1
|
Thulasidharan A, Garg L, Tendulkar S, Ratnaparkhi GS. Age-dependent dynamics of neuronal VAPB ALS inclusions in the adult brain. Neurobiol Dis 2024; 196:106517. [PMID: 38679111 DOI: 10.1016/j.nbd.2024.106517] [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: 02/12/2024] [Revised: 04/01/2024] [Accepted: 04/25/2024] [Indexed: 05/01/2024] Open
Abstract
Amyotrophic Lateral Sclerosis (ALS) is a relentlessly progressive and fatal disease, caused by the degeneration of upper and lower motor neurons within the brain and spinal cord in the ageing human. The dying neurons contain cytoplasmic inclusions linked to the onset and progression of the disease. Here, we use a Drosophila model of ALS8 (VAPP58S) to understand the modulation of these inclusions in the ageing adult brain. The adult VAPP58S fly shows progressive deterioration in motor function till its demise 25 days post-eclosion. The density of VAPP58S-positive brain inclusions is stable for 5-15 days of age. In contrast, adding a single copy of VAPWT to the VAPP58S animal leads to a large decrease in inclusion density with concomitant rescue of motor function and lifespan. ER stress, a contributing factor in disease, shows reduction with ageing for the disease model. Autophagy, rather than the Ubiquitin Proteasome system, is the dominant mechanism for aggregate clearance. We explored the ability of Drosophila Valosin-containing protein (VCP/TER94), the ALS14 locus, which is involved in cellular protein clearance, to regulate age-dependent aggregation. Contrary to expectation, TER94 overexpression increased VAPP58S punctae density, while its knockdown led to enhanced clearance. Expression of a dominant positive allele, TER94R152H, further stabilised VAPP58S puncta, cementing roles for an ALS8-ALS14 axis. Our results are explained by a mechanism where autophagy is modulated by TER94 knockdown. Our study sheds light on the complex regulatory events involved in the neuronal maintenance of ALS8 aggregates, suggesting a context-dependent switch between proteasomal and autophagy-based mechanisms as the larvae develop into an adult. A deeper understanding of the nucleation and clearance of the inclusions, which affect cellular stress and function, is essential for understanding the initiation and progression of ALS.
Collapse
Affiliation(s)
- Aparna Thulasidharan
- Department of Biology, Indian Institute of Science Education & Research (IISER), Pune 411008, India
| | - Lovleen Garg
- Department of Biology, Indian Institute of Science Education & Research (IISER), Pune 411008, India
| | - Shweta Tendulkar
- Department of Biology, Indian Institute of Science Education & Research (IISER), Pune 411008, India
| | - Girish S Ratnaparkhi
- Department of Biology, Indian Institute of Science Education & Research (IISER), Pune 411008, India.
| |
Collapse
|
2
|
Landry C, Costanzo J, Mitne-Neto M, Zatz M, Schaffer A, Hatzoglou M, Muotri A, Miranda HC. Mitochondrial dysfunction heightens the integrated stress response to drive ALS pathogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.13.594000. [PMID: 38798645 PMCID: PMC11118434 DOI: 10.1101/2024.05.13.594000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Vesicle-associated membrane protein-associated protein-B (VAPB) is an ER membrane bound protein. VAPB P56S causes a dominant, familial form of amyotrophic lateral sclerosis (ALS), however, the mechanism through which this mutation causes motor neuron (MN) disease remains unknown. Using inducible wild type (WT) and VAPB P56S expressing iPSC-derived MNs we show that VAPB P56S, but not WT, protein decreased neuronal firing and mitochondrial-ER contact (MERC) with an associated age-dependent decrease in mitochondrial membrane potential (MMP); all typical characteristics of MN-disease. We further show that VAPB P56S expressing iPSC-derived MNs have enhanced age-dependent sensitivity to ER stress. We identified elevated expression of the master regulator of the Integrated Stress Response (ISR) marker ATF4 and decreased protein synthesis in the VAPB P56S iPSC-derived MNs. Chemical inhibition of ISR with the compound, ISRIB, rescued all MN disease phenotype in VAPB P56S MNs. Thus, our results not only support ISR inhibition as a potential therapeutic target for ALS patients, but also provides evidence to pathogenesis.
Collapse
|
3
|
Wang Y, Yang J. ER-organelle contacts: A signaling hub for neurological diseases. Pharmacol Res 2024; 203:107149. [PMID: 38518830 DOI: 10.1016/j.phrs.2024.107149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 03/07/2024] [Accepted: 03/19/2024] [Indexed: 03/24/2024]
Abstract
Neuronal health is closely linked to the homeostasis of intracellular organelles, and organelle dysfunction affects the pathological progression of neurological diseases. In contrast to isolated cellular compartments, a growing number of studies have found that organelles are largely interdependent structures capable of communicating through membrane contact sites (MCSs). MCSs have been identified as key pathways mediating inter-organelle communication crosstalk in neurons, and their alterations have been linked to neurological disease pathology. The endoplasmic reticulum (ER) is a membrane-bound organelle capable of forming an extensive network of pools and tubules with important physiological functions within neurons. There are multiple MCSs between the ER and other organelles and the plasma membrane (PM), which regulate a variety of cellular processes. In this review, we focus on ER-organelle MCSs and their role in a variety of neurological diseases. We compared the biological effects between different tethering proteins and the effects of their respective disease counterparts. We also discuss how altered ER-organelle contacts may affect disease pathogenesis. Therefore, understanding the molecular mechanisms of ER-organelle MCSs in neuronal homeostasis will lay the foundation for the development of new therapies targeting ER-organelle contacts.
Collapse
Affiliation(s)
- Yunli Wang
- Key Laboratory of Environmental Stress and Chronic Disease Control & Prevention (China Medical University), Ministry of Education, PR China; Department of Toxicology, School of Public Health, China Medical University, Shenyang 110122, PR China
| | - Jinghua Yang
- Key Laboratory of Environmental Stress and Chronic Disease Control & Prevention (China Medical University), Ministry of Education, PR China; Department of Toxicology, School of Public Health, China Medical University, Shenyang 110122, PR China.
| |
Collapse
|
4
|
Obara CJ, Nixon-Abell J, Moore AS, Riccio F, Hoffman DP, Shtengel G, Xu CS, Schaefer K, Pasolli HA, Masson JB, Hess HF, Calderon CP, Blackstone C, Lippincott-Schwartz J. Motion of VAPB molecules reveals ER-mitochondria contact site subdomains. Nature 2024; 626:169-176. [PMID: 38267577 PMCID: PMC10830423 DOI: 10.1038/s41586-023-06956-y] [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: 08/27/2022] [Accepted: 12/08/2023] [Indexed: 01/26/2024]
Abstract
To coordinate cellular physiology, eukaryotic cells rely on the rapid exchange of molecules at specialized organelle-organelle contact sites1,2. Endoplasmic reticulum-mitochondrial contact sites (ERMCSs) are particularly vital communication hubs, playing key roles in the exchange of signalling molecules, lipids and metabolites3,4. ERMCSs are maintained by interactions between complementary tethering molecules on the surface of each organelle5,6. However, due to the extreme sensitivity of these membrane interfaces to experimental perturbation7,8, a clear understanding of their nanoscale organization and regulation is still lacking. Here we combine three-dimensional electron microscopy with high-speed molecular tracking of a model organelle tether, Vesicle-associated membrane protein (VAMP)-associated protein B (VAPB), to map the structure and diffusion landscape of ERMCSs. We uncovered dynamic subdomains within VAPB contact sites that correlate with ER membrane curvature and undergo rapid remodelling. We show that VAPB molecules enter and leave ERMCSs within seconds, despite the contact site itself remaining stable over much longer time scales. This metastability allows ERMCSs to remodel with changes in the physiological environment to accommodate metabolic needs of the cell. An amyotrophic lateral sclerosis-associated mutation in VAPB perturbs these subdomains, likely impairing their remodelling capacity and resulting in impaired interorganelle communication. These results establish high-speed single-molecule imaging as a new tool for mapping the structure of contact site interfaces and reveal that the diffusion landscape of VAPB at contact sites is a crucial component of ERMCS homeostasis.
Collapse
Affiliation(s)
| | - Jonathon Nixon-Abell
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
- Cambridge Institute for Medical Research (CIMR), Cambridge, UK
| | - Andrew S Moore
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Federica Riccio
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
- Centre for Gene Therapy & Regenerative Medicine, King's College London, London, UK
| | - David P Hoffman
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- 10x Genomics, Pleasanton, CA, USA
| | - Gleb Shtengel
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - C Shan Xu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA
| | - Kathy Schaefer
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - H Amalia Pasolli
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Jean-Baptiste Masson
- Decision and Bayesian Computation, Neuroscience, & Computational Biology Departments, CNRS UMR 3751, Institut Pasteur, Université de Paris, Paris, France
| | - Harald F Hess
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Christopher P Calderon
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO, USA
- Ursa Analytics, Inc., Denver, CO, USA
| | - Craig Blackstone
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
- MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Charlestown, MA, USA
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | | |
Collapse
|
5
|
Bapat O, Purimetla T, Kruessel S, Shah M, Fan R, Thum C, Rupprecht F, Langer JD, Rangaraju V. VAP spatially stabilizes dendritic mitochondria to locally support synaptic plasticity. Nat Commun 2024; 15:205. [PMID: 38177103 PMCID: PMC10766606 DOI: 10.1038/s41467-023-44233-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 12/05/2023] [Indexed: 01/06/2024] Open
Abstract
Synapses are pivotal sites of plasticity and memory formation. Consequently, synapses are energy consumption hotspots susceptible to dysfunction when their energy supplies are perturbed. Mitochondria are stabilized near synapses via the cytoskeleton and provide the local energy required for synaptic plasticity. However, the mechanisms that tether and stabilize mitochondria to support synaptic plasticity are unknown. We identified proteins exclusively tethering mitochondria to actin near postsynaptic spines. We find that VAP, the vesicle-associated membrane protein-associated protein implicated in amyotrophic lateral sclerosis, stabilizes mitochondria via actin near the spines. To test if the VAP-dependent stable mitochondrial compartments can locally support synaptic plasticity, we used two-photon glutamate uncaging for spine plasticity induction and investigated the induced and adjacent uninduced spines. We find VAP functions as a spatial stabilizer of mitochondrial compartments for up to ~60 min and as a spatial ruler determining the ~30 μm dendritic segment supported during synaptic plasticity.
Collapse
Affiliation(s)
- Ojasee Bapat
- Max Planck Florida Institute for Neuroscience, Jupiter, FL, 33458, USA
- International Max Planck Research School for Synapses and Circuits, Jupiter, FL, 33458, USA
| | - Tejas Purimetla
- Max Planck Florida Institute for Neuroscience, Jupiter, FL, 33458, USA
- Geisel School of Medicine at Dartmouth, Hanover, NH, 03755-1404, USA
| | - Sarah Kruessel
- Max Planck Institute for Brain Research, Frankfurt, 60438, Germany
- Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Monil Shah
- Max Planck Florida Institute for Neuroscience, Jupiter, FL, 33458, USA
- International Max Planck Research School for Synapses and Circuits, Jupiter, FL, 33458, USA
| | - Ruolin Fan
- Max Planck Florida Institute for Neuroscience, Jupiter, FL, 33458, USA
| | - Christina Thum
- Max Planck Institute for Brain Research, Frankfurt, 60438, Germany
| | - Fiona Rupprecht
- Max Planck Institute for Brain Research, Frankfurt, 60438, Germany
- Max Planck Institute of Biophysics, Frankfurt, 60438, Germany
- Thermo Fisher Diagnostics GmbH, Henningsdorf, 16761, Germany
| | - Julian D Langer
- Max Planck Institute for Brain Research, Frankfurt, 60438, Germany
- Max Planck Institute of Biophysics, Frankfurt, 60438, Germany
| | - Vidhya Rangaraju
- Max Planck Florida Institute for Neuroscience, Jupiter, FL, 33458, USA.
| |
Collapse
|
6
|
Faria Assoni A, Giove Mitsugi T, Wardenaar R, Oliveira Ferreira R, Farias Jandrey EH, Machado Novaes G, Fonseca de Oliveira Granha I, Bakker P, Kaid C, Zatz M, Foijer F, Keith Okamoto O. Neurodegeneration-associated protein VAPB regulates proliferation in medulloblastoma. Sci Rep 2023; 13:19481. [PMID: 37945695 PMCID: PMC10636017 DOI: 10.1038/s41598-023-45319-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Accepted: 10/18/2023] [Indexed: 11/12/2023] Open
Abstract
VAMP (Vesicle-associated membrane protein)-associated protein B and C (VAPB) has been widely studied in neurodegenerative diseases such as ALS, but little is known about its role in cancer. Medulloblastoma is a common brain malignancy in children and arises from undifferentiated cells during neuronal development. Therefore, medulloblastoma is an interesting model to investigate the possible relationship between VAPB and tumorigenesis. Here we demonstrate that high VAPB expression in medulloblastoma correlates with decreased overall patient survival. Consistent with this clinical correlation, we find that VAPB is required for normal proliferation rates of medulloblastoma cells in vitro and in vivo. Knockout of VAPB (VAPBKO) delayed cell cycle progression. Furthermore, transcript levels of WNT-related proteins were decreased in the VAPBKO. We conclude that VAPB is required for proliferation of medulloblastoma cells, thus revealing VAPB as a potential therapeutic target for medulloblastoma treatment.
Collapse
Affiliation(s)
- Amanda Faria Assoni
- Human Genome and Stem Cell Research Center, Institute of Biosciences, University of São Paulo, 106, Rua do Matão, Cidade Universitária, São Paulo, 05508-090, Brazil.
