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Weeratunga S, Gormal RS, Liu M, Eldershaw D, Livingstone EK, Malapaka A, Wallis TP, Bademosi AT, Jiang A, Healy MD, Meunier FA, Collins BM. Interrogation and validation of the interactome of neuronal Munc18-interacting Mint proteins with AlphaFold2. J Biol Chem 2024; 300:105541. [PMID: 38072052 PMCID: PMC10820826 DOI: 10.1016/j.jbc.2023.105541] [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: 11/27/2023] [Accepted: 11/29/2023] [Indexed: 01/13/2024] Open
Abstract
Munc18-interacting proteins (Mints) are multidomain adaptors that regulate neuronal membrane trafficking, signaling, and neurotransmission. Mint1 and Mint2 are highly expressed in the brain with overlapping roles in the regulation of synaptic vesicle fusion required for neurotransmitter release by interacting with the essential synaptic protein Munc18-1. Here, we have used AlphaFold2 to identify and then validate the mechanisms that underpin both the specific interactions of neuronal Mint proteins with Munc18-1 as well as their wider interactome. We found that a short acidic α-helical motif within Mint1 and Mint2 is necessary and sufficient for specific binding to Munc18-1 and binds a conserved surface on Munc18-1 domain3b. In Munc18-1/2 double knockout neurosecretory cells, mutation of the Mint-binding site reduces the ability of Munc18-1 to rescue exocytosis, and although Munc18-1 can interact with Mint and Sx1a (Syntaxin1a) proteins simultaneously in vitro, we find that they have mutually reduced affinities, suggesting an allosteric coupling between the proteins. Using AlphaFold2 to then examine the entire cellular network of putative Mint interactors provides a structural model for their assembly with a variety of known and novel regulatory and cargo proteins including ADP-ribosylation factor (ARF3/ARF4) small GTPases and the AP3 clathrin adaptor complex. Validation of Mint1 interaction with a new predicted binder TJAP1 (tight junction-associated protein 1) provides experimental support that AlphaFold2 can correctly predict interactions across such large-scale datasets. Overall, our data provide insights into the diversity of interactions mediated by the Mint family and show that Mints may help facilitate a key trigger point in SNARE (soluble N-ethylmaleimide-sensitive factor attachment receptor) complex assembly and vesicle fusion.
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Affiliation(s)
- Saroja Weeratunga
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Rachel S Gormal
- Clem Jones Centre for Ageing and Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland, Australia
| | - Meihan Liu
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Denaye Eldershaw
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Emma K Livingstone
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Anusha Malapaka
- Clem Jones Centre for Ageing and Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland, Australia
| | - Tristan P Wallis
- Clem Jones Centre for Ageing and Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland, Australia
| | - Adekunle T Bademosi
- Clem Jones Centre for Ageing and Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland, Australia
| | - Anmin Jiang
- Clem Jones Centre for Ageing and Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland, Australia
| | - Michael D Healy
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Frederic A Meunier
- Clem Jones Centre for Ageing and Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland, Australia; School of Biomedical Sciences, The University of Queensland, Queensland, Australia
| | - Brett M Collins
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia.
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Chau DDL, Ng LLH, Zhai Y, Lau KF. Amyloid precursor protein and its interacting proteins in neurodevelopment. Biochem Soc Trans 2023; 51:1647-1659. [PMID: 37387352 PMCID: PMC10629809 DOI: 10.1042/bst20221527] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 06/22/2023] [Accepted: 06/26/2023] [Indexed: 07/01/2023]
Abstract
Amyloid precursor protein (APP) is a key molecule in the pathogenesis of Alzheimer's disease (AD) as the pathogenic amyloid-β peptide is derived from it. Two closely related APP family proteins (APPs) have also been identified in mammals. Current knowledge, including genetic analyses of gain- and loss-of-function mutants, highlights the importance of APPs in various physiological functions. Notably, APPs consist of multiple extracellular and intracellular protein-binding regions/domains. Protein-protein interactions are crucial for many cellular processes. In past decades, many APPs interactors have been identified which assist the revelation of the putative roles of APPs. Importantly, some of these interactors have been shown to influence several APPs-mediated neuronal processes which are found defective in AD and other neurodegenerative disorders. Studying APPs-interactor complexes would not only advance our understanding of the physiological roles of APPs but also provide further insights into the association of these processes to neurodegeneration, which may lead to the development of novel therapies. In this mini-review, we summarize the roles of APPs-interactor complexes in neurodevelopmental processes including neurogenesis, neurite outgrowth, axonal guidance and synaptogenesis.
