to analyze the structure of transmembrane domains (TMDs) 4 and 5 of human presenilin 1 (PS1), a catalytic subunit of γ-secretase. We revealed that TMD4 and TMD5 face the intramembranous hydrophilic milieu together with TMD1, TMD6, TMD7, and TMD9 of PS1 to form the catalytic pore structure. Notably, we found a correlation in the distance between the cytosolic sides of TMD4/TMD7 and Aβ42 production levels, suggesting that allosteric conformational changes of the cytosolic side of TMD4 affect Aβ42-generating γ-secretase activity. Our results provide new insights into the relationship between the structure and activity of human PS1. SIGNIFICANCE STATEMENT Modulation of γ-secretase activity to reduce toxic amyloid-β peptide species is one plausible therapeutic approaches for Alzheimer's disease. However, precise mechanistic information of γ-secretase still remains unclear. Here we identified the conformational changes in transmembrane domains of presenilin 1 that affect the proteolytic activity of the γ-secretase. Our results highlight the importance of understanding the structural dynamics of presenilin 1 in drug development against Alzheimer's disease.
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Fukumori A, Steiner H. Substrate recruitment of γ-secretase and mechanism of clinical presenilin mutations revealed by photoaffinity mapping. EMBO J 2016; 35:1628-43. [PMID: 27220847 DOI: 10.15252/embj.201694151] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 04/26/2016] [Indexed: 12/27/2022] Open
Abstract
Intramembrane proteases execute fundamental biological processes ranging from crucial signaling events to general membrane proteostasis. Despite the availability of structural information on these proteases, it remains unclear how these enzymes bind and recruit substrates, particularly for the Alzheimer's disease-associated γ-secretase. Systematically scanning amyloid precursor protein substrates containing a genetically inserted photocrosslinkable amino acid for binding to γ-secretase allowed us to identify residues contacting the protease. These were primarily found in the transmembrane cleavage domain of the substrate and were also present in the extramembranous domains. The N-terminal fragment of the catalytic subunit presenilin was determined as principal substrate-binding site. Clinical presenilin mutations altered substrate binding in the active site region, implying a pathogenic mechanism for familial Alzheimer's disease. Remarkably, PEN-2 was identified besides nicastrin as additional substrate-binding subunit. Probing proteolysis of crosslinked substrates revealed a mechanistic model of how these subunits interact to mediate a stepwise transfer of bound substrate to the catalytic site. We propose that sequential binding steps might be common for intramembrane proteases to sample and select cognate substrates for catalysis.
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Affiliation(s)
- Akio Fukumori
- Biomedical Center (BMC), Metabolic Biochemistry, Ludwig-Maximilians-University Munich, Munich, Germany German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Harald Steiner
- Biomedical Center (BMC), Metabolic Biochemistry, Ludwig-Maximilians-University Munich, Munich, Germany German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
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Bursavich MG, Harrison BA, Blain JF. Gamma Secretase Modulators: New Alzheimer's Drugs on the Horizon? J Med Chem 2016; 59:7389-409. [PMID: 27007185 DOI: 10.1021/acs.jmedchem.5b01960] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The rapidly aging population desperately requires new therapies for Alzheimer's disease. Despite years of pharmaceutical research, limited clinical success has been realized, with several failed disease modification therapies in recent years. On the basis of compelling genetic evidence, the pharmaceutical industry has put a large emphasis on brain beta amyloid (Aβ) either through its removal via antibodies or by targeting the proteases responsible for its production. In this Perspective, we focus on the development of small molecules that improve the activity of one such protease, gamma secretase, through an allosteric binding site to preferentially increase the concentration of the shorter non-amyloidogenic Aβ species. After a few early failures due to poor drug-like properties, the industry is now on the cusp of delivering gamma secretase modulators for clinical proof-of-mechanism studies that combine potency and efficacy with improved drug-like properties such as lower cLogP, high central nervous system multiparameter optimization scores, and high sp(3) character.
