1
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Jiang A, Kudo K, Gormal RS, Ellis S, Guo S, Wallis TP, Longfield SF, Robinson PJ, Johnson ME, Joensuu M, Meunier FA. Dynamin1 long- and short-tail isoforms exploit distinct recruitment and spatial patterns to form endocytic nanoclusters. Nat Commun 2024; 15:4060. [PMID: 38744819 PMCID: PMC11094030 DOI: 10.1038/s41467-024-47677-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Accepted: 04/09/2024] [Indexed: 05/16/2024] Open
Abstract
Endocytosis requires a coordinated framework of molecular interactions that ultimately lead to the fission of nascent endocytic structures. How cytosolic proteins such as dynamin concentrate at discrete sites that are sparsely distributed across the plasma membrane remains poorly understood. Two dynamin-1 major splice variants differ by the length of their C-terminal proline-rich region (short-tail and long-tail). Using sptPALM in PC12 cells, neurons and MEF cells, we demonstrate that short-tail dynamin-1 isoforms ab and bb display an activity-dependent recruitment to the membrane, promptly followed by their concentration into nanoclusters. These nanoclusters are sensitive to both Calcineurin and dynamin GTPase inhibitors, and are larger, denser, and more numerous than that of long-tail isoform aa. Spatiotemporal modelling confirms that dynamin-1 isoforms perform distinct search patterns and undergo dimensional reduction to generate endocytic nanoclusters, with short-tail isoforms more robustly exploiting lateral trapping in the generation of nanoclusters compared to the long-tail isoform.
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Affiliation(s)
- Anmin Jiang
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Kye Kudo
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Rachel S Gormal
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Sevannah Ellis
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Sikao Guo
- Department of Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD, 21218, USA
| | - Tristan P Wallis
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Shanley F Longfield
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Phillip J Robinson
- Cell Signalling Unit, Children's Medical Research Institute, The University of Sydney, Sydney, NSW, 2145, Australia
| | - Margaret E Johnson
- Department of Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD, 21218, USA
| | - Merja Joensuu
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia.
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, 4072, Australia.
| | - Frédéric A Meunier
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia.
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, 4072, Australia.
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2
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Wallis TP, Jiang A, Young K, Hou H, Kudo K, McCann AJ, Durisic N, Joensuu M, Oelz D, Nguyen H, Gormal RS, Meunier FA. Super-resolved trajectory-derived nanoclustering analysis using spatiotemporal indexing. Nat Commun 2023; 14:3353. [PMID: 37291117 PMCID: PMC10250379 DOI: 10.1038/s41467-023-38866-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 05/11/2023] [Indexed: 06/10/2023] Open
Abstract
Single-molecule localization microscopy techniques are emerging as vital tools to unravel the nanoscale world of living cells by understanding the spatiotemporal organization of protein clusters at the nanometer scale. Current analyses define spatial nanoclusters based on detections but neglect important temporal information such as cluster lifetime and recurrence in "hotspots" on the plasma membrane. Spatial indexing is widely used in video games to detect interactions between moving geometric objects. Here, we use the R-tree spatial indexing algorithm to determine the overlap of the bounding boxes of individual molecular trajectories to establish membership in nanoclusters. Extending the spatial indexing into the time dimension allows the resolution of spatial nanoclusters into multiple spatiotemporal clusters. Using spatiotemporal indexing, we found that syntaxin1a and Munc18-1 molecules transiently cluster in hotspots, offering insights into the dynamics of neuroexocytosis. Nanoscale spatiotemporal indexing clustering (NASTIC) has been implemented as a free and open-source Python graphic user interface.
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Affiliation(s)
- Tristan P Wallis
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia.
| | - Anmin Jiang
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Kyle Young
- School of Mathematics and Physics, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Huiyi Hou
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Kye Kudo
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Alex J McCann
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Nela Durisic
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Merja Joensuu
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Dietmar Oelz
- School of Mathematics and Physics, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Hien Nguyen
- School of Mathematics and Physics, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Rachel S Gormal
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia.
| | - Frédéric A Meunier
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia.
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, 4072, Australia.
