1
|
Kersten N, Farías GG. A voyage from the ER: spatiotemporal insights into polarized protein secretion in neurons. Front Cell Dev Biol 2023; 11:1333738. [PMID: 38188013 PMCID: PMC10766823 DOI: 10.3389/fcell.2023.1333738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Accepted: 12/04/2023] [Indexed: 01/09/2024] Open
Abstract
To function properly, neurons must maintain a proteome that differs in their somatodendritic and axonal domain. This requires the polarized sorting of newly synthesized secretory and transmembrane proteins into different vesicle populations as they traverse the secretory pathway. Although the trans-Golgi-network is generally considered to be the main sorting hub, this sorting process may already begin at the ER and continue through the Golgi cisternae. At each step in the sorting process, specificity is conferred by adaptors, GTPases, tethers, and SNAREs. Besides this, local synthesis and unconventional protein secretion may contribute to the polarized proteome to enable rapid responses to stimuli. For some transmembrane proteins, some of the steps in the sorting process are well-studied. These will be highlighted here. The universal rules that govern polarized protein sorting remain unresolved, therefore we emphasize the need to approach this problem in an unbiased, top-down manner. Unraveling these rules will contribute to our understanding of neuronal development and function in health and disease.
Collapse
Affiliation(s)
- Noortje Kersten
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, Netherlands
| | - Ginny G Farías
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, Netherlands
| |
Collapse
|
2
|
Georgiev SV, Rizzoli SO. The long-loop recycling (LLR) of synaptic components as a question of economics. Mol Cell Neurosci 2023; 126:103862. [PMID: 37236414 DOI: 10.1016/j.mcn.2023.103862] [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: 02/28/2023] [Revised: 05/15/2023] [Accepted: 05/19/2023] [Indexed: 05/28/2023] Open
Abstract
The pre- and post-synaptic compartments contain a variety of molecules that are known to recycle between the plasma membrane and intracellular organelles. The recycling steps have been amply described in functional terms, with, for example, synaptic vesicle recycling being essential for neurotransmitter release, and postsynaptic receptor recycling being a fundamental feature of synaptic plasticity. However, synaptic protein recycling may also serve a more prosaic role, simply ensuring the repeated use of specific components, thereby minimizing the energy expenditure on the synthesis of synaptic proteins. This type of process has been recently described for components of the extracellular matrix, which undergo long-loop recycling (LLR), to and from the cell body. Here we suggest that the energy-saving recycling of synaptic components may be more widespread than is generally acknowledged, potentially playing a role in both synaptic vesicle protein usage and postsynaptic receptor metabolism.
Collapse
Affiliation(s)
- Svilen Veselinov Georgiev
- University Medical Center Göttingen, Institute for Neuro- and Sensory Physiology, Germany; International Max Planck Research School for Neuroscience, Göttingen, Germany.
| | - Silvio O Rizzoli
- University Medical Center Göttingen, Institute for Neuro- and Sensory Physiology, Germany; Biostructural Imaging of Neurodegeneration (BIN) Center, Göttingen, Germany; Excellence Cluster Multiscale Bioimaging, Göttingen, Germany.
| |
Collapse
|
3
|
Landau LM, Kagan JC. Beyond natural biology: rewiring cellular networks to study innate immunity. Curr Opin Immunol 2023; 83:102349. [PMID: 37269786 PMCID: PMC10526630 DOI: 10.1016/j.coi.2023.102349] [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: 04/07/2023] [Accepted: 05/05/2023] [Indexed: 06/05/2023]
Abstract
Within immune cells, microbial and self-ligands trigger pattern recognition receptors (PRRs) to nucleate and activate the signaling organelles of the immune system. Much work in this area has derived from observational biology of natural innate immune signaling. More recently, synthetic biology approaches have been used to rewire and study innate immune networks. By utilizing controllable chemical or optogenetic inputs, rearranging protein building blocks, or engineering signal recording circuits, synthetic biology-based techniques complement and inform studies of natural immune pathway operation. In this review, we describe recent synthetic biology-based approaches that have uncovered new insights into PRR signaling, virus-host interactions, and systemic cytokine responses.