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Affiliation(s)
- Matthew G Bursavich
- FORUM Pharmaceuticals , 225 Second Avenue, Waltham, Massachusetts 02451, United States
| | - Bryce A Harrison
- FORUM Pharmaceuticals , 225 Second Avenue, Waltham, Massachusetts 02451, United States
| | - Jean-François Blain
- FORUM Pharmaceuticals , 225 Second Avenue, Waltham, Massachusetts 02451, United States
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Hu C, Zeng L, Li T, Meyer MA, Cui MZ, Xu X. Nicastrin is required for amyloid precursor protein (APP) but not Notch processing, while anterior pharynx-defective 1 is dispensable for processing of both APP and Notch. J Neurochem 2016; 136:1246-1258. [PMID: 26717550 DOI: 10.1111/jnc.13518] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 12/20/2015] [Accepted: 12/22/2015] [Indexed: 11/27/2022]
Abstract
The γ-secretase complex is composed of at least four components: presenilin 1 or presenilin-2, nicastrin (NCT), anterior pharynx-defective 1 (Aph-1), and presenilin enhancer 2. In this study, using knockout cell lines, our data demonstrated that knockout of NCT, as well as knockout of presenilin enhancer 2, completely blocked γ-secretase-catalyzed processing of C-terminal fragment (CTF)α and CTFβ, the C-terminal fragments of β-amyloid precursor protein (APP) produced by α-secretase and β-secretase cleavages, respectively. Interestingly, in Aph-1-knockout cells, CTFα and CTFβ were still processed by γ-secretase, indicating Aph-1 is dispensable for APP processing. Furthermore, our results indicate that Aph-1 as well as NCT is not absolutely required for Notch processing, suggesting that NCT is differentially required for APP and Notch processing. In addition, our data revealed that components of the γ-secretase complex are also important for proteasome- and lysosome-dependent degradation of APP and that endogenous APP is mostly degraded by lysosome while exogenous APP is mainly degraded by proteasome. There are unanswered questions regarding the roles of each component of the γ-secretase complex in amyloid precursor protein (APP) and Notch processing. The most relevant, novel finding of this study is that nicastrin (NCT) is required for APP but not Notch processing, while Aph-1 is not essential for processing of both APP and Notch, suggesting NCT as a therapeutic target to restrict Aβ formation without impairing Notch signaling.
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Affiliation(s)
- Chen Hu
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, Tennessee, USA
| | - Linlin Zeng
- School of Life Sciences, Jilin University, Changchun, China
| | - Ting Li
- Department of Cell Biology, Tianjin Medical University, Tianjin, China
| | | | - Mei-Zhen Cui
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, Tennessee, USA
| | - Xuemin Xu
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, Tennessee, USA
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Duggan SP, McCarthy JV. Beyond γ-secretase activity: The multifunctional nature of presenilins in cell signalling pathways. Cell Signal 2015; 28:1-11. [PMID: 26498858 DOI: 10.1016/j.cellsig.2015.10.006] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 10/19/2015] [Indexed: 01/24/2023]
Abstract
The presenilins are the catalytic subunit of the membrane-embedded tetrameric γ-secretase protease complexes. More that 90 transmembrane proteins have been reported to be γ-secretase substrates, including the widely studied amyloid precursor protein (APP) and the Notch receptor, which are precursors for the generation of amyloid-β peptides and biologically active APP intracellular domain (AICD) and Notch intracellular domain (NICD). The diversity of γ-secretase substrates highlights the importance of presenilin-dependent γ-secretase protease activities as a regulatory mechanism in a range of biological systems. However, there is also a growing body of evidence that supports the existence of γ-secretase-independent functions for the presenilins in the regulation and progression of an array of cell signalling pathways. In this review, we will present an overview of current literature that proposes evolutionarily conserved presenilin functions outside of the γ-secretase complex, with a focus on the suggested role of the presenilins in the regulation of Wnt/β-catenin signalling, protein trafficking and degradation, calcium homeostasis and apoptosis.
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Affiliation(s)
- Stephen P Duggan
- Signal Transduction Laboratory, School of Biochemistry & Cell Biology, ABCRF, Western Gateway Building, University College Cork, Cork, Ireland
| | - Justin V McCarthy
- Signal Transduction Laboratory, School of Biochemistry & Cell Biology, ABCRF, Western Gateway Building, University College Cork, Cork, Ireland.
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Zhang X, Yu CJ, Sisodia SS. The topology of pen-2, a γ-secretase subunit, revisited: evidence for a reentrant loop and a single pass transmembrane domain. Mol Neurodegener 2015; 10:39. [PMID: 26296997 PMCID: PMC4546279 DOI: 10.1186/s13024-015-0037-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2015] [Accepted: 08/13/2015] [Indexed: 12/04/2022] Open
Abstract
Background The γ-secretase complex, composed of transmembrane proteins termed presenilin (PS), anterior pharynx defective (APH), nicastrin (NCT), and presenilin enhancer-2 (Pen-2) catalyzes intramembranous hydrolysis of a variety of Type I membrane protein substrates. In order to understand aspects of subunit assembly, interactions, dynamics and catalysis, it is essential to clarify the membrane topology of each polypeptide. Hydophathicity plots predict that the 101 amino acid Pen-2 molecule has two hydrophobic domains (HP1 and HP2) that may serve as transmembrane spanning domains. Earlier reports indicated that transiently overexpressed Pen-2 uses these two hydrophobic domains as transmembrane helices that generates a “U-shaped” hairpin topology with both amino- (N-) and carboxyl-(C-) termini facing the lumen. In this report, we have reexamined the topology of endogenous Pen-2 and Pen-2 chimeras that are stably expressed in mammalian cells, and have assessed the function of these molecules in rescuing γ-secretase activity in Pen-2-deficient fibroblasts. Results We confirm that the Pen-2 C-terminus is lumenal, but the N-terminus of Pen-2 is exposed to the cytoplasm, thus indicating that HP1 does not traverse the lipid bilayer as a transmembrane domain. Domain swapping studies reveal the importance of specific regions within the first hydrophobic domain of Pen-2 that are critical for generating the topology that is a prerequisite for mediating PS1 endoproteolysis and γ-secretase activity. Finally, we report that the first fourteen amino acids of the Pen-2 HP1 are required for γ-secretase activity. Conclusions We propose that the first hydrophobic domain of Pen-2 forms a structure similar to a reentrant loop while the second hydrophobic domain spans the lipid bilayer.