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3
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Bowers DT, McCulloch ME, Brown JL. Evaluation of focal adhesion mediated subcellular curvature sensing in response to engineered extracellular matrix. Biointerphases 2023; 18:021004. [PMID: 37019799 PMCID: PMC10079328 DOI: 10.1116/6.0002440] [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: 12/19/2022] [Revised: 02/24/2023] [Accepted: 03/14/2023] [Indexed: 04/07/2023] Open
Abstract
Fibril curvature is bioinstructive to attached cells. Similar to natural healthy tissues, an engineered extracellular matrix can be designed to stimulate cells to adopt desired phenotypes. To take full advantage of the curvature control in biomaterial fabrication methodologies, an understanding of the response to fibril subcellular curvature is required. In this work, we examined morphology, signaling, and function of human cells attached to electrospun nanofibers. We controlled curvature across an order of magnitude using nondegradable poly(methyl methacrylate) (PMMA) attached to a stiff substrate with flat PMMA as a control. Focal adhesion length and the distance of maximum intensity from the geographic center of the vinculin positive focal adhesion both peaked at a fiber curvature of 2.5 μm-1 (both ∼2× the flat surface control). Vinculin experienced slightly less tension when attached to nanofiber substrates. Vinculin expression was also more affected by a subcellular curvature than structural proteins α-tubulin or α-actinin. Among the phosphorylation sites we examined (FAK397, 576/577, 925, and Src416), FAK925 exhibited the most dependance on the nanofiber curvature. A RhoA/ROCK dependance of migration velocity across curvatures combined with an observation of cell membrane wrapping around nanofibers suggested a hybrid of migration modes for cells attached to fibers as has been observed in 3D matrices. Careful selection of nanofiber curvature for regenerative engineering scaffolds and substrates used to study cell biology is required to maximize the potential of these techniques for scientific exploration and ultimately improvement of human health.
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Affiliation(s)
- Daniel T. Bowers
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Mary Elizabeth McCulloch
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Justin L. Brown
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802
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4
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Bademosi AT, Meunier FA. Unveiling the Nanoscale Dynamics of the Exocytic Machinery in Chromaffin Cells with Single-Molecule Imaging. Methods Mol Biol 2023; 2565:311-327. [PMID: 36205903 DOI: 10.1007/978-1-0716-2671-9_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Neuronal and hormonal communication relies on the exocytic fusion of vesicles containing neurotransmitters and hormones with the plasma membrane. This process is tightly regulated by key protein-protein and protein-lipid interactions and culminates in the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex formation and zippering that promotes vesicular fusion. Located on both sides of the vesicle and the plasma membrane, the zippering of the SNARE complex acts to overcome the energy barrier afforded by the repulsive electrostatic force stemming from apposing two negatively charged phospholipid membranes. Another component opposing the timely organization of the fusion machinery is thermal Brownian energy that tends to homogenize all cellular molecules by constantly switching their motions and directions through short-lived molecular interactions. Much less is known of the mechanisms counteracting these chaotic forces, allowing seamless cellular functions such as exocytic fusion. Super-resolution microscopy techniques such as single-molecule imaging have proven useful to start uncovering these nanoscale mechanisms. Here, we used single-particle tracking photoactivatable localization microscopy (sptPALM) to track syntaxin-1-mEos, a SNARE protein located on the plasma membrane of cultured bovine chromaffin cells. We demonstrate that syntaxin-1-mEos undergoes dramatic change in its mobility in response to secretagogue stimulation leading to increased nanoclustering. These nanoclusters are transient in nature and likely to provide docked vesicles with a molecular environment conducive to exocytic fusion.
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Affiliation(s)
- Adekunle T Bademosi
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland, St Lucia Campus, Brisbane, QLD, Australia.
| | - Frédéric A Meunier
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland, St Lucia Campus, Brisbane, QLD, Australia.
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5
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Schenk EB, Meunier FA, Oelz DB. Spatial redistribution of neurosecretory vesicles upon stimulation accelerates their directed transport to the plasma membrane. PLoS One 2022; 17:e0264521. [PMID: 35294476 PMCID: PMC8926195 DOI: 10.1371/journal.pone.0264521] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 02/11/2022] [Indexed: 11/19/2022] Open
Abstract
Through the integration of results from an imaging analysis of intracellular trafficking of labelled neurosecretory vesicles in chromaffin cells, we develop a Markov state model to describe their transport and binding kinetics. Our simulation results indicate that a spatial redistribution of neurosecretory vesicles occurs upon secretagogue stimulation leading vesicles to the plasma membrane where they undergo fusion thereby releasing adrenaline and noradrenaline. Furthermore, we find that this redistribution alone can explain the observed up-regulation of vesicle transport upon stimulation and its directional bias towards the plasma membrane. Parameter fitting indicates that in the deeper compartment within the cell, vesicle transport is asymmetric and characterised by a bias towards the plasma membrane.