Collapse
Affiliation(s)
- Lauren M Landau
- Division of Gastroenterology, Boston Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Jonathan C Kagan
- Division of Gastroenterology, Boston Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA.
| |
Collapse
|
4
|
Andres-Alonso M, Borgmeyer M, Mirzapourdelavar H, Lormann J, Klein K, Schweizer M, Hoffmeister-Ullerich S, Oelschlegel AM, Dityatev A, Kreutz MR. Golgi satellites are essential for polysialylation of NCAM and expression of LTP at distal synapses. Cell Rep 2023; 42:112692. [PMID: 37355986 DOI: 10.1016/j.celrep.2023.112692] [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: 12/22/2022] [Revised: 04/28/2023] [Accepted: 06/08/2023] [Indexed: 06/27/2023] Open
Abstract
The complex cytoarchitecture of neurons poses significant challenges for the maturation of synaptic membrane proteins. It is currently unclear whether locally secreted synaptic proteins bypass the Golgi or whether they traffic through Golgi satellites (GSs). Here, we create a transgenic GS reporter mouse line and show that GSs are widely distributed along dendrites and are capable of mature glycosylation, in particular sialylation. We find that polysialylation of locally secreted NCAM takes place at GSs. Accordingly, in mice lacking a component of trans-Golgi network-to-plasma membrane trafficking, we find fewer GSs and significantly reduced PSA-NCAM levels in distal dendrites of CA1 neurons that receive input from the temporoammonic pathway. Induction of long-term potentiation at those, but not more proximal, synapses is severely impaired. We conclude that GSs serve the need for local mature glycosylation of synaptic membrane proteins in distal dendrites and thereby contribute to rapid changes in synaptic strength.
Collapse
Affiliation(s)
- Maria Andres-Alonso
- Leibniz Group "Dendritic Organelles and Synaptic Function," Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany; RG Neuroplasticity, Leibniz Institute for Neurobiology, 39118 Magdeburg, Germany.
| | - Maximilian Borgmeyer
- Leibniz Group "Dendritic Organelles and Synaptic Function," Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany; RG Neuroplasticity, Leibniz Institute for Neurobiology, 39118 Magdeburg, Germany
| | | | - Jakob Lormann
- Leibniz Group "Dendritic Organelles and Synaptic Function," Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany; RG Neuroplasticity, Leibniz Institute for Neurobiology, 39118 Magdeburg, Germany
| | - Kim Klein
- Leibniz Group "Dendritic Organelles and Synaptic Function," Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Michaela Schweizer
- Core Facility Morphology und Electron Microscopy, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Sabine Hoffmeister-Ullerich
- Core Facility Bioanalytik, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Anja M Oelschlegel
- RG Neuroplasticity, Leibniz Institute for Neurobiology, 39118 Magdeburg, Germany
| | - Alexander Dityatev
- German Center for Neurodegenerative Diseases (DZNE), 39120 Magdeburg, Germany; Center for Behavioral Brain Sciences, Otto von Guericke University, 39120 Magdeburg, Germany; Medical Faculty, Otto von Guericke University, 39120 Magdeburg, Germany
| | - Michael R Kreutz
- Leibniz Group "Dendritic Organelles and Synaptic Function," Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany; RG Neuroplasticity, Leibniz Institute for Neurobiology, 39118 Magdeburg, Germany; German Center for Neurodegenerative Diseases (DZNE), 39120 Magdeburg, Germany; Center for Behavioral Brain Sciences, Otto von Guericke University, 39120 Magdeburg, Germany.
| |
Collapse
|
5
|
Kemal S, Richardson HS, Dyne ED, Fu MM. ER and Golgi trafficking in axons, dendrites, and glial processes. Curr Opin Cell Biol 2022; 78:102119. [PMID: 35964523 PMCID: PMC9590103 DOI: 10.1016/j.ceb.2022.102119] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 06/28/2022] [Accepted: 07/01/2022] [Indexed: 01/31/2023]
Abstract
Both neurons and glia in mammalian brains are highly ramified. Neurons form complex neural networks using axons and dendrites. Axons are long with few branches and form pre-synaptic boutons that connect to target neurons and effector tissues. Dendrites are shorter, highly branched, and form post-synaptic boutons. Astrocyte processes contact synapses and blood vessels in order to regulate neuronal activity and blood flow, respectively. Oligodendrocyte processes extend toward axons to make myelin sheaths. Microglia processes dynamically survey their environments. Here, we describe the local secretory system (ER and Golgi) in neuronal and glial processes. We focus on Golgi outpost functions in acentrosomal microtubule nucleation, cargo trafficking, and protein glycosylation. Thus, satellite ER and Golgi are critical for local structure and function in neurons and glia.