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Affiliation(s)
- Xulun Zhang
- Department of Neurobiology, The University of Chicago, 947 E. 58th St. MC0928, Chicago, Il 60637, USA.
| | - Chunjiang J Yu
- Department of Neurobiology, The University of Chicago, 1128 S. Eastside Ave, Oak Park, Chicago, Il 60304, USA.
| | - Sangram S Sisodia
- Department of Neurobiology, The University of Chicago, 947 E. 58th St. MC0928, Chicago, Il 60637, USA.
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Midde K, Rich R, Saxena A, Gryczynski I, Borejdo J, Das HK. Membrane topology of human presenilin-1 in SK-N-SH cells determined by fluorescence correlation spectroscopy and fluorescent energy transfer. Cell Biochem Biophys 2015; 70:923-32. [PMID: 24839116 DOI: 10.1007/s12013-014-9999-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Presenilin-1 (PS1) protein acts as passive ER Ca(2+) leak channels that facilitate passive Ca(2+) leak across ER membrane. Mutations in the gene encoding PS1 protein cause neurodegeneration in the brains of patients with familial Alzheimer's disease (FAD). FADPS1 mutations abrogate the function of ER Ca(2+) leak channel activity in human neuroblastoma SK-N-SH cells in vitro (Das et al., J Neurochem 122(3):487-500, 2012) and in mouse embryonic fibroblasts. Consequently, genetic deletion or mutations of the PS1 gene cause calcium (Ca(2+)) signaling abnormalities leading to neurodegeneration in FAD patients. By analogy with other known ion channels it has been proposed that the functional PS1 channels in ER may be multimers of several PS1 subunits. To test this hypothesis, we conjugated the human PS1 protein with an NH2-terminal YFP-tag and a COOH-terminal CFP-tag. As expected YFP-PS1, and PS1-CFP were found to be expressed on the plasma membranes by TIRF microscopy, and both these fusion proteins increased ER Ca(2+) leak channel activity similar to PS1 (WT) in SK-N-SH cells, as determined by functional calcium imaging. PS1-CFP was either expressed alone or together with YFP-PS1 into SK-N-SH cell line and the interaction between YFP-PS1 and PS1-CFP was determined by Förster resonance energy transfer analysis. Our results suggest interaction between YFP-PS1 and PS1-CFP confirming the presence of a dimeric or multimeric form of PS1 in SK-N-SH cells. Lateral diffusion of PS1-CFP and YFP-PS1 in the plasma membrane of SK-N-SH cells was measured in the absence or in the presence of glycerol by fluorescence correlation spectroscopy to show that both COOH-terminal and NH2-terminal of human PS1 are located on the cytoplasmic side of the plasma membrane. Therefore, we conclude that both COOH-terminal and NH2-terminal of human PS1 may also be oriented on the cytosolic side of ER membrane.