- European Research Institute for the Biology of Ageing, University of Groningen, 1, Antonius Deusinglaan, 9713 AV, Groningen, The Netherlands.
| | - Thiago Giove Mitsugi
- Human Genome and Stem Cell Research Center, Institute of Biosciences, University of São Paulo, 106, Rua do Matão, Cidade Universitária, São Paulo, 05508-090, Brazil
| | - René Wardenaar
- European Research Institute for the Biology of Ageing, University of Groningen, 1, Antonius Deusinglaan, 9713 AV, Groningen, The Netherlands
| | - Raiane Oliveira Ferreira
- Human Genome and Stem Cell Research Center, Institute of Biosciences, University of São Paulo, 106, Rua do Matão, Cidade Universitária, São Paulo, 05508-090, Brazil
| | - Elisa Helena Farias Jandrey
- Human Genome and Stem Cell Research Center, Institute of Biosciences, University of São Paulo, 106, Rua do Matão, Cidade Universitária, São Paulo, 05508-090, Brazil
| | - Gabriela Machado Novaes
- Human Genome and Stem Cell Research Center, Institute of Biosciences, University of São Paulo, 106, Rua do Matão, Cidade Universitária, São Paulo, 05508-090, Brazil
| | - Isabela Fonseca de Oliveira Granha
- Human Genome and Stem Cell Research Center, Institute of Biosciences, University of São Paulo, 106, Rua do Matão, Cidade Universitária, São Paulo, 05508-090, Brazil
| | - Petra Bakker
- European Research Institute for the Biology of Ageing, University of Groningen, 1, Antonius Deusinglaan, 9713 AV, Groningen, The Netherlands
| | - Carolini Kaid
- Human Genome and Stem Cell Research Center, Institute of Biosciences, University of São Paulo, 106, Rua do Matão, Cidade Universitária, São Paulo, 05508-090, Brazil
| | - Mayana Zatz
- Human Genome and Stem Cell Research Center, Institute of Biosciences, University of São Paulo, 106, Rua do Matão, Cidade Universitária, São Paulo, 05508-090, Brazil
| | - Floris Foijer
- European Research Institute for the Biology of Ageing, University of Groningen, 1, Antonius Deusinglaan, 9713 AV, Groningen, The Netherlands.
| | - Oswaldo Keith Okamoto
- Human Genome and Stem Cell Research Center, Institute of Biosciences, University of São Paulo, 106, Rua do Matão, Cidade Universitária, São Paulo, 05508-090, Brazil.
| |
Collapse
|
7
|
Genin EC, Abou-Ali M, Paquis-Flucklinger V. Mitochondria, a Key Target in Amyotrophic Lateral Sclerosis Pathogenesis. Genes (Basel) 2023; 14:1981. [PMID: 38002924 PMCID: PMC10671245 DOI: 10.3390/genes14111981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 10/19/2023] [Accepted: 10/21/2023] [Indexed: 11/26/2023] Open
Abstract
Mitochondrial dysfunction occurs in numerous neurodegenerative diseases, particularly amyotrophic lateral sclerosis (ALS), where it contributes to motor neuron (MN) death. Of all the factors involved in ALS, mitochondria have been considered as a major player, as secondary mitochondrial dysfunction has been found in various models and patients. Abnormal mitochondrial morphology, defects in mitochondrial dynamics, altered activities of respiratory chain enzymes and increased production of reactive oxygen species have been described. Moreover, the identification of CHCHD10 variants in ALS patients was the first genetic evidence that a mitochondrial defect may be a primary cause of MN damage and directly links mitochondrial dysfunction to the pathogenesis of ALS. In this review, we focus on the role of mitochondria in ALS and highlight the pathogenic variants of ALS genes associated with impaired mitochondrial functions. The multiple pathways demonstrated in ALS pathogenesis suggest that all converge to a common endpoint leading to MN loss. This may explain the disappointing results obtained with treatments targeting a single pathological process. Fighting against mitochondrial dysfunction appears to be a promising avenue for developing combined therapies in the future.
Collapse
Affiliation(s)
- Emmanuelle C. Genin
- Institute for Research on Cancer and Aging, Nice (IRCAN), Université Côte d’Azur, Inserm U1081, CNRS UMR7284, Centre Hospitalier Universitaire (CHU) de Nice, 06200 Nice, France; (M.A.-A.); (V.P.-F.)
| | | | | |
Collapse
|
8
|
Parkkinen I, Their A, Asghar MY, Sree S, Jokitalo E, Airavaara M. Pharmacological Regulation of Endoplasmic Reticulum Structure and Calcium Dynamics: Importance for Neurodegenerative Diseases. Pharmacol Rev 2023; 75:959-978. [PMID: 37127349 DOI: 10.1124/pharmrev.122.000701] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 03/27/2023] [Accepted: 04/04/2023] [Indexed: 05/03/2023] Open
Abstract
The endoplasmic reticulum (ER) is the largest organelle of the cell, composed of a continuous network of sheets and tubules, and is involved in protein, calcium (Ca2+), and lipid homeostasis. In neurons, the ER extends throughout the cell, both somal and axodendritic compartments, and is highly important for neuronal functions. A third of the proteome of a cell, secreted and membrane-bound proteins, are processed within the ER lumen and most of these proteins are vital for neuronal activity. The brain itself is high in lipid content, and many structural lipids are produced, in part, by the ER. Cholesterol and steroid synthesis are strictly regulated in the ER of the blood-brain barrier protected brain cells. The high Ca2+ level in the ER lumen and low cytosolic concentration is needed for Ca2+-based intracellular signaling, for synaptic signaling and Ca2+ waves, and for preparing proteins for correct folding in the presence of high Ca2+ concentrations to cope with the high concentrations of extracellular milieu. Particularly, ER Ca2+ is controlled in axodendritic areas for proper neurito- and synaptogenesis and synaptic plasticity and remodeling. In this review, we cover the physiologic functions of the neuronal ER and discuss it in context of common neurodegenerative diseases, focusing on pharmacological regulation of ER Ca2+ Furthermore, we postulate that heterogeneity of the ER, its protein folding capacity, and ensuring Ca2+ regulation are crucial factors for the aging and selective vulnerability of neurons in various neurodegenerative diseases. SIGNIFICANCE STATEMENT: Endoplasmic reticulum (ER) Ca2+ regulators are promising therapeutic targets for degenerative diseases for which efficacious drug therapies do not exist. The use of pharmacological probes targeting maintenance and restoration of ER Ca2+ can provide restoration of protein homeostasis (e.g., folding of complex plasma membrane signaling receptors) and slow down the degeneration process of neurons.
Collapse
Affiliation(s)
- Ilmari Parkkinen
- Neuroscience Center (I.P., A.T., M.A.), Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy (I.P., M.A.), Cell and Tissue Dynamics Research Program, Institute of Biotechnology, Helsinki Institute of Life Sciences (M.Y.A., S.S., E.J.), and Electron Microscopy Unit, Institute of Biotechnology, Helsinki Institute of Life Sciences (E.J.), University of Helsinki, Helsinki, Finland
| | - Anna Their
- Neuroscience Center (I.P., A.T., M.A.), Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy (I.P., M.A.), Cell and Tissue Dynamics Research Program, Institute of Biotechnology, Helsinki Institute of Life Sciences (M.Y.A., S.S., E.J.), and Electron Microscopy Unit, Institute of Biotechnology, Helsinki Institute of Life Sciences (E.J.), University of Helsinki, Helsinki, Finland
| | - Muhammad Yasir Asghar
- Neuroscience Center (I.P., A.T., M.A.), Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy (I.P., M.A.), Cell and Tissue Dynamics Research Program, Institute of Biotechnology, Helsinki Institute of Life Sciences (M.Y.A., S.S., E.J.), and Electron Microscopy Unit, Institute of Biotechnology, Helsinki Institute of Life Sciences (E.J.), University of Helsinki, Helsinki, Finland
| | - Sreesha Sree
- Neuroscience Center (I.P., A.T., M.A.), Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy (I.P., M.A.), Cell and Tissue Dynamics Research Program, Institute of Biotechnology, Helsinki Institute of Life Sciences (M.Y.A., S.S., E.J.), and Electron Microscopy Unit, Institute of Biotechnology, Helsinki Institute of Life Sciences (E.J.), University of Helsinki, Helsinki, Finland
| | - Eija Jokitalo
- Neuroscience Center (I.P., A.T., M.A.), Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy (I.P., M.A.), Cell and Tissue Dynamics Research Program, Institute of Biotechnology, Helsinki Institute of Life Sciences (M.Y.A., S.S., E.J.), and Electron Microscopy Unit, Institute of Biotechnology, Helsinki Institute of Life Sciences (E.J.), University of Helsinki, Helsinki, Finland
| | - Mikko Airavaara
- Neuroscience Center (I.P., A.T., M.A.), Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy (I.P., M.A.), Cell and Tissue Dynamics Research Program, Institute of Biotechnology, Helsinki Institute of Life Sciences (M.Y.A., S.S., E.J.), and Electron Microscopy Unit, Institute of Biotechnology, Helsinki Institute of Life Sciences (E.J.), University of Helsinki, Helsinki, Finland
| |
Collapse
|
9
|
Gao XK, Sheng ZK, Lu YH, Sun YT, Rao XS, Shi LJ, Cong XX, Chen X, Wu HB, Huang M, Zheng Q, Guo JS, Jiang LJ, Zheng LL, Zhou YT. VAPB-mediated ER-targeting stabilizes IRS-1 signalosomes to regulate insulin/IGF signaling. Cell Discov 2023; 9:83. [PMID: 37528084 PMCID: PMC10394085 DOI: 10.1038/s41421-023-00576-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 06/08/2023] [Indexed: 08/03/2023] Open
Abstract
The scaffold protein IRS-1 is an essential node in insulin/IGF signaling. It has long been recognized that the stability of IRS-1 is dependent on its endomembrane targeting. However, how IRS-1 targets the intracellular membrane, and what type of intracellular membrane is actually targeted, remains poorly understood. Here, we found that the phase separation-mediated IRS-1 puncta attached to endoplasmic reticulum (ER). VAPB, an ER-anchored protein that mediates tethers between ER and membranes of other organelles, was identified as a direct interacting partner of IRS-1. VAPB mainly binds active IRS-1 because IGF-1 enhanced the VAPB-IRS-1 association and replacing of the nine tyrosine residues of YXXM motifs disrupted the VAPB-IRS-1 association. We further delineated that the Y745 and Y746 residues in the FFAT-like motif of IRS-1 mediated the association with VAPB. Notably, VAPB targeted IRS-1 to the ER and subsequently maintained its stability. Consistently, ablation of VAPB in mice led to downregulation of IRS-1, suppression of insulin signaling, and glucose intolerance. The amyotrophic lateral sclerosis (ALS)-derived VAPB P56S mutant also impaired IRS-1 stability by interfering with the ER-tethering of IRS-1. Our findings thus revealed a previously unappreciated condensate-membrane contact (CMC), by which VAPB stabilizes the membraneless IRS-1 signalosome through targeting it to ER membrane.
Collapse
Affiliation(s)
- Xiu Kui Gao
- Department of Biochemistry and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
- International Institutes of Medicine, the Fourth Affiliated Hospital of Zhejiang University School of Medicine, Yiwu, Zhejiang, China.
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
| | - Zu Kang Sheng
- Department of Biochemistry and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Ye Hong Lu
- Department of Biochemistry and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Yu Ting Sun
- Department of Biochemistry and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Xi Sheng Rao
- Department of Biochemistry and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Lin Jing Shi
- Department of Biochemistry and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Xiao Xia Cong
- Department of Biochemistry and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Xiao Chen
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Hao Bo Wu
- Department of Biochemistry and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Man Huang
- Department of Biochemistry and Department of General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejinag, China
- Key Laboratory of Multiple Organ Failure (Zhejiang University), Ministry of Education, Hangzhou, Zhejiang, China
| | - Qiang Zheng
- Department of Biochemistry and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Jian-Sheng Guo
- Department of Pathology of Sir Run Run Shaw Hospital, Center of Cryo-Electron Microscopy, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Liang Jun Jiang
- Department of Biochemistry and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
| | - Li Ling Zheng
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
- Department of Biochemistry and Department of General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejinag, China.
- Key Laboratory of Multiple Organ Failure (Zhejiang University), Ministry of Education, Hangzhou, Zhejiang, China.
| | - Yi Ting Zhou
- Department of Biochemistry and Department of Orthopaedic Surgery of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
- Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
- Key Laboratory of Multiple Organ Failure (Zhejiang University), Ministry of Education, Hangzhou, Zhejiang, China.
- ZJU-UoE Institute, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
- Cancer Center, Zhejiang University, Hangzhou, Zhejiang, China.
- Liangzhu Laboratory, Hangzhou, Zhejiang, China.
| |
Collapse
|
10
|
Stump AL, Rioux DJ, Albright R, Melki GL, Prosser DC. Yeast Models of Amyotrophic Lateral Sclerosis Type 8 Mimic Phenotypes Seen in Mammalian Cells Expressing Mutant VAPB P56S. Biomolecules 2023; 13:1147. [PMID: 37509182 PMCID: PMC10377116 DOI: 10.3390/biom13071147] [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: 05/14/2023] [Revised: 07/09/2023] [Accepted: 07/17/2023] [Indexed: 07/30/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a complex neurodegenerative disease that results in the loss of motor neurons and can occur sporadically or due to genetic mutations. Among the 30 genes linked to familial ALS, a P56S mutation in VAPB, an ER-resident protein that functions at membrane contact sites, causes ALS type 8. Mammalian cells expressing VAPBP56S have distinctive phenotypes, including ER collapse, protein and/or membrane-containing inclusions, and sensitivity to ER stress. VAPB is conserved through evolution and has two homologs in budding yeast, SCS2 and SCS22. Previously, a humanized version of SCS2 bearing disease-linked mutations was described, and it caused Scs2-containing inclusions when overexpressed in yeast. Here, we describe a yeast model for ALS8 in which the two SCS genes are deleted and replaced with a single chromosomal copy of either wild-type or mutant yeast SCS2 or human VAPB expressed from the SCS2 promoter. These cells display ER collapse, the formation of inclusion-like structures, and sensitivity to tunicamycin, an ER stress-inducing drug. Based on the phenotypic similarity to mammalian cells expressing VAPBP56S, we propose that these models can be used to study the molecular basis of cell death or dysfunction in ALS8. Moreover, other conserved ALS-linked genes may create opportunities for the generation of yeast models of disease.
