1
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Robinson BP, Bass NR, Bhakt P, Spiliotis ET. Septin-coated microtubules promote maturation of multivesicular bodies by inhibiting their motility. J Cell Biol 2024; 223:e202308049. [PMID: 38668767 PMCID: PMC11046855 DOI: 10.1083/jcb.202308049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 02/06/2024] [Accepted: 04/10/2024] [Indexed: 04/29/2024] Open
Abstract
The microtubule cytoskeleton consists of microtubule subsets with distinct compositions of microtubule-associated proteins, which instruct the position and traffic of subcellular organelles. In the endocytic pathway, these microtubule-associated cues are poorly understood. Here, we report that in MDCK cells, endosomes with multivesicular body (MVB) and late endosome (LE) markers localize preferentially to microtubules coated with septin GTPases. Compared with early endosomes, CD63-containing MVBs/LEs are largely immotile on septin-coated microtubules. In vitro reconstitution assays revealed that the motility of isolated GFP-CD63 endosomes is directly inhibited by microtubule-associated septins. Quantification of CD63-positive endosomes containing the early endosome antigen (EEA1), the Rab7 effector and dynein adaptor RILP or Rab27a, showed that intermediary EEA1- and RILP-positive GFP-CD63 preferentially associate with septin-coated microtubules. Septin knockdown enhanced GFP-CD63 motility and decreased the percentage of CD63-positive MVBs/LEs with lysobiphosphatidic acid without impacting the fraction of EEA1-positive CD63. These results suggest that MVB maturation involves immobilization on septin-coated microtubules, which may facilitate multivesiculation and/or organelle-organelle contacts.
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Affiliation(s)
| | - Naomi R. Bass
- Department of Biology, Drexel University, Philadelphia, PA, USA
| | - Priyanka Bhakt
- Department of Biology, Drexel University, Philadelphia, PA, USA
| | - Elias T. Spiliotis
- Department of Biology, Drexel University, Philadelphia, PA, USA
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, VA, USA
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2
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Tyagi S, Higerd-Rusli GP, Akin EJ, Baker CA, Liu S, Dib-Hajj FB, Waxman SG, Dib-Hajj SD. Real-time imaging of axonal membrane protein life cycles. Nat Protoc 2024:10.1038/s41596-024-00997-x. [PMID: 38831222 DOI: 10.1038/s41596-024-00997-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 02/12/2024] [Indexed: 06/05/2024]
Abstract
The construction of neuronal membranes is a dynamic process involving the biogenesis, vesicular packaging, transport, insertion and recycling of membrane proteins. Optical imaging is well suited for the study of protein spatial organization and transport. However, various shortcomings of existing imaging techniques have prevented the study of specific types of proteins and cellular processes. Here we describe strategies for protein tagging and labeling, cell culture and microscopy that enable the real-time imaging of axonal membrane protein trafficking and subcellular distribution as they progress through some stages of their life cycle. First, we describe a process for engineering membrane proteins with extracellular self-labeling tags (either HaloTag or SNAPTag), which can be labeled with fluorescent ligands of various colors and cell permeability, providing flexibility for investigating the trafficking and spatiotemporal regulation of multiple membrane proteins in neuronal compartments. Next, we detail the dissection, transfection and culture of dorsal root ganglion sensory neurons in microfluidic chambers, which physically compartmentalizes cell bodies and distal axons. Finally, we describe four labeling and imaging procedures that utilize these enzymatically tagged proteins, flexible fluorescent labels and compartmentalized neuronal cultures to study axonal membrane protein anterograde and retrograde transport, the cotransport of multiple proteins, protein subcellular localization, exocytosis and endocytosis. Additionally, we generated open-source software for analyzing the imaging data in a high throughput manner. The experimental and analysis workflows provide an approach for studying the dynamics of neuronal membrane protein homeostasis, addressing longstanding challenges in this area. The protocol requires 5-7 days and expertise in cell culture and microscopy.
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Affiliation(s)
- Sidharth Tyagi
- Medical Scientist Training Program, Yale School of Medicine, New Haven, CT, USA
- Center for Neuroscience and Regeneration Research, West Haven, CT, USA
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
- Center for Restoration of Nervous System Function, VA Connecticut Healthcare System, West Haven, CT, USA
| | - Grant P Higerd-Rusli
- Medical Scientist Training Program, Yale School of Medicine, New Haven, CT, USA
- Center for Neuroscience and Regeneration Research, West Haven, CT, USA
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
- Center for Restoration of Nervous System Function, VA Connecticut Healthcare System, West Haven, CT, USA
| | - Elizabeth J Akin
- Center for Neuroscience and Regeneration Research, West Haven, CT, USA
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
- Center for Restoration of Nervous System Function, VA Connecticut Healthcare System, West Haven, CT, USA
- Department of Pharmacology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Christopher A Baker
- Center for Neuroscience and Regeneration Research, West Haven, CT, USA
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
- Center for Restoration of Nervous System Function, VA Connecticut Healthcare System, West Haven, CT, USA
| | - Shujun Liu
- Center for Neuroscience and Regeneration Research, West Haven, CT, USA
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
- Center for Restoration of Nervous System Function, VA Connecticut Healthcare System, West Haven, CT, USA
| | - Fadia B Dib-Hajj
- Center for Neuroscience and Regeneration Research, West Haven, CT, USA
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
- Center for Restoration of Nervous System Function, VA Connecticut Healthcare System, West Haven, CT, USA
| | - Stephen G Waxman
- Center for Neuroscience and Regeneration Research, West Haven, CT, USA.
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA.
- Center for Restoration of Nervous System Function, VA Connecticut Healthcare System, West Haven, CT, USA.
| | - Sulayman D Dib-Hajj
- Center for Neuroscience and Regeneration Research, West Haven, CT, USA.
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA.
- Center for Restoration of Nervous System Function, VA Connecticut Healthcare System, West Haven, CT, USA.
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3
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Gujar V, Pande RD, Das S. Nerve Growth Factor Shows Biphasic Expression during Adjuvant-Induced Neurogenic Inflammation. Int J Mol Sci 2024; 25:4029. [PMID: 38612839 PMCID: PMC11012393 DOI: 10.3390/ijms25074029] [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: 02/29/2024] [Revised: 03/23/2024] [Accepted: 04/03/2024] [Indexed: 04/14/2024] Open
Abstract
Chronic inflammatory diseases are considered the most significant cause of death worldwide. Current treatments for inflammatory diseases are limited due to the lack of understanding of the biological factors involved in early-stage disease progression. Nerve growth factor (NGF) is a neurotrophic factor directly associated with inflammatory and autoimmune diseases like osteoarthritis, multiple sclerosis, and rheumatoid arthritis. It has been shown that NGF levels are significantly upregulated at the site of inflammation and play a crucial role in developing a robust inflammatory response. However, little is known about NGF's temporal expression profile during the initial progressive phase of inflammation. This study aimed to determine the temporal expression patterns of NGF in rat skin (epidermis) during adjuvant-induced arthritis (AIA). Sprague Dawley rats were randomly divided into control and complete Freund's adjuvant (CFA)-treated groups. Levels of NGF were evaluated following unilateral AIA at different time points, and it was found that peripheral inflammation due to AIA significantly upregulated the expression of NGF mRNA and protein in a biphasic pattern. These results suggest that NGF signaling is crucial for initiating and maintaining peripheral neurogenic inflammation in rats during AIA.
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Affiliation(s)
- Vikramsingh Gujar
- Department of Anatomy and Cell Biology, Oklahoma State University, Center for Health Sciences, Tulsa, OK 74107, USA
| | - Radhika D. Pande
- Department of Biochemistry and Microbiology, Oklahoma State University, Center for Health Sciences, Tulsa, OK 74107, USA; (R.D.P.); (S.D.)
| | - Subhas Das
- Department of Biochemistry and Microbiology, Oklahoma State University, Center for Health Sciences, Tulsa, OK 74107, USA; (R.D.P.); (S.D.)
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4
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Mason AJ, Deppmann C, Winckler B. Emerging Roles of Neuronal Extracellular Vesicles at the Synapse. Neuroscientist 2024; 30:199-213. [PMID: 36942881 DOI: 10.1177/10738584231160521] [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: 03/23/2023]
Abstract
Extracellular vesicles (EVs) are secreted from most, if not all, cell types and are implicated in short- and long-distance signaling throughout the body. EVs are also secreted from neurons and represent an emergent neuronal communication platform. Understanding the functional implications of EV signaling to recipient neurons and glia requires understanding the cell biology involved in EV biogenesis, cargo loading, secretion, uptake, and signal transduction in the recipient cell. Here we review these major questions of EV biology while highlighting recent new insights and examples within the nervous system, such as modulating synaptic function or morphogenesis in recipient neurons.
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Affiliation(s)
- Ashley J Mason
- Neuroscience Graduate Program, University of Virginia, Charlottesville, VA, USA
- Department of Biology, University of Virginia, Charlottesville, VA, USA
- Department of Cell Biology, University of Virginia, Charlottesville, VA, USA
| | - Christopher Deppmann
- Neuroscience Graduate Program, University of Virginia, Charlottesville, VA, USA
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Bettina Winckler
- Neuroscience Graduate Program, University of Virginia, Charlottesville, VA, USA
- Department of Cell Biology, University of Virginia, Charlottesville, VA, USA
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5
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Peach CJ, Tonello R, Gomez K, Calderon-Rivera A, Bruni R, Bansia H, Maile L, Manu AM, Hahn H, Thomsen ARB, Schmidt BL, Davidson S, des Georges A, Khanna R, Bunnett NW. Neuropilin-1 is a co-receptor for NGF and TrkA-evoked pain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.06.570398. [PMID: 38106002 PMCID: PMC10723411 DOI: 10.1101/2023.12.06.570398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Nerve growth factor (NGF) monoclonal antibodies (mAb) are one of the few patient-validated non-opioid treatments for chronic pain, despite failing to gain FDA approval due to worsened joint damage in some osteoarthritis patients. Herein, we demonstrate that neuropilin-1 (NRP1) is a nociceptor-enriched co-receptor for NGF that is necessary for tropomyosin-related kinase A (TrkA) signaling of pain. NGF binds NRP1 with nanomolar affinity. NRP1 and G Alpha Interacting Protein C-terminus 1 (GIPC1), a NRP1/TrkA adaptor, are coexpressed with TrkA in human and mouse nociceptors. NRP1 small molecule inhibitors and blocking mAb prevent NGF-stimulated action potential firing and activation of Na+ and Ca2+ channels in human and mouse nociceptors and abrogate NGF-evoked and inflammatory nociception in mice. NRP1 knockdown blunts NGF-stimulated TrkA phosphorylation, kinase signaling and transcription, whereas NRP1 overexpression enhances NGF and TrkA signaling. As well as interacting with NGF, NRP1 forms a heteromeric complex with TrkA. NRP1 thereby chaperones TrkA from the biosynthetic pathway to the plasma membrane and then to signaling endosomes, which enhances NGF-induced TrkA dimerization, endocytosis and signaling. Knockdown of GIPC1, a PDZ-binding protein that scaffolds NRP1 and TrkA to myosin VI, abrogates NGF-evoked excitation of nociceptors and pain-like behavior in mice. We identify NRP1 as a previously unrecognized co-receptor necessary for NGF/TrkA pain signaling by direct NGF binding and by chaperoning TrkA to the plasma membrane and signaling endosomes via the adaptor protein GIPC1. Antagonism of NRP1 and GIPC1 in nociceptors offers a long-awaited alternative to systemic sequestration of NGF with mAbs for the treatment of pain.