Collapse
Affiliation(s)
- Shahrnaz Kemal
- NINDS (National Institute of Neurological Disorders and Stroke), National Institutes of Health, Bethesda, MD 20893, USA
| | - Hunter S Richardson
- NINDS (National Institute of Neurological Disorders and Stroke), National Institutes of Health, Bethesda, MD 20893, USA
| | - Eric D Dyne
- NINDS (National Institute of Neurological Disorders and Stroke), National Institutes of Health, Bethesda, MD 20893, USA
| | - Meng-Meng Fu
- NINDS (National Institute of Neurological Disorders and Stroke), National Institutes of Health, Bethesda, MD 20893, USA.
| |
Collapse
|
6
|
Khan S. Endoplasmic Reticulum in Metaplasticity: From Information Processing to Synaptic Proteostasis. Mol Neurobiol 2022; 59:5630-5655. [PMID: 35739409 DOI: 10.1007/s12035-022-02916-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 06/05/2022] [Indexed: 11/29/2022]
Abstract
The ER (endoplasmic reticulum) is a Ca2+ reservoir and the unique protein-synthesizing machinery which is distributed throughout the neuron and composed of multiple different structural domains. One such domain is called EMC (endoplasmic reticulum membrane protein complex), pleiotropic nature in cellular functions. The ER/EMC position inside the neurons unmasks its contribution to synaptic plasticity via regulating various cellular processes from protein synthesis to Ca2+ signaling. Since presynaptic Ca2+ channels and postsynaptic ionotropic receptors are organized into the nanodomains, thus ER can be a crucial player in establishing TMNCs (transsynaptic molecular nanocolumns) to shape efficient neural communications. This review hypothesized that ER is not only involved in stress-mediated neurodegeneration but also axon regrowth, remyelination, neurotransmitter switching, information processing, and regulation of pre- and post-synaptic functions. Thus ER might not only be a protein-synthesizing and quality control machinery but also orchestrates plasticity of plasticity (metaplasticity) within the neuron to execute higher-order brain functions and neural repair.
Collapse
Affiliation(s)
- Shumsuzzaman Khan
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, USA.
| |
Collapse
|
7
|
Seiler DK, Hay JC. Genetically encoded fluorescent tools: Shining a little light on ER-to-Golgi transport. Free Radic Biol Med 2022; 183:14-24. [PMID: 35272000 PMCID: PMC9097910 DOI: 10.1016/j.freeradbiomed.2022.03.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 03/03/2022] [Accepted: 03/05/2022] [Indexed: 12/11/2022]
Abstract
Since the first fluorescent proteins (FPs) were identified and isolated over fifty years ago, FPs have become commonplace yet indispensable tools for studying the constitutive secretory pathway in live cells. At the same time, genetically encoded chemical tags have provided a new use for much older fluorescent dyes. Innovation has also produced several specialized methods to allow synchronous release of cargo proteins from the endoplasmic reticulum (ER), enabling precise characterization of sequential trafficking steps in the secretory pathway. Without the constant innovation of the researchers who design these tools to control, image, and quantitate protein secretion, major discoveries about ER-to-Golgi transport and later stages of the constitutive secretory pathway would not have been possible. We review many of the tools and tricks, some 25 years old and others brand new, that have been successfully implemented to study ER-to-Golgi transport in intact and living cells.