Collapse
Affiliation(s)
- AnnaMari L. Stump
- Department of Biology, Virginia Commonwealth University, Richmond, VA 23284, USA
- VCU Life Sciences, Virginia Commonwealth University, Richmond, VA 23284, USA
| | - Daniel J. Rioux
- Department of Biology, Virginia Commonwealth University, Richmond, VA 23284, USA
- VCU Life Sciences, Virginia Commonwealth University, Richmond, VA 23284, USA
| | - Richard Albright
- Department of Biology, Virginia Commonwealth University, Richmond, VA 23284, USA
| | - Guiliano L. Melki
- Department of Biology, Virginia Commonwealth University, Richmond, VA 23284, USA
| | - Derek C. Prosser
- Department of Biology, Virginia Commonwealth University, Richmond, VA 23284, USA
| |
Collapse
|
11
|
Guillén-Samander A, De Camilli P. Endoplasmic Reticulum Membrane Contact Sites, Lipid Transport, and Neurodegeneration. Cold Spring Harb Perspect Biol 2023; 15:a041257. [PMID: 36123033 PMCID: PMC10071438 DOI: 10.1101/cshperspect.a041257] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The Endoplasmic Reticulum (ER) is an endomembrane system that plays a multiplicity of roles in cell physiology and populates even the most distal cell compartments, including dendritic tips and axon terminals of neurons. Some of its functions are achieved by a cross talk with other intracellular membranous organelles and with the plasma membrane at membrane contacts sites (MCSs). As the ER synthesizes most membrane lipids, lipid exchanges mediated by lipid transfer proteins at MCSs are a particularly important aspect of this cross talk, which synergizes with the cross talk mediated by vesicular transport. Several mutations of genes that encode proteins localized at ER MCSs result in familial neurodegenerative diseases, emphasizing the importance of the normal lipid traffic within cells for a healthy brain. Here, we provide an overview of such diseases, with a specific focus on proteins that directly or indirectly impact lipid transport.
Collapse
Affiliation(s)
- Andrés Guillén-Samander
- Departments of Neuroscience and of Cell Biology, Howard Hughes Medical Institute, Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, Connecticut 06520, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, Maryland 20815, USA
| | - Pietro De Camilli
- Departments of Neuroscience and of Cell Biology, Howard Hughes Medical Institute, Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, Connecticut 06520, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, Maryland 20815, USA
| |
Collapse
|
12
|
Yperman K, Kuijpers M. Neuronal endoplasmic reticulum architecture and roles in axonal physiology. Mol Cell Neurosci 2023; 125:103822. [PMID: 36781033 DOI: 10.1016/j.mcn.2023.103822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 02/06/2023] [Accepted: 02/08/2023] [Indexed: 02/13/2023] Open
Abstract
The endoplasmic reticulum (ER) is the largest membrane compartment within eukaryotic cells and is emerging as a key coordinator of many cellular processes. The ER can modulate local calcium fluxes and communicate with other organelles like the plasma membrane. The importance of ER in neuronal processes such as neurite growth, axon repair and neurotransmission has recently gained much attention. In this review, we highlight the importance of the ER tubular network in axonal homeostasis and discuss how the generation and maintenance of the thin tubular ER network in axons and synapses, requires a cooperative effort of ER-shaping proteins, cytoskeleton and autophagy processes.
Collapse
Affiliation(s)
- Klaas Yperman
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Marijn Kuijpers
- Department of Molecular Neurobiology, Donders Institute for Brain, Cognition and Behaviour and Faculty of Science, Radboud University, 6525 AJ Nijmegen, the Netherlands.
| |
Collapse
|
13
|
Vullhorst D, Bloom MS, Akella N, Buonanno A. ER-PM Junctions on GABAergic Interneurons Are Organized by Neuregulin 2/VAP Interactions and Regulated by NMDA Receptors. Int J Mol Sci 2023; 24:2908. [PMID: 36769244 PMCID: PMC9917868 DOI: 10.3390/ijms24032908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 01/24/2023] [Accepted: 01/27/2023] [Indexed: 02/05/2023] Open
Abstract
Neuregulins (NRGs) signal via ErbB receptors to regulate neural development, excitability, synaptic and network activity, and behaviors relevant to psychiatric disorders. Bidirectional signaling between NRG2/ErbB4 and NMDA receptors is thought to homeostatically regulate GABAergic interneurons in response to increased excitatory neurotransmission or elevated extracellular glutamate levels. Unprocessed proNRG2 forms discrete clusters on cell bodies and proximal dendrites that colocalize with the potassium channel Kv2.1 at specialized endoplasmic reticulum-plasma membrane (ER-PM) junctions, and NMDA receptor activation triggers rapid dissociation from ER-PM junctions and ectodomain shedding by ADAM10. Here, we elucidate the mechanistic basis of proNRG2 clustering at ER-PM junctions and its regulation by NMDA receptors. Importantly, we demonstrate that proNRG2 promotes the formation of ER-PM junctions by directly binding the ER-resident membrane tether VAP, like Kv2.1. The proNRG2 intracellular domain harbors two non-canonical, low-affinity sites that cooperatively mediate VAP binding. One of these is a cryptic and phosphorylation-dependent VAP binding motif that is dephosphorylated following NMDA receptor activation, thus revealing how excitatory neurotransmission promotes the dissociation of proNRG2 from ER-PM junctions. Therefore, proNRG2 and Kv2.1 can independently function as VAP-dependent organizers of neuronal ER-PM junctions. Based on these and prior studies, we propose that proNRG2 and Kv2.1 serve as co-regulated downstream effectors of NMDA receptors to homeostatically regulate GABAergic interneurons.
Collapse
Affiliation(s)
- Detlef Vullhorst
- Section on Molecular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA
| | | | | | | |
Collapse
|
14
|
Striepen JF, Voeltz GK. Endosome biogenesis is controlled by ER and the cytoskeleton at tripartite junctions. Curr Opin Cell Biol 2023; 80:102155. [PMID: 36848759 DOI: 10.1016/j.ceb.2023.102155] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 01/10/2023] [Accepted: 01/19/2023] [Indexed: 02/27/2023]
Abstract
The plasma membrane (PM) and its associated cargo are internalized into small vesicles via endocytosis funneling cargo into endosomes. The endosomal system must efficiently deliver cargos, as well as recycle cargo receptors and membrane to maintain homeostasis. In animal cells, endosome trafficking, maturation, and cargo recycling rely on the actin and microtubule cytoskeleton. Microtubules and their associated motor proteins provide the roads on which endosomes move and fuse during cargo sorting and delivery. In addition, highly dynamic assemblies of actin adjust the shape of the endosomal membrane to promote cargo segregation into budding domains allowing for receptor recycling. Recent work has revealed that the endoplasmic reticulum (ER) frequently acts as an intermediary between endosomes and their cytoskeletal regulators via membrane contact sites (MCSs). This review will discuss the factors which form these tripartite junction between the ER, endosomes, and the cytoskeleton as well as their function.
Collapse
Affiliation(s)
- Jonathan F Striepen
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO, USA; Howard Hughes Medical Institute, USA
| | - Gia K Voeltz
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO, USA; Howard Hughes Medical Institute, USA.
| |
Collapse
|
15
|
Kim S, Coukos R, Gao F, Krainc D. Dysregulation of organelle membrane contact sites in neurological diseases. Neuron 2022; 110:2386-2408. [PMID: 35561676 PMCID: PMC9357093 DOI: 10.1016/j.neuron.2022.04.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 03/21/2022] [Accepted: 04/18/2022] [Indexed: 10/18/2022]
Abstract
The defining evolutionary feature of eukaryotic cells is the emergence of membrane-bound organelles. Compartmentalization allows each organelle to maintain a spatially, physically, and chemically distinct environment, which greatly bolsters individual organelle function. However, the activities of each organelle must be balanced and are interdependent for cellular homeostasis. Therefore, properly regulated interactions between organelles, either physically or functionally, remain critical for overall cellular health and behavior. In particular, neuronal homeostasis depends heavily on the proper regulation of organelle function and cross talk, and deficits in these functions are frequently associated with diseases. In this review, we examine the emerging role of organelle contacts in neurological diseases and discuss how the disruption of contacts contributes to disease pathogenesis. Understanding the molecular mechanisms underlying the formation and regulation of organelle contacts will broaden our knowledge of their role in health and disease, laying the groundwork for the development of new therapies targeting interorganelle cross talk and function.
Collapse
Affiliation(s)
- Soojin Kim
- Department of Neurology, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Chicago, IL, 60611, USA
| | - Robert Coukos
- Department of Neurology, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Chicago, IL, 60611, USA
| | - Fanding Gao
- Department of Neurology, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Chicago, IL, 60611, USA
| | - Dimitri Krainc
- Department of Neurology, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Chicago, IL 60611, USA.
| |
Collapse
|
16
|
Cozzi M, Ferrari V. Autophagy Dysfunction in ALS: from Transport to Protein Degradation. J Mol Neurosci 2022; 72:1456-1481. [PMID: 35708843 PMCID: PMC9293831 DOI: 10.1007/s12031-022-02029-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 05/17/2022] [Indexed: 01/18/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease affecting upper and lower motor neurons (MNs). Since the identification of the first ALS mutation in 1993, more than 40 genes have been associated with the disorder. The most frequent genetic causes of ALS are represented by mutated genes whose products challenge proteostasis, becoming unable to properly fold and consequently aggregating into inclusions that impose proteotoxic stress on affected cells. In this context, increasing evidence supports the central role played by autophagy dysfunctions in the pathogenesis of ALS. Indeed, in early stages of disease, high levels of proteins involved in autophagy are present in ALS MNs; but at the same time, with neurodegeneration progression, autophagy-mediated degradation decreases, often as a result of the accumulation of toxic protein aggregates in affected cells. Autophagy is a complex multistep pathway that has a central role in maintaining cellular homeostasis. Several proteins are involved in its tight regulation, and importantly a relevant fraction of ALS-related genes encodes products that directly take part in autophagy, further underlining the relevance of this key protein degradation system in disease onset and progression. In this review, we report the most relevant findings concerning ALS genes whose products are involved in the several steps of the autophagic pathway, from phagophore formation to autophagosome maturation and transport and finally to substrate degradation.
Collapse
Affiliation(s)
- Marta Cozzi
- Dipartimento Di Scienze Farmacologiche E Biomolecolari, Università Degli Studi Di Milano, 20133, Milan, Italy.
| | - Veronica Ferrari
- Dipartimento Di Scienze Farmacologiche E Biomolecolari, Università Degli Studi Di Milano, 20133, Milan, Italy.
| |
Collapse
|
17
|
Deng C, Reinhard S, Hennlein L, Eilts J, Sachs S, Doose S, Jablonka S, Sauer M, Moradi M, Sendtner M. Impaired dynamic interaction of axonal endoplasmic reticulum and ribosomes contributes to defective stimulus-response in spinal muscular atrophy. Transl Neurodegener 2022; 11:31. [PMID: 35650592 PMCID: PMC9161492 DOI: 10.1186/s40035-022-00304-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 04/28/2022] [Indexed: 11/19/2022] Open
Abstract
Background Axonal degeneration and defects in neuromuscular neurotransmission represent a pathological hallmark in spinal muscular atrophy (SMA) and other forms of motoneuron disease. These pathological changes do not only base on altered axonal and presynaptic architecture, but also on alterations in dynamic movements of organelles and subcellular structures that are not necessarily reflected by static histopathological changes. The dynamic interplay between the axonal endoplasmic reticulum (ER) and ribosomes is essential for stimulus-induced local translation in motor axons and presynaptic terminals. However, it remains enigmatic whether the ER and ribosome crosstalk is impaired in the presynaptic compartment of motoneurons with Smn (survival of motor neuron) deficiency that could contribute to axonopathy and presynaptic dysfunction in SMA. Methods Using super-resolution microscopy, proximity ligation assay (PLA) and live imaging of cultured motoneurons from a mouse model of SMA, we investigated the dynamics of the axonal ER and ribosome distribution and activation. Results We observed that the dynamic remodeling of ER was impaired in axon terminals of Smn-deficient motoneurons. In addition, in axon terminals of Smn-deficient motoneurons, ribosomes failed to respond to the brain-derived neurotrophic factor stimulation, and did not undergo rapid association with the axonal ER in response to extracellular stimuli. Conclusions These findings implicate impaired dynamic interplay between the ribosomes and ER in axon terminals of motoneurons as a contributor to the pathophysiology of SMA and possibly also other motoneuron diseases. Supplementary Information The online version contains supplementary material available at 10.1186/s40035-022-00304-2.