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6
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Simpson JE, Muir MT, Lee M, Naughton C, Gilbert N, Pollard SM, Gammoh N. Autophagy supports PDGFRA-dependent brain tumor development by enhancing oncogenic signaling. Dev Cell 2024; 59:228-243.e7. [PMID: 38113891 DOI: 10.1016/j.devcel.2023.11.023] [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: 11/29/2022] [Revised: 07/29/2023] [Accepted: 11/20/2023] [Indexed: 12/21/2023]
Abstract
Autophagy is a conserved cellular degradation process. While autophagy-related proteins were shown to influence the signaling and trafficking of some receptor tyrosine kinases, the relevance of this during cancer development is unclear. Here, we identify a role for autophagy in regulating platelet-derived growth factor receptor alpha (PDGFRA) signaling and levels. We find that PDGFRA can be targeted for autophagic degradation through the activity of the autophagy cargo receptor p62. As a result, short-term autophagy inhibition leads to elevated levels of PDGFRA but an unexpected defect in PDGFA-mediated signaling due to perturbed receptor trafficking. Defective PDGFRA signaling led to its reduced levels during prolonged autophagy inhibition, suggesting a mechanism of adaptation. Importantly, PDGFA-driven gliomagenesis in mice was disrupted when autophagy was inhibited in a manner dependent on Pten status, thus highlighting a genotype-specific role for autophagy during tumorigenesis. In summary, our data provide a mechanism by which cells require autophagy to drive tumor formation.
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Affiliation(s)
- Joanne E Simpson
- Cancer Research UK Scotland Centre, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road South, Edinburgh EH4 2XR, UK
| | - Morwenna T Muir
- Cancer Research UK Scotland Centre, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road South, Edinburgh EH4 2XR, UK
| | - Martin Lee
- Cancer Research UK Scotland Centre, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road South, Edinburgh EH4 2XR, UK
| | - Catherine Naughton
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road South, Edinburgh EH4 2XU, UK
| | - Nick Gilbert
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road South, Edinburgh EH4 2XU, UK
| | - Steven M Pollard
- Cancer Research UK Scotland Centre, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road South, Edinburgh EH4 2XR, UK; Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, 5 Little France Drive, Edinburgh EH16 4UU, UK
| | - Noor Gammoh
- Cancer Research UK Scotland Centre, Institute of Genetics and Cancer, University of Edinburgh, Crewe Road South, Edinburgh EH4 2XR, UK.
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7
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Mulligan RJ, Winckler B. Regulation of Endosomal Trafficking by Rab7 and Its Effectors in Neurons: Clues from Charcot-Marie-Tooth 2B Disease. Biomolecules 2023; 13:1399. [PMID: 37759799 PMCID: PMC10527268 DOI: 10.3390/biom13091399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 09/09/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023] Open
Abstract
Intracellular endosomal trafficking controls the balance between protein degradation and synthesis, i.e., proteostasis, but also many of the cellular signaling pathways that emanate from activated growth factor receptors after endocytosis. Endosomal trafficking, sorting, and motility are coordinated by the activity of small GTPases, including Rab proteins, whose function as molecular switches direct activity at endosomal membranes through effector proteins. Rab7 is particularly important in the coordination of the degradative functions of the pathway. Rab7 effectors control endosomal maturation and the properties of late endosomal and lysosomal compartments, such as coordination of recycling, motility, and fusion with downstream compartments. The spatiotemporal regulation of endosomal receptor trafficking is particularly challenging in neurons because of their enormous size, their distinct intracellular domains with unique requirements (dendrites vs. axons), and their long lifespans as postmitotic, differentiated cells. In Charcot-Marie-Tooth 2B disease (CMT2B), familial missense mutations in Rab7 cause alterations in GTPase cycling and trafficking, leading to an ulcero-mutilating peripheral neuropathy. The prevailing hypothesis to account for CMT2B pathologies is that CMT2B-associated Rab7 alleles alter endocytic trafficking of the neurotrophin NGF and its receptor TrkA and, thereby, disrupt normal trophic signaling in the peripheral nervous system, but other Rab7-dependent pathways are also impacted. Here, using TrkA as a prototypical endocytic cargo, we review physiologic Rab7 effector interactions and control in neurons. Since neurons are among the largest cells in the body, we place particular emphasis on the temporal and spatial regulation of endosomal sorting and trafficking in neuronal processes. We further discuss the current findings in CMT2B mutant Rab7 models, the impact of mutations on effector interactions or balance, and how this dysregulation may confer disease.
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Affiliation(s)
- Ryan J. Mulligan
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22903, USA
- Medical Scientist Training Program, University of Virginia, Charlottesville, VA 22903, USA
| | - Bettina Winckler
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22903, USA
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8
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Krzystek TJ, White JA, Rathnayake R, Thurston L, Hoffmar-Glennon H, Li Y, Gunawardena S. HTT (huntingtin) and RAB7 co-migrate retrogradely on a signaling LAMP1-containing late endosome during axonal injury. Autophagy 2023; 19:1199-1220. [PMID: 36048753 PMCID: PMC10012955 DOI: 10.1080/15548627.2022.2119351] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 08/24/2022] [Accepted: 08/26/2022] [Indexed: 12/09/2022] Open
Abstract
ABBREVIATIONS Atg5: Autophagy-related 5; Atg8a: Autophagy-related 8a; AL: autolysosome; AP: autophagosome; BAF1: bafilomycin A1; BDNF: brain derived neurotrophic factor; BMP: bone morphogenetic protein; Cyt-c-p: Cytochrome c proximal; CQ: chloroquine; DCTN1: dynactin 1; Dhc: dynein heavy chain; EE: early endosome; DYNC1I1: dynein cytoplasmic 1 intermediate chain 1; HD: Huntington disease; HIP1/Hip1: huntingtin interacting protein 1; HTT/htt: huntingtin; iNeuron: iPSC-derived human neurons; IP: immunoprecipitation; Khc: kinesin heavy chain; KIF5C: kinesin family member 5C; LAMP1/Lamp1: lysosomal associated membrane protein 1; LE: late endosome; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MAP3K12/DLK: mitogen-activated protein kinase kinase kinase 12; MAPK8/JNK/bsk: mitogen-activated protein kinase 8/basket; MAPK8IP3/JIP3: mitogen-activated protein kinase 8 interacting protein 3; NGF: nerve growth factor; NMJ: neuromuscular junction; NTRK1/TRKA: neurotrophic receptor tyrosine kinase 1; NRTK2/TRKB: neurotrophic receptor tyrosine kinase 2; nuf: nuclear fallout; PG: phagophore; PtdIns3P: phosphatidylinositol-3-phosphate; puc: puckered; ref(2)P: refractory to sigma P; Rilpl: Rab interacting lysosomal protein like; Rip11: Rab11 interacting protein; RTN1: reticulon 1; syd: sunday driver; SYP: synaptophysin; SYT1/Syt1: synaptotagmin 1; STX17/Syx17: syntaxin 17; tkv: thickveins; VF: vesicle fraction; wit: wishful thinking; wnd: wallenda.
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Affiliation(s)
- Thomas J. Krzystek
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, New York, USA
| | - Joseph A. White
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, New York, USA
| | - Rasika Rathnayake
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, New York, USA
| | - Layne Thurston
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, New York, USA
| | - Hayley Hoffmar-Glennon
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, New York, USA
| | - Yichen Li
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, New York, USA
| | - Shermali Gunawardena
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, New York, USA
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9
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Yap CC, Digilio L, McMahon L, Winckler B. "Disruption of Golgi markers by two RILP-directed shRNAs in neurons: a new role for RILP or a neuron-specific off-target phenotype?". BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.08.531742. [PMID: 36945482 PMCID: PMC10028860 DOI: 10.1101/2023.03.08.531742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
In neurons, degradation of dendritic cargos requires RAB7 and dynein-mediated retrograde transport to somatic lysosomes. In order to test if the dynein adaptor RILP (RAB-interacting lysosomal protein) mediated the recruitment of dynein to late endosomes for retrograde transport in dendrites, we obtained several knockdown reagents which had been previously validated in non-neuronal cells. We found that striking endosomal phenotypes elicited by one shRILP plasmid were not reproduced by another one. Furthermore, we discovered a profound depletion of Golgi/TGN markers for both shRILP plasmids. This Golgi disruption was only observed in neurons and could not be rescued by re-expression of RILP. This Golgi phenotype was also not found in neurons treated with siRILP or gRILP/Cas9. Lastly, we tested if a different RAB protein that interacts with RILP, namely the Golgi-associated RAB34, might be responsible for the loss of Golgi markers. Expression of a dominant-negative RAB34 did indeed cause changes in Golgi staining in a small subset of neurons but manifested as fragmentation rather than loss of markers. Unlike in non-neuronal cells, interference with RAB34 did not cause dispersal of lysosomes in neurons. Based on multiple lines of experimentation, we conclude that the neuronal Golgi phenotype observed with shRILP is likely off-target in this cell type specifically. Any observed disruptions of endosomal trafficking caused by shRILP in neurons might thus be downstream of Golgi disruption. Different approaches will be needed to test if RILP is required for late endosomal transport in dendrites. Cell type-specific off-target phenotypes therefore likely occur in neurons, making it prudent to re-validate reagents that were previously validated in other cell types.