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Affiliation(s)
- Dennis Dik-Long Chau
- School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Laura Lok-Haang Ng
- School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Yuqi Zhai
- School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Kwok-Fai Lau
- School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Hong Kong SAR, China
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3
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Bartling CRO, Jensen TMT, Henry SM, Colliander AL, Sereikaite V, Wenzler M, Jain P, Maric HM, Harpsøe K, Pedersen SW, Clemmensen LS, Haugaard-Kedström LM, Gloriam DE, Ho A, Strømgaard K. Targeting the APP-Mint2 Protein-Protein Interaction with a Peptide-Based Inhibitor Reduces Amyloid-β Formation. J Am Chem Soc 2021; 143:891-901. [PMID: 33398998 DOI: 10.1021/jacs.0c10696] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
There is an urgent need for novel therapeutic approaches to treat Alzheimer's disease (AD) with the ability to both alleviate the clinical symptoms and halt the progression of the disease. AD is characterized by the accumulation of amyloid-β (Aβ) peptides which are generated through the sequential proteolytic cleavage of the amyloid precursor protein (APP). Previous studies reported that Mint2, a neuronal adaptor protein binding both APP and the γ-secretase complex, affects APP processing and formation of pathogenic Aβ. However, there have been contradicting results concerning whether Mint2 has a facilitative or suppressive effect on Aβ generation. Herein, we deciphered the APP-Mint2 protein-protein interaction (PPI) via extensive probing of both backbone H-bond and side-chain interactions. We also developed a proteolytically stable, high-affinity peptide targeting the APP-Mint2 interaction. We found that both an APP binding-deficient Mint2 variant and a cell-permeable PPI inhibitor significantly reduced Aβ42 levels in a neuronal in vitro model of AD. Together, these findings demonstrate a facilitative role of Mint2 in Aβ formation, and the combination of genetic and pharmacological approaches suggests that targeting Mint2 is a promising therapeutic strategy to reduce pathogenic Aβ levels.
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Affiliation(s)
- Christian R O Bartling
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, DK-2100 Copenhagen, Denmark.,Department of Biology, Boston University, 24 Cummington Mall, Boston, Massachusetts 02215, United States
| | - Thomas M T Jensen
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, DK-2100 Copenhagen, Denmark
| | - Shawna M Henry
- Department of Biology, Boston University, 24 Cummington Mall, Boston, Massachusetts 02215, United States
| | - Anna L Colliander
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, DK-2100 Copenhagen, Denmark
| | - Vita Sereikaite
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, DK-2100 Copenhagen, Denmark
| | - Marcella Wenzler
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, DK-2100 Copenhagen, Denmark
| | - Palash Jain
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, DK-2100 Copenhagen, Denmark
| | - Hans M Maric
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, DK-2100 Copenhagen, Denmark
| | - Kasper Harpsøe
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, DK-2100 Copenhagen, Denmark
| | - Søren W Pedersen
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, DK-2100 Copenhagen, Denmark
| | - Louise S Clemmensen
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, DK-2100 Copenhagen, Denmark
| | - Linda M Haugaard-Kedström
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, DK-2100 Copenhagen, Denmark
| | - David E Gloriam
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, DK-2100 Copenhagen, Denmark
| | - Angela Ho
- Department of Biology, Boston University, 24 Cummington Mall, Boston, Massachusetts 02215, United States
| | - Kristian Strømgaard
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, DK-2100 Copenhagen, Denmark
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Sherva R, Gross A, Mukherjee S, Koesterer R, Amouyel P, Bellenguez C, Dufouil C, Bennett DA, Chibnik L, Cruchaga C, del-Aguila J, Farrer LA, Mayeux R, Munsie L, Winslow A, Newhouse S, Saykin AJ, Kauwe JS, Crane PK, Green RC. Genome-wide association study of rate of cognitive decline in Alzheimer's disease patients identifies novel genes and pathways. Alzheimers Dement 2020; 16:1134-1145. [PMID: 32573913 PMCID: PMC7924136 DOI: 10.1002/alz.12106] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 11/18/2019] [Accepted: 03/11/2020] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Variability exists in the disease trajectories of Alzheimer's disease (AD) patients. We performed a genome-wide association study to examine rate of cognitive decline (ROD) in patients with AD. METHODS We tested for interactions between genetic variants and time since diagnosis to predict the ROD of a composite cognitive score in 3946 AD cases and performed pathway analysis on the top genes. RESULTS Suggestive associations (P < 1.0 × 10-6 ) were observed on chromosome 15 in DNA polymerase-γ (rs3176205, P = 1.11 × 10-7 ), chromosome 7 (rs60465337,P = 4.06 × 10-7 ) in contactin-associated protein-2, in RP11-384F7.1 on chromosome 3 (rs28853947, P = 5.93 × 10-7 ), family with sequence similarity 214 member-A on chromosome 15 (rs2899492, P = 5.94 × 10-7 ), and intergenic regions on chromosomes 16 (rs4949142, P = 4.02 × 10-7 ) and 4 (rs1304013, P = 7.73 × 10-7 ). Significant pathways involving neuronal development and function, apoptosis, memory, and inflammation were identified. DISCUSSION Pathways related to AD, intelligence, and neurological function determine AD progression, while previously identified AD risk variants, including the apolipoprotein (APOE) ε4 and ε2 variants, do not have a major impact.