Collapse
Affiliation(s)
- Chunchu Deng
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, 97078, Würzburg, Germany
| | - Sebastian Reinhard
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilians-University Wuerzburg, 97074, Würzburg, Germany
| | - Luisa Hennlein
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, 97078, Würzburg, Germany
| | - Janna Eilts
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilians-University Wuerzburg, 97074, Würzburg, Germany
| | - Stefan Sachs
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilians-University Wuerzburg, 97074, Würzburg, Germany
| | - Sören Doose
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilians-University Wuerzburg, 97074, Würzburg, Germany
| | - Sibylle Jablonka
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, 97078, Würzburg, Germany
| | - Markus Sauer
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilians-University Wuerzburg, 97074, Würzburg, Germany
| | - Mehri Moradi
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, 97078, Würzburg, Germany.
| | - Michael Sendtner
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, 97078, Würzburg, Germany.
| |
Collapse
|
18
|
Tortosa E, Sengupta Ghosh A, Li Q, Wong WR, Hinkle T, Sandoval W, Rose CM, Hoogenraad CC. Stress-induced vesicular assemblies of dual leucine zipper kinase are signaling hubs involved in kinase activation and neurodegeneration. EMBO J 2022; 41:e110155. [PMID: 35611591 PMCID: PMC9289706 DOI: 10.15252/embj.2021110155] [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: 11/09/2021] [Revised: 04/21/2022] [Accepted: 04/22/2022] [Indexed: 11/09/2022] Open
Abstract
Mitogen-activated protein kinases (MAPKs) drive key signaling cascades during neuronal survival and degeneration. The localization of kinases to specific subcellular compartments is a critical mechanism to locally control signaling activity and specificity upon stimulation. However, how MAPK signaling components tightly control their localization remains largely unknown. Here, we systematically analyzed the phosphorylation and membrane localization of all MAPKs expressed in dorsal root ganglia (DRG) neurons, under control and stress conditions. We found that MAP3K12/dual leucine zipper kinase (DLK) becomes phosphorylated and palmitoylated, and it is recruited to sphingomyelin-rich vesicles upon stress. Stress-induced DLK vesicle recruitment is essential for kinase activation; blocking DLK-membrane interaction inhibits downstream signaling, while DLK recruitment to ectopic subcellular structures is sufficient to induce kinase activation. We show that the localization of DLK to newly formed vesicles is essential for local signaling. Inhibition of membrane internalization blocks DLK activation and protects against neurodegeneration in DRG neurons. These data establish vesicular assemblies as dynamically regulated platforms for DLK signaling during neuronal stress responses.
Collapse
Affiliation(s)
- Elena Tortosa
- Department of Neuroscience, Genentech, Inc., South San Francisco, CA, USA
| | | | - Qingling Li
- Department of Microchemistry, Proteomics and Lipidomics, Genentech, Inc., South San Francisco, CA, USA
| | - Weng Ruh Wong
- Department of Microchemistry, Proteomics and Lipidomics, Genentech, Inc., South San Francisco, CA, USA
| | - Trent Hinkle
- Department of Microchemistry, Proteomics and Lipidomics, Genentech, Inc., South San Francisco, CA, USA
| | - Wendy Sandoval
- Department of Microchemistry, Proteomics and Lipidomics, Genentech, Inc., South San Francisco, CA, USA
| | - Christopher M Rose
- Department of Microchemistry, Proteomics and Lipidomics, Genentech, Inc., South San Francisco, CA, USA
| | | |
Collapse
|
19
|
Tendulkar S, Hegde S, Garg L, Thulasidharan A, Kaduskar B, Ratnaparkhi A, Ratnaparkhi GS. Caspar, an adapter for VAPB and TER94, modulates the progression of ALS8 by regulating IMD/NFκB mediated glial inflammation in a drosophila model of human disease. Hum Mol Genet 2022; 31:2857-2875. [PMID: 35377453 PMCID: PMC9433731 DOI: 10.1093/hmg/ddac076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 03/25/2022] [Accepted: 03/29/2022] [Indexed: 11/16/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal, late-onset, progressive motor neurodegenerative disorder. A key pathological feature of the disease is the presence of heavily ubiquitinated protein inclusions. Both the unfolded protein response and the ubiquitin–proteasome system appear significantly impaired in patients and animal models of ALS. We have studied cellular and molecular mechanisms involved in ALS using a vesicle-associated membrane protein-associated protein B (VAPB/ALS8) Drosophila model [Moustaqim-Barrette, A., Lin, Y.Q., Pradhan, S., Neely, G.G., Bellen, H.J. and Tsuda, H. (2014) The ALS 8 protein, VAP, is required for ER protein quality control. Hum. Mol. Genet., 23, 1975–1989], which mimics many systemic aspects of the human disease. Here, we show that VAPB, located on the cytoplasmic face of the endoplasmic reticulum membrane, interacts with Caspar, an orthologue of human fas associated factor 1 (FAF1). Caspar, in turn, interacts with transitional endoplasmic reticulum ATPase (TER94), a fly orthologue of ALS14 (VCP/p97, valosin-containing protein). Caspar overexpression in the glia extends lifespan and also slows the progression of motor dysfunction in the ALS8 disease model, a phenomenon that we ascribe to its ability to restrain age-dependent inflammation, which is modulated by Relish/NFκB signalling. Caspar binds to VAPB via an FFAT motif, and we find that Caspar’s ability to negatively regulate NFκB signalling is not dependent on the VAPB:Caspar interaction. We hypothesize that Caspar is a key molecule in the pathogenesis of ALS. The VAPB:Caspar:TER94 complex appears to be a candidate for regulating both protein homeostasis and NFκB signalling, with our study highlighting a role for Caspar in glial inflammation. We project human FAF1 as an important protein target to alleviate the progression of motor neuron disease.
Collapse
Affiliation(s)
- Shweta Tendulkar
- Indian Institute of Science Education & Research (IISER) Pune 411008, India
| | - Sushmitha Hegde
- Indian Institute of Science Education & Research (IISER) Pune 411008, India
| | - Lovleen Garg
- Indian Institute of Science Education & Research (IISER) Pune 411008, India
| | | | | | | | | |
Collapse
|
20
|
Epigenomic and Proteomic Changes in Fetal Spleens Persistently Infected with Bovine Viral Diarrhea Virus: Repercussions for the Developing Immune System, Bone, Brain, and Heart. Viruses 2022; 14:v14030506. [PMID: 35336913 PMCID: PMC8949278 DOI: 10.3390/v14030506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 02/18/2022] [Accepted: 02/20/2022] [Indexed: 12/10/2022] Open
Abstract
Bovine viral diarrhea virus (BVDV) infection during early gestation results in persistently infected (PI) immunotolerant calves that are the primary reservoirs of the virus. Pathologies observed in PI cattle include congenital defects of the brain, heart, and bone as well as marked functional defects in their immune system. It was hypothesized that fetal BVDV infection alters T cell activation and signaling genes by epigenetic mechanisms. To test this, PI and control fetal splenic tissues were collected on day 245 of gestation, 170 days post maternal infection. DNA was isolated for reduced representation bisulfite sequencing, protein was isolated for proteomics, both were analyzed with appropriate bioinformatic methods. Within set parameters, 1951 hypermethylated and 691 hypomethylated DNA regions were identified in PI compared to control fetuses. Pathways associated with immune system, neural, cardiac, and bone development were associated with heavily methylated DNA. The proteomic analysis revealed 12 differentially expressed proteins in PI vs. control animals. Upregulated proteins were associated with protein processing, whereas downregulated proteins were associated with lymphocyte migration and development in PI compared to control fetal spleens. The epigenetic changes in DNA may explain the immune dysfunctions, abnormal bone formation, and brain and heart defects observed in PI animals.
Collapse
|
21
|
Kors S, Costello JL, Schrader M. VAP Proteins - From Organelle Tethers to Pathogenic Host Interactors and Their Role in Neuronal Disease. Front Cell Dev Biol 2022; 10:895856. [PMID: 35756994 PMCID: PMC9213790 DOI: 10.3389/fcell.2022.895856] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 04/25/2022] [Indexed: 12/26/2022] Open
Abstract
Vesicle-associated membrane protein (VAMP)-associated proteins (VAPs) are ubiquitous ER-resident tail-anchored membrane proteins in eukaryotic cells. Their N-terminal major sperm protein (MSP) domain faces the cytosol and allows them to interact with a wide variety of cellular proteins. Therefore, VAP proteins are vital to many cellular processes, including organelle membrane tethering, lipid transfer, autophagy, ion homeostasis and viral defence. Here, we provide a timely overview of the increasing number of VAPA/B binding partners and discuss the role of VAPA/B in maintaining organelle-ER interactions and cooperation. Furthermore, we address how viruses and intracellular bacteria hijack VAPs and their binding partners to induce interactions between the host ER and pathogen-containing compartments and support pathogen replication. Finally, we focus on the role of VAP in human disease and discuss how mutated VAPB leads to the disruption of cellular homeostasis and causes amyotrophic lateral sclerosis.
Collapse
Affiliation(s)
- Suzan Kors
- *Correspondence: Suzan Kors, ; Michael Schrader,
| | | | | |
Collapse
|
22
|
James C, Lenz C, Urlaub H, Kehlenbach RH. Sequestosome 1 Is Part of the Interaction Network of VAPB. Int J Mol Sci 2021; 22:ijms222413271. [PMID: 34948065 PMCID: PMC8707790 DOI: 10.3390/ijms222413271] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 12/01/2021] [Accepted: 12/07/2021] [Indexed: 12/14/2022] Open
Abstract
VAPB (Vesicle-Associated-membrane Protein-associated protein B) is a tail-anchored membrane protein of the endoplasmic reticulum that can also be detected at the inner nuclear membrane. As a component of many contact sites between the endoplasmic reticulum and other organelles, VAPB is engaged in multiple protein interactions with a plethora of binding partners. A mutant version of VAPB, P56S-VAPB, which results from a single point mutation, is involved in a familial form of amyotrophic lateral sclerosis (ALS8). We performed RAPIDS (rapamycin- and APEX-dependent identification of proteins by SILAC) to identify proteins that interact with or are in close proximity to P56S-VAPB. The mutation abrogates the interaction of VAPB with many known binding partners. Here, we identify Sequestosome 1 (SQSTM1), a well-known autophagic adapter protein, as a major interaction/proximity partner of P56S-VAPB. Remarkably, not only the mutant protein, but also wild-type VAPB interacts with SQSTM1, as shown by proximity ligation assays and co-immunoprecipiation experiments.
Collapse
Affiliation(s)
- Christina James
- Department of Molecular Biology, Faculty of Medicine, GZMB (Göttinger Zentrum für Molekulare Biowissenschaften), Georg-August-University Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
- Correspondence: (C.J.); (R.H.K.)
| | - Christof Lenz
- Bioanalytics Group, Institute of Clinical Chemistry, University Medical Center Göttingen, Robert-Koch-Straße 40, 37075 Göttingen, Germany; (C.L.); (H.U.)
| | - Henning Urlaub
- Bioanalytics Group, Institute of Clinical Chemistry, University Medical Center Göttingen, Robert-Koch-Straße 40, 37075 Göttingen, Germany; (C.L.); (H.U.)
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Ralph H. Kehlenbach
- Department of Molecular Biology, Faculty of Medicine, GZMB (Göttinger Zentrum für Molekulare Biowissenschaften), Georg-August-University Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
- Correspondence: (C.J.); (R.H.K.)
| |
Collapse
|
23
|
Deng C, Moradi M, Reinhard S, Ji C, Jablonka S, Hennlein L, Lüningschrör P, Doose S, Sauer M, Sendtner M. Dynamic remodeling of ribosomes and endoplasmic reticulum in axon terminals of motoneurons. J Cell Sci 2021; 134:272552. [PMID: 34668554 DOI: 10.1242/jcs.258785] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 10/14/2021] [Indexed: 12/23/2022] Open
Abstract
In neurons, the endoplasmic reticulum (ER) forms a highly dynamic network that enters axons and presynaptic terminals and plays a central role in Ca2+ homeostasis and synapse maintenance; however, the underlying mechanisms involved in regulation of its dynamic remodeling as well as its function in axon development and presynaptic differentiation remain elusive. Here, we used high-resolution microscopy and live-cell imaging to investigate rapid movements of the ER and ribosomes in axons of cultured motoneurons after stimulation with brain-derived neurotrophic factor. Our results indicate that the ER extends into axonal growth cone filopodia, where its integrity and dynamic remodeling are regulated mainly by actin and the actin-based motor protein myosin VI (encoded by Myo6). Additionally, we found that in axonal growth cones, ribosomes assemble into 80S subunits within seconds and associate with the ER in response to extracellular stimuli, which describes a novel function of axonal ER in dynamic regulation of local translation. This article has an associated First Person interview with Chunchu Deng, joint first author of the paper.