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Affiliation(s)
- Chan Choo Yap
- Corresponding authors: Bettina Winckler and Chan Choo Yap, Phone: (434)924-5528/5526. ,
| | | | | | - Bettina Winckler
- Corresponding authors: Bettina Winckler and Chan Choo Yap, Phone: (434)924-5528/5526. ,
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10
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Sympathetic neurons secrete retrogradely transported TrkA on extracellular vesicles. Sci Rep 2023; 13:3657. [PMID: 36871060 PMCID: PMC9985603 DOI: 10.1038/s41598-023-30728-3] [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: 01/11/2023] [Accepted: 02/28/2023] [Indexed: 03/06/2023] Open
Abstract
Proper wiring of the peripheral nervous system relies on neurotrophic signaling via nerve growth factor (NGF). NGF secreted by target organs (i.e. eye) binds to the TrkA receptor expressed on the distal axons of postganglionic neurons. Upon binding, TrkA is internalized into a signaling endosome and retrogradely trafficked back to the soma and into the dendrites to promote cell survival and postsynaptic maturation, respectively. Much progress has been made in recent years to define the fate of the retrogradely trafficked TrkA signaling endosome, yet it has not been fully characterized. Here we investigate extracellular vesicles (EVs) as a novel route of neurotrophic signaling. Using the mouse superior cervical ganglion (SCG) as a model, we isolate EVs derived from sympathetic cultures and characterize them using immunoblot assays, nanoparticle tracking analysis, and cryo-electron microscopy. Furthermore, using a compartmentalized culture system, we find that TrkA derived from endosomes originating in the distal axon can be detected on EVs secreted from the somatodendritic domain. In addition, inhibition of classic TrkA downstream pathways, specifically in somatodendritic compartments, greatly decreases TrkA packaging into EVs. Our results suggest a novel trafficking route for TrkA: it can travel long distances to the cell body, be packaged into EVs, and be secreted. Secretion of TrkA via EVs appears to be regulated by its own downstream effector cascades, raising intriguing future questions about novel functionalities associated with TrkA+ EVs.
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11
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Burk K. The endocytosis, trafficking, sorting and signaling of neurotrophic receptors. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2023; 196:141-165. [PMID: 36813356 DOI: 10.1016/bs.pmbts.2022.06.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Neurotrophins are soluble factors secreted by neurons themselves as well as by post-synaptic target tissues. Neurotrophic signaling regulates several processes such as neurite growth, neuronal survival and synaptogenesis. In order to signal, neurotrophins bind to their receptors, the tropomyosin receptor tyrosine kinase (Trk), which causes internalization of the ligand-receptor complex. Subsequently, this complex is routed into the endosomal system from where Trks can start their downstream signaling. Depending on their endosomal localization, co-receptors involved, but also due to the expression patterns of adaptor proteins, Trks regulate a variety of mechanisms. In this chapter, I provide an overview of the endocytosis, trafficking, sorting and signaling of neurotrophic receptors.
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Affiliation(s)
- Katja Burk
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany; Center for Biostructural Imaging of Neurodegeneration, Göttingen, Germany.
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12
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Higerd-Rusli GP, Tyagi S, Liu S, Dib-Hajj FB, Waxman SG, Dib-Hajj SD. The fates of internalized Na V1.7 channels in sensory neurons: Retrograde cotransport with other ion channels, axon-specific recycling, and degradation. J Biol Chem 2023; 299:102816. [PMID: 36539035 PMCID: PMC9843449 DOI: 10.1016/j.jbc.2022.102816] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 12/05/2022] [Accepted: 12/11/2022] [Indexed: 12/23/2022] Open
Abstract
Neuronal function relies on the maintenance of appropriate levels of various ion channels at the cell membrane, which is accomplished by balancing secretory, degradative, and recycling pathways. Neuronal function further depends on membrane specialization through polarized distribution of specific proteins to distinct neuronal compartments such as axons. Voltage-gated sodium channel NaV1.7, a threshold channel for firing action potentials in nociceptors, plays a major role in human pain, and its abundance in the plasma membrane is tightly regulated. We have recently characterized the anterograde axonal trafficking of NaV1.7 channels in Rab6A-positive vesicles, but the fate of internalized channels is not known. Membrane proteins that have undergone endocytosis can be directed into multiple pathways including those for degradation, recycling to the membrane, and transcytosis. Here, we demonstrate NaV1.7 endocytosis and dynein-dependent retrograde trafficking in Rab7-containing late endosomes together with other axonal membrane proteins using real-time imaging of live neurons. We show that some internalized NaV1.7 channels are delivered to lysosomes within the cell body, and that there is no evidence for NaV1.7 transcytosis. In addition, we show that NaV1.7 is recycled specifically to the axonal membrane as opposed to the soma membrane, suggesting a novel mechanism for the development of neuronal polarity. Together, these results shed light on the mechanisms by which neurons maintain excitable membranes and may inform efforts to target ion channel trafficking for the treatment of disorders of excitability.
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Affiliation(s)
- Grant P Higerd-Rusli
- MD/PhD Program, Yale University School of Medicine, New Haven, Connecticut, USA; Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA; Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut, USA
| | - Sidharth Tyagi
- MD/PhD Program, Yale University School of Medicine, New Haven, Connecticut, USA; Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA; Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut, USA
| | - Shujun Liu
- Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA; Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut, USA
| | - Fadia B Dib-Hajj
- Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA; Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut, USA
| | - Stephen G Waxman
- Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA; Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut, USA.
| | - Sulayman D Dib-Hajj
- Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA; Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut, USA.
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13
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A multivesicular body-like organelle mediates stimulus-regulated trafficking of olfactory ciliary transduction proteins. Nat Commun 2022; 13:6889. [PMID: 36371422 PMCID: PMC9653401 DOI: 10.1038/s41467-022-34604-y] [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: 05/16/2022] [Accepted: 10/28/2022] [Indexed: 11/13/2022] Open
Abstract
Stimulus transduction in cilia of olfactory sensory neurons is mediated by odorant receptors, Gαolf, adenylate cyclase-3, cyclic nucleotide-gated and chloride ion channels. Mechanisms regulating trafficking and localization of these proteins in the dendrite are unknown. By lectin/immunofluorescence staining and in vivo correlative light-electron microscopy (CLEM), we identify a retinitis pigmentosa-2 (RP2), ESCRT-0 and synaptophysin-containing multivesicular organelle that is not part of generic recycling/degradative/exosome pathways. The organelle's intraluminal vesicles contain the olfactory transduction proteins except for Golf subunits Gγ13 and Gβ1. Instead, Gβ1 colocalizes with RP2 on the organelle's outer membrane. The organelle accumulates in response to stimulus deprivation, while odor stimuli or adenylate cyclase activation cause outer membrane disintegration, release of intraluminal vesicles, and RP2/Gβ1 translocation to the base of olfactory cilia. Together, these findings reveal the existence of a dendritic organelle that mediates both stimulus-regulated storage of olfactory ciliary transduction proteins and membrane-delimited sorting important for G protein heterotrimerization.
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14
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Yap CC, Digilio L, McMahon LP, Wang T, Winckler B. Dynein Is Required for Rab7-Dependent Endosome Maturation, Retrograde Dendritic Transport, and Degradation. J Neurosci 2022; 42:4415-4434. [PMID: 35474277 PMCID: PMC9172292 DOI: 10.1523/jneurosci.2530-21.2022] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 03/30/2022] [Accepted: 04/15/2022] [Indexed: 11/21/2022] Open
Abstract
In all cell types, endocytosed cargo is transported along a set of endosomal compartments, which are linked maturationally from early endosomes (EEs) via late endosomes (LEs) to lysosomes. Lysosomes are critical for degradation of proteins that enter through endocytic as well as autophagic pathways. Rab7 is the master regulator of early-to-late endosome maturation, motility, and fusion with lysosomes. We previously showed that most degradative lysosomes are localized in the soma and in the first 25 µm of the dendrite and that bulk degradation of dendritic membrane proteins occurs in/near the soma. Dendritic late endosomes therefore move retrogradely in a Rab7-dependent manner for fusion with somatic lysosomes. We now used cultured E18 rat hippocampal neurons of both sexes to determine which microtubule motor is responsible for degradative flux of late endosomes. Based on multiple approaches (inhibiting dynein/dynactin itself or inhibiting dynein recruitment to endosomes by expressing the C-terminus of the Rab7 effector, RILP), we now demonstrate that net retrograde flux of late endosomes in dendrites is supported by dynein. Inhibition of dynein also delays maturation of somatic endosomes, as evidenced by excessive accumulation of Rab7. In addition, degradation of dendritic cargos is inhibited. Our results also suggest that GDP-GTP cycling of Rab7 appears necessary not only for endosomal maturation but also for fusion with lysosomes subsequent to arrival in the soma. In conclusion, Rab7-dependent dynein/dynactin recruitment to dendritic endosomes plays multifaceted roles in dendritic endosome maturation as well as retrograde transport of late endosomes to sustain normal degradative flux.SIGNIFICANCE STATEMENT Lysosomes are critical for degradation of membrane and extracellular proteins that enter through endocytosis. Lysosomes are also the endpoint of autophagy and thus responsible for protein and organelle homeostasis. Endosomal-lysosomal dysfunction is linked to neurodegeneration and aging. We identify roles in dendrites for two proteins with links to human diseases, Rab7 and dynein. Our previous work identified a process that requires directional retrograde transport in dendrites, namely, efficient degradation of short-lived membrane proteins. Based on multiple approaches, we demonstrate that Rab7-dependent recruitment of dynein motors supports net retrograde transport to lysosomes and is needed for endosome maturation. Our data also suggest that GDP-GTP cycling of Rab7 is required for fusion with lysosomes and degradation, subsequent to arrival in the soma.
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Affiliation(s)
- Chan Choo Yap
- Department of Cell Biology, University of Virginia, Charlottesville, Virginia 22908
| | - Laura Digilio
- Department of Cell Biology, University of Virginia, Charlottesville, Virginia 22908
| | - Lloyd P McMahon
- Department of Cell Biology, University of Virginia, Charlottesville, Virginia 22908
| | - Tuanlao Wang
- School of Pharmaceutical Sciences, Xiamen University, Xiamen, Fujian Province 361005, China
| | - Bettina Winckler
- Department of Cell Biology, University of Virginia, Charlottesville, Virginia 22908
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15
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Scaramuzzino C, Cuoc EC, Pla P, Humbert S, Saudou F. Calcineurin and huntingtin form a calcium-sensing machinery that directs neurotrophic signals to the nucleus. SCIENCE ADVANCES 2022; 8:eabj8812. [PMID: 34985962 PMCID: PMC8730605 DOI: 10.1126/sciadv.abj8812] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
When a neurotrophin binds at the presynapse, it sends survival signals all the way to the nucleus on signaling endosomes. These endosomes fuel their own journey with on-board glycolysis—but how is that journey initiated and maintained? Using microfluidic devices and mice, we find that the calcium released upon brain-derived neurotrophic factor (BDNF) binding to its receptor, tropomyosin receptor kinase B (TrkB), is sensed by calcineurin on the cytosolic face of the endosome. Calcineurin dephosphorylates huntingtin, the BDNF scaffold, which sets the endosome moving in a retrograde direction. In an in vitro reconstituted microtubule transport system, controlled calcium uncaging prompts purified vesicles to move to the microtubule minus end. We observed similar retrograde waves of TrkA- and epidermal growth factor receptor (EGFR)-bearing endosomes. Signaling endosomes in neurons thus carry not only their own fuel, but their own navigational system.