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Affiliation(s)
- Elaine B. Schenk
- School of Mathematics & Physics, The University of Queensland, Brisbane, Australia
| | - Frederic A. Meunier
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute (QBI), The University of Queensland, Brisbane, Australia
| | - Dietmar B. Oelz
- School of Mathematics & Physics, The University of Queensland, Brisbane, Australia
- * E-mail:
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6
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Izumi T. In vivo Roles of Rab27 and Its Effectors in Exocytosis. Cell Struct Funct 2021; 46:79-94. [PMID: 34483204 PMCID: PMC10511049 DOI: 10.1247/csf.21043] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 08/31/2021] [Indexed: 11/11/2022] Open
Abstract
The monomeric GTPase Rab27 regulates exocytosis of a broad range of vesicles in multicellular organisms. Several effectors bind GTP-bound Rab27a and/or Rab27b on secretory vesicles to execute a series of exocytic steps, such as vesicle maturation, movement along microtubules, anchoring within the peripheral F-actin network, and tethering to the plasma membrane, via interactions with specific proteins and membrane lipids in a local milieu. Although Rab27 effectors generally promote exocytosis, they can also temporarily restrict it when they are involved in the rate-limiting step. Genetic alterations in Rab27-related molecules cause discrete diseases manifesting pigment dilution and immunodeficiency, and can also affect common diseases such as diabetes and cancer in complex ways. Although the function and mechanism of action of these effectors have been explored, it is unclear how multiple effectors act in coordination within a cell to regulate the secretory process as a whole. It seems that Rab27 and various effectors constitutively reside on individual vesicles to perform consecutive exocytic steps. The present review describes the unique properties and in vivo roles of the Rab27 system, and the functional relationship among different effectors coexpressed in single cells, with pancreatic beta cells used as an example.Key words: membrane trafficking, regulated exocytosis, insulin granules, pancreatic beta cells.
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Affiliation(s)
- Tetsuro Izumi
- Laboratory of Molecular Endocrinology and Metabolism, Department of Molecular Medicine, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma 371-8512, Japan
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7
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Pan X, Zhou Y, Hotulainen P, Meunier FA, Wang T. The axonal radial contractility: Structural basis underlying a new form of neural plasticity. Bioessays 2021; 43:e2100033. [PMID: 34145916 DOI: 10.1002/bies.202100033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 05/27/2021] [Accepted: 06/02/2021] [Indexed: 12/25/2022]
Abstract
Axons are the longest cellular structure reaching over a meter in the case of human motor axons. They have a relatively small diameter and contain several cytoskeletal elements that mediate both material and information exchange within neurons. Recently, a novel type of axonal plasticity, termed axonal radial contractility, has been unveiled. It is represented by dynamic and transient diameter changes of the axon shaft to accommodate the passages of large organelles. Mechanisms underpinning this plasticity are not fully understood. Here, we first summarised recent evidence of the functional relevance for axon radial contractility, then discussed the underlying structural basis, reviewing nanoscopic evidence of the subtle changes. Two models are proposed to explain how actomyosin rings are organised. Possible roles of non-muscle myosin II (NM-II) in axon degeneration are discussed. Finally, we discuss the concept of periodic functional nanodomains, which could sense extracellular cues and coordinate the axonal responses. Also see the video abstract here: https://youtu.be/ojCnrJ8RCRc.
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Affiliation(s)
- Xiaorong Pan
- Center for Brain Science, School of Life Science and Technology, Shanghaitech University, Shanghai, China
| | - Yimin Zhou
- Center for Brain Science, School of Life Science and Technology, Shanghaitech University, Shanghai, China
| | - Pirta Hotulainen
- Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | - Frédéric A Meunier
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - Tong Wang
- Center for Brain Science, School of Life Science and Technology, Shanghaitech University, Shanghai, China
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8
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Dembla E, Becherer U. Biogenesis of large dense core vesicles in mouse chromaffin cells. Traffic 2021; 22:78-93. [PMID: 33369005 DOI: 10.1111/tra.12783] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 12/21/2020] [Accepted: 12/21/2020] [Indexed: 12/14/2022]
Abstract
Large dense core vesicle (LDCVs) biogenesis in neuroendocrine cells involves: (a) production of cargo peptides processed in the Golgi; (b) fission of cargo loaded LDCVs undergoing maturation steps; (c) movement of these LDCVs to the plasma membrane. These steps have been resolved over several decades in PC12 cells and in bovine chromaffin cells. More recently, the molecular machinery involved in LDCV biogenesis has been examined using genetically modified mice, generating contradictory results. To address these contradictions, we have used NPY-mCherry electroporation combined with immunolabeling and super-resolution structured illumination microscopy. We show that LDCVs separate from an intermediate Golgi compartment, mature in its proximity for about 1 hour and then travel to the plasma membrane. The exocytotic machinery composed of vSNAREs and synaptotagmin1, which originate from either de novo synthesis or recycling, is most likely acquired via fusion with precursor vesicles during maturation. Finally, recycling of LDCV membrane protein is achieved in less than 2 hours. With this comprehensive scheme of LDCV biogenesis we have established a framework for future studies in mouse chromaffin cells.