Collapse
Affiliation(s)
- Chunchu Deng
- Institute of Clinical Neurobiology, University Hospital Würzburg, 97078 Würzburg, Germany
| | - Mehri Moradi
- Institute of Clinical Neurobiology, University Hospital Würzburg, 97078 Würzburg, Germany
| | - Sebastian Reinhard
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilians-University Würzburg, 97074 Würzburg, Germany
| | - Changhe Ji
- Institute of Clinical Neurobiology, University Hospital Würzburg, 97078 Würzburg, Germany
| | - Sibylle Jablonka
- Institute of Clinical Neurobiology, University Hospital Würzburg, 97078 Würzburg, Germany
| | - Luisa Hennlein
- Institute of Clinical Neurobiology, University Hospital Würzburg, 97078 Würzburg, Germany
| | - Patrick Lüningschrör
- Institute of Clinical Neurobiology, University Hospital Würzburg, 97078 Würzburg, Germany
| | - Sören Doose
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilians-University Würzburg, 97074 Würzburg, Germany
| | - Markus Sauer
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilians-University Würzburg, 97074 Würzburg, Germany
| | - Michael Sendtner
- Institute of Clinical Neurobiology, University Hospital Würzburg, 97078 Würzburg, Germany
| |
Collapse
|
24
|
Intertwined and Finely Balanced: Endoplasmic Reticulum Morphology, Dynamics, Function, and Diseases. Cells 2021; 10:cells10092341. [PMID: 34571990 PMCID: PMC8472773 DOI: 10.3390/cells10092341] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/02/2021] [Accepted: 09/04/2021] [Indexed: 02/07/2023] Open
Abstract
The endoplasmic reticulum (ER) is an organelle that is responsible for many essential subcellular processes. Interconnected narrow tubules at the periphery and thicker sheet-like regions in the perinuclear region are linked to the nuclear envelope. It is becoming apparent that the complex morphology and dynamics of the ER are linked to its function. Mutations in the proteins involved in regulating ER structure and movement are implicated in many diseases including neurodegenerative diseases such as Alzheimer’s, Parkinson’s, and amyotrophic lateral sclerosis (ALS). The ER is also hijacked by pathogens to promote their replication. Bacteria such as Legionella pneumophila and Chlamydia trachomatis, as well as the Zika virus, bind to ER morphology and dynamics-regulating proteins to exploit the functions of the ER to their advantage. This review covers our understanding of ER morphology, including the functional subdomains and membrane contact sites that the organelle forms. We also focus on ER dynamics and the current efforts to quantify ER motion and discuss the diseases related to ER morphology and dynamics.
Collapse
|
25
|
Ghosh A, Singh S. Regulation Of Microtubule: Current Concepts And Relevance To Neurodegenerative Diseases. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2021; 21:656-679. [PMID: 34323203 DOI: 10.2174/1871527320666210728144043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 01/05/2021] [Accepted: 02/23/2021] [Indexed: 11/22/2022]
Abstract
Neurodevelopmental disorders (NDDs) are abnormalities linked to neuronal structure and irregularities associated with the proliferation of cells, transportation, and differentiation. NDD also involves synaptic circuitry and neural network alterations known as synaptopathies. Microtubules (MTs) and MTs-associated proteins help to maintain neuronal health as well as their development. The microtubular dynamic structure plays a crucial role in the division of cells and forms mitotic spindles, thus take part in initiating stages of differentiation and polarization for various types of cells. The MTs also take part in the cellular death but MT-based cellular degenerations are not yet well excavated. In the last few years, studies have provided the protagonist activity of MTs in neuronal degeneration. In this review, we largely engrossed our discussion on the change of MT cytoskeleton structure, describing their organization, dynamics, transportation, and their failure causing NDDs. At end of this review, we are targeting the therapeutic neuroprotective strategies on clinical priority and also try to discuss the clues for the development of new MT-based therapy as a new pharmacological intervention. This will be a new potential site to block not only neurodegeneration but also promotes the regeneration of neurons.
Collapse
Affiliation(s)
- Anirban Ghosh
- Neuroscience Division, Department of Pharmacology, ISF College of Pharmacy, Moga-142001 Punjab, India
| | - Shamsher Singh
- Neuroscience Division, Department of Pharmacology, ISF College of Pharmacy, Moga-142001 Punjab, India
| |
Collapse
|
26
|
Borgese N, Iacomino N, Colombo SF, Navone F. The Link between VAPB Loss of Function and Amyotrophic Lateral Sclerosis. Cells 2021; 10:1865. [PMID: 34440634 PMCID: PMC8392409 DOI: 10.3390/cells10081865] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 07/16/2021] [Accepted: 07/16/2021] [Indexed: 02/06/2023] Open
Abstract
The VAP proteins are integral adaptor proteins of the endoplasmic reticulum (ER) membrane that recruit a myriad of interacting partners to the ER surface. Through these interactions, the VAPs mediate a large number of processes, notably the generation of membrane contact sites between the ER and essentially all other cellular membranes. In 2004, it was discovered that a mutation (p.P56S) in the VAPB paralogue causes a rare form of dominantly inherited familial amyotrophic lateral sclerosis (ALS8). The mutant protein is aggregation-prone, non-functional and unstable, and its expression from a single allele appears to be insufficient to support toxic gain-of-function effects within motor neurons. Instead, loss-of-function of the single wild-type allele is required for pathological effects, and VAPB haploinsufficiency may be the main driver of the disease. In this article, we review the studies on the effects of VAPB deficit in cellular and animal models. Several basic cell physiological processes are affected by downregulation or complete depletion of VAPB, impinging on phosphoinositide homeostasis, Ca2+ signalling, ion transport, neurite extension, and ER stress. In the future, the distinction between the roles of the two VAP paralogues (A and B), as well as studies on motor neurons generated from induced pluripotent stem cells (iPSC) of ALS8 patients will further elucidate the pathogenic basis of p.P56S familial ALS, as well as of other more common forms of the disease.
Collapse
Affiliation(s)
- Nica Borgese
- CNR Institute of Neuroscience, Via Follereau 3, Bldg U28, 20854 Vedano al Lambro, Italy; (N.I.); (S.F.C.)
| | | | | | - Francesca Navone
- CNR Institute of Neuroscience, Via Follereau 3, Bldg U28, 20854 Vedano al Lambro, Italy; (N.I.); (S.F.C.)
| |
Collapse
|
27
|
Özkan N, Koppers M, van Soest I, van Harten A, Jurriens D, Liv N, Klumperman J, Kapitein LC, Hoogenraad CC, Farías GG. ER - lysosome contacts at a pre-axonal region regulate axonal lysosome availability. Nat Commun 2021; 12:4493. [PMID: 34301956 PMCID: PMC8302662 DOI: 10.1038/s41467-021-24713-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 07/01/2021] [Indexed: 11/16/2022] Open
Abstract
Neuronal function relies on careful coordination of organelle organization and transport. Kinesin-1 mediates transport of the endoplasmic reticulum (ER) and lysosomes into the axon and it is increasingly recognized that contacts between the ER and lysosomes influence organelle organization. However, it is unclear how organelle organization, inter-organelle communication and transport are linked and how this contributes to local organelle availability in neurons. Here, we show that somatic ER tubules are required for proper lysosome transport into the axon. Somatic ER tubule disruption causes accumulation of enlarged and less motile lysosomes at the soma. ER tubules regulate lysosome size and axonal translocation by promoting lysosome homo-fission. ER tubule - lysosome contacts often occur at a somatic pre-axonal region, where the kinesin-1-binding ER-protein P180 binds microtubules to promote kinesin-1-powered lysosome fission and subsequent axonal translocation. We propose that ER tubule - lysosome contacts at a pre-axonal region finely orchestrate axonal lysosome availability for proper neuronal function.
Collapse
Affiliation(s)
- Nazmiye Özkan
- Cell Biology, Neurobiology and Biophysics. Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Max Koppers
- Cell Biology, Neurobiology and Biophysics. Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Inge van Soest
- Cell Biology, Neurobiology and Biophysics. Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Alexandra van Harten
- Cell Biology, Neurobiology and Biophysics. Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Daphne Jurriens
- Cell Biology, Neurobiology and Biophysics. Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Nalan Liv
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Judith Klumperman
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Lukas C Kapitein
- Cell Biology, Neurobiology and Biophysics. Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Casper C Hoogenraad
- Cell Biology, Neurobiology and Biophysics. Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Ginny G Farías
- Cell Biology, Neurobiology and Biophysics. Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands.
| |
Collapse
|
28
|
James C, Kehlenbach RH. The Interactome of the VAP Family of Proteins: An Overview. Cells 2021; 10:cells10071780. [PMID: 34359948 PMCID: PMC8306308 DOI: 10.3390/cells10071780] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 06/28/2021] [Accepted: 07/08/2021] [Indexed: 12/11/2022] Open
Abstract
Membrane contact sites (MCS) are sites of close apposition of two organelles that help in lipid transport and synthesis, calcium homeostasis and several other biological processes. The VAMP-associated proteins (VAPs) VAPA, VAPB, MOSPD2 and the recently described MOSPD1 and MOSPD3 are tether proteins of MCSs that are mainly found at the endoplasmic reticulum (ER). VAPs interact with various proteins with a motif called FFAT (two phenylalanines in an acidic tract), recruiting the associated organelle to the ER. In addition to the conventional FFAT motif, the recently described FFNT (two phenylalanines in a neutral tract) and phospho-FFAT motifs contribute to the interaction with VAPs. In this review, we summarize and compare the recent interactome studies described for VAPs, including in silico and proximity labeling methods. Collectively, the interaction repertoire of VAPs is very diverse and highlights the complexity of interactions mediated by the different FFAT motifs to the VAPs.
Collapse
|
29
|
Dorsch AD, Hölper JE, Franzke K, Zaeck LM, Mettenleiter TC, Klupp BG. Role of Vesicle-Associated Membrane Protein-Associated Proteins (VAP) A and VAPB in Nuclear Egress of the Alphaherpesvirus Pseudorabies Virus. Viruses 2021; 13:v13061117. [PMID: 34200728 PMCID: PMC8229525 DOI: 10.3390/v13061117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/31/2021] [Accepted: 06/07/2021] [Indexed: 11/16/2022] Open
Abstract
The molecular mechanism affecting translocation of newly synthesized herpesvirus nucleocapsids from the nucleus into the cytoplasm is still not fully understood. The viral nuclear egress complex (NEC) mediates budding at and scission from the inner nuclear membrane, but the NEC is not sufficient for efficient fusion of the primary virion envelope with the outer nuclear membrane. Since no other viral protein was found to be essential for this process, it was suggested that a cellular machinery is recruited by viral proteins. However, knowledge on fusion mechanisms involving the nuclear membranes is rare. Recently, vesicle-associated membrane protein-associated protein B (VAPB) was shown to play a role in nuclear egress of herpes simplex virus 1 (HSV-1). To test this for the related alphaherpesvirus pseudorabies virus (PrV), we mutated genes encoding VAPB and VAPA by CRISPR/Cas9-based genome editing in our standard rabbit kidney cells (RK13), either individually or in combination. Single as well as double knockout cells were tested for virus propagation and for defects in nuclear egress. However, no deficiency in virus replication nor any effect on nuclear egress was obvious suggesting that VAPB and VAPA do not play a significant role in this process during PrV infection in RK13 cells.
Collapse
Affiliation(s)
- Anna D. Dorsch
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, 17493 Greifswald, Insel Riems, Germany; (A.D.D.); (J.E.H.); (L.M.Z.); (T.C.M.)
| | - Julia E. Hölper
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, 17493 Greifswald, Insel Riems, Germany; (A.D.D.); (J.E.H.); (L.M.Z.); (T.C.M.)
| | - Kati Franzke
- Institute of Infectology, Friedrich-Loeffler-Institut, 17493 Greifswald, Insel Riems, Germany;
| | - Luca M. Zaeck
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, 17493 Greifswald, Insel Riems, Germany; (A.D.D.); (J.E.H.); (L.M.Z.); (T.C.M.)
| | - Thomas C. Mettenleiter
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, 17493 Greifswald, Insel Riems, Germany; (A.D.D.); (J.E.H.); (L.M.Z.); (T.C.M.)
| | - Barbara G. Klupp
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, 17493 Greifswald, Insel Riems, Germany; (A.D.D.); (J.E.H.); (L.M.Z.); (T.C.M.)
- Correspondence:
| |
Collapse
|
30
|
Pathomechanisms of ALS8: altered autophagy and defective RNA binding protein (RBP) homeostasis due to the VAPB P56S mutation. Cell Death Dis 2021; 12:466. [PMID: 33972508 PMCID: PMC8110809 DOI: 10.1038/s41419-021-03710-y] [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] [Received: 11/30/2020] [Revised: 04/12/2021] [Accepted: 04/13/2021] [Indexed: 02/03/2023]
Abstract
Mutations in RNA binding proteins (RBPs) and in genes regulating autophagy are frequent causes of familial amyotrophic lateral sclerosis (fALS). The P56S mutation in vesicle-associated membrane protein-associated protein B (VAPB) leads to fALS (ALS8) and spinal muscular atrophy (SMA). While VAPB is primarily involved in the unfolded protein response (UPR), vesicular trafficking and in initial steps of the autophagy pathway, the effect of mutant P56S-VAPB on autophagy regulation in connection with RBP homeostasis has not been explored yet. Examining the muscle biopsy of our index ALS8 patient of European origin revealed globular accumulations of VAPB aggregates co-localised with autophagy markers LC3 and p62 in partially atrophic and atrophic muscle fibres. In line with this skin fibroblasts obtained from the same patient showed accumulation of P56S-VAPB aggregates together with LC3 and p62. Detailed investigations of autophagic flux in cell culture models revealed that P56S-VAPB alters both initial and late steps of the autophagy pathway. Accordingly, electron microscopy complemented with live cell imaging highlighted the impaired fusion of accumulated autophagosomes with lysosomes in cells expressing P56S-VAPB. Consistent with these observations, neuropathological studies of brain and spinal cord of P56S-VAPB transgenic mice revealed signs of neurodegeneration associated with altered protein quality control and defective autophagy. Autophagy and RBP homeostasis are interdependent, as demonstrated by the cytoplasmic mis-localisation of several RBPs including pTDP-43, FUS, Matrin 3 which often sequestered with P56S-VAPB aggregates both in cell culture and in the muscle biopsy of the ALS8 patient. Further confirming the notion that aggregation of the RBPs proceeds through the stress granule (SG) pathway, we found persistent G3BP- and TIAR1-positive SGs in P56S-VAPB expressing cells as well as in the ALS8 patient muscle biopsy. We conclude that P56S-VAPB-ALS8 involves a cohesive pathomechanism of aberrant RBP homeostasis together with dysfunctional autophagy.