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16
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Abstract
The sympathetic nervous system prepares the body for 'fight or flight' responses and maintains homeostasis during daily activities such as exercise, eating a meal or regulation of body temperature. Sympathetic regulation of bodily functions requires the establishment and refinement of anatomically and functionally precise connections between postganglionic sympathetic neurons and peripheral organs distributed widely throughout the body. Mechanistic studies of key events in the formation of postganglionic sympathetic neurons during embryonic and early postnatal life, including axon growth, target innervation, neuron survival, and dendrite growth and synapse formation, have advanced the understanding of how neuronal development is shaped by interactions with peripheral tissues and organs. Recent progress has also been made in identifying how the cellular and molecular diversity of sympathetic neurons is established to meet the functional demands of peripheral organs. In this Review, we summarize current knowledge of signalling pathways underlying the development of the sympathetic nervous system. These findings have implications for unravelling the contribution of sympathetic dysfunction stemming, in part, from developmental perturbations to the pathophysiology of peripheral neuropathies and cardiovascular and metabolic disorders.
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17
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Markworth R, Dambeck V, Steinbeck LM, Koufali A, Bues B, Dankovich TM, Wichmann C, Burk K. Tubular microdomains of Rab7-positive endosomes retrieve TrkA, a mechanism disrupted in Charcot-Marie-Tooth disease 2B. J Cell Sci 2021; 134:272650. [PMID: 34486665 DOI: 10.1242/jcs.258559] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 08/23/2021] [Indexed: 01/04/2023] Open
Abstract
Axonal survival and growth requires signalling from tropomyosin receptor kinases (Trks). To transmit their signals, receptor-ligand complexes are endocytosed and undergo retrograde trafficking to the soma, where downstream signalling occurs. Vesicles transporting neurotrophic receptors to the soma are reported to be Rab7-positive late endosomes and/or multivesicular bodies (MVBs), where receptors localize within so-called intraluminal vesicles (herein Rab7 corresponds to Rab7A unless specified otherwise). Therefore, one challenging question is how downstream signalling is possible given the insulating properties of intraluminal vesicles. In this study, we report that Rab7-positive endosomes and MVBs retrieve TrkA (also known as NTRK1) through tubular microdomains. Interestingly, this phenotype is absent for the EGF receptor. Furthermore, we found that endophilinA1, endophilinA2 and endophilinA3, together with WASH1 (also known as WASHC1), are involved in the tubulation process. In Charcot-Marie-Tooth disease 2B (CMT2B), a neuropathy of the peripheral nervous system, this tubulating mechanism is disrupted. In addition, the ability to tubulate correlates with the phosphorylation levels of TrkA as well as with neurite length in neuronal cultures from dorsal root ganglia. In all, we report a new retrieval mechanism of late Rab7-positive endosomes, which enables TrkA signalling and sheds new light onto how neurotrophic signalling is disrupted in CMT2B. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Ronja Markworth
- Department of Neurology, University Medical Center Göttingen, Robert Koch Straße 40, 37075 Göttingen, Germany.,European Neuroscience Institute, Grisebachstraße 5, 37077 Göttingen, Germany.,Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Von-Siebold Straße 3A, 37075 Göttingen, Germany
| | - Vivian Dambeck
- Department of Neurology, University Medical Center Göttingen, Robert Koch Straße 40, 37075 Göttingen, Germany.,Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Von-Siebold Straße 3A, 37075 Göttingen, Germany
| | - Lars Malte Steinbeck
- Department of Neurology, University Medical Center Göttingen, Robert Koch Straße 40, 37075 Göttingen, Germany.,Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Von-Siebold Straße 3A, 37075 Göttingen, Germany
| | - Angeliki Koufali
- Department of Neurology, University Medical Center Göttingen, Robert Koch Straße 40, 37075 Göttingen, Germany.,Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Von-Siebold Straße 3A, 37075 Göttingen, Germany
| | - Bastian Bues
- Department of Neurology, University Medical Center Göttingen, Robert Koch Straße 40, 37075 Göttingen, Germany.,Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Von-Siebold Straße 3A, 37075 Göttingen, Germany
| | - Tal M Dankovich
- Institute for Neuro- and Sensory Physiology, Humboldtallee 23, 37073 Göttingen, Germany
| | - Carolin Wichmann
- Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Von-Siebold Straße 3A, 37075 Göttingen, Germany.,Molecular Architecture of Synapses Group, Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany.,Collaborative Research Centers 889 'Cellular Mechanisms of Sensory Processing' and 1286 'Quantitative Synaptology', 37099 Göttingen, Germany
| | - Katja Burk
- Department of Neurology, University Medical Center Göttingen, Robert Koch Straße 40, 37075 Göttingen, Germany.,European Neuroscience Institute, Grisebachstraße 5, 37077 Göttingen, Germany.,Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Von-Siebold Straße 3A, 37075 Göttingen, Germany
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18
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Markworth R, Bähr M, Burk K. Held Up in Traffic-Defects in the Trafficking Machinery in Charcot-Marie-Tooth Disease. Front Mol Neurosci 2021; 14:695294. [PMID: 34483837 PMCID: PMC8415527 DOI: 10.3389/fnmol.2021.695294] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/23/2021] [Indexed: 12/13/2022] Open
Abstract
Charcot-Marie-Tooth disease (CMT), also known as motor and sensory neuropathy, describes a clinically and genetically heterogenous group of disorders affecting the peripheral nervous system. CMT typically arises in early adulthood and is manifested by progressive loss of motor and sensory functions; however, the mechanisms leading to the pathogenesis are not fully understood. In this review, we discuss disrupted intracellular transport as a common denominator in the pathogenesis of different CMT subtypes. Intracellular transport via the endosomal system is essential for the delivery of lipids, proteins, and organelles bidirectionally to synapses and the soma. As neurons of the peripheral nervous system are amongst the longest neurons in the human body, they are particularly susceptible to damage of the intracellular transport system, leading to a loss in axonal integrity and neuronal death. Interestingly, defects in intracellular transport, both in neurons and Schwann cells, have been found to provoke disease. This review explains the mechanisms of trafficking and subsequently summarizes and discusses the latest findings on how defects in trafficking lead to CMT. A deeper understanding of intracellular trafficking defects in CMT will expand our understanding of CMT pathogenesis and will provide novel approaches for therapeutic treatments.
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Affiliation(s)
- Ronja Markworth
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany.,Center for Biostructural Imaging of Neurodegeneration, Göttingen, Germany
| | - Mathias Bähr
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Katja Burk
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany.,Center for Biostructural Imaging of Neurodegeneration, Göttingen, Germany
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19
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Understanding amphisomes. Biochem J 2021; 478:1959-1976. [PMID: 34047789 DOI: 10.1042/bcj20200917] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/27/2021] [Accepted: 05/06/2021] [Indexed: 12/14/2022]
Abstract
Amphisomes are intermediate/hybrid organelles produced through the fusion of endosomes with autophagosomes within cells. Amphisome formation is an essential step during a sequential maturation process of autophagosomes before their ultimate fusion with lysosomes for cargo degradation. This process is highly regulated with multiple protein machineries, such as SNAREs, Rab GTPases, tethering complexes, and ESCRTs, are involved to facilitate autophagic flux to proceed. In neurons, autophagosomes are robustly generated in axonal terminals and then rapidly fuse with late endosomes to form amphisomes. This fusion event allows newly generated autophagosomes to gain retrograde transport motility and move toward the soma, where proteolytically active lysosomes are predominantly located. Amphisomes are not only the products of autophagosome maturation but also the intersection of the autophagy and endo-lysosomal pathways. Importantly, amphisomes can also participate in non-canonical functions, such as retrograde neurotrophic signaling or autophagy-based unconventional secretion by fusion with the plasma membrane. In this review, we provide an updated overview of the recent discoveries and advancements on the molecular and cellular mechanisms underlying amphisome biogenesis and the emerging roles of amphisomes. We discuss recent developments towards the understanding of amphisome regulation as well as the implications in the context of major neurodegenerative diseases, with a comparative focus on Alzheimer's disease and Parkinson's disease.
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20
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Camblor-Perujo S, Kononenko NL. Brain-specific functions of the endocytic machinery. FEBS J 2021; 289:2219-2246. [PMID: 33896112 DOI: 10.1111/febs.15897] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 03/29/2021] [Indexed: 12/12/2022]
Abstract
Endocytosis is an essential cellular process required for multiple physiological functions, including communication with the extracellular environment, nutrient uptake, and signaling by the cell surface receptors. In a broad sense, endocytosis is accomplished through either constitutive or ligand-induced invagination of the plasma membrane, which results in the formation of the plasma membrane-retrieved endocytic vesicles, which can either be sent for degradation to the lysosomes or recycled back to the PM. This additional function of endocytosis in membrane retrieval has been adopted by excitable cells, such as neurons, for membrane equilibrium maintenance at synapses. The last two decades were especially productive with respect to the identification of brain-specific functions of the endocytic machinery, which additionally include but not limited to regulation of neuronal differentiation and migration, maintenance of neuron morphology and synaptic plasticity, and prevention of neurotoxic aggregates spreading. In this review, we highlight the current knowledge of brain-specific functions of endocytic machinery with a specific focus on three brain cell types, neuronal progenitor cells, neurons, and glial cells.