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Affiliation(s)
- Richard Sherva
- Department of Medicine (Biomedical Genetics), Boston University School of Medicine, 72 East Concord St., E-200, Boston, MA 02118, USA
| | - Alden Gross
- Johns Hopkins Bloomberg School of Public Health, 2024 E. Monument St, Johns Hopkins Center on Aging and Health, Suite 2-700, Baltimore, MD 21205, USA
| | - Shubhabrata Mukherjee
- Department of Medicine, University of Washington, Box 359780, 325 Ninth Avenue, Seattle, WA 98104, USA
| | - Ryan Koesterer
- Programs in Metabolism and Medical & Population Genetics, Broad Institute, Cambridge, MA, USA
| | - Philippe Amouyel
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, F-59000 Inserm UMR-1167, Institut Pasteur de Lille, 1 rue du Professeur Calmette, BP 245 - 59019 LILLE cedex, FRANCE
- Institut Pasteur de Lille, Lille, France
- University of Lille, DISTALZ Laboratory of Excellence (LabEx), Lille, France
| | - Celine Bellenguez
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, F-59000 Inserm UMR-1167, Institut Pasteur de Lille, 1 rue du Professeur Calmette, BP 245 - 59019 LILLE cedex, FRANCE
- Institut Pasteur de Lille, Lille, France
- University of Lille, DISTALZ Laboratory of Excellence (LabEx), Lille, France
| | - Carole Dufouil
- Inserm Unit 1219 Bordeaux Population Health, CIC 1401-EC (Clinical Epidemiology), University of Bordeaux, ISPED (Bordeaux School of Public Health), Bordeaux University Hospital, Bordeaux, France
| | - David A. Bennett
- Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, Illinois, USA
- Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois, USA
| | - Lori Chibnik
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Carlos Cruchaga
- Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, USA
- Department of Psychiatry, Washington University School of Medicine, Campus Box 8134, 425 S. Euclid Ave, Office 9607, St. Louis, MO 63110, USA
- Knight Alzheimer’s Disease Research Center, Washington University School of Medicine, St. Louis, MO, USA
- NeuroGenomics and Informatics. Washington University School of Medicine, Saint Louis, USA
| | - Jorge del-Aguila
- Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, USA
- Department of Psychiatry, Washington University School of Medicine, Campus Box 8134, 425 S. Euclid Ave, Office 9607, St. Louis, MO 63110, USA
- Knight Alzheimer’s Disease Research Center, Washington University School of Medicine, St. Louis, MO, USA
- NeuroGenomics and Informatics. Washington University School of Medicine, Saint Louis, USA
| | - Lindsay A. Farrer
- Department of Medicine (Biomedical Genetics), Boston University School of Medicine, 72 East Concord St., E-200, Boston, MA 02118, USA
- Bioinformatics Graduate Program, Boston University, Boston, Massachusetts
- Department of Neurology, Boston University School of Medicine, Boston, Massachusetts
- Department of Biostatistics, Boston University School of Public Health, Boston, Massachusetts
- Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts
- Department of Epidemiology, Boston University School of Public Health, Boston, Massachusetts
| | - Richard Mayeux
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
- The Gertrude H. Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA
- Department of Neurology, College of Physicians and Surgeons, New York-Presbyterian Hospital, Columbia University Medical Center, New York, NY, USA
| | - Leanne Munsie
- Eli Lilly and Company, Lilly Corporate Center, Indianapolis, IN 46285, USA
| | - Ashley Winslow
- Orphan Disease Center, Perelman School of Medicine, University of Pennsylvania, 125 South 31st Street, Pennsylvania, PA 19104, USA
| | - Stephen Newhouse
- Department of Biostatistics and Health Informatics, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
- NIHR BioResource Centre Maudsley, NIHR Maudsley Biomedical Research Centre (BRC) at South London and Maudsley NHS Foundation Trust (SLaM) & Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King’s College London, London, UK