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Affiliation(s)
- Ekta Dembla
- Cellular Neurophysiology, CIPMM, Saarland University, Homburg, Germany
| | - Ute Becherer
- Cellular Neurophysiology, CIPMM, Saarland University, Homburg, Germany
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9
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Montenegro M, Bayonés L, Moya-Díaz J, Borassi C, Martín Toscani A, Gallo LI, Marengo FD. Rapid vesicle replenishment after the immediately releasable pool exocytosis is tightly linked to fast endocytosis, and depends on basal calcium and cortical actin in chromaffin cells. J Neurochem 2021; 157:1069-1085. [PMID: 33338257 DOI: 10.1111/jnc.15276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 11/25/2020] [Accepted: 12/12/2020] [Indexed: 01/06/2023]
Abstract
The maintenance of the secretory response requires a continuous replenishment of releasable vesicles. It was proposed that the immediately releasable pool (IRP) is important in chromaffin cell secretion during action potentials applied at basal physiological frequencies, because of the proximity of IRP vesicles to voltage-dependent Ca2+ channels. However, previous reports showed that IRP replenishment after depletion is too slow to manage such a situation. In this work, we used patch-clamp measurements of membrane capacitance, confocal imaging of F-actin distribution, and cytosolic Ca2+ measurements with Fura-2 to re-analyze this problem in primary cultures of mouse chromaffin cells. We provide evidence that IRP replenishment has one slow (time constant between 5 and 10 s) and one rapid component (time constant between 0.5 and 1.5 s) linked to a dynamin-dependent fast endocytosis. Both, the fast endocytosis and the rapid replenishment component were eliminated when 500 nM Ca2+ was added to the internal solution during patch-clamp experiments, but they became dominant and accelerated when the cytosolic Ca2+ buffer capacity was increased. In addition, both rapid replenishment and fast endocytosis were retarded when cortical F-actin cytoskeleton was disrupted with cytochalasin D. Finally, in permeabilized chromaffin cells stained with rhodamine-phalloidin, the cortical F-actin density was reduced when the Ca2+ concentration was increased in a range of 10-1000 nM. We conclude that low cytosolic Ca2+ concentrations, which favor cortical F-actin stabilization, allow the activation of a fast endocytosis mechanism linked to a rapid replenishment component of IRP.
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Affiliation(s)
- Mauricio Montenegro
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIByNE). CONICET, Departamento de Fisiología y Biología Molecular y Celular. Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Lucas Bayonés
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIByNE). CONICET, Departamento de Fisiología y Biología Molecular y Celular. Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - José Moya-Díaz
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIByNE). CONICET, Departamento de Fisiología y Biología Molecular y Celular. Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,School of Life Sciences, University of Sussex, Brighton, UK
| | - Cecilia Borassi
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA), CONICET, Buenos Aires, Argentina
| | - Andrés Martín Toscani
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN). CONICET, Departamento de Química Biológica. Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Centro Científico Tecnológico -, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), La Plata, Argentina
| | - Luciana I Gallo
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIByNE). CONICET, Departamento de Fisiología y Biología Molecular y Celular. Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Fernando D Marengo
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIByNE). CONICET, Departamento de Fisiología y Biología Molecular y Celular. Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
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10
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Hormones Secretion and Rho GTPases in Neuroendocrine Tumors. Cancers (Basel) 2020; 12:cancers12071859. [PMID: 32664294 PMCID: PMC7408961 DOI: 10.3390/cancers12071859] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 07/03/2020] [Accepted: 07/06/2020] [Indexed: 12/14/2022] Open
Abstract
Neuroendocrine tumors (NETs) belong to a heterogeneous group of neoplasms arising from hormone secreting cells. These tumors are often associated with a dysfunction of their secretory activity. Neuroendocrine secretion occurs through calcium-regulated exocytosis, a process that is tightly controlled by Rho GTPases family members. In this review, we compiled the numerous mutations and modification of expression levels of Rho GTPases or their regulators (Rho guanine nucleotide-exchange factors and Rho GTPase-activating proteins) that have been identified in NETs. We discussed how they might regulate neuroendocrine secretion.
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11
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Wang T, Li W, Martin S, Papadopulos A, Joensuu M, Liu C, Jiang A, Shamsollahi G, Amor R, Lanoue V, Padmanabhan P, Meunier FA. Radial contractility of actomyosin rings facilitates axonal trafficking and structural stability. J Cell Biol 2020; 219:e201902001. [PMID: 32182623 PMCID: PMC7199852 DOI: 10.1083/jcb.201902001] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 09/17/2019] [Accepted: 02/10/2020] [Indexed: 02/07/2023] Open
Abstract
Most mammalian neurons have a narrow axon, which constrains the passage of large cargoes such as autophagosomes that can be larger than the axon diameter. Radial axonal expansion must therefore occur to ensure efficient axonal trafficking. In this study, we reveal that the speed of various large cargoes undergoing axonal transport is significantly slower than that of small ones and that the transit of diverse-sized cargoes causes an acute, albeit transient, axonal radial expansion, which is immediately restored by constitutive axonal contractility. Using live super-resolution microscopy, we demonstrate that actomyosin-II controls axonal radial contractility and local expansion, and that NM-II filaments associate with periodic F-actin rings via their head domains. Pharmacological inhibition of NM-II activity significantly increases axon diameter by detaching the NM-II from F-actin and impacts the trafficking speed, directionality, and overall efficiency of long-range retrograde trafficking. Consequently, prolonged NM-II inactivation leads to disruption of periodic actin rings and formation of focal axonal swellings, a hallmark of axonal degeneration.