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Affiliation(s)
| | - Natalia L Kononenko
- CECAD Cluster of Excellence, University of Cologne, Germany.,Center for Physiology & Pathophysiology, Medical Faculty, University of Cologne, Germany
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21
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Pathak A, Clark S, Bronfman FC, Deppmann CD, Carter BD. Long-distance regressive signaling in neural development and disease. WILEY INTERDISCIPLINARY REVIEWS. DEVELOPMENTAL BIOLOGY 2021; 10:e382. [PMID: 32391977 PMCID: PMC7655682 DOI: 10.1002/wdev.382] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 03/23/2020] [Accepted: 04/06/2020] [Indexed: 02/06/2023]
Abstract
Nervous system development proceeds via well-orchestrated processes involving a balance between progressive and regressive events including stabilization or elimination of axons, synapses, and even entire neurons. These progressive and regressive events are driven by functionally antagonistic signaling pathways with the dominant pathway eventually determining whether a neural element is retained or removed. Many of these developmental sculpting events are triggered by final target innervation necessitating a long-distance mode of communication. While long-distance progressive signaling has been well characterized, particularly for neurotrophic factors, there remains relatively little known about how regressive events are triggered from a distance. Here we discuss the emergent phenomenon of long-distance regressive signaling pathways. In particular, we will cover (a) progressive and regressive cues known to be employed after target innervation, (b) the mechanisms of long-distance signaling from an endosomal platform, (c) recent evidence that long-distance regressive cues emanate from platforms like death receptors or repulsive axon guidance receptors, and (d) evidence that these pathways are exploited in pathological scenarios. This article is categorized under: Nervous System Development > Vertebrates: General Principles Signaling Pathways > Global Signaling Mechanisms Establishment of Spatial and Temporal Patterns > Cytoplasmic Localization.
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Affiliation(s)
- Amrita Pathak
- Department of Biochemistry and Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Shayla Clark
- Neuroscience Graduate Program, University of Virginia, Charlottesville, Virginia
| | - Francisca C. Bronfman
- Institute of Biomedical Sciences (ICB), Faculty of Medicine, Faculty of Life Science, Universidad Andres Bello, Santiago, Chile
| | - Christopher D. Deppmann
- Departments of Biology, Cell Biology, Biomedical Engineering, and Neuroscience, University of Virginia, Charlottesville, Virginia
| | - Bruce D. Carter
- Department of Biochemistry and Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, Tennessee
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22
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Kuijpers M, Azarnia Tehran D, Haucke V, Soykan T. The axonal endolysosomal and autophagic systems. J Neurochem 2021; 158:589-602. [PMID: 33372296 DOI: 10.1111/jnc.15287] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 12/23/2020] [Accepted: 12/23/2020] [Indexed: 12/26/2022]
Abstract
Neurons, because of their elaborate morphology and the long distances between distal axons and the soma as well as their longevity, pose special challenges to autophagy and to the endolysosomal system, two of the main degradative routes for turnover of defective proteins and organelles. Autophagosomes sequester cytoplasmic or organellar cargos by engulfing them into their lumen before fusion with degradative lysosomes enriched in neuronal somata and participate in retrograde signaling to the soma. Endosomes are mainly involved in the sorting, recycling, or lysosomal turnover of internalized or membrane-bound macromolecules to maintain axonal membrane homeostasis. Lysosomes and the multiple shades of lysosome-related organelles also serve non-degradative roles, for example, in nutrient signaling and in synapse formation. Recent years have begun to shed light on the distinctive organization of the autophagy and endolysosomal systems in neurons, in particular their roles in axons. We review here our current understanding of the localization, distribution, and growing list of functions of these organelles in the axon in health and disease and outline perspectives for future research.
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Affiliation(s)
- Marijn Kuijpers
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | | | - Volker Haucke
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany.,Freie Universität Berlin, Faculty of Biology, Chemistry, Berlin, Germany.,Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Berlin, Germany
| | - Tolga Soykan
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
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23
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Abstract
During the development of the nervous system, neurons respond to diffusible cues secreted by target cells. Because such target-derived factors regulate development, maturation, and maintenance of axons as well as somatodendritic compartments, signals initiated at distal axons must be retrogradely transmitted toward cell bodies. Neurotrophins, including the nerve growth factor (NGF), provide one of the best-known examples of target-derived growth factors. The cell biological processes of endocytosis and retrograde trafficking of their Trk receptors from growth cones to cell bodies are key mechanisms by which target-derived neurotrophins influence neurons. Evidence accumulated over the past several decades has begun to uncover the molecular mechanisms of formation, transport, and biological functions of these specialized endosomes called "signaling endosomes."
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24
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Zhang Y, Qin Y, Chopp M, Li C, Kemper A, Liu X, Wang X, Zhang L, Zhang ZG. Ischemic Cerebral Endothelial Cell-Derived Exosomes Promote Axonal Growth. Stroke 2020; 51:3701-3712. [PMID: 33138691 PMCID: PMC7686085 DOI: 10.1161/strokeaha.120.031728] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND AND PURPOSE Cerebral endothelial cells (CECs) and axons of neurons interact to maintain vascular and neuronal homeostasis and axonal remodeling in normal and ischemic brain, respectively. However, the role of exosomes in the interaction of CECs and axons in brain under normal conditions and after stroke is unknown. METHODS Exosomes were isolated from CECs of nonischemic rats and is chemic rats (nCEC-exos and isCEC-exos), respectively. A multicompartmental cell culture system was used to separate axons from neuronal cell bodies. RESULTS Axonal application of nCEC-exos promotes axonal growth of cortical neurons, whereas isCEC-exos further enhance axonal growth than nCEC-exos. Ultrastructural analysis revealed that CEC-exos applied into distal axons were internalized by axons and reached to their parent somata. Bioinformatic analysis revealed that both nCEC-exos and isCEC-exos contain abundant mature miRNAs; however, isCEC-exos exhibit more robust elevation of select miRNAs than nCEC-exos. Mechanistically, axonal application of nCEC-exos and isCEC-exos significantly elevated miRNAs and reduced proteins in distal axons and their parent somata that are involved in inhibiting axonal outgrowth. Blockage of axonal transport suppressed isCEC-exo-altered miRNAs and proteins in somata but not in distal axons. CONCLUSIONS nCEC-exos and isCEC-exos facilitate axonal growth by altering miRNAs and their target protein profiles in recipient neurons.
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Affiliation(s)
- Yi Zhang
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, 48202
| | - Yi Qin
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, 48202
| | - Michael Chopp
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, 48202
- Department of Physics, Oakland University, Rochester, Michigan, 48309
| | - Chao Li
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, 48202
| | - Amy Kemper
- Department of Pathology, Henry Ford Hospital, Detroit, Michigan, 48202
| | - Xianshuang Liu
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, 48202
| | - Xinli Wang
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, 48202
| | - Li Zhang
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, 48202
| | - Zheng Gang Zhang
- Department of Neurology, Henry Ford Hospital, Detroit, Michigan, 48202
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25
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Overhoff M, De Bruyckere E, Kononenko NL. Mechanisms of neuronal survival safeguarded by endocytosis and autophagy. J Neurochem 2020; 157:263-296. [PMID: 32964462 DOI: 10.1111/jnc.15194] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 08/21/2020] [Accepted: 09/08/2020] [Indexed: 12/11/2022]
Abstract
Multiple aspects of neuronal physiology crucially depend on two cellular pathways, autophagy and endocytosis. During endocytosis, extracellular components either unbound or recognized by membrane-localized receptors (termed "cargo") become internalized into plasma membrane-derived vesicles. These can serve to either recycle the material back to the plasma membrane or send it for degradation to lysosomes. Autophagy also uses lysosomes as a terminal degradation point, although instead of degrading the plasma membrane-derived cargo, autophagy eliminates detrimental cytosolic material and intracellular organelles, which are transported to lysosomes by means of double-membrane vesicles, referred to as autophagosomes. Neurons, like all non-neuronal cells, capitalize on autophagy and endocytosis to communicate with the environment and maintain protein and organelle homeostasis. Additionally, the highly polarized, post-mitotic nature of neurons made them adopt these two pathways for cell-specific functions. These include the maintenance of the synaptic vesicle pool in the pre-synaptic terminal and the long-distance transport of signaling molecules. Originally discovered independently from each other, it is now clear that autophagy and endocytosis are closely interconnected and share several common participating molecules. Considering the crucial role of autophagy and endocytosis in cell type-specific functions in neurons, it is not surprising that defects in both pathways have been linked to the pathology of numerous neurodegenerative diseases. In this review, we highlight the recent knowledge of the role of endocytosis and autophagy in neurons with a special focus on synaptic physiology and discuss how impairments in genes coding for autophagy and endocytosis proteins can cause neurodegeneration.
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Affiliation(s)
- Melina Overhoff
- CECAD Cluster of Excellence, Institute for Genetics, University of Cologne, Cologne, Germany
| | - Elodie De Bruyckere
- CECAD Cluster of Excellence, Institute for Genetics, University of Cologne, Cologne, Germany
| | - Natalia L Kononenko
- CECAD Cluster of Excellence, Institute for Genetics, University of Cologne, Cologne, Germany
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26
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Pasterkamp RJ, Burk K. Axon guidance receptors: Endocytosis, trafficking and downstream signaling from endosomes. Prog Neurobiol 2020; 198:101916. [PMID: 32991957 DOI: 10.1016/j.pneurobio.2020.101916] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/06/2020] [Accepted: 09/21/2020] [Indexed: 02/06/2023]
Abstract
During the development of the nervous system, axons extend through complex environments. Growth cones at the axon tip allow axons to find and innervate their appropriate targets and form functional synapses. Axon pathfinding requires axons to respond to guidance signals and these cues need to be detected by specialized receptors followed by intracellular signal integration and translation. Several downstream signaling pathways have been identified for axon guidance receptors and it has become evident that these pathways are often initiated from intracellular vesicles called endosomes. Endosomes allow receptors to traffic intracellularly, re-locating receptors from one cellular region to another. The localization of axon guidance receptors to endosomal compartments is crucial for their function, signaling output and expression levels. For example, active receptors within endosomes can recruit downstream proteins to the endosomal membrane and facilitate signaling. Also, endosomal trafficking can re-locate receptors back to the plasma membrane to allow re-activation or mediate downregulation of receptor signaling via degradation. Accumulating evidence suggests that axon guidance receptors do not follow a pre-set default trafficking route but may change their localization within endosomes. This re-routing appears to be spatially and temporally regulated, either by expression of adaptor proteins or co-receptors. These findings shed light on how signaling in axon guidance is regulated and diversified - a mechanism which explains how a limited set of guidance cues can help to establish billions of neuronal connections. In this review, we summarize and discuss our current knowledge of axon guidance receptor trafficking and provide directions for future research.
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Affiliation(s)
- R J Pasterkamp
- Department of Translational Neuroscience, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, 3584 CG Utrecht, the Netherlands.
| | - K Burk
- Department of Neurology, University Medical Center Göttingen, 37075 Göttingen, Germany; Center for Biostructural Imaging of Neurodegeneration, 37075 Göttingen, Germany.