- Health Data Research UK London, University College London, London, UK
- dd Institute of Health Informatics, University College London, London, UK
- The National Institute for Health Research University College London Hospitals Biomedical Research Centre, University College London, London, UK
| | - Andrew J. Saykin
- Indiana Alzheimer Disease Center and Department of Radiology and Imaging Sciences, Indiana University School of Medicine, IU Health Neuroscience Center, Suite 4100, 355 West 16th Street, Indianapolis, IN 46202, USA
| | - John S.K. Kauwe
- Department of Biology, Brigham Young University, 105 FPH, Provo, UT 84602, USA
| | | | - Paul K. Crane
- Department of Medicine, University of Washington, Box 359780, 325 Ninth Avenue, Seattle, WA 98104, USA
| | - Robert C. Green
- Division of Genetics, Department of Medicine, Brigham and Women’s Hospital, EC Alumnae Building, Suite 301, 41 Avenue Louis Pasteur, Boston, MA 02115, USA
- The Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Harvard Medical School, Boston, MA, USA
- Partners HealthCare Personalized Medicine, Boston, MA, USA
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Chau DDL, Yung KWY, Chan WWL, An Y, Hao Y, Chan HYE, Ngo JCK, Lau KF. Attenuation of amyloid-β generation by atypical protein kinase C-mediated phosphorylation of engulfment adaptor PTB domain containing 1 threonine 35. FASEB J 2019; 33:12019-12035. [PMID: 31373844 DOI: 10.1096/fj.201802825rr] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Amyloid-β (Aβ) is derived from the proteolytic processing of amyloid precursor protein (APP), and the deposition of extracellular Aβ to form amyloid plaques is a pathologic hallmark of Alzheimer's disease (AD). Although reducing Aβ generation and accumulation has been proposed as a means of treating the disease, adverse side effects and unsatisfactory efficacy have been reported in several clinical trials that sought to lower Aβ levels. Engulfment adaptor phosphotyrosine-binding (PTB) domain containing 1 (GULP1) is a molecular adaptor that has been shown to interact with APP to alter Aβ production. Therefore, the modulation of the GULP1-APP interaction may be an alternative approach to reducing Aβ. However, the mechanisms that regulate GULP1-APP binding remain elusive. As GULP1 is a phosphoprotein, and because phosphorylation is a common mechanism that regulates protein interaction, we anticipated that GULP1 phosphorylation would influence GULP1-APP interaction and thereby Aβ production. We show here that the phosphorylation of GULP1 threonine 35 (T35) reduces GULP1-APP interaction and suppresses the stimulatory effect of GULP1 on APP processing. The residue is phosphorylated by an isoform of atypical PKC (PKCζ). Overexpression of PKCζ reduces both GULP1-APP interaction and GULP1-mediated Aβ generation. Moreover, the activation of PKCζ via insulin suppresses APP processing. In contrast, GULP1-mediated APP processing is enhanced in PKCζ knockout cells. Similarly, PKC ι, another member of atypical PKC, also decreases GULP1-mediated APP processing. Intriguingly, our X-ray crystal structure of GULP1 PTB-APP intracellular domain (AICD) peptide reveals that GULP1 T35 is not located at the GULP1-AICD binding interface; rather, it immediately precedes the β1-α2 loop that forms a portion of the binding groove for the APP helix αC. Phosphorylating the residue may induce an allosteric effect on the conformation of the binding groove. Our results indicate that GULP1 T35 phosphorylation is a mechanism for the regulation of GULP1-APP interaction and thereby APP processing. Moreover, the activation of atypical PKC, such as by insulin, may confer a beneficial effect on AD by lowering GULP1-mediated Aβ production.-Chau, D. D.-L., Yung, K. W.-Y., Chan, W. W.-L., An, Y., Hao, Y., Chan, H.-Y. E., Ngo, J. C.-K., Lau, K.-F. Attenuation of amyloid-β generation by atypical protein kinase C-mediated phosphorylation of engulfment adaptor PTB domain containing 1 threonine 35.