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Affiliation(s)
- Krishna Midde
- Department of Cell Biology & Immunology and Center for Commercialization of Fluorescence Technologies, UNT Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107, USA
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Chu Y, Peng X, Long Z, Wang K, Luo S, Sharma A, He G. Distribution and expression of Pen-2 in the central nervous system of APP/PS1 double transgenic mice. Acta Biochim Biophys Sin (Shanghai) 2015; 47:258-66. [PMID: 25736404 DOI: 10.1093/abbs/gmv010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The γ-secretase complex catalyzes the final cleavage step of amyloid β-protein precursor (APP) to generate amyloid β (Aβ) peptide, a pathogenic component of senile plaques in the brain of Alzheimer's disease (AD) patients. Recent studies have shown that presenilin enhancer-2 (Pen-2), presenilin (PS, including PS1 and PS2), nicastrin, and anterior pharynx-defective 1 are essential components of the γ-secretase. The structure and function of Pen-2 in vitro have been well defined. However, little is known about the neuroanatomical distribution and expression of Pen-2 in the central nervous system (CNS) of AD model mice. We report here, using various methods such as immunohistochemical staining and immunoblotting, that Pen-2 is widely expressed at specific neuronal cells of major areas in AD model mice, including the olfactory bulb, basal forebrain, striatum, cortex, hippocampus, amygdala, thalamus, hypothalamus, cerebellum, brainstem, and spinal cord. It is co-expressed with PS1 in specific neuronal cells in mouse brain. Pen-2 is distributed much more extensively than extracellular amyloid deposits, suggesting the importance of other factors in localized amyloid deposition. Pen-2 is localized predominantly in cell membrane and cytoplasma in adult AD mice, but only distributed at cell membrane in controls. At the early stages of postnatal development, the expression level of Pen-2 is relatively high in CNS, but declines, gradually in adult mice. The present study provides an anatomical basis for Pen-2 as a key component of γ-secretase complex in the brain of developing and adult mice, and Pen-2 might be closely related to Aβ burden in aging nervous system.
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Affiliation(s)
- Yanan Chu
- Institute of Neuroscience, Chongqing Medical University, Chongqing 400016, China
| | - Xuehua Peng
- Department of Radiology, Pediatric Hospital, Chongqing Medical University, Chongqing 400016, China
| | - Zhiming Long
- Department of Anatomy, Chongqing Medical University, Chongqing 400016, China
| | - Kejian Wang
- Department of Anatomy, Chongqing Medical University, Chongqing 400016, China
| | - Shifang Luo
- Department of Anatomy, Chongqing Medical University, Chongqing 400016, China
| | - Akhilesh Sharma
- Institute of Neuroscience, Chongqing Medical University, Chongqing 400016, China
| | - Guiqiong He
- Institute of Neuroscience, Chongqing Medical University, Chongqing 400016, China Department of Anatomy, Chongqing Medical University, Chongqing 400016, China
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Gertsik N, Chiu D, Li YM. Complex regulation of γ-secretase: from obligatory to modulatory subunits. Front Aging Neurosci 2015; 6:342. [PMID: 25610395 PMCID: PMC4285130 DOI: 10.3389/fnagi.2014.00342] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 12/09/2014] [Indexed: 11/29/2022] Open
Abstract
γ-Secretase is a four subunit, 19-pass transmembrane enzyme that cleaves amyloid precursor protein (APP), catalyzing the formation of amyloid beta (Aβ) peptides that form amyloid plaques, which contribute to Alzheimer’s disease (AD) pathogenesis. γ-Secretase also cleaves Notch, among many other type I transmembrane substrates. Despite its seemingly promiscuous enzymatic capacity, γ-secretase activity is tightly regulated. This regulation is a function of many cellular entities, including but not limited to the essential γ-secretase subunits, nonessential (modulatory) subunits, and γ-secretase substrates. Regulation is also accomplished by an array of cellular events, such as presenilin (active subunit of γ-secretase) endoproteolysis and hypoxia. In this review we discuss how γ-secretase is regulated with the hope that an advanced understanding of these mechanisms will aid in the development of effective therapeutics for γ-secretase-associated diseases like AD and Notch-addicted cancer.
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Affiliation(s)
- Natalya Gertsik
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center New York, NY, USA ; Biochemistry and Molecular Biology Program, Weill Graduate School of Medical Sciences of Cornell University New York, NY, USA
| | - Danica Chiu
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center New York, NY, USA ; Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University New York, NY, USA
| | - Yue-Ming Li
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center New York, NY, USA ; Program of Pharmacology, Weill Graduate School of Medical Sciences of Cornell University New York, NY, USA
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Holmes O, Paturi S, Selkoe DJ, Wolfe MS. Pen-2 is essential for γ-secretase complex stability and trafficking but partially dispensable for endoproteolysis. Biochemistry 2014; 53:4393-406. [PMID: 24941111 PMCID: PMC4216188 DOI: 10.1021/bi500489j] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
![]()
The
19-transmembrane γ-secretase complex generates the amyloid
β-peptide of Alzheimer’s disease by intramembrane proteolysis
of the β-amyloid precursor
protein. This complex is comprised of presenilin, Aph1, nicastrin,
and Pen-2. The exact function and mechanism of the highly conserved
Pen-2 subunit remain poorly understood. Using systematic mutagenesis,
we confirm and extend our understanding of which key regions and specific
residues play roles in various aspects of γ-secretase function,
including maturation, localization, and activity, but not processivity.
In general, mutations (1) within the first half of transmembrane domain
(TMD) 1 of Pen-2 decreased PS1 endoproteolysis and γ-secretase
proteolytic activity, (2) within the second half of TMD1 increased
proteolytic activity, (3) within the cytosolic loop region decreased
proteolytic activity, (4) within TMD2 decreased PS1 endoproteolysis,
(5) within the first half of TMD2 decreased proteolytic activity,
and (6) within C-terminal residues decreased proteolytic activity.