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Foltz L, Palacios-Moreno J, Mayfield M, Kinch S, Dillon J, Syrenne J, Levy T, Grimes M. PAG1 directs SRC-family kinase intracellular localization to mediate receptor tyrosine kinase-induced differentiation. Mol Biol Cell 2020; 31:2269-2282. [PMID: 32726167 PMCID: PMC7550700 DOI: 10.1091/mbc.e20-02-0135] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
All receptor tyrosine kinases (RTKs) activate similar downstream signaling pathways through a common set of effectors, yet it is not fully understood how different receptors elicit distinct cellular responses to cause cell proliferation, differentiation, or other cell fates. We tested the hypothesis that regulation of SRC family kinase (SFK) signaling by the scaffold protein, PAG1, influences cell fate decisions following RTK activation. We generated a neuroblastoma cell line expressing a PAG1 fragment that lacks the membrane-spanning domain (PAG1TM-) and localized to the cytoplasm. PAG1TM- cells exhibited higher amounts of active SFKs and increased growth rate. PAG1TM- cells were unresponsive to TRKA and RET signaling, two RTKs that induce neuronal differentiation, but retained responses to EGFR and KIT. Under differentiation conditions, PAG1TM- cells continued to proliferate and did not extend neurites or increase β-III tubulin expression. FYN and LYN were sequestered in multivesicular bodies (MVBs), and dramatically more FYN and LYN were in the lumen of MVBs in PAG1TM- cells. In particular, activated FYN was sequestered in PAG1TM- cells, suggesting that disruption of FYN localization led to the observed defects in differentiation. The results demonstrate that PAG1 directs SFK intracellular localization to control activity and to mediate signaling by RTKs that induce neuronal differentiation.
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Affiliation(s)
- Lauren Foltz
- Division of Biological Sciences, Center for Biomolecular Structure and Dynamics, and Center for Structural and Functional Neuroscience, University of Montana, Missoula, MT 59812
| | | | - Makenzie Mayfield
- Division of Biological Sciences, Center for Biomolecular Structure and Dynamics, and Center for Structural and Functional Neuroscience, University of Montana, Missoula, MT 59812
| | - Shelby Kinch
- Division of Biological Sciences, Center for Biomolecular Structure and Dynamics, and Center for Structural and Functional Neuroscience, University of Montana, Missoula, MT 59812
| | - Jordan Dillon
- Division of Biological Sciences, Center for Biomolecular Structure and Dynamics, and Center for Structural and Functional Neuroscience, University of Montana, Missoula, MT 59812
| | - Jed Syrenne
- Division of Biological Sciences, Center for Biomolecular Structure and Dynamics, and Center for Structural and Functional Neuroscience, University of Montana, Missoula, MT 59812
| | - Tyler Levy
- Cell Signaling Technology, Danvers, MA 01923
| | - Mark Grimes
- Division of Biological Sciences, Center for Biomolecular Structure and Dynamics, and Center for Structural and Functional Neuroscience, University of Montana, Missoula, MT 59812
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28
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Drissi I, Woods WA, Woods CG. Understanding the genetic basis of congenital insensitivity to pain. Br Med Bull 2020; 133:65-78. [PMID: 32219415 PMCID: PMC7227775 DOI: 10.1093/bmb/ldaa003] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 01/21/2020] [Accepted: 01/31/2020] [Indexed: 12/15/2022]
Abstract
INTRODUCTION OR BACKGROUND Congenital insensitivity to pain (CIP) is caused by extremely rare Mendelian genetic disorders. CIP individuals demonstrate the unexpectedly severe consequences of painlessness. Although only a small number of causative conditions and genes are known, most have led to profound insights into human nociception. CIP gene discovery is catalyzing the manufacture of completely new classes of analgesics, and these are needed as alternatives to synthetic highly potent opioids. SOURCES OF DATA Pubmed.gov peer-reviewed journal articles and reviews. AREAS OF AGREEMENT The importance of nerve growth factor-tropomyosin receptor kinase A (NGF-TRKA) signalling for nociceptor genesis and subsequent pain sensing.New analgesics can be generated from knowledge of the NGF-TRKA nociceptor pathway.Increased susceptibility to Staphylococcus aureus infection is a consequence of deficient NGF-TRKA signalling.Mutations in the voltage-gated sodium channels SCN9A and SCN11A can cause congenital painlessness, and in contradistinction, other mutations can cause episodic neuropathic pain. SCN9A/Nav1.7 is an analgesic target. SCN11A/Nav1.9 is unlikely to be an analgesic target.There are further Mendelian causes of painlessness to be discovered. AREAS OF CONTROVERSY Which NGF-TRKA intracellular signalling pathways operate in nociceptor development and which in post-natal pain sensing?Why have no clinically effective Nav1.7 antagonist been generated? SCN9A-CIP causes analgesia, at least in part, through endogenous opioids.Why do all CIP phenotypes involve a complete loss of all types of nociception? AREAS TIMELY FOR DEVELOPING RESEARCH PRDM12 as an analgesic target.Discovery of the function and analgesic potential of new CIP genes.Can NGF-TRKA be used in the treatment of S. aureus?
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Affiliation(s)
- Ichrak Drissi
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge Biomedical Campus, The Keith Peters Building, Hills Road, Cambridge CB2 0XY, UK
| | - William Aidan Woods
- School of Medicine, David Weatherall building, University Road, Keele University, Staffordshire ST5 5BG, UK
| | - Christopher Geoffrey Woods
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge Biomedical Campus, The Keith Peters Building, Hills Road, Cambridge CB2 0XY, UK
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29
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Abstract
The intracellular transport system in neurons is specialized to an extraordinary degree, enabling the delivery of critical cargo to sites in axons or dendrites that are far removed from the cell center. Vesicles formed in the cell body are actively transported by kinesin motors along axonal microtubules to presynaptic sites that can be located more than a meter away. Both growth factors and degradative vesicles carrying aged organelles or aggregated proteins take the opposite route, driven by dynein motors. Distance is not the only challenge; precise delivery of cargos to sites of need must also be accomplished. For example, localized delivery of presynaptic components to hundreds of thousands of "en passant" synapses distributed along the length of a single axon in some neuronal subtypes provides a layer of complexity that must be successfully navigated to maintain synaptic transmission. We review recent advances in the field of axonal transport, with a focus on conceptual developments, and highlight our growing quantitative understanding of neuronal trafficking and its role in maintaining the synaptic function that underlies higher cognitive processes such as learning and memory.
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Affiliation(s)
- Pedro Guedes-Dias
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Institute of Neuronal Cell Biology, Technische Universität München, 80802 Munich, Germany
| | - Erika L F Holzbaur
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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30
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The Endolysosomal System and Proteostasis: From Development to Degeneration. J Neurosci 2019; 38:9364-9374. [PMID: 30381428 DOI: 10.1523/jneurosci.1665-18.2018] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 09/17/2018] [Accepted: 09/20/2018] [Indexed: 12/12/2022] Open
Abstract
How do neurons adapt their endolysosomal system to address the particular challenge of membrane transport across their elaborate cellular landscape and to maintain proteostasis for the lifetime of the organism? Here we review recent findings that address this central question. We discuss the cellular and molecular mechanisms of endolysosomal trafficking and the autophagy pathway in neurons, as well as their role in neuronal development and degeneration. These studies highlight the importance of understanding the basic cell biology of endolysosomal trafficking and autophagy and their roles in the maintenance of proteostasis within the context of neurons, which will be critical for developing effective therapies for various neurodevelopmental and neurodegenerative disorders.
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31
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Claes M, De Groef L, Moons L. Target-Derived Neurotrophic Factor Deprivation Puts Retinal Ganglion Cells on Death Row: Cold Hard Evidence and Caveats. Int J Mol Sci 2019; 20:E4314. [PMID: 31484425 PMCID: PMC6747494 DOI: 10.3390/ijms20174314] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 08/28/2019] [Accepted: 08/30/2019] [Indexed: 12/14/2022] Open
Abstract
Glaucoma and other optic neuropathies are characterized by axonal transport deficits. Axonal cargo travels back and forth between the soma and the axon terminus, a mechanism ensuring homeostasis and the viability of a neuron. An example of vital molecules in the axonal cargo are neurotrophic factors (NTFs). Hindered retrograde transport can cause a scarcity of those factors in the retina, which in turn can tilt the fate of retinal ganglion cells (RGCs) towards apoptosis. This postulation is one of the most widely recognized theories to explain RGC death in the disease progression of glaucoma and is known as the NTF deprivation theory. For several decades, research has been focused on the use of NTFs as a novel neuroprotective glaucoma treatment. Until now, results in animal models have been promising, but translation to the clinic has been highly disappointing. Are we lacking important knowledge to lever NTF therapies towards the therapeutic armamentarium? Or did we get the wrong end of the stick regarding the NTF deprivation theory? In this review, we will tackle the existing evidence and caveats advocating for and against the target-derived NTF deprivation theory in glaucoma, whilst digging into associated therapy efforts.
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Affiliation(s)
- Marie Claes
- Laboratory of Neural Circuit Development and Regeneration, Department of Biology, KU Leuven, 3000 Leuven, Belgium
| | - Lies De Groef
- Laboratory of Neural Circuit Development and Regeneration, Department of Biology, KU Leuven, 3000 Leuven, Belgium
| | - Lieve Moons
- Laboratory of Neural Circuit Development and Regeneration, Department of Biology, KU Leuven, 3000 Leuven, Belgium.
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32
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Wang S, Zhao Z, Rodal AA. Higher-order assembly of Sorting Nexin 16 controls tubulation and distribution of neuronal endosomes. J Cell Biol 2019; 218:2600-2618. [PMID: 31253649 PMCID: PMC6683739 DOI: 10.1083/jcb.201811074] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 04/25/2019] [Accepted: 06/05/2019] [Indexed: 01/01/2023] Open
Abstract
Endosomal maturation and distribution, driven by membrane remodeling, are critical for receptor traffic and signaling. Using both in vitro and in vivo approaches, Wang et al. reveal an unexpected coiled-coil–mediated membrane remodeling activity of SNX16 that controls neuronal endosomal tubulation, distribution, and receptor traffic. The activities of neuronal signaling receptors depend heavily on the maturation state of the endosomal compartments in which they reside. However, it remains unclear how the distribution of these compartments within the uniquely complex morphology of neurons is regulated and how this distribution itself affects signaling. Here, we identified mechanisms by which Sorting Nexin 16 (SNX16) controls neuronal endosomal maturation and distribution. We found that higher-order assembly of SNX16 via its coiled-coil (CC) domain drives membrane tubulation in vitro and endosome association in cells. In Drosophila melanogaster motor neurons, activation of Rab5 and CC-dependent self-association of SNX16 lead to its endosomal enrichment, accumulation in Rab5- and Rab7-positive tubulated compartments in the cell body, and concomitant depletion of SNX16-positive endosomes from the synapse. This results in accumulation of synaptic growth–promoting bone morphogenetic protein receptors in the cell body and correlates with increased synaptic growth. Our results indicate that Rab regulation of SNX16 assembly controls the endosomal distribution and signaling activities of receptors in neurons.