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Affiliation(s)
- Dennis Dik-Long Chau
- Faculty of Science, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Kristen Wing-Yu Yung
- Faculty of Science, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - William Wai-Lun Chan
- Faculty of Science, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Ying An
- Faculty of Science, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Yan Hao
- Faculty of Science, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Ho-Yin Edwin Chan
- Faculty of Science, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Jacky Chi-Ki Ngo
- Faculty of Science, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Kwok-Fai Lau
- Faculty of Science, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
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GULP1/CED-6 ameliorates amyloid-β toxicity in a Drosophila model of Alzheimer's disease. Oncotarget 2017; 8:99274-99283. [PMID: 29245900 PMCID: PMC5725091 DOI: 10.18632/oncotarget.20062] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 07/30/2017] [Indexed: 01/24/2023] Open
Abstract
Amyloidogenic processing of APP by β- and γ-secretases leads to the generation of amyloid-β peptide (Aβ), and the accumulation of Aβ in senile plaques is a hallmark of Alzheimer’s disease (AD). Understanding the mechanisms of APP processing is therefore paramount. Increasing evidence suggests that APP intracellular domain (AICD) interacting proteins influence APP processing. In this study, we characterized the overexpression of AICD interactor GULP1 in a Drosophila AD model expressing human BACE and APP695. Transgenic GULP1 significantly lowered the levels of both Aβ1-40 and Aβ1-42 without decreasing the BACE and APP695 levels. Overexpression of GULP1 also reduced APP/BACE-mediated retinal degeneration, rescued motor dysfunction and extended longevity of the flies. Our results indicate that GULP1 regulate APP processing and reduce neurotoxicity in a Drosophila AD model.
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7
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Arbor SC, LaFontaine M, Cumbay M. Amyloid-beta Alzheimer targets - protein processing, lipid rafts, and amyloid-beta pores. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2016; 89:5-21. [PMID: 27505013 PMCID: PMC4797837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Amyloid beta (Aβ), the hallmark of Alzheimer's Disease (AD), now appears to be deleterious in its low number aggregate form as opposed to the macroscopic Aβ fibers historically seen postmortem. While Alzheimer targets, such as the tau protein, amyloid precursor protein (APP) processing, and immune system activation continue to be investigated, the recent discovery that amyloid beta aggregates at lipid rafts and likely forms neurotoxic pores has led to a new paradigm regarding why past therapeutics may have failed and how to design the next round of compounds for clinical trials. An atomic resolution understanding of Aβ aggregates, which appear to exist in multiple conformations, is most desirable for future therapeutic development. The investigative difficulties, structures of these small Aβ aggregates, and current therapeutics are summarized in this review.
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Affiliation(s)
- Sage C. Arbor
- Marian University College of Osteopathic Medicine, 3200 Cold Spring Road, Indianapolis, Indiana, 46222
| | - Mike LaFontaine
- Marian University College of Osteopathic Medicine, 3200 Cold Spring Road, Indianapolis, Indiana, 46222
| | - Medhane Cumbay
- Marian University College of Osteopathic Medicine, 3200 Cold Spring Road, Indianapolis, Indiana, 46222
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8
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The effects of the cellular and infectious prion protein on the neuronal adaptor protein X11α. Biochim Biophys Acta Gen Subj 2015; 1850:2213-21. [PMID: 26297964 DOI: 10.1016/j.bbagen.2015.08.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 07/27/2015] [Accepted: 08/18/2015] [Indexed: 01/06/2023]
Abstract
BACKGROUND The neuronal adaptor protein X11α is a multidomain protein with a phosphotyrosine binding (PTB) domain, two PDZ (PSD_95, Drosophila disks-large, ZO-1) domains, a Munc Interacting (MI) domain and a CASK interacting region. Amongst its functions is a role in the regulation of the abnormal processing of the amyloid precursor protein (APP). It also regulates the activity of Cu/Zn Superoxide dismutase (SOD1) through binding with its chaperone the copper chaperone for SOD1. How X11α production is controlled has remained unclear. METHODS Using the neuroblastoma cell line, N2a, and knockdown studies, the effect of the cellular and infectious prion protein, PrP(C) and PrP(Sc), on X11α is examined. RESULTS We show that X11α expression is directly proportional to the expression of PrP(C), whereas its levels are reduced by PrP(Sc). We also show PrP(Sc) to affect X11α at a functional level. One of the effects of prion infection is lowered cellular SOD1 levels, here by knockdown of X11α we identify that the effect of PrP(Sc) on SOD1 can be reversed indicating that X11α is involved in prion disease pathogenesis. CONCLUSIONS A role for the cellular and infectious prion protein, PrP(C) and PrP(Sc), respectively, in regulating X11α is identified in this work. GENERAL SIGNIFICANCE Due to the multiple interacting partners of X11α, dysfunction or alteration in X11α will have a significant cellular effect. This work highlights the role of PrP(C) and PrP(Sc) in the regulation of X11α, and provides a new target pathway to control X11α and its related functions.