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Affiliation(s)
- Tong Wang
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
- The Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Australia
| | - Wei Li
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
- The Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Australia
| | - Sally Martin
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
- The Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Australia
| | - Andreas Papadopulos
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - Merja Joensuu
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - Chunxia Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Anmin Jiang
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - Golnoosh Shamsollahi
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - Rumelo Amor
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - Vanessa Lanoue
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - Pranesh Padmanabhan
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - Frédéric A. Meunier
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
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12
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Pons-Vizcarra M, Kurps J, Tawfik B, Sørensen JB, van Weering JRT, Verhage M. MUNC18-1 regulates the submembrane F-actin network, independently of syntaxin1 targeting, via hydrophobicity in β-sheet 10. J Cell Sci 2019; 132:jcs.234674. [PMID: 31719162 DOI: 10.1242/jcs.234674] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 11/01/2019] [Indexed: 01/08/2023] Open
Abstract
MUNC18-1 (also known as STXBP1) is an essential protein for docking and fusion of secretory vesicles. Mouse chromaffin cells (MCCs) lacking MUNC18-1 show impaired secretory vesicle docking, but also mistargeting of SNARE protein syntaxin1 and an abnormally dense submembrane F-actin network. Here, we tested the contribution of both these phenomena to docking and secretion defects in MUNC18-1-deficient MCCs. We show that an abnormal F-actin network and syntaxin1 targeting defects are not observed in Snap25- or Syt1-knockout (KO) MCCs, which are also secretion deficient. We identified a MUNC18-1 mutant (V263T in β-sheet 10) that fully restores syntaxin1 targeting but not F-actin abnormalities in Munc18-1-KO cells. MUNC18-2 and -3 (also known as STXBP2 and STXBP3, respectively), which lack the hydrophobic residue at position 263, also did not restore a normal F-actin network in Munc18-1-KO cells. However, these proteins did restore the normal F-actin network when a hydrophobic residue was introduced at the corresponding position. Munc18-1-KO MCCs expressing MUNC18-1(V263T) showed normal vesicle docking and exocytosis. These results demonstrate that MUNC18-1 regulates the F-actin network independently of syntaxin1 targeting via hydrophobicity in β-sheet 10. The abnormally dense F-actin network in Munc18-1-deficient cells is not a rate-limiting barrier in secretory vesicle docking or fusion.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Maria Pons-Vizcarra
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije Universiteit Amsterdam, de Boelelaan 1085, Amsterdam 1081 HV, The Netherlands
| | - Julia Kurps
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije Universiteit Amsterdam, de Boelelaan 1085, Amsterdam 1081 HV, The Netherlands
| | - Bassam Tawfik
- Neurosecretion group, Signaling Laboratory, Department of Neuroscience and Pharmacology, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - Jakob B Sørensen
- Neurosecretion group, Signaling Laboratory, Department of Neuroscience and Pharmacology, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - Jan R T van Weering
- Department of Clinical Genetics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Amsterdam UMC, location VUmc, de Boelelaan 1085, Amsterdam 1081 HV, The Netherlands
| | - Matthijs Verhage
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije Universiteit Amsterdam, de Boelelaan 1085, Amsterdam 1081 HV, The Netherlands .,Department of Clinical Genetics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Amsterdam UMC, location VUmc, de Boelelaan 1085, Amsterdam 1081 HV, The Netherlands
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13
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Han P, Frith JE, Gomez GA, Yap AS, O'Neill GM, Cooper-White JJ. Five Piconewtons: The Difference between Osteogenic and Adipogenic Fate Choice in Human Mesenchymal Stem Cells. ACS NANO 2019; 13:11129-11143. [PMID: 31580055 DOI: 10.1021/acsnano.9b03914] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The ability of mesenchymal stem cells to sense nanoscale variations in extracellular matrix (ECM) compositions in their local microenvironment is crucial to their survival and their fate; however, the underlying molecular mechanisms defining how such fates are temporally modulated remain poorly understood. In this work, we have utilized self-assembled block copolymer surfaces to present nanodomains of an adhesive peptide found in many ECM proteins at different lateral spacings (from 30 to 60 nm) and studied the temporal response (2 h to 14 days) of human mesenchymal stem cells (hMSCs) using a panel of real-time localization and activity biosensors. Our findings revealed that within the first 4 to 24 h postadhesion and spreading, hMSCs on smaller nanodomain spacings recruit more activated FAK and Src proteins to produce larger, longer-lived, and increased numbers of focal adhesions (FAs). The adhesions formed on smaller nanospacings rapidly recruit higher amounts of nonmuscle myosin IIA and vinculin and experience tension forces (by >5 pN/FA) significantly higher than those observed on larger nanodomain spacings. The transmission of higher levels of tension into the cytoskeleton at short times was accompanied by higher Rac1, cytosolic β-catenin, and nuclear localization of YAP/TAZ and RUNX2, which together biased the commitment of hMSCs to an osteogenic fate. This investigation provides mechanistic insights to confirm that smaller lateral spacings of adhesive nanodomains alter hMSC mechanosensing and biases mechanotransduction at short times via differential coupling of FAK/Src/Rac1/myosin IIA/YAP/TAZ signaling pathways to support longer-term changes in stem cell differentiation and state.