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Affiliation(s)
- ShiYu Wang
- Department of Biology, Brandeis University, Waltham, MA
| | - Zechuan Zhao
- Department of Biology, Brandeis University, Waltham, MA
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33
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Chen XQ, Mobley WC. Exploring the Pathogenesis of Alzheimer Disease in Basal Forebrain Cholinergic Neurons: Converging Insights From Alternative Hypotheses. Front Neurosci 2019; 13:446. [PMID: 31133787 PMCID: PMC6514132 DOI: 10.3389/fnins.2019.00446] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 04/18/2019] [Indexed: 01/01/2023] Open
Abstract
Alzheimer disease (AD) represents an oncoming epidemic that without an effective treatment promises to exact extraordinary financial and emotional burdens (Apostolova, 2016). Studies of pathogenesis are essential for defining critical molecular and cellular events and for discovering therapies to prevent or mitigate their effects. Through studies of neuropathology, genetic and cellular, and molecular biology recent decades have provided many important insights. Several hypotheses have been suggested. Documentation in the 1980s of selective loss of cholinergic neurons of the basal forebrain, followed by clinical improvement in those treated with inhibitors of acetylycholinesterase, supported the “cholinergic hypothesis of age-related cognitive dysfunction” (Bartus et al., 1982). A second hypothesis, prompted by the selective loss of cholinergic neurons and the discovery of central nervous system (CNS) neurotrophic factors, including nerve growth factor (NGF), prompted the “deficient neurotrophic hypothesis” (Chen et al., 2018). The most persuasive hypothesis, the amyloid cascade hypothesis first proposed more than 25 years ago (Selkoe and Hardy, 2016), is supported by a wealth of observations. Genetic studies were exceptionally important, pointing to increased dose of the gene for the amyloid precursor protein (APP) in Down syndrome (DS) and a familial AD (FAD) due to duplication of APP and to mutations in APP and in the genes for Presenilin 1 and 2 (PSEN1, 2), which encode the γ-secretase enzyme that processes APP (Dorszewska et al., 2016). The “tau hypothesis” noted the prominence of tau-related pathology and its correlation with dementia (Kametani and Hasegawa, 2018). Recent interest in induction of microglial activation in the AD brain, as well as other manifestations of inflammation, supports the “inflammatory hypothesis” (Mcgeer et al., 2016). We place these findings in the context of the selective, but by no means unique, involvement of BFCNs and their trophic dependence on NGF signaling and speculate as to how pathogenesis in these neurons is initiated, amplified and ultimately results in their dysfunction and death. In so doing we attempt to show how the different hypotheses for AD may interact and reinforce one another. Finally, we address current attempts to prevent and/or treat AD in light of advances in understanding pathogenetic mechanisms and suggest that studies in the DS population may provide unique insights into AD pathogenesis and treatment.
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Affiliation(s)
- Xu-Qiao Chen
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, United States
| | - William C Mobley
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, United States
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34
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Escudero CA, Cabeza C, Moya-Alvarado G, Maloney MT, Flores CM, Wu C, Court FA, Mobley WC, Bronfman FC. c-Jun N-terminal kinase (JNK)-dependent internalization and Rab5-dependent endocytic sorting mediate long-distance retrograde neuronal death induced by axonal BDNF-p75 signaling. Sci Rep 2019; 9:6070. [PMID: 30988348 PMCID: PMC6465280 DOI: 10.1038/s41598-019-42420-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 03/25/2019] [Indexed: 02/01/2023] Open
Abstract
During the development of the sympathetic nervous system, signals from tropomyosin-related kinase receptors (Trks) and p75 neurotrophin receptors (p75) compete to regulate survival and connectivity. During this process, nerve growth factor (NGF)- TrkA signaling in axons communicates NGF-mediated trophic responses in signaling endosomes. Whether axonal p75 signaling contributes to neuronal death and how signaling endosomes contribute to p75 signaling has not been established. Using compartmentalized sympathetic neuronal cultures (CSCGs) as a model, we observed that the addition of BDNF to axons increased the transport of p75 and induced death of sympathetic neurons in a dynein-dependent manner. In cell bodies, internalization of p75 required the activity of JNK, a downstream kinase mediating p75 death signaling in neurons. Additionally, the activity of Rab5, the key GTPase regulating early endosomes, was required for p75 death signaling. In axons, JNK and Rab5 were required for retrograde transport and death signaling mediated by axonal BDNF-p75 in CSCGs. JNK was also required for the proper axonal transport of p75-positive endosomes. Thus, our findings provide evidence that the activation of JNK by p75 in cell bodies and axons is required for internalization to a Rab5-positive signaling endosome and the further propagation of p75-dependent neuronal death signals.
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Affiliation(s)
- C A Escudero
- Center for Aging and Regeneration (CARE UC) and Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - C Cabeza
- Center for Aging and Regeneration (CARE UC) and Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile.,Center of Cellular and Integrative Physiology, Faculty of Medicine, Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
| | - G Moya-Alvarado
- Center for Aging and Regeneration (CARE UC) and Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - M T Maloney
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
| | - C M Flores
- Center for Aging and Regeneration (CARE UC) and Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - C Wu
- Department of Neurosciences, University of California, San Diego, La Jolla, California, 92093, USA
| | - F A Court
- Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile and FONDAP Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
| | - W C Mobley
- Department of Neurosciences, University of California, San Diego, La Jolla, California, 92093, USA
| | - F C Bronfman
- Center for Aging and Regeneration (CARE UC) and Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile.
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35
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Goto-Silva L, McShane MP, Salinas S, Kalaidzidis Y, Schiavo G, Zerial M. Retrograde transport of Akt by a neuronal Rab5-APPL1 endosome. Sci Rep 2019; 9:2433. [PMID: 30792402 PMCID: PMC6385319 DOI: 10.1038/s41598-019-38637-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 12/27/2018] [Indexed: 01/19/2023] Open
Abstract
Long-distance axonal trafficking plays a critical role in neuronal function and transport defects have been linked to neurodegenerative disorders. Various lines of evidence suggest that the small GTPase Rab5 plays a role in neuronal signaling via early endosomal transport. Here, we characterized the motility of Rab5 endosomes in primary cultures of mouse hippocampal pyramidal cells by live-cell imaging and showed that they exhibit bi-directional long-range motility in axons, with a strong bias toward retrograde transport. Characterization of key Rab5 effectors revealed that endogenous Rabankyrin-5, Rabenosyn-5 and APPL1 are all present in axons. Further analysis of APPL1-positive endosomes showed that, similar to Rab5-endosomes, they display more frequent long-range retrograde than anterograde movement, with the endosomal levels of APPL1 correlated with faster retrograde movement. Interestingly, APPL1-endosomes transport the neurotrophin receptor TrkB and mediate retrograde axonal transport of the kinase Akt1. FRET analysis revealed that APPL1 and Akt1 interact in an endocytosis-dependent manner. We conclude that Rab5-APPL1 endosomes exhibit the hallmarks of axonal signaling endosomes to transport Akt1 in hippocampal pyramidal cells.
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Affiliation(s)
- Livia Goto-Silva
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307, Dresden, Germany.,D'Or Institute for Research and Education (IDOR), Rua Diniz Cordeiro, 30, 22281-100, Rio de Janeiro, Brazil
| | - Marisa P McShane
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307, Dresden, Germany
| | - Sara Salinas
- Faculty of Bioengineering and Bioinformatics, Moscow State University, Moscow, Russia.,UMR1058. INSERM/Université de Montpellier/Etablissement Français du Sang Pathogenesis and Control of Chronic Infections, Montpellier, France
| | - Yannis Kalaidzidis
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307, Dresden, Germany.,Faculty of Bioengineering and Bioinformatics, Moscow State University, Moscow, Russia
| | - Giampietro Schiavo
- Molecular NeuroPathobiology Laboratory, Sobell Department of Motor Neuroscience & Movement Disorders, UCL Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Marino Zerial
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307, Dresden, Germany.
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36
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Olenick MA, Dominguez R, Holzbaur ELF. Dynein activator Hook1 is required for trafficking of BDNF-signaling endosomes in neurons. J Cell Biol 2019; 218:220-233. [PMID: 30373907 PMCID: PMC6314548 DOI: 10.1083/jcb.201805016] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 09/18/2018] [Accepted: 10/15/2018] [Indexed: 01/16/2023] Open
Abstract
Axonal transport is required for neuronal development and survival. Transport from the axon to the soma is driven by the molecular motor cytoplasmic dynein, yet it remains unclear how dynein is spatially and temporally regulated. We find that the dynein effector Hook1 mediates transport of TrkB-BDNF-signaling endosomes in primary hippocampal neurons. Hook1 comigrates with a subpopulation of Rab5 endosomes positive for TrkB and BDNF, which exhibit processive retrograde motility with faster velocities than the overall Rab5 population. Knockdown of Hook1 significantly reduced the motility of BDNF-signaling endosomes without affecting the motility of other organelles. In microfluidic chambers, Hook1 depletion resulted in a significant decrease in the flux and processivity of BDNF-Qdots along the mid-axon, an effect specific for Hook1 but not Hook3. Hook1 depletion inhibited BDNF trafficking to the soma and blocked downstream BDNF- and TrkB-dependent signaling to the nucleus. Together, these studies support a model in which differential association with cargo-specific effectors efficiently regulates dynein in neurons.