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Takei N, Sobu Y, Kimura A, Urano S, Piao Y, Araki Y, Taru H, Yamamoto T, Hata S, Nakaya T, Suzuki T. Cytoplasmic fragment of Alcadein α generated by regulated intramembrane proteolysis enhances amyloid β-protein precursor (APP) transport into the late secretory pathway and facilitates APP cleavage. J Biol Chem 2014; 290:987-95. [PMID: 25406318 DOI: 10.1074/jbc.m114.599852] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The neural type I membrane protein Alcadein α (Alcα), is primarily cleaved by amyloid β-protein precursor (APP) α-secretase to generate a membrane-associated carboxyl-terminal fragment (Alcα CTF), which is further cleaved by γ-secretase to secrete p3-Alcα peptides and generate an intracellular cytoplasmic domain fragment (Alcα ICD) in the late secretory pathway. By association with the neural adaptor protein X11L (X11-like), Alcα and APP form a ternary complex that suppresses the cleavage of both Alcα and APP by regulating the transport of these membrane proteins into the late secretory pathway where secretases are active. However, it has not been revealed how Alcα and APP are directed from the ternary complex formed largely in the Golgi into the late secretory pathway to reach a nerve terminus. Using a novel transgenic mouse line expressing excess amounts of human Alcα CTF (hAlcα CTF) in neurons, we found that expression of hAlcα CTF induced excess production of hAlcα ICD, which facilitated APP transport into the nerve terminus and enhanced APP metabolism, including Aβ generation. In vitro cell studies also demonstrated that excess expression of Alcα ICD released both APP and Alcα from the ternary complex. These results indicate that regulated intramembrane proteolysis of Alcα by γ-secretase regulates APP trafficking and the production of Aβ in vivo.
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Affiliation(s)
- Norio Takei
- From the Laboratory of Neuroscience, Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12 Nishi-6, Kita-ku, Sapporo 060-0812, Japan and
| | - Yuriko Sobu
- From the Laboratory of Neuroscience, Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12 Nishi-6, Kita-ku, Sapporo 060-0812, Japan and
| | - Ayano Kimura
- From the Laboratory of Neuroscience, Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12 Nishi-6, Kita-ku, Sapporo 060-0812, Japan and
| | - Satomi Urano
- From the Laboratory of Neuroscience, Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12 Nishi-6, Kita-ku, Sapporo 060-0812, Japan and
| | - Yi Piao
- From the Laboratory of Neuroscience, Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12 Nishi-6, Kita-ku, Sapporo 060-0812, Japan and
| | - Yoichi Araki
- From the Laboratory of Neuroscience, Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12 Nishi-6, Kita-ku, Sapporo 060-0812, Japan and
| | - Hidenori Taru
- From the Laboratory of Neuroscience, Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12 Nishi-6, Kita-ku, Sapporo 060-0812, Japan and
| | - Tohru Yamamoto
- Department of Molecular Neurobiology, Faculty of Medicine, Kagawa University, Miki-cho 761-0793, Japan
| | - Saori Hata
- From the Laboratory of Neuroscience, Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12 Nishi-6, Kita-ku, Sapporo 060-0812, Japan and
| | - Tadashi Nakaya
- From the Laboratory of Neuroscience, Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12 Nishi-6, Kita-ku, Sapporo 060-0812, Japan and
| | - Toshiharu Suzuki
- From the Laboratory of Neuroscience, Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12 Nishi-6, Kita-ku, Sapporo 060-0812, Japan and
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10
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Csiszar A, Tucsek Z, Toth P, Sosnowska D, Gautam T, Koller A, Deak F, Sonntag WE, Ungvari Z. Synergistic effects of hypertension and aging on cognitive function and hippocampal expression of genes involved in β-amyloid generation and Alzheimer's disease. Am J Physiol Heart Circ Physiol 2013; 305:H1120-30. [PMID: 23955715 DOI: 10.1152/ajpheart.00288.2013] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Strong epidemiological and experimental evidence indicate that hypertension in the elderly predisposes to the development of Alzheimer's disease (AD), but the underlying mechanisms remain elusive. The present study was designed to characterize the additive/synergistic effects of hypertension and aging on the expression of genes involved in β-amyloid generation and AD in the hippocampus, an area of brain contributing to higher cognitive function, which is significantly affected by AD both in humans and in mouse models of the disease. To achieve that goal, we induced hypertension in young (3 mo) and aged (24 mo) C57BL/6 mice by chronic (4 wk) infusion of angiotensin II and assessed changes in hippocampal mRNA expression of genes involved in amyloid precursor protein (APP)-dependent signaling, APP cleavage, Aβ processing and Aβ-degradation, synaptic function, dysregulation of microtubule-associated τ protein, and apolipoprotein-E signaling. Aged hypertensive mice exhibited spatial memory impairments in the Y-maze and impaired performance in the novel object recognition assay. Surprisingly, hypertension in aging did not increase the expression of APP, β- and γ-secretases, or genes involved in tauopathy. These genes are all involved in the early onset form of AD. Yet, hypertension in aging was associated with changes in hippocampal expression of APP binding proteins, e.g., [Mint3/amyloid β A4 precursor protein-binding family A member 3 (APBA3), Fe65/amyloid β A4 precursor protein-binding family B member 1 (APBB1)], amyloid β (A4) precursor-like protein 1 (APLP1), muscarinic M1 receptor, and serum amyloid P component, all of which may have a role in the pathogenesis of late-onset AD. The hippocampal gene expression signature observed in aged hypertensive mice in the present study provides important clues for subsequent studies to elucidate the mechanisms by which hypertension may contribute to the pathogenesis and clinical manifestation of AD.