Collapse
|
31
|
Neefjes J, Cabukusta B. What the VAP: The Expanded VAP Family of Proteins Interacting With FFAT and FFAT-Related Motifs for Interorganellar Contact. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2021; 4:25152564211012246. [PMID: 34036242 PMCID: PMC7610837 DOI: 10.1177/25152564211012246] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Membrane contact sites are formed by tether proteins that have the ability to bring two organellar membranes together. VAP proteins are a family of endoplasmic reticulum (ER)-resident tether proteins specialized in interacting with FFAT (two phenylalanines in an acidic tract) peptide motifs in other proteins. If the FFAT-motif-containing proteins reside on other organelles, VAP proteins form contact sites between these organelles and the ER. The role of VAPA and VAPB, the two founding members of the VAP family in recruiting proteins to the ER and forming membrane contact sites is well appreciated as numerous interaction partners of VAPA and VAPB at different intracellular contact sites have been characterized. Recently, three new proteins -MOSPD1, MOSPD2 and MOSPD3-have been added to the VAP family. While MOSPD2 has a motif preference similar to VAPA and VAPB, MOSPD1 and MOSPD3 prefer to interact with proteins containing FFNT (two phenylalanines in a neutral tract) motifs. In this review, we discuss the recent advances in motif binding by VAP proteins along with the other biological processes VAP proteins are involved in.
Collapse
Affiliation(s)
- Jacques Neefjes
- Cell and Chemical Biology, Oncode Institute, Leiden University Medical Center, Leiden, the Netherlands
| | - Birol Cabukusta
- Cell and Chemical Biology, Oncode Institute, Leiden University Medical Center, Leiden, the Netherlands
| |
Collapse
|
32
|
Quistgaard EM. BAP31: Physiological functions and roles in disease. Biochimie 2021; 186:105-129. [PMID: 33930507 DOI: 10.1016/j.biochi.2021.04.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 04/20/2021] [Accepted: 04/21/2021] [Indexed: 12/22/2022]
Abstract
B-cell receptor-associated protein 31 (BAP31 or BCAP31) is a ubiquitously expressed transmembrane protein found mainly in the endoplasmic reticulum (ER), including in mitochondria-associated membranes (MAMs). It acts as a broad-specificity membrane protein chaperone and quality control factor, which can promote different fates for its clients, including ER retention, ER export, ER-associated degradation (ERAD), or evasion of degradation, and it also acts as a MAM tetherer and regulatory protein. It is involved in several cellular processes - it supports ER and mitochondrial homeostasis, promotes proliferation and migration, plays several roles in metabolism and the immune system, and regulates autophagy and apoptosis. Full-length BAP31 can be anti-apoptotic, but can also mediate activation of caspase-8, and itself be cleaved by caspase-8 into p20-BAP31, which promotes apoptosis by mobilizing ER calcium stores at MAMs. BAP31 loss-of-function mutations is the cause of 'deafness, dystonia, and central hypomyelination' (DDCH) syndrome, characterized by severe neurological symptoms and early death. BAP31 is furthermore implicated in a growing number of cancers and other diseases, and several viruses have been found to target it to promote their survival or life cycle progression. The purpose of this review is to provide an overview and examination of the basic properties, functions, mechanisms, and roles in disease of BAP31.
Collapse
Affiliation(s)
- Esben M Quistgaard
- Department of Molecular Biology and Genetics - DANDRITE, Aarhus University, Gustav Wieds Vej 10, DK-8000 Aarhus C, Denmark.
| |
Collapse
|
33
|
Parakh S, Atkin JD. The Mitochondrial-associated ER membrane (MAM) compartment and its dysregulation in Amyotrophic Lateral Sclerosis (ALS). Semin Cell Dev Biol 2021; 112:105-113. [PMID: 33707063 DOI: 10.1016/j.semcdb.2021.02.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 02/04/2021] [Accepted: 02/05/2021] [Indexed: 12/11/2022]
Abstract
The endoplasmic reticulum (ER) and mitochondria connect at multiple contact sites to form a unique cellular compartment, termed the 'mitochondria-associated ER membranes' (MAMs). MAMs are hubs for signalling pathways that regulate cellular homeostasis and survival, metabolism, and sensitivity to apoptosis. MAMs are therefore involved in vital cellular functions, but they are dysregulated in several human diseases. Whilst MAM dysfunction is increasingly implicated in the pathogenesis of neurodegenerative diseases, its role in amyotrophic lateral sclerosis (ALS) is poorly understood. However, in ALS both ER and mitochondrial dysfunction are well documented pathophysiological events. Moreover, alterations to lipid metabolism in neurons regulate processes linked to neurodegenerative diseases, and a link between dysfunction of lipid metabolism and ALS has also been proposed. In this review we discuss the structural and functional relevance of MAMs in ALS and how targeting MAM could be therapeutically beneficial in this disorder.
Collapse
Affiliation(s)
- Sonam Parakh
- Macquarie University Centre for MND Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Julie D Atkin
- Macquarie University Centre for MND Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia; Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Victoria, 3065, Australia.
| |
Collapse
|
34
|
Zakyrjanova GF, Giniatullin AR, Mukhutdinova KA, Kuznetsova EA, Petrov AM. Early differences in membrane properties at the neuromuscular junctions of ALS model mice: Effects of 25-hydroxycholesterol. Life Sci 2021; 273:119300. [PMID: 33662433 DOI: 10.1016/j.lfs.2021.119300] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 02/13/2021] [Accepted: 02/25/2021] [Indexed: 12/11/2022]
Abstract
AIMS Plasma hyperlipidemia is a protective factor in amyotrophic lateral sclerosis (ALS) while cholesterol-lowering drugs aggravate the pathology. We hypothesize that this phenomenon can be linked with membrane lipid alterations in the neuromuscular junctions (NMJs) occurring before motor neuron loss. METHODS Neurotransmitter release in parallel with lipid membrane properties in diaphragm NMJs of SOD1G93A (mSOD) mice at nine weeks of age (pre-onset stage) were assessed. KEY FINDINGS Despite on slight changes in spontaneous and evoked quantum release of acetylcholine, extracellular levels of choline at resting conditions, an indicator of non-quantum release, were significantly increased in mSOD mice. The use of lipid-sensitive fluorescent probes points to lipid raft disruption in the NMJs of mSOD mice. However, content of cholesterol, a key raft component was unchanged implying another pathway responsible for the loss of raft integrity. In the mSOD mice we found marked increase in levels of raft-destabilizing lipid ceramide. This was accompanied by enhanced ability to uptake of exogenous ceramide in NMJs. Acute and chronic administration of 25-hydroxycholesterol, whose levels increase due to hypercholesterolemia, recovered early alterations in membrane properties. Furthermore, chronic treatment with 25-hydroxycholesterol prevented increase in ceramide and extracellular choline levels as well as suppressed lipid peroxidation of NMJ membranes and fragmentation of end plates. SIGNIFICANCE Thus, lipid raft disruption likely due to ceramide accumulation could be early event in ALS which may trigger neuromuscular abnormalities. Cholesterol derivative 25-hydroxycholesterol may serve as a molecule restoring the membrane and functional properties of NMJs at the early stage.
Collapse
Affiliation(s)
- Guzel F Zakyrjanova
- Laboratory of Biophysics of Synaptic Processes, Kazan Institute of Biochemistry and Biophysics, Federal Research Center "Kazan Scientific Center of RAS", 2/31 Lobachevsky Street, box 30, Kazan 420111, Russia; Institute of Neuroscience, Kazan State Medial University, 49 Butlerova Street, Kazan, 420012, Russia
| | - Arthur R Giniatullin
- Department of Normal Physiology, Kazan State Medial University, 49 Butlerova Street, Kazan 420012, Russia
| | - Kamilla A Mukhutdinova
- Institute of Neuroscience, Kazan State Medial University, 49 Butlerova Street, Kazan, 420012, Russia
| | - Eva A Kuznetsova
- Laboratory of Biophysics of Synaptic Processes, Kazan Institute of Biochemistry and Biophysics, Federal Research Center "Kazan Scientific Center of RAS", 2/31 Lobachevsky Street, box 30, Kazan 420111, Russia
| | - Alexey M Petrov
- Laboratory of Biophysics of Synaptic Processes, Kazan Institute of Biochemistry and Biophysics, Federal Research Center "Kazan Scientific Center of RAS", 2/31 Lobachevsky Street, box 30, Kazan 420111, Russia; Institute of Neuroscience, Kazan State Medial University, 49 Butlerova Street, Kazan, 420012, Russia.
| |
Collapse
|
35
|
Deregulation of phosphatidylinositol-4-phosphate in the development of amyotrophic lateral sclerosis 8. Adv Biol Regul 2021; 79:100779. [PMID: 33461946 DOI: 10.1016/j.jbior.2020.100779] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 12/15/2020] [Accepted: 12/21/2020] [Indexed: 01/19/2023]
Abstract
Amyotrophic lateral sclerosis 8 (ALS8) is one of a heterogeneous group of progressive neurodegenerative disorders characterized by the death of motor neurons. ALS8 is caused by mutations in VAPB, a protein that acts at multiple membrane contact sites between the endoplasmic reticulum (ER) and almost all other organelles and thus affects functions at diverse cellular locations. One prominent function mediated by VAPB at these sites is lipid exchange, and a recurrent phenotype observed in all models investigating knockout or knockdown of VAPs is a significant increase in the levels of phosphatidylinositol-4-phosphate (PI4P). Here we consider the relevance of this PI4P deregulation in the development of ALS8 that might represent a potential target for therapeutic intervention.
Collapse
|
36
|
TSUBOI M, HIRABAYASHI Y. New insights into the regulation of synaptic transmission and plasticity by the endoplasmic reticulum and its membrane contacts. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2021; 97:559-572. [PMID: 34897182 PMCID: PMC8687855 DOI: 10.2183/pjab.97.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 10/18/2021] [Indexed: 06/14/2023]
Abstract
Mammalian neurons are highly compartmentalized yet very large cells. To provide each compartment with its distinct properties, metabolic homeostasis and molecular composition need to be precisely coordinated in a compartment-specific manner. Despite the importance of the endoplasmic reticulum (ER) as a platform for various biochemical reactions, such as protein synthesis, protein trafficking, and intracellular calcium control, the contribution of the ER to neuronal compartment-specific functions and plasticity remains elusive. Recent advances in the development of live imaging and serial scanning electron microscopy (sSEM) analysis have revealed that the neuronal ER is a highly dynamic organelle with compartment-specific structures. sSEM studies also revealed that the ER forms contacts with other membranes, such as the mitochondria and plasma membrane, although little is known about the functions of these ER-membrane contacts. In this review, we discuss the mechanisms and physiological roles of the ER structure and ER-mitochondria contacts in synaptic transmission and plasticity, thereby highlighting a potential link between organelle ultrastructure and neuronal functions.
Collapse
Affiliation(s)
- Masafumi TSUBOI
- Graduate School of Engineering, The University of Tokyo, Tokyo, Japan
| | | |
Collapse
|
37
|
Borgese N, Navone F, Nukina N, Yamanaka T. Mutant VAPB: Culprit or Innocent Bystander of Amyotrophic Lateral Sclerosis? CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2021; 4:25152564211022515. [PMID: 37366377 PMCID: PMC10243577 DOI: 10.1177/25152564211022515] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 05/08/2021] [Accepted: 05/12/2021] [Indexed: 06/28/2023]
Abstract
Nearly twenty years ago a mutation in the VAPB gene, resulting in a proline to serine substitution (p.P56S), was identified as the cause of a rare, slowly progressing, familial form of the motor neuron degenerative disease Amyotrophic Lateral Sclerosis (ALS). Since then, progress in unravelling the mechanistic basis of this mutation has proceeded in parallel with research on the VAP proteins and on their role in establishing membrane contact sites between the ER and other organelles. Analysis of the literature on cellular and animal models reviewed here supports the conclusion that P56S-VAPB, which is aggregation-prone, non-functional and unstable, is expressed at levels that are insufficient to support toxic gain-of-function or dominant negative effects within motor neurons. Instead, insufficient levels of the product of the single wild-type allele appear to be required for pathological effects, and may be the main driver of the disease. In light of the multiple interactions of the VAP proteins, we address the consequences of specific VAPB depletion and highlight various affected processes that could contribute to motor neuron degeneration. In the future, distinction of specific roles of each of the two VAP paralogues should help to further elucidate the basis of p.P56S familial ALS, as well as of other more common forms of the disease.
Collapse
Affiliation(s)
- Nica Borgese
- CNR Institute of
Neuroscience, Vedano al Lambro (MB), Italy
| | | | - Nobuyuki Nukina
- Laboratory of Structural
Neuropathology, Doshisha University Graduate School of Brain Science,
Kyoto, Japan
| | - Tomoyuki Yamanaka
- Laboratory of Structural
Neuropathology, Doshisha University Graduate School of Brain Science,
Kyoto, Japan
| |
Collapse
|
38
|
Abnormalities of synaptic mitochondria in autism spectrum disorder and related neurodevelopmental disorders. J Mol Med (Berl) 2020; 99:161-178. [PMID: 33340060 PMCID: PMC7819932 DOI: 10.1007/s00109-020-02018-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 11/27/2020] [Accepted: 12/02/2020] [Indexed: 12/18/2022]
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental condition primarily characterized by an impairment of social interaction combined with the occurrence of repetitive behaviors. ASD starts in childhood and prevails across the lifespan. The variability of its clinical presentation renders early diagnosis difficult. Mutations in synaptic genes and alterations of mitochondrial functions are considered important underlying pathogenic factors, but it is obvious that we are far from a comprehensive understanding of ASD pathophysiology. At the synapse, mitochondria perform diverse functions, which are clearly not limited to their classical role as energy providers. Here, we review the current knowledge about mitochondria at the synapse and summarize the mitochondrial disturbances found in mouse models of ASD and other ASD-related neurodevelopmental disorders, like DiGeorge syndrome, Rett syndrome, Tuberous sclerosis complex, and Down syndrome.