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Affiliation(s)
- Pingping Han
- Tissue Engineering and Microfluidics Laboratory (TE&M), Australian Institute for Bioengineering and Nanotechnology (AIBN) , The University of Queensland , Brisbane , St. Lucia, QLD 4067 , Australia
- The UQ Centre in Stem Cell Ageing and Regenerative Engineering (StemCARE), Australian Institute for Bioengineering and Nanotechnology , The University of Queensland , Brisbane , St. Lucia, QLD 4067 , Australia
| | - Jessica E Frith
- Tissue Engineering and Microfluidics Laboratory (TE&M), Australian Institute for Bioengineering and Nanotechnology (AIBN) , The University of Queensland , Brisbane , St. Lucia, QLD 4067 , Australia
- Materials Science and Engineering , Monash University , Melbourne , VIC 3168 , Australia
| | - Guillermo A Gomez
- Institute of Molecular Biosciences , The University of Queensland , Brisbane , St. Lucia, QLD 4067 , Australia
- Centre for Cancer Biology , South Australia Pathology and The University of South Australia , Adelaide , SA 5001 , Australia
| | - Alpha S Yap
- Institute of Molecular Biosciences , The University of Queensland , Brisbane , St. Lucia, QLD 4067 , Australia
| | - Geraldine M O'Neill
- Kids Research Institute , Children's Hospital at Westmead , Sydney , NSW 2006 , Australia
- Discipline of Child and Adolescent Health , University of Sydney , Sydney , NSW 2006 , Australia
| | - Justin J Cooper-White
- Tissue Engineering and Microfluidics Laboratory (TE&M), Australian Institute for Bioengineering and Nanotechnology (AIBN) , The University of Queensland , Brisbane , St. Lucia, QLD 4067 , Australia
- The UQ Centre in Stem Cell Ageing and Regenerative Engineering (StemCARE), Australian Institute for Bioengineering and Nanotechnology , The University of Queensland , Brisbane , St. Lucia, QLD 4067 , Australia
- Commonwealth Scientific and Industrial Research Organization (CSIRO), Manufacturing , Melbourne , Clayton, VIC 3168 , Australia
- School of Chemical Engineering , The University of Queensland , Brisbane , St. Lucia, QLD 4067 , Australia
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14
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A multifunctional lipid that forms contrast-agent liposomes with dual-control release capabilities for precise MRI-guided drug delivery. Biomaterials 2019; 221:119412. [PMID: 31419656 DOI: 10.1016/j.biomaterials.2019.119412] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 07/18/2019] [Accepted: 08/03/2019] [Indexed: 01/04/2023]
Abstract
Monitoring of nanoparticle-based therapy in vivo and controlled drug release are urgently needed for the precise treatment of disease. We have synthesized a multifunctional Gd-DTPA-ONB (GDO) lipid by introducing the Gd-DTPA contrast agent moiety into an o-nitro-benzyl ester lipid. By design, liposomes formed from the GDO lipid combine MRI tracking ability and dual-trigger release capabilities with maximum sensitivity (because all lipids bear the cleavable moiety) without reducing the drug encapsulation rate. We first confirmed that both photo-treatment and pH-triggered hydrolysis are able to cleave the GDO lipid and lyse GDO liposomes. We then investigated the efficiency of drug release via the combined release processes for GDO liposomes loaded with doxorubicin (DOX). Relative to neutral pH, the release efficiency in acidic environment increased by 10.4% (at pH = 6.5) and 13.3% (at pH = 4.2). This pH-dependent release response is conducive to distinguishing pathological tissue such as tumors and endolysosomal compartments. The photo-induced release efficiency increases with illumination time as well as with distance of the pH from neutral. Photolysis increased the release efficiency by 13.8% at pH = 4.2, which is remarkable considering the already increased amount of drug release in the acidic environment. In addition, the relaxation time of GDO liposomes was 4.1 times that of clinical Gd-DTPA, with brighter T1-weighted imaging in vitro and in vivo. Real-time MRI imaging and in vivo fluorescence experiments demonstrated tumor targeting and MRI guided release. Furthermore, significant tumor growth inhibition in a treatment experiment using DOX-loaded GDO liposomes clearly demonstrated the benefit of photo-treatment for efficacy: the tumor size in the photo-treatment group was 3.7 times smaller than in the control group. The present study thus highlights the benefit of the design idea of combining efficient imaging/guiding, targeting, and triggerable release functions in one lipid molecule for drug delivery applications.