Specific mutational effects included N33A in TMD1 causing an increase
in γ-secretase complexes at the cell surface and a modest decrease
in stability and the previously unreported I53A mutation in the loop
region reducing stability 10-fold and proteolytic activity by half.
In addition, we confirm that minor PS1 endoproteolysis can occur in
the complete absence of Pen-2. Together, these data suggest that rather
than solely being a catalyst for γ-secretase endoproteolysis,
Pen-2 may also stabilize the complex prior to PS1 endoproteolysis,
allowing time for full assembly and proper trafficking.
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Affiliation(s)
- Oliver Holmes
- Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School , Boston, Massachusetts 02115, United States
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Lu P, Bai XC, Ma D, Xie T, Yan C, Sun L, Yang G, Zhao Y, Zhou R, Scheres SHW, Shi Y. Three-dimensional structure of human γ-secretase. Nature 2014; 512:166-170. [PMID: 25043039 DOI: 10.1038/nature13567] [Citation(s) in RCA: 255] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 06/09/2014] [Indexed: 12/12/2022]
Abstract
The γ-secretase complex, comprising presenilin 1 (PS1), PEN-2, APH-1 and nicastrin, is a membrane-embedded protease that controls a number of important cellular functions through substrate cleavage. Aberrant cleavage of the amyloid precursor protein (APP) results in aggregation of amyloid-β, which accumulates in the brain and consequently causes Alzheimer's disease. Here we report the three-dimensional structure of an intact human γ-secretase complex at 4.5 Å resolution, determined by cryo-electron-microscopy single-particle analysis. The γ-secretase complex comprises a horseshoe-shaped transmembrane domain, which contains 19 transmembrane segments (TMs), and a large extracellular domain (ECD) from nicastrin, which sits immediately above the hollow space formed by the TM horseshoe. Intriguingly, nicastrin ECD is structurally similar to a large family of peptidases exemplified by the glutamate carboxypeptidase PSMA. This structure serves as an important basis for understanding the functional mechanisms of the γ-secretase complex.
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Affiliation(s)
- Peilong Lu
- Ministry of Education Key Laboratory of Protein Science, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China.,Tsinghua-Peking Joint Center for Life Sciences, Center for Structural Biology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Xiao-Chen Bai
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
| | - Dan Ma
- Ministry of Education Key Laboratory of Protein Science, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China.,Tsinghua-Peking Joint Center for Life Sciences, Center for Structural Biology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Tian Xie
- Ministry of Education Key Laboratory of Protein Science, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China.,Tsinghua-Peking Joint Center for Life Sciences, Center for Structural Biology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Chuangye Yan
- State Key Laboratory of Bio-membrane and Membrane Biotechnology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China.,Tsinghua-Peking Joint Center for Life Sciences, Center for Structural Biology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Linfeng Sun
- Ministry of Education Key Laboratory of Protein Science, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China.,Tsinghua-Peking Joint Center for Life Sciences, Center for Structural Biology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Guanghui Yang
- State Key Laboratory of Bio-membrane and Membrane Biotechnology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China.,Tsinghua-Peking Joint Center for Life Sciences, Center for Structural Biology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Yanyu Zhao
- Ministry of Education Key Laboratory of Protein Science, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China.,Tsinghua-Peking Joint Center for Life Sciences, Center for Structural Biology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Rui Zhou
- Ministry of Education Key Laboratory of Protein Science, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China.,Tsinghua-Peking Joint Center for Life Sciences, Center for Structural Biology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Sjors H W Scheres
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
| | - Yigong Shi
- Ministry of Education Key Laboratory of Protein Science, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China.,Tsinghua-Peking Joint Center for Life Sciences, Center for Structural Biology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
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Holmes O, Paturi S, Wolfe MS, Selkoe DJ. Functional analysis and purification of a Pen-2 fusion protein for γ-secretase structural studies. J Neurochem 2014; 131:94-100. [PMID: 24865334 DOI: 10.1111/jnc.12772] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 05/22/2014] [Indexed: 01/24/2023]
Abstract
The 19-transmembrane, multisubunit γ-secretase complex generates the amyloid β-peptide (Aβ) of Alzheimer's disease (AD) by an unusual intramembrane proteolysis of the β-amyloid precursor protein. The complex, which similarly processes many other type 1 transmembrane substrates, is composed of presenilin, Aph1, nicastrin, and presenilin enhancer (Pen-2), all of which are necessary for proper complex maturation and enzymatic activity. Obtaining a high-resolution atomic structure of the intact complex would greatly aid the rational design of compounds to modulate activity but is a very difficult task. A complementary method is to generate structures for each individual subunit to allow one to build a model of the entire complex. Here, we describe a method by which recombinant human Pen-2 can be purified from bacteria to > 95% purity at milligram quantities per liter, utilizing a maltose binding protein tag to both increase solubility and facilitate purification. Expressing the same construct in mammalian cells, we show that the large N-terminal maltose binding protein tag on Pen-2 still permits incorporation into the complex and subsequent presenilin-1 endoproteolysis, nicastrin glycosylation and proteolytic activity. These new methods provide valuable tools to study the structure and function of Pen-2 and the γ-secretase complex.