Collapse
|
39
|
Zein-Sabatto H, Cole T, Hoang HD, Tiwary E, Chang C, Miller MA. The type II integral ER membrane protein VAP-B homolog in C. elegans is cleaved to release the N-terminal MSP domain to signal non-cell-autonomously. Dev Biol 2020; 470:10-20. [PMID: 33160939 DOI: 10.1016/j.ydbio.2020.10.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 10/30/2020] [Accepted: 10/31/2020] [Indexed: 11/18/2022]
Abstract
VAMP/synaptobrevin-associated protein B (VAP-B) is a type II ER membrane protein, but its N-terminal MSP domain (MSPd) can be cleaved and secreted. Mutations preventing the cleavage and secretion of MSPd have been implicated in cases of human neurodegenerative diseases. The site of VAP cleavage and the tissues capable in releasing the processed MSPd are not understood. In this study, we analyze the C. elegans VAP-B homolog, VPR-1, for its processing and secretion from the intestine. We show that intestine-specific expression of an N-terminally FLAG-tagged VPR-1 rescues underdeveloped gonad and sterility defects in vpr-1 null hermaphrodites. Immunofluorescence studies reveal that the tagged intestinal expressed VPR-1 is present at the distal gonad. Mass spectrometry analysis of a smaller product of the N-terminally tagged VPR-1 identifies a specific cleavage site at Leu156. Mutation of the leucine results in loss of gonadal MSPd signal and reduced activity of the mutant VPR-1. Thus, we report for the first time the cleavage site of VPR-1 and provide direct evidence that intestinally expressed VPR-1 can be released and signal in the distal gonad. These results establish the foundation for further exploration of VAP cleavage, MSPd secretion, and non-cell-autonomous signaling in development and diseases.
Collapse
Affiliation(s)
- Hala Zein-Sabatto
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1900 University Blvd, Birmingham, AL, 35294-0006, USA.
| | - Tim Cole
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1900 University Blvd, Birmingham, AL, 35294-0006, USA
| | - Hieu D Hoang
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1900 University Blvd, Birmingham, AL, 35294-0006, USA
| | - Ekta Tiwary
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1900 University Blvd, Birmingham, AL, 35294-0006, USA
| | - Chenbei Chang
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1900 University Blvd, Birmingham, AL, 35294-0006, USA
| | - Michael A Miller
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, 1900 University Blvd, Birmingham, AL, 35294-0006, USA
| |
Collapse
|
40
|
Muzio L, Sirtori R, Gornati D, Eleuteri S, Fossaghi A, Brancaccio D, Manzoni L, Ottoboni L, Feo LD, Quattrini A, Mastrangelo E, Sorrentino L, Scalone E, Comi G, Marinelli L, Riva N, Milani M, Seneci P, Martino G. Retromer stabilization results in neuroprotection in a model of Amyotrophic Lateral Sclerosis. Nat Commun 2020; 11:3848. [PMID: 32737286 PMCID: PMC7395176 DOI: 10.1038/s41467-020-17524-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 07/02/2020] [Indexed: 11/24/2022] Open
Abstract
Amyotrophic Lateral Sclerosis (ALS) is a fatal disease characterized by the degeneration of upper and lower motor neurons (MNs). We find a significant reduction of the retromer complex subunit VPS35 in iPSCs-derived MNs from ALS patients, in MNs from ALS post mortem explants and in MNs from SOD1G93A mice. Being the retromer involved in trafficking of hydrolases, a pathological hallmark in ALS, we design, synthesize and characterize an array of retromer stabilizers based on bis-guanylhydrazones connected by a 1,3-phenyl ring linker. We select compound 2a as a potent and bioavailable interactor of VPS35-VPS29. Indeed, while increasing retromer stability in ALS mice, compound 2a attenuates locomotion impairment and increases MNs survival. Moreover, compound 2a increases VPS35 in iPSCs-derived MNs and shows brain bioavailability. Our results clearly suggest the retromer as a valuable druggable target in ALS. ALS is a neurodegenerative disease characterized by loss of motor neurons. Here, the authors showed that reduced levels of the VSP35 subunit in the retromer complex is a conserved ALS feature and identified a new lead compound increasing retromer stability ameliorating the disease phenotype.
Collapse
Affiliation(s)
- Luca Muzio
- INSPE-Institute of Experimental Neurology, San Raffaele Scientific Institute, Milano, Italy.
| | - Riccardo Sirtori
- INSPE-Institute of Experimental Neurology, San Raffaele Scientific Institute, Milano, Italy
| | - Davide Gornati
- Department of Chemistry, University of Milan, Milano, Italy
| | - Simona Eleuteri
- INSPE-Institute of Experimental Neurology, San Raffaele Scientific Institute, Milano, Italy
| | - Andrea Fossaghi
- INSPE-Institute of Experimental Neurology, San Raffaele Scientific Institute, Milano, Italy
| | - Diego Brancaccio
- Department of Pharmacy, University of Naples "Federico II", Naples, Italy
| | - Leonardo Manzoni
- Institute of Molecular Science and Technology (ISTM), CNR, Milan, Italy
| | - Linda Ottoboni
- INSPE-Institute of Experimental Neurology, San Raffaele Scientific Institute, Milano, Italy
| | - Luca De Feo
- INSPE-Institute of Experimental Neurology, San Raffaele Scientific Institute, Milano, Italy
| | - Angelo Quattrini
- INSPE-Institute of Experimental Neurology, San Raffaele Scientific Institute, Milano, Italy
| | | | | | - Emanuele Scalone
- Department of Chemistry, University of Milan, Milano, Italy.,Institute of Biophysics (IBF), CNR, Milan, Italy
| | - Giancarlo Comi
- INSPE-Institute of Experimental Neurology, San Raffaele Scientific Institute, Milano, Italy
| | - Luciana Marinelli
- Department of Pharmacy, University of Naples "Federico II", Naples, Italy
| | - Nilo Riva
- INSPE-Institute of Experimental Neurology, San Raffaele Scientific Institute, Milano, Italy
| | - Mario Milani
- Institute of Biophysics (IBF), CNR, Milan, Italy
| | | | - Gianvito Martino
- INSPE-Institute of Experimental Neurology, San Raffaele Scientific Institute, Milano, Italy
| |
Collapse
|
41
|
Yamanaka T, Nishiyama R, Shimogori T, Nukina N. Proteomics-Based Approach Identifies Altered ER Domain Properties by ALS-Linked VAPB Mutation. Sci Rep 2020; 10:7610. [PMID: 32376919 PMCID: PMC7203144 DOI: 10.1038/s41598-020-64517-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Accepted: 04/17/2020] [Indexed: 12/13/2022] Open
Abstract
An ER transmembrane protein, vesicle-associated membrane protein-associated protein B (VAPB), binds to several organelle-resident membrane proteins to mediate ER-organelle tethering. Mutation in amyotrophic lateral sclerosis (ALS) induces protein misfolding and aggregation, leading to ER disorganization. Gain or loss of function is suggested for VAPB mutation, however comprehensive study focusing on VAPB-ER domain has yet been performed. We here conducted proteomic characterization of the ER containing VAPB and its ALS-linked P56S mutant. For this purpose, we first optimized the proteomics of different ER domains immuno-isolated from cultured cells, and identified ER sheet- and tubule-specific proteomes. By using these as references, we found that VAPB-ER proteome had intermediate ER domain properties but its tubular property was specifically decreased by its mutation. Biochemical, immunofluorescence and proximity ligation assays suggested this was mediated by delocalization of VAPB from ER tubules. The VAPB-ER proteomics further suggested reduced incorporation of multiple proteins located in different organelles, which was confirmed by proximity ligation assay. Taken together, our proteomics-based approach indicates altered ER domain properties and impaired ER-organelle tethering by VAPB mutation.
Collapse
Affiliation(s)
- Tomoyuki Yamanaka
- Laboratory of Structural Neuropathology, Doshisha University Graduate School of Brain Science, Kyoto, Japan.
| | - Risa Nishiyama
- Laboratory of Structural Neuropathology, Doshisha University Graduate School of Brain Science, Kyoto, Japan
| | - Tomomi Shimogori
- Molecular Mechanisms of Brain Development, RIKEN Center for Brain Science, Saitama, 351-0198, Japan
| | - Nobuyuki Nukina
- Laboratory of Structural Neuropathology, Doshisha University Graduate School of Brain Science, Kyoto, Japan.
| |
Collapse
|
42
|
Bolus H, Crocker K, Boekhoff-Falk G, Chtarbanova S. Modeling Neurodegenerative Disorders in Drosophila melanogaster. Int J Mol Sci 2020; 21:E3055. [PMID: 32357532 PMCID: PMC7246467 DOI: 10.3390/ijms21093055] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 04/14/2020] [Accepted: 04/21/2020] [Indexed: 12/12/2022] Open
Abstract
Drosophila melanogaster provides a powerful genetic model system in which to investigate the molecular mechanisms underlying neurodegenerative diseases. In this review, we discuss recent progress in Drosophila modeling Alzheimer's Disease, Parkinson's Disease, Amyotrophic Lateral Sclerosis (ALS), Huntington's Disease, Ataxia Telangiectasia, and neurodegeneration related to mitochondrial dysfunction or traumatic brain injury. We close by discussing recent progress using Drosophila models of neural regeneration and how these are likely to provide critical insights into future treatments for neurodegenerative disorders.
Collapse
Affiliation(s)
- Harris Bolus
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL 35487, USA;
| | - Kassi Crocker
- Genetics Graduate Training Program, School of Medicine and Public Health, University of Wisconsin–Madison, Madison, WI 53705, USA;
- Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin–Madison, Madison, WI 53705, USA
| | - Grace Boekhoff-Falk
- Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin–Madison, Madison, WI 53705, USA
| | | |
Collapse
|
43
|
Öztürk Z, O’Kane CJ, Pérez-Moreno JJ. Axonal Endoplasmic Reticulum Dynamics and Its Roles in Neurodegeneration. Front Neurosci 2020; 14:48. [PMID: 32116502 PMCID: PMC7025499 DOI: 10.3389/fnins.2020.00048] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 01/13/2020] [Indexed: 12/13/2022] Open
Abstract
The physical continuity of axons over long cellular distances poses challenges for their maintenance. One organelle that faces this challenge is endoplasmic reticulum (ER); unlike other intracellular organelles, this forms a physically continuous network throughout the cell, with a single membrane and a single lumen. In axons, ER is mainly smooth, forming a tubular network with occasional sheets or cisternae and low amounts of rough ER. It has many potential roles: lipid biosynthesis, glucose homeostasis, a Ca2+ store, protein export, and contacting and regulating other organelles. This tubular network structure is determined by ER-shaping proteins, mutations in some of which are causative for neurodegenerative disorders such as hereditary spastic paraplegia (HSP). While axonal ER shares many features with the tubular ER network in other contexts, these features must be adapted to the long and narrow dimensions of axons. ER appears to be physically continuous throughout axons, over distances that are enormous on a subcellular scale. It is therefore a potential channel for long-distance or regional communication within neurons, independent of action potentials or physical transport of cargos, but involving its physiological roles such as Ca2+ or organelle homeostasis. Despite its apparent stability, axonal ER is highly dynamic, showing features like anterograde and retrograde transport, potentially reflecting continuous fusion and breakage of the network. Here we discuss the transport processes that must contribute to this dynamic behavior of ER. We also discuss the model that these processes underpin a homeostatic process that ensures both enough ER to maintain continuity of the network and repair breaks in it, but not too much ER that might disrupt local cellular physiology. Finally, we discuss how failure of ER organization in axons could lead to axon degenerative diseases, and how a requirement for ER continuity could make distal axons most susceptible to degeneration in conditions that disrupt ER continuity.
Collapse
Affiliation(s)
| | - Cahir J. O’Kane
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | | |
Collapse
|
44
|
VAPB ER-Aggregates, A Possible New Biomarker in ALS Pathology. Cells 2020; 9:cells9010164. [PMID: 31936602 PMCID: PMC7017080 DOI: 10.3390/cells9010164] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 12/16/2019] [Accepted: 12/30/2019] [Indexed: 12/11/2022] Open
Abstract
A point mutation (P56S) in the gene-encoding vesicle-associated membrane-protein-associated protein B (VAPB) leads to an autosomal-dominant form of amyotrophic lateral sclerosis (ALS), classified as ALS-8. The mutant VAPB is characterized by ER-associated aggregates that lead to a complete reorganization of ER structures. Growing evidences suggest VAPB involvement in ALS pathomechanisms. In fact, numerous studies demonstrated VAPB alteration also in sporadic ALS (sALS) and showed the presence of its aggregates when others ALS-related gene are mutant. Recently, the identification of new biomarkers in peripheral blood mononuclear cells (PBMCs) has been proposed as a good noninvasive option for studying ALS. Here, we evaluated VAPB as a possible ALS pathologic marker analyzing PBMCs of sALS patients. Immunofluorescence analysis (IFA) showed a peculiar pattern of VAPB aggregates in sALS, not evident in healthy control (HC) subjects and in Parkinson’s disease (PD) PBMCs. This specific pattern led us to suppose that VAPB could be misfolded in sALS. The data indirectly confirmed by flow cytometry assay (FCA) showed a reduction of VAPB fluorescent signals in sALS. However, our observations were not associated with the presence of a genetic mutation or altered gene expression of VAPB. Our study brings further evidences of the VAPB role in ALS as a diagnostic biomarker.