Collapse
Affiliation(s)
- Danette Kowal Seiler
- Division of Biological Sciences, Center for Structural & Functional Neuroscience, University of Montana, Missoula, MT, 59812, USA
| | - Jesse C Hay
- Division of Biological Sciences, Center for Structural & Functional Neuroscience, University of Montana, Missoula, MT, 59812, USA.
| |
Collapse
|
8
|
Grochowska KM, Andres‐Alonso M, Karpova A, Kreutz MR. The needs of a synapse—How local organelles serve synaptic proteostasis. EMBO J 2022; 41:e110057. [PMID: 35285533 PMCID: PMC8982616 DOI: 10.15252/embj.2021110057] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 12/24/2021] [Accepted: 02/10/2022] [Indexed: 12/12/2022] Open
Abstract
Synaptic function crucially relies on the constant supply and removal of neuronal membranes. The morphological complexity of neurons poses a significant challenge for neuronal protein transport since the machineries for protein synthesis and degradation are mainly localized in the cell soma. In response to this unique challenge, local micro‐secretory systems have evolved that are adapted to the requirements of neuronal membrane protein proteostasis. However, our knowledge of how neuronal proteins are synthesized, trafficked to membranes, and eventually replaced and degraded remains scarce. Here, we review recent insights into membrane trafficking at synaptic sites and into the contribution of local organelles and micro‐secretory pathways to synaptic function. We describe the role of endoplasmic reticulum specializations in neurons, Golgi‐related organelles, and protein complexes like retromer in the synthesis and trafficking of synaptic transmembrane proteins. We discuss the contribution of autophagy and of proteasome‐mediated and endo‐lysosomal degradation to presynaptic proteostasis and synaptic function, as well as nondegradative roles of autophagosomes and lysosomes in signaling and synapse remodeling. We conclude that the complexity of neuronal cyto‐architecture necessitates long‐distance protein transport that combines degradation with signaling functions.
Collapse
Affiliation(s)
- Katarzyna M Grochowska
- Leibniz Group “Dendritic Organelles and Synaptic Function” Center for Molecular Neurobiology ZMNH University Medical Center Hamburg‐Eppendorf Hamburg Germany
- Research Group Neuroplasticity Leibniz Institute for Neurobiology Magdeburg Germany
| | - Maria Andres‐Alonso
- Leibniz Group “Dendritic Organelles and Synaptic Function” Center for Molecular Neurobiology ZMNH University Medical Center Hamburg‐Eppendorf Hamburg Germany
- Research Group Neuroplasticity Leibniz Institute for Neurobiology Magdeburg Germany
| | - Anna Karpova
- Research Group Neuroplasticity Leibniz Institute for Neurobiology Magdeburg Germany
- Center for Behavioral Brain Sciences Otto von Guericke University Magdeburg Germany
| | - Michael R Kreutz
- Leibniz Group “Dendritic Organelles and Synaptic Function” Center for Molecular Neurobiology ZMNH University Medical Center Hamburg‐Eppendorf Hamburg Germany
- Research Group Neuroplasticity Leibniz Institute for Neurobiology Magdeburg Germany
- Center for Behavioral Brain Sciences Otto von Guericke University Magdeburg Germany
- German Center for Neurodegenerative Diseases (DZNE) Magdeburg Germany
| |
Collapse
|
9
|
Bourke AM, Kennedy MJ. Spatial and Temporal Control of Protein Secretion with Light. Methods Mol Biol 2022; 2473:29-45. [PMID: 35819757 PMCID: PMC10907983 DOI: 10.1007/978-1-0716-2209-4_4] [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] [Indexed: 10/17/2022]
Abstract
How newly synthesized integral membrane proteins and secreted factors are sorted and trafficked to the appropriate location in different cell types remains an important problem in cell biology. One powerful approach for elucidating the trafficking route of a specific protein is to sequester it following synthesis in the endoplasmic reticulum and trigger its release with an externally applied cue. Combined with fluorescent probes, this approach can be used to directly visualize each trafficking step as cargo molecules progress through the different organelles of the secretory network. Here, we discuss design strategies and practical implementation of an inducible protein secretion system we recently developed (zapalog mediated ER trap: zapERtrap) that allows one to use light to initiate secretory trafficking from targeted cells or subcellular domains. We provide detailed protocols for experiments using this approach to visualize protein trafficking from the endoplasmic reticulum to the plasma membrane in fibroblast cell lines and primary cultured neurons.
Collapse
Affiliation(s)
- Ashley M Bourke
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Matthew J Kennedy
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO, USA.
| |
Collapse
|