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15
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Jiang ZJ, Delaney TL, Zanin MP, Haberberger RV, Pitson SM, Huang J, Alford S, Cologna SM, Keating DJ, Gong LW. Extracellular and intracellular sphingosine-1-phosphate distinctly regulates exocytosis in chromaffin cells. J Neurochem 2019; 149:729-746. [PMID: 30963576 DOI: 10.1111/jnc.14703] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 12/28/2018] [Accepted: 03/27/2019] [Indexed: 01/18/2023]
Abstract
Sphingosine-1-phosphate (S1P) is an essential bioactive sphingosine lipid involved in many neurological disorders. Sphingosine kinase 1 (SphK1), a key enzyme for S1P production, is concentrated in presynaptic terminals. However, the role of S1P/SphK1 signaling in exocytosis remains elusive. By detecting catecholamine release from single vesicles in chromaffin cells, we show that a dominant negative SphK1 (SphK1DN ) reduces the number of amperometric spikes and increases the duration of foot, which reflects release through a fusion pore, implying critical roles for S1P in regulating the rate of exocytosis and fusion pore expansion. Similar phenotypes were observed in chromaffin cells obtained from SphK1 knockout mice compared to those from wild-type mice. In addition, extracellular S1P treatment increased the number of amperometric spikes, and this increase, in turn, was inhibited by a selective S1P3 receptor blocker, suggesting extracellular S1P may regulate the rate of exocytosis via activation of S1P3. Furthermore, intracellular S1P application induced a decrease in foot duration of amperometric spikes in control cells, indicating intracellular S1P may regulate fusion pore expansion during exocytosis. Taken together, our study represents the first demonstration that S1P regulates exocytosis through distinct mechanisms: extracellular S1P may modulate the rate of exocytosis via activation of S1P receptors while intracellular S1P may directly control fusion pore expansion during exocytosis. OPEN SCIENCE BADGES: This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/.
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Affiliation(s)
- Zhong-Jiao Jiang
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Taylor L Delaney
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Mark P Zanin
- State Key Laboratory of Respiratory Disease, Guangzhou Medical University, Guangzhou, Guangdong, P.R. China
| | - Rainer V Haberberger
- College of Medicine and Public Health and Centre for Neuroscience, Flinders University, Adelaide, Australia
| | - Stuart M Pitson
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, South Australia, Australia
| | - Jian Huang
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Simon Alford
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Stephanie M Cologna
- Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Damien J Keating
- College of Medicine and Public Health and Centre for Neuroscience, Flinders University, Adelaide, Australia
| | - Liang-Wei Gong
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
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16
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Griesche N, Sanchez G, Hermans C, Idevall-Hagren O. Cortical mitochondria regulate insulin secretion by local Ca 2+ buffering in rodent beta cells. J Cell Sci 2019; 132:jcs.228544. [PMID: 30926624 DOI: 10.1242/jcs.228544] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 03/11/2019] [Indexed: 12/27/2022] Open
Abstract
Mitochondria play an essential role in regulating insulin secretion from beta cells by providing the ATP needed for the membrane depolarization that results in voltage-dependent Ca2+ influx and subsequent insulin granule exocytosis. Ca2+, in turn, is also rapidly taken up by the mitochondria and exerts important feedback regulation of metabolism. The aim of this study was to determine whether the distribution of mitochondria within beta cells is important for the secretory capacity of these cells. We find that cortically localized mitochondria are abundant in rodent beta cells, and that these mitochondria redistribute towards the cell interior following depolarization. The redistribution requires Ca2+-induced remodeling of the cortical F-actin network. Using light-regulated motor proteins, we increased the cortical density of mitochondria twofold and found that this blunted the voltage-dependent increase in cytosolic Ca2+ concentration and suppressed insulin secretion. The activity-dependent changes in mitochondria distribution are likely to be important for the generation of Ca2+ microdomains required for efficient insulin granule release.
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Affiliation(s)
- Nadine Griesche
- Department of Medical Cell Biology, Uppsala University, BMC Box 571, 75123 Uppsala, Sweden
| | - Gonzalo Sanchez
- Department of Medical Cell Biology, Uppsala University, BMC Box 571, 75123 Uppsala, Sweden
| | - Cedric Hermans
- Department of Medical Cell Biology, Uppsala University, BMC Box 571, 75123 Uppsala, Sweden
| | - Olof Idevall-Hagren
- Department of Medical Cell Biology, Uppsala University, BMC Box 571, 75123 Uppsala, Sweden
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17
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Gates EM, LaCroix AS, Rothenberg KE, Hoffman BD. Improving Quality, Reproducibility, and Usability of FRET-Based Tension Sensors. Cytometry A 2018; 95:201-213. [PMID: 30523675 DOI: 10.1002/cyto.a.23688] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 10/30/2018] [Accepted: 11/05/2018] [Indexed: 02/07/2023]
Abstract
Mechanobiology, the study of how mechanical forces affect cellular behavior, is an emerging field of study that has garnered broad and significant interest. Researchers are currently seeking to better understand how mechanical signals are transmitted, detected, and integrated at a subcellular level. One tool for addressing these questions is a Förster resonance energy transfer (FRET)-based tension sensor, which enables the measurement of molecular-scale forces across proteins based on changes in emitted light. However, the reliability and reproducibility of measurements made with these sensors has not been thoroughly examined. To address these concerns, we developed numerical methods that improve the accuracy of measurements made using sensitized emission-based imaging. To establish that FRET-based tension sensors are versatile tools that provide consistent measurements, we used these methods, and demonstrated that a vinculin tension sensor is unperturbed by cell fixation, permeabilization, and immunolabeling. This suggests FRET-based tension sensors could be coupled with a variety of immuno-fluorescent labeling techniques. Additionally, as tension sensors are frequently employed in complex biological samples where large experimental repeats may be challenging, we examined how sample size affects the uncertainty of FRET measurements. In total, this work establishes guidelines to improve FRET-based tension sensor measurements, validate novel implementations of these sensors, and ensure that results are precise and reproducible. © 2018 International Society for Advancement of Cytometry.