Collapse
|
45
|
Fowler PC, Garcia-Pardo ME, Simpson JC, O'Sullivan NC. NeurodegenERation: The Central Role for ER Contacts in Neuronal Function and Axonopathy, Lessons From Hereditary Spastic Paraplegias and Related Diseases. Front Neurosci 2019; 13:1051. [PMID: 31680803 PMCID: PMC6801308 DOI: 10.3389/fnins.2019.01051] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 09/19/2019] [Indexed: 12/17/2022] Open
Abstract
The hereditary spastic paraplegias (HSPs) are a group of inherited neurodegenerative conditions whose characteristic feature is degeneration of the longest axons within the corticospinal tract which leads to progressive spasticity and weakness of the lower limbs. Though highly genetically heterogeneous, the majority of HSP cases are caused by mutations in genes encoding proteins that are responsible for generating and organizing the tubular endoplasmic reticulum (ER). Despite this, the role of the ER within neurons, particularly the long axons affected in HSP, is not well understood. Throughout axons, ER tubules make extensive contacts with other organelles, the cytoskeleton and the plasma membrane. At these ER contacts, protein complexes work in concert to perform specialized functions including organelle shaping, calcium homeostasis and lipid biogenesis, all of which are vital for neuronal survival and may be disrupted by HSP-causing mutations. In this article we summarize the proteins which mediate ER contacts, review the functions these contacts are known to carry out within neurons, and discuss the potential contribution of disruption of ER contacts to axonopathy in HSP.
Collapse
Affiliation(s)
- Philippa C Fowler
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - M Elena Garcia-Pardo
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Jeremy C Simpson
- UCD School of Biology and Environmental Science, UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Niamh C O'Sullivan
- UCD School of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Dublin, Ireland
| |
Collapse
|
46
|
Johnson B, Leek AN, Tamkun MM. Kv2 channels create endoplasmic reticulum / plasma membrane junctions: a brief history of Kv2 channel subcellular localization. Channels (Austin) 2019; 13:88-101. [PMID: 30712450 PMCID: PMC6380216 DOI: 10.1080/19336950.2019.1568824] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The potassium channels Kv2.1 and Kv2.2 are widely expressed throughout the mammalian brain. Kv2.1 provides the majority of delayed rectifying current in rat hippocampus while both channels are differentially expressed in cortex. Particularly unusual is their neuronal surface localization pattern: while half the channel population is freely-diffusive on the plasma membrane as expected from the generalized Singer & Nicolson fluid mosaic model, the other half localizes into micron-sized clusters on the soma, dendrites, and axon initial segment. These clusters contain hundreds of channels, which for Kv2.1, are largely non-conducting. Competing theories of the mechanism underlying Kv2.1 clustering have included static tethering to being corralled by an actin fence. Now, recent work has demonstrated channel clustering is due to formation of endoplasmic reticulum/plasma membrane (ER/PM) junctions through interaction with ER-resident VAMP-associated proteins (VAPs). Interaction between surface Kv2 channels and ER VAPs groups channels together in clusters. ER/PM junctions play important roles in inter-organelle communication: they regulate ion flux, are involved in lipid transfer, and are sites of endo- and exocytosis. Kv2-induced ER/PM junctions are regulated through phosphorylation of the channel C-terminus which in turn regulates VAP binding, providing a rapid means to create or dismantle these microdomains. In addition, insults such as hypoxia or ischemia disrupt this interaction resulting in ER/PM junction disassembly. Kv2 channels are the only known plasma membrane protein to form regulated, injury sensitive junctions in this manner. Furthermore, it is likely that concentrated VAPs at these microdomains sequester additional interactors whose functions are not yet fully understood.
Collapse
Affiliation(s)
- Ben Johnson
- a Molecular, Cellular and Integrative Neurosciences Graduate Program , Colorado State University , Fort Collins , CO , USA.,b Department of Biomedical Sciences , Colorado State University , Fort Collins , CO , USA
| | - Ashley N Leek
- a Molecular, Cellular and Integrative Neurosciences Graduate Program , Colorado State University , Fort Collins , CO , USA.,b Department of Biomedical Sciences , Colorado State University , Fort Collins , CO , USA
| | - Michael M Tamkun
- a Molecular, Cellular and Integrative Neurosciences Graduate Program , Colorado State University , Fort Collins , CO , USA.,b Department of Biomedical Sciences , Colorado State University , Fort Collins , CO , USA.,c Department of Biochemistry and Molecular Biology , Colorado State University , Fort Collins , CO , USA
| |
Collapse
|
47
|
Guo W, Stoklund Dittlau K, Van Den Bosch L. Axonal transport defects and neurodegeneration: Molecular mechanisms and therapeutic implications. Semin Cell Dev Biol 2019; 99:133-150. [PMID: 31542222 DOI: 10.1016/j.semcdb.2019.07.010] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Revised: 06/22/2019] [Accepted: 07/09/2019] [Indexed: 12/12/2022]
Abstract
Because of the extremely polarized morphology, the proper functioning of neurons largely relies on the efficient cargo transport along the axon. Axonal transport defects have been reported in multiple neurodegenerative diseases as an early pathological feature. The discovery of mutations in human genes involved in the transport machinery provide a direct causative relationship between axonal transport defects and neurodegeneration. Here, we summarize the current genetic findings related to axonal transport in neurodegenerative diseases, and we discuss the relationship between axonal transport defects and other pathological changes observed in neurodegeneration. In addition, we summarize the therapeutic approaches targeting the axonal transport machinery in studies of neurodegenerative diseases. Finally, we review the technical advances in tracking axonal transport both in vivo and in vitro.
Collapse
Affiliation(s)
- Wenting Guo
- KU Leuven - University of Leuven, Department of Neurosciences, Experimental Neurology, and Leuven Brain Institute (LBI), Leuven, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium; KU Leuven-Stem Cell Institute (SCIL), Leuven, Belgium
| | - Katarina Stoklund Dittlau
- KU Leuven - University of Leuven, Department of Neurosciences, Experimental Neurology, and Leuven Brain Institute (LBI), Leuven, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium
| | - Ludo Van Den Bosch
- KU Leuven - University of Leuven, Department of Neurosciences, Experimental Neurology, and Leuven Brain Institute (LBI), Leuven, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium.
| |
Collapse
|
48
|
Lindhout FW, Cao Y, Kevenaar JT, Bodzęta A, Stucchi R, Boumpoutsari MM, Katrukha EA, Altelaar M, MacGillavry HD, Hoogenraad CC. VAP-SCRN1 interaction regulates dynamic endoplasmic reticulum remodeling and presynaptic function. EMBO J 2019; 38:e101345. [PMID: 31441084 PMCID: PMC6792018 DOI: 10.15252/embj.2018101345] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 07/11/2019] [Accepted: 07/17/2019] [Indexed: 01/08/2023] Open
Abstract
In neurons, the continuous and dynamic endoplasmic reticulum (ER) network extends throughout the axon, and its dysfunction causes various axonopathies. However, it remains largely unknown how ER integrity and remodeling modulate presynaptic function in mammalian neurons. Here, we demonstrated that ER membrane receptors VAPA and VAPB are involved in modulating the synaptic vesicle (SV) cycle. VAP interacts with secernin‐1 (SCRN1) at the ER membrane via a single FFAT‐like motif. Similar to VAP, loss of SCRN1 or SCRN1‐VAP interactions resulted in impaired SV cycling. Consistently, SCRN1 or VAP depletion was accompanied by decreased action potential‐evoked Ca2+ responses. Additionally, we found that VAP‐SCRN1 interactions play an important role in maintaining ER continuity and dynamics, as well as presynaptic Ca2+ homeostasis. Based on these findings, we propose a model where the ER‐localized VAP‐SCRN1 interactions provide a novel control mechanism to tune ER remodeling and thereby modulate Ca2+ dynamics and SV cycling at presynaptic sites. These data provide new insights into the molecular mechanisms controlling ER structure and dynamics, and highlight the relevance of ER function for SV cycling.
Collapse
Affiliation(s)
- Feline W Lindhout
- Department of Biology, Cell Biology, Utrecht University, Utrecht, The Netherlands
| | - Yujie Cao
- Department of Biology, Cell Biology, Utrecht University, Utrecht, The Netherlands
| | - Josta T Kevenaar
- Department of Biology, Cell Biology, Utrecht University, Utrecht, The Netherlands
| | - Anna Bodzęta
- Department of Biology, Cell Biology, Utrecht University, Utrecht, The Netherlands
| | - Riccardo Stucchi
- Department of Biology, Cell Biology, Utrecht University, Utrecht, The Netherlands.,Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands
| | - Maria M Boumpoutsari
- Department of Biology, Cell Biology, Utrecht University, Utrecht, The Netherlands
| | - Eugene A Katrukha
- Department of Biology, Cell Biology, Utrecht University, Utrecht, The Netherlands
| | - Maarten Altelaar
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands
| | - Harold D MacGillavry
- Department of Biology, Cell Biology, Utrecht University, Utrecht, The Netherlands
| | - Casper C Hoogenraad
- Department of Biology, Cell Biology, Utrecht University, Utrecht, The Netherlands.,Department of Neuroscience, Genentech, Inc., South San Francisco, CA, USA
| |
Collapse
|
49
|
Kotian V, Sarmah D, Kaur H, Kesharwani R, Verma G, Mounica L, Veeresh P, Kalia K, Borah A, Wang X, Dave KR, Yavagal DR, Bhattacharya P. Evolving Evidence of Calreticulin as a Pharmacological Target in Neurological Disorders. ACS Chem Neurosci 2019; 10:2629-2646. [PMID: 31017385 DOI: 10.1021/acschemneuro.9b00158] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Calreticulin (CALR), a lectin-like ER chaperone, was initially known only for its housekeeping function, but today it is recognized for many versatile roles in different compartments of a cell. Apart from canonical roles in protein folding and calcium homeostasis, it performs a variety of noncanonical roles, mostly in CNS development. In the past, studies have linked Calreticulin with various other biological components which are detrimental in deciding the fate of neurons. Many neurological disorders that differ in their etiology are commonly associated with aberrant levels of Calreticulin, that lead to modulation of apoptosis and phagocytosis, and impact on transcriptional pathways, impairment in proteostatis, and calcium imbalances. Such multifaceted properties of Calreticulin are the reason why it has been implicated in vital roles of the nervous system in recent years. Hence, understanding its role in the physiology of neurons would help to unearth its involvement in the spectrum of neurological disorders. This Review aims toward exploring the interplay of Calreticulin in neurological disorders which would aid in targeting Calreticulin for developing novel neurotherapeutics.
Collapse
Affiliation(s)
- Vignesh Kotian
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gandhinagar, Gujarat 382355, India
| | - Deepaneeta Sarmah
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gandhinagar, Gujarat 382355, India
| | - Harpreet Kaur
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gandhinagar, Gujarat 382355, India
| | - Radhika Kesharwani
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gandhinagar, Gujarat 382355, India
| | - Geetesh Verma
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gandhinagar, Gujarat 382355, India
| | - Leela Mounica
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gandhinagar, Gujarat 382355, India
| | - Pabbala Veeresh
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gandhinagar, Gujarat 382355, India
| | - Kiran Kalia
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gandhinagar, Gujarat 382355, India
| | - Anupom Borah
- Cellular and Molecular Neurobiology Laboratory, Department of Life Science and Bioinformatics, Assam University, Silchar, Assam 788011, India
| | - Xin Wang
- Department of Neurosurgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Kunjan R. Dave
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida 33136, United States
| | - Dileep R. Yavagal
- Department of Neurology and Neurosurgery, University of Miami Miller School of Medicine, Miami, Florida 33136, United States
| | - Pallab Bhattacharya
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gandhinagar, Gujarat 382355, India
| |
Collapse
|
50
|
Bishop A, Kamoshita M, Passmore JB, Hacker C, Schrader TA, Waterham HR, Costello JL, Schrader M. Fluorescent tools to analyse peroxisome-ER interactions in mammalian cells. ACTA ACUST UNITED AC 2019; 2. [PMID: 31198905 DOI: 10.1177/2515256419848641] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Peroxisomes and the endoplasmic reticulum (ER) cooperate extensively in lipid-related metabolic pathways, and the ER also provides phospholipids to enable the peroxisomal membrane to expand prior to division. Recently, we identified peroxisomal proteins ACBD5 and ACBD4, and the ER protein VAPB as tethering components which physically interact to foster peroxisome-ER associations at membrane contact sites. Overexpression or loss of these tether proteins alters the extent of peroxisome-ER interactions, impacting on lipid exchange between these two compartments. To facilitate further studies into peroxisome-ER associations at the level of membrane contact sites, their role, composition and regulation, we have developed two fluorescence-based systems to monitor peroxisome-ER interactions. We modified a proximity ligation assay and a split-fluorescence reporter system using split superfolder green fluorescent protein. Using the proximity ligation assay we were able to measure changes in peroxisome-ER interactions whilst the split-fluorescence reporter was more limited and only allowed us to label ER-peroxisome contacts. We show that both techniques can be useful additions to the toolkit of methods to study peroxisome-ER associations and explore the relative merits of each.
Collapse
Affiliation(s)
- Alexa Bishop
- Biosciences, University of Exeter, Exeter, EX4 4QD, UK.,Centre for Vascular Biology, Institute of Molecular and Clinical Sciences, St George's, University of London, London SW17 0RE, UK
| | | | | | | | | | - Hans R Waterham
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Academic Medical Center, Amsterdam, The Netherlands
| | | | | |
Collapse
|