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Affiliation(s)
- Mara A Olenick
- The Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
- Center for Engineering Mechanobiology, University of Pennsylvania, Philadelphia, PA
| | - Roberto Dominguez
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
- The Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Erika L F Holzbaur
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
- The Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
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37
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Yamashita N. [Recent findings of nerve growth factor-dependent retrograde signaling]. Nihon Yakurigaku Zasshi 2019; 154:84. [PMID: 31406048 DOI: 10.1254/fpj.154.84] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
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38
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Villarroel-Campos D, Schiavo G, Lazo OM. The many disguises of the signalling endosome. FEBS Lett 2018; 592:3615-3632. [PMID: 30176054 PMCID: PMC6282995 DOI: 10.1002/1873-3468.13235] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 08/29/2018] [Indexed: 01/09/2023]
Abstract
Neurons are highly complex and polarised cells that must overcome a series of logistic challenges to maintain homeostasis across their morphological domains. A very clear example is the propagation of neurotrophic signalling from distal axons, where target-released neurotrophins bind to their receptors and initiate signalling, towards the cell body, where nuclear and cytosolic responses are integrated. The mechanisms of propagation of neurotrophic signalling have been extensively studied and, eventually, the model of a 'signalling endosome', transporting activated receptors and associated complexes, has emerged. Nevertheless, the exact nature of this organelle remains elusive. In this Review, we examine the evidence for the retrograde transport of neurotrophins and their receptors in endosomes, outline some of their diverse physiological and pathological roles, and discuss the main interactors, morphological features and trafficking destinations of a highly flexible endosomal signalling organelle with multiple molecular signatures.
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Affiliation(s)
- David Villarroel-Campos
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, UK
| | - Giampietro Schiavo
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, UK.,UK Dementia Research Institute at UCL, London, UK.,Discoveries Centre for Regenerative and Precision Medicine, University College London Campus, UK
| | - Oscar Marcelo Lazo
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, UK
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39
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Pathak A, Stanley EM, Hickman FE, Wallace N, Brewer B, Li D, Gluska S, Perlson E, Fuhrmann S, Akassoglou K, Bronfman F, Casaccia P, Burnette DT, Carter BD. Retrograde Degenerative Signaling Mediated by the p75 Neurotrophin Receptor Requires p150 Glued Deacetylation by Axonal HDAC1. Dev Cell 2018; 46:376-387.e7. [PMID: 30086304 PMCID: PMC6093198 DOI: 10.1016/j.devcel.2018.07.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Revised: 05/19/2018] [Accepted: 07/01/2018] [Indexed: 12/23/2022]
Abstract
During development, neurons undergo apoptosis if they do not receive adequate trophic support from tissues they innervate or when detrimental factors activate the p75 neurotrophin receptor (p75NTR) at their axon ends. Trophic factor deprivation (TFD) or activation of p75NTR in distal axons results in a retrograde degenerative signal. However, the nature of this signal and the regulation of its transport are poorly understood. Here, we identify p75NTR intracellular domain (ICD) and histone deacetylase 1 (HDAC1) as part of a retrograde pro-apoptotic signal generated in response to TFD or ligand binding to p75NTR in sympathetic neurons. We report an unconventional function of HDAC1 in retrograde transport of a degenerative signal and its constitutive presence in sympathetic axons. HDAC1 deacetylates dynactin subunit p150Glued, which enhances its interaction with dynein. These findings define p75NTR ICD as a retrograde degenerative signal and reveal p150Glued deacetylation as a unique mechanism regulating axonal transport.
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Affiliation(s)
- Amrita Pathak
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA; Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA
| | - Emily M Stanley
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA; Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA
| | - F Edward Hickman
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA; Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA
| | - Natalie Wallace
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Bryson Brewer
- Vanderbilt University School of Engineering, Nashville, TN, USA
| | - Deyu Li
- Vanderbilt University School of Engineering, Nashville, TN, USA
| | - Shani Gluska
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Eran Perlson
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Sabine Fuhrmann
- Department of Cell & Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA; Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Katerina Akassoglou
- Gladstone Institute of Neurological Disease and Department of Neurology, University of California, San Francisco, CA, USA
| | - Francisca Bronfman
- Center for Ageing and Regeneration (CARE UC), Faculty of Biological Sciences, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Patrizia Casaccia
- Hunter College Department of Biology, Advanced Science Research Center at The Graduate Center of the City University of New York, New York, NY, USA
| | - Dylan T Burnette
- Department of Cell & Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Bruce D Carter
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA; Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA.
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40
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Scott-Solomon E, Kuruvilla R. Mechanisms of neurotrophin trafficking via Trk receptors. Mol Cell Neurosci 2018; 91:25-33. [PMID: 29596897 DOI: 10.1016/j.mcn.2018.03.013] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 03/19/2018] [Accepted: 03/26/2018] [Indexed: 12/31/2022] Open
Abstract
In neurons, long-distance communication between axon terminals and cell bodies is a critical determinant in establishing and maintaining neural circuits. Neurotrophins are soluble factors secreted by post-synaptic target tissues that retrogradely control axon and dendrite growth, survival, and synaptogenesis of innervating neurons. Neurotrophins bind Trk receptor tyrosine kinases in axon terminals to promote endocytosis of ligand-bound phosphorylated receptors into signaling endosomes. Trk-harboring endosomes function locally in axons to acutely promote growth events, and can also be retrogradely transported long-distances to remote cell bodies and dendrites to stimulate cytoplasmic and transcriptional signaling necessary for neuron survival, morphogenesis, and maturation. Neuronal responsiveness to target-derived neurotrophins also requires the precise axonal targeting of newly synthesized Trk receptors. Recent studies suggest that anterograde delivery of Trk receptors is regulated by retrograde neurotrophin signaling. In this review, we summarize current knowledge on the functions and mechanisms of retrograde trafficking of Trk signaling endosomes, and highlight recent discoveries on the forward trafficking of nascent receptors.
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Affiliation(s)
- Emily Scott-Solomon
- Department of Biology, Johns Hopkins University, 3400 N. Charles St, 227 Mudd Hall, Baltimore, MD 21218, USA
| | - Rejji Kuruvilla
- Department of Biology, Johns Hopkins University, 3400 N. Charles St, 227 Mudd Hall, Baltimore, MD 21218, USA.
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Barford K, Keeler A, McMahon L, McDaniel K, Yap CC, Deppmann CD, Winckler B. Transcytosis of TrkA leads to diversification of dendritic signaling endosomes. Sci Rep 2018; 8:4715. [PMID: 29549340 PMCID: PMC5856830 DOI: 10.1038/s41598-018-23036-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 03/05/2018] [Indexed: 01/16/2023] Open
Abstract
The development of the peripheral nervous system relies on long-distance signaling from target organs back to the soma. In sympathetic neurons, this long-distance signaling is mediated by target derived Nerve Growth Factor (NGF) interacting with its axonal receptor, TrkA. This ligand receptor complex internalizes into what is commonly referred to as the signaling endosome which is transported retrogradely to the soma and dendrites to mediate survival signaling and synapse formation, respectively. The molecular identity of signaling endosomes in dendrites has not yet been determined. Here, we perform a detailed analysis of TrkA endosomal compartments and trafficking patterns. We find that signaling endosomes are not uniform but molecularly diversified into Rab7 (late endosome) and Rab11 (recycling endosome) populations in axons and dendrites in vitro and in the soma in vivo. Surprisingly, TrkA-NGF signaling endosomes in dendrites undergo dynamic trafficking events, including putative fusion and fission. Overall, we find that signaling endosomes do not remain as a singular endosomal subtype but instead exist in multiple populations that undergo dynamic endosomal trafficking events. These dynamic events might drive functional diversification of the signaling endosome.
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Affiliation(s)
- Kelly Barford
- Department of Cell Biology, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, Virginia, 22908, USA
| | - Austin Keeler
- Department of Biology, University of Virginia, Physical Life Sciences Building (PLSB), 90 Geldard Drive, Charlottesville, Virginia, 22903, USA
| | - Lloyd McMahon
- Department of Cell Biology, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, Virginia, 22908, USA
| | - Kathryn McDaniel
- Department of Cell Biology, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, Virginia, 22908, USA
| | - Chan Choo Yap
- Department of Cell Biology, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, Virginia, 22908, USA
| | - Christopher D Deppmann
- Department of Biology, University of Virginia, Physical Life Sciences Building (PLSB), 90 Geldard Drive, Charlottesville, Virginia, 22903, USA. .,Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, 22903, USA.
| | - Bettina Winckler
- Department of Cell Biology, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, Virginia, 22908, USA.
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Li X, Bao H, Wang Z, Wang M, Fan B, Zhu C, Chen Z. Biogenesis and Function of Multivesicular Bodies in Plant Immunity. FRONTIERS IN PLANT SCIENCE 2018; 9:979. [PMID: 30038635 PMCID: PMC6047128 DOI: 10.3389/fpls.2018.00979] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 06/15/2018] [Indexed: 05/19/2023]
Abstract
Multivesicular bodies (MVBs) are specialized endosomes that contain intraluminal vesicles generated from invagination and budding of the limiting membrane. In the endocytic pathway, MVBs are late endosomes whose content can be degraded through fusion with lysosomes/vacuoles or released into the extracellular space after fusion with the plasma membrane (PM). The proteins retained on the limiting membrane of MVBs are translocated to the membrane of lysosomes/vacuoles or delivered back to the PM. It has been long suspected that MVBs might fuse with the PM to form paramural bodies in plant cells, possibly leading to release of building blocks for deposition of papillae and antimicrobial molecules against invading pathogens. Over the past decade or so, major progress has been made in establishing the critical roles of MVBs and associated membrane trafficking in pathogen recognition, defense signaling, and deployment of defense-related molecules during plant immune responses. Regulatory proteins and signaling pathways associated with induced biogenesis and trafficking of MVBs during plant immune responses have also been identified and characterized. Recent successful isolation of plant extracellular vesicles and proteomic profiling of their content have provided additional support for the roles of MVBs in plant-pathogen interactions. In this review, we summarize the important progress and discuss how MVBs, particularly through routing of cellular components to different destinations, contribute to the complex network of plant immune system.
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Affiliation(s)
- Xifeng Li
- Department of Horticulture, Zhejiang University, Hangzhou, China
| | - Hexigeduleng Bao
- College of Life Sciences, China Jiliang University, Hangzhou, China
| | - Zhe Wang
- Department of Botany and Plant Pathology, Center for Plant Biology, Purdue University, West Lafayette, IN, United States
| | - Mengxue Wang
- College of Life Sciences, China Jiliang University, Hangzhou, China
| | - Baofang Fan
- Department of Botany and Plant Pathology, Center for Plant Biology, Purdue University, West Lafayette, IN, United States
| | - Cheng Zhu
- College of Life Sciences, China Jiliang University, Hangzhou, China
- *Correspondence: Cheng Zhu, ; Zhixiang Chen,
| | - Zhixiang Chen
- Department of Horticulture, Zhejiang University, Hangzhou, China
- College of Life Sciences, China Jiliang University, Hangzhou, China
- Department of Botany and Plant Pathology, Center for Plant Biology, Purdue University, West Lafayette, IN, United States
- *Correspondence: Cheng Zhu, ; Zhixiang Chen,
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