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Affiliation(s)
- Anna Csiszar
- Reynolds Oklahoma Center on Aging, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
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Abstract
Mislocalization of axonal proteins can result in misassembly and/or miswiring of neural circuits, causing disease. To date, only a handful of genes that control polarized localization of axonal membrane proteins have been identified. Here we report that Drosophila X11/Mint proteins are required for targeting several proteins, including human amyloid precursor protein (APP) and Drosophila APP-like protein (APPL), to axonal membranes and for their exclusion from dendrites of the mushroom body in Drosophila, a brain structure involved in learning and memory. Axonal localization of APP is mediated by an endocytic motif, and loss of X11/Mint results in a dramatic increase in cell-surface levels of APPL, especially on dendrites. Mutations in genes required for endocytosis show similar mislocalization of these proteins to dendrites, and strongly enhance defects seen in X11/Mint mutants. These results suggest that X11/Mint-dependent endocytosis in dendrites may serve to promote the axonal localization of membrane proteins. Since X11/Mint binds to APP, and abnormal trafficking of APP contributes to Alzheimer's disease, deregulation of X11/Mint may be important for Alzheimer's disease pathogenesis.
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12
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A new Mint1 isoform, but not the conventional Mint1, interacts with the small GTPase Rab6. PLoS One 2013; 8:e64149. [PMID: 23737971 PMCID: PMC3667844 DOI: 10.1371/journal.pone.0064149] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 04/09/2013] [Indexed: 12/31/2022] Open
Abstract
Small GTPases of the Rab family are important regulators of a large variety of different cellular functions such as membrane organization and vesicle trafficking. They have been shown to play a role in several human diseases. One prominent member, Rab6, is thought to be involved in the development of Alzheimer's Disease, the most prevalent mental disorder worldwide. Previous studies have shown that Rab6 impairs the processing of the amyloid precursor protein (APP), which is cleaved to β-amyloid in brains of patients suffering from Alzheimer's Disease. Additionally, all three members of the Mint adaptor family are implied to participate in the amyloidogenic pathway. Here, we report the identification of a new Mint1 isoform in a yeast two-hybrid screening, Mint1 826, which lacks an eleven amino acid (aa) sequence in the conserved C-terminal region. Mint1 826, but not the conventional Mint1, interacts with Rab6 via the PTB domain. This interaction is nucleotide-dependent, Rab6-specific and influences the subcellular localization of Mint1 826. We were able to detect and sequence a corresponding proteolytic peptide derived from cellular Mint1 826 by mass spectrometry proving the absence of aa 495-505 and could show that the deletion does not influence the ability of this adaptor protein to interact with APP. Taking into account that APP interacts and co-localizes with Mint1 826 and is transported in Rab6 positive vesicles, our data suggest that Mint1 826 bridges APP to the small GTPase at distinct cellular sorting points, establishing Mint1 826 as an important player in regulation of APP trafficking and processing.
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13
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Abstract
Alzheimer's disease (AD), the leading cause of dementia worldwide, is characterized by the accumulation of the β-amyloid peptide (Aβ) within the brain along with hyperphosphorylated and cleaved forms of the microtubule-associated protein tau. Genetic, biochemical, and behavioral research suggest that physiologic generation of the neurotoxic Aβ peptide from sequential amyloid precursor protein (APP) proteolysis is the crucial step in the development of AD. APP is a single-pass transmembrane protein expressed at high levels in the brain and metabolized in a rapid and highly complex fashion by a series of sequential proteases, including the intramembranous γ-secretase complex, which also process other key regulatory molecules. Why Aβ accumulates in the brains of elderly individuals is unclear but could relate to changes in APP metabolism or Aβ elimination. Lessons learned from biochemical and genetic studies of APP processing will be crucial to the development of therapeutic targets to treat AD.