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Affiliation(s)
- Oliver Holmes
- Center for Neurologic Diseases, Brigham and Women's Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
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Involvement of the Notch pathway in terminal astrocytic differentiation: role of PKA. ASN Neuro 2013; 5:e00130. [PMID: 24286475 PMCID: PMC3891361 DOI: 10.1042/an20130023] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The Notch pathway is a highly conserved signaling system essential for modulating neurogenesis and promoting astrogenesis. Similarly, the cAMP signaling cascade can promote astrocytic commitment in several cell culture models, such as the C6 glioma cell line. These cells have the capacity to differentiate into oligodendrocytes or astrocytes, characteristics that allow their use as a glial progenitor model. In this context, we explore here the plausible involvement of cAMP in Notch-dependent signal transactions. The exposure of C6 cells to a non-hydrolysable cAMP analogue resulted in a sustained augmentation of Notch activity, as detected by nuclear translocation of its intracellular domain portion (NICD) and transcriptional activity. The cAMP effect is mediated through the activation of the γ-secretase complex, responsible for Notch cleavage and is sensitive to inhibitors of the cAMP-dependent protein kinase, PKA. As expected, Notch cleavage and nuclear translocation resulted in the up-regulation of the mRNA levels of one of its target genes, the transcription factor Hair and enhancer of split 5. Moreover, the glutamate uptake activity, as well as the expression of astrocytic markers such as glial fibrillary acidic protein, S100β protein and GLAST was also enhanced in cAMP-exposed cells. Our results clearly suggest that during the process of C6 astrocytic differentiation, cAMP activates the PKA/γ-secretase/NICD/RBPJκ pathway and Notch1 expression, leading to transcriptional activation of the genes responsible for glial progenitor cell fate decision.
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Jurisch-Yaksi N, Sannerud R, Annaert W. A fast growing spectrum of biological functions of γ-secretase in development and disease. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2815-27. [PMID: 24099003 DOI: 10.1016/j.bbamem.2013.04.016] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 04/03/2013] [Accepted: 04/11/2013] [Indexed: 12/17/2022]
Abstract
γ-secretase, which assembles as a tetrameric complex, is an aspartyl protease that proteolytically cleaves substrate proteins within their membrane-spanning domain; a process also known as regulated intramembrane proteolysis (RIP). RIP regulates signaling pathways by abrogating or releasing signaling molecules. Since the discovery, already >15 years ago, of its catalytic component, presenilin, and even much earlier with the identification of amyloid precursor protein as its first substrate, γ-secretase has been commonly associated with Alzheimer's disease. However, starting with Notch and thereafter a continuously increasing number of novel substrates, γ-secretase is becoming linked to an equally broader range of biological processes. This review presents an updated overview of the current knowledge on the diverse molecular mechanisms and signaling pathways controlled by γ-secretase, with a focus on organ development, homeostasis and dysfunction. This article is part of a Special Issue entitled: Intramembrane Proteases.
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Affiliation(s)
- Nathalie Jurisch-Yaksi
- Laboratory for Membrane Trafficking, VIB-Center for the Biology of Disease & Department for Human Genetics (KU Leuven), Leuven, Belgium
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Smolarkiewicz M, Skrzypczak T, Wojtaszek P. The very many faces of presenilins and the γ-secretase complex. PROTOPLASMA 2013; 250:997-1011. [PMID: 23504135 PMCID: PMC3788181 DOI: 10.1007/s00709-013-0494-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2013] [Accepted: 03/01/2013] [Indexed: 05/02/2023]
Abstract
Presenilin is a central, catalytic component of the γ-secretase complex which conducts intramembrane cleavage of various protein substrates. Although identified and mainly studied through its role in the development of amyloid plaques in Alzheimer disease, γ-secretase has many other important functions. The complex seems to be evolutionary conserved throughout the Metazoa, but recent findings in plants and Dictyostelium discoideum as well as in archeons suggest that its evolution and functions might be much more diversified than previously expected. In this review, a selective survey of the multitude of functions of presenilins and the γ-secretase complex is presented. Following a brief overview of γ-secretase structure, assembly and maturation, three functional aspects are analyzed: (1) the role of γ-secretase in autophagy and phagocytosis; (2) involvement of the complex in signaling related to endocytosis; and (3) control of calcium fluxes by presenilins.