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14
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Activation of Liver X Receptor Decreases BACE1 Expression and Activity by Reducing Membrane Cholesterol Levels. Neurochem Res 2011; 36:1910-21. [DOI: 10.1007/s11064-011-0513-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/14/2011] [Indexed: 11/26/2022]
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15
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Kondo M, Shiono M, Itoh G, Takei N, Matsushima T, Maeda M, Taru H, Hata S, Yamamoto T, Saito Y, Suzuki T. Increased amyloidogenic processing of transgenic human APP in X11-like deficient mouse brain. Mol Neurodegener 2010; 5:35. [PMID: 20843325 PMCID: PMC2949864 DOI: 10.1186/1750-1326-5-35] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Accepted: 09/15/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND X11-family proteins, including X11, X11-like (X11L) and X11-like 2 (X11L2), bind to the cytoplasmic domain of amyloid β-protein precursor (APP) and regulate APP metabolism. Both X11 and X11L are expressed specifically in brain, while X11L2 is expressed ubiquitously. X11L is predominantly expressed in excitatory neurons, in contrast to X11, which is strongly expressed in inhibitory neurons. In vivo gene-knockout studies targeting X11, X11L, or both, and studies of X11 or X11L transgenic mice have reported that X11-family proteins suppress the amyloidogenic processing of endogenous mouse APP and ectopic human APP with one exception: knockout of X11, X11L or X11L2 has been found to suppress amyloidogenic metabolism in transgenic mice overexpressing the human Swedish mutant APP (APPswe) and the mutant human PS1, which lacks exon 9 (PS1dE9). Therefore, the data on X11-family protein function in transgenic human APP metabolism in vivo are inconsistent. RESULTS To confirm the interaction of X11L with human APP ectopically expressed in mouse brain, we examined the amyloidogenic metabolism of human APP in two lines of human APP transgenic mice generated to also lack X11L. In agreement with previous reports from our lab and others, we found that the amyloidogenic metabolism of human APP increased in the absence of X11L. CONCLUSION X11L appears to aid in the suppression of amyloidogenic processing of human APP in brain in vivo, as has been demonstrated by previous studies using several human APP transgenic lines with various genetic backgrounds. X11L appears to regulate human APP in a manner similar to that seen in endogenous mouse APP metabolism.
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Affiliation(s)
- Maho Kondo
- Laboratory of Neuroscience, Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita12-Nishi6, Kita-ku, Sapporo 060-0812, Japan.
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16
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Mitchell JC, Perkinton MS, Yates DM, Lau KF, Rogelj B, Miller CC, McLoughlin DM. Expression of the neuronal adaptor protein X11alpha protects against memory dysfunction in a transgenic mouse model of Alzheimer's disease. J Alzheimers Dis 2010; 20:31-6. [PMID: 20378958 PMCID: PMC3023903 DOI: 10.3233/jad-2009-1341] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
X11alpha is a neuronal-specific adaptor protein that binds to the amyloid-beta protein precursor (AbetaPP). Overexpression of X11alpha reduces Abeta production but whether X11alpha also protects against Abeta-related memory dysfunction is not known. To test this possibility, we crossed X11alpha transgenic mice with AbetaPP-Tg2576 mice. AbetaPP-Tg2576 mice produce high levels of brain Abeta and develop age-related defects in memory function that correlate with increasing Abeta load. Overexpression of X11alpha alone had no detectable adverse effect upon behavior. However, X11alpha reduced brain Abeta levels and corrected spatial reference memory defects in aged X11alpha/AbetaPP double transgenics. Thus, X11alpha may be a therapeutic target for Alzheimer's disease.
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Affiliation(s)
- Jacqueline C. Mitchell
- MRC Centre for Neurodegeneration Research, King’s College London, Institute of Psychiatry, London, UK
| | - Michael S. Perkinton
- MRC Centre for Neurodegeneration Research, King’s College London, Institute of Psychiatry, London, UK
| | - Darran M. Yates
- MRC Centre for Neurodegeneration Research, King’s College London, Institute of Psychiatry, London, UK
| | - Kwok-Fai Lau
- Department of Biochemistry (Science), The Chinese University of Hong Kong, Shatin NT, Hong Kong SAR
| | - Boris Rogelj
- MRC Centre for Neurodegeneration Research, King’s College London, Institute of Psychiatry, London, UK
| | - Christopher C.J. Miller
- MRC Centre for Neurodegeneration Research, King’s College London, Institute of Psychiatry, London, UK
| | - Declan M. McLoughlin
- MRC Centre for Neurodegeneration Research, King’s College London, Institute of Psychiatry, London, UK
- Department of Psychiatry and Trinity College Institute of Neuroscience, Trinity College Dublin, St Patrick’s University Hospital, Dublin, Ireland
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