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Affiliation(s)
- Michalina Smolarkiewicz
- Department of Molecular and Cellular Biology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland
| | - Tomasz Skrzypczak
- Department of Molecular and Cellular Biology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland
| | - Przemysław Wojtaszek
- Department of Molecular and Cellular Biology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland
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A patient with posterior cortical atrophy possesses a novel mutation in the presenilin 1 gene. PLoS One 2013; 8:e61074. [PMID: 23593396 PMCID: PMC3625161 DOI: 10.1371/journal.pone.0061074] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 03/05/2013] [Indexed: 12/17/2022] Open
Abstract
Posterior cortical atrophy is a dementia syndrome with symptoms of cortical visual dysfunction, associated with amyloid plaques and neurofibrillary tangles predominantly affecting visual association cortex. Most patients diagnosed with posterior cortical atrophy will finally develop a typical Alzheimer's disease. However, there are a variety of neuropathological processes, which could lead towards a clinical presentation of posterior cortical atrophy. Mutations in the presenilin 1 gene, affecting the function of γ-secretase, are the most common genetic cause of familial, early-onset Alzheimer's disease. Here we present a patient with a clinical diagnosis of posterior cortical atrophy who harbors a novel Presenilin 1 mutation (I211M). In silico analysis predicts that the mutation could influence the interaction between presenilin 1 and presenilin1 enhancer-2 protein, a protein partner within the γ-secretase complex. These findings along with published literature support the inclusion of posterior cortical atrophy on the Alzheimer's disease spectrum.
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Liu X, Zhao X, Zeng X, Bossers K, Swaab DF, Zhao J, Pei G. β-arrestin1 regulates γ-secretase complex assembly and modulates amyloid-β pathology. Cell Res 2012. [PMID: 23208420 PMCID: PMC3587707 DOI: 10.1038/cr.2012.167] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Alzheimer's disease (AD) is a progressive and complex neurodegenerative disease in which the γ-secretase-mediated amyloid-β (Aβ) pathology plays an important role. We found that a multifunctional protein, β-arrestin1, facilitated the formation of NCT/APH-1 (anterior pharynx-defective phenotype 1) precomplex and mature γ-secretase complex through its functional interaction with APH-1. Deficiency of β-arrestin1 or inhibition of binding of β-arrestin1 with APH-1 by small peptides reduced Aβ production without affecting Notch processing. Genetic ablation of β-arrestin1 diminished Aβ pathology and behavioral deficits in transgenic AD mice. Moreover, in brains of sporadic AD patients and transgenic AD mice, the expression of β-arrestin1 was upregulated and correlated well with neuropathological severity and senile Aβ plaques. Thus, our study identifies a regulatory mechanism underlying both γ-secretase assembly and AD pathogenesis, and indicates that specific reduction of Aβ pathology can be achieved by regulation of the γ-secretase assembly.
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Affiliation(s)
- Xiaosong Liu
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
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Sutinen EM, Pirttilä T, Anderson G, Salminen A, Ojala JO. Pro-inflammatory interleukin-18 increases Alzheimer's disease-associated amyloid-β production in human neuron-like cells. J Neuroinflammation 2012; 9:199. [PMID: 22898493 PMCID: PMC3458954 DOI: 10.1186/1742-2094-9-199] [Citation(s) in RCA: 146] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Accepted: 07/28/2012] [Indexed: 11/10/2022] Open
Abstract
Background Alzheimer’s disease (AD) involves increased accumulation of amyloid-β (Aβ) plaques and neurofibrillary tangles as well as neuronal loss in various regions of the neocortex. Neuroinflammation is also present, but its role in AD is not fully understood. We previously showed increased levels of pro-inflammatory cytokine interleukin-18 (IL-18) in different regions of AD brains, where it co-localized with Aβ-plaques, as well as the ability of IL-18 to increase expression of glycogen synthase kinase-3β (GSK-3β) and cyclin dependent kinase 5, involved in hyperphosphorylation of tau-protein. Elevated IL-18 has been detected in several risk conditions for AD, including obesity, type-II diabetes, and cardiovascular diseases as well as in stress. Methods We differentiated SH-SY5Y neuroblastoma cells as neuron-like and exposed them to IL-18 for various times. We examined the protein levels of amyloid-β precursor protein (APP) and its processing products, its cleaving enzymes, involved in amyloidogenic processing of APP, and markers of apoptosis. Results IL-18 increased protein levels of the β-site APP-cleaving enzyme BACE-1, the N-terminal fragment of presenilin-1 and slightly presenilin enhancer 2, both of which are members of the γ-secretase complex, as well as Fe65, which is a binding protein of the C-terminus of APP and one regulator for GSK-3β. IL-18 also increased APP expression and phosphorylation, which preceded increased BACE-1 levels. Further, IL-18 altered APP processing, increasing Aβ40 production in particular, which was inhibited by IL-18 binding protein. Increased levels of soluble APPβ were detected in culture medium after the IL-18 exposure. IL-18 also increased anti-apoptotic bcl-xL levels, which likely counteracted the minor increase of the pro-apoptotic caspase-3. Lactate dehydrogenase activity in culture medium was unaffected. Conclusions The IL-18 induction of BACE-1, APP processing, and Aβ is likely to be linked to stress-associated adaptations in neurons during the course of normal functioning and development. However, in the course of wider changes in the aging brain, and particularly in AD, the effects of heightened or prolonged levels of IL-18 may contribute to the process of AD, including via increased Aβ.
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Affiliation(s)
- Elina M Sutinen
- University of Eastern Finland, Institute of Clinical Medicine/ Neurology, Canthia, FI-70211, Kuopio, Finland
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Nesic I, Guix FX, Vennekens K, Michaki V, Van Veldhoven PP, Feiguin F, De Strooper B, Dotti CG, Wahle T. Alterations in phosphatidylethanolamine levels affect the generation of Aβ. Aging Cell 2012; 11:63-72. [PMID: 22023223 DOI: 10.1111/j.1474-9726.2011.00760.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Several studies suggest that the generation of Aβ is highly dependent on the levels of cholesterol within membranes' detergent-resistant microdomains (DRM). Indeed, the β-amyloid precursor protein (APP) cleaving machinery, namely β- and γ-secretases, has been shown to be present in DRM and its activity depends on membrane cholesterol levels. Counterintuitive to the localization of the cleavage machinery, the substrate, APP, localizes to membranes' detergent-soluble microdomains enriched in phospholipids (PL), indicating that Aβ generation is highly dependent on the capacity of enzyme and substrate to diffuse along the lateral plane of the membrane and therefore on the internal equilibrium of the different lipids of DRM and non-DRM domains. Here, we studied to which extent changes in the content of a main non-DRM lipid might affect the proteolytic processing of APP. As phosphatidylethanolamine (PE) accounts for the majority of PL, we focused on its impact on the regulation of APP proteolysis. In mammalian cells, siRNA-mediated knock-down of PE synthesis resulted in decreased Aβ owing to a dual effect: promoted α-secretase cleavage and decreased γ-secretase processing of APP. In vivo, in Drosophila melanogaster, genetic reduction in PL synthesis results in decreased γ-secretase-dependent cleavage of APP. These results suggest that modulation of the membrane-soluble domains could be a valuable alternative to reduce excessive Aβ generation.
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Affiliation(s)
- Iva Nesic
- Center for Human Genetics, Leuven Institute for Neurodegenerative diseases, KU Leuven, Leuven, Belgium
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D'Onofrio G, Panza F, Frisardi V, Solfrizzi V, Imbimbo BP, Paroni G, Cascavilla L, Seripa D, Pilotto A. Advances in the identification of γ-secretase inhibitors for the treatment of Alzheimer's disease. Expert Opin Drug Discov 2011; 7:19-37. [DOI: 10.1517/17460441.2012.645534] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Michaki V, Guix FX, Vennekens K, Munck S, Dingwall C, Davis JB, Townsend DM, Tew KD, Feiguin F, De Strooper B, Dotti CG, Wahle T. Down-regulation of the ATP-binding cassette transporter 2 (Abca2) reduces amyloid-β production by altering Nicastrin maturation and intracellular localization. J Biol Chem 2011; 287:1100-11. [PMID: 22086926 DOI: 10.1074/jbc.m111.288258] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Clinical, pharmacological, biochemical, and genetic evidence support the notion that alteration of cholesterol homeostasis strongly predisposes to Alzheimer disease (AD). The ATP-binding cassette transporter-2 (Abca2), which plays a role in intracellular sterol trafficking, has been genetically linked to AD. It is unclear how these two processes are related. Here we demonstrate that down-regulation of Abca2 in mammalian cells leads to decreased amyloid-β (Aβ) generation. In vitro studies revealed altered γ-secretase complex formation in Abca2 knock-out cells due to the altered levels, post-translational modification, and subcellular localization of Nicastrin. Reduced Abca2 levels in mammalian cells in vitro, in Drosophila melanogaster and in mice resulted in altered γ-secretase processing of APP, and thus Aβ generation, without affecting Notch cleavage.
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Affiliation(s)
- Vasiliki Michaki
- Center for Human Genetics and Leuven Institute for Neurodegenerative Diseases, KU Leuven, 3000 Leuven, Belgium
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