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Affiliation(s)
- Evan M Gates
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, 27708
| | - Andrew S LaCroix
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, 27708
| | - Katheryn E Rothenberg
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, 27708
| | - Brenton D Hoffman
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, 27708
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18
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Gimenez-Molina Y, Villanueva J, Francés MDM, Viniegra S, Gutiérrez LM. Multiple Mechanisms Driving F-actin-Dependent Transport of Organelles to and From Secretory Sites in Bovine Chromaffin Cells. Front Cell Neurosci 2018; 12:344. [PMID: 30356839 PMCID: PMC6190647 DOI: 10.3389/fncel.2018.00344] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 09/18/2018] [Indexed: 01/12/2023] Open
Abstract
Neuroendocrine chromaffin cells represent an excellent model to study the molecular mechanisms associated with the exo-endocytotic cycle of neurotransmitter release. In this study, EGFP-Lifeact and confocal microscopy has been used to analyze the re-organization of the cortical F-actin cytoskeleton associated to organelle transport during secretion with unprecedented detail. In these cells secretory events accumulate in temperature-sensitive and myosin II-dependent F-actin expansions and retractions affecting specific regions of the sub-membrane space. Interestingly, not only vesicles but also mitochondria are transported toward the plasmalemma during these expansions. Simultaneously, we found F-actin cytoskeletal retraction withdraws vesicles from the sub-plasmalemmal space, forming novel empty internal spaces into which organelles can be transported. In addition to these well-coordinated, F-actin-myosin II dependent processes that drive the transport of the majority of vesicles, fast transport of chromaffin vesicles was observed, albeit less frequently, which used F-actin comet tails nucleated from the granular membrane. Thus, upon cell stimulation F-actin structures use diverse mechanisms to transport organelles to and from the membrane during the exo-endocytotic cycle taking place in specific areas of cell periphery.
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Affiliation(s)
- Yolanda Gimenez-Molina
- Instituto de Neurociencias, Centro Mixto CSIC-Universidad Miguel Hernández, San Juan de Alicante, Spain
| | - José Villanueva
- Instituto de Neurociencias, Centro Mixto CSIC-Universidad Miguel Hernández, San Juan de Alicante, Spain
| | - Maria Del Mar Francés
- Instituto de Neurociencias, Centro Mixto CSIC-Universidad Miguel Hernández, San Juan de Alicante, Spain
| | - Salvador Viniegra
- Instituto de Neurociencias, Centro Mixto CSIC-Universidad Miguel Hernández, San Juan de Alicante, Spain
| | - Luis M Gutiérrez
- Instituto de Neurociencias, Centro Mixto CSIC-Universidad Miguel Hernández, San Juan de Alicante, Spain
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19
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de Diego AMG, García AG. Altered exocytosis in chromaffin cells from mouse models of neurodegenerative diseases. Acta Physiol (Oxf) 2018; 224:e13090. [PMID: 29742321 DOI: 10.1111/apha.13090] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 04/19/2018] [Accepted: 04/25/2018] [Indexed: 12/26/2022]
Abstract
Chromaffin cells from the adrenal gland (CCs) have extensively been used to explore the molecular structure and function of the exocytotic machinery, neurotransmitter release and synaptic transmission. The CC is integrated in the sympathoadrenal axis that helps the body maintain homoeostasis during both routine life and in acute stress conditions. This function is exquisitely controlled by the cerebral cortex and the hypothalamus. We propose the hypothesis that damage undergone by the brain during neurodegenerative diseases is also affecting the neurosecretory function of adrenal medullary CCs. In this context, we review here the following themes: (i) How the discharge of catecholamines is centrally and peripherally regulated at the sympathoadrenal axis; (ii) which are the intricacies of the amperometric techniques used to study the quantal release of single-vesicle exocytotic events; (iii) which are the alterations of the exocytotic fusion pore so far reported, in CCs of mouse models of neurodegenerative diseases; (iv) how some proteins linked to neurodegenerative pathologies affect the kinetics of exocytotic events; (v) finally, we try to integrate available data into a hypothesis to explain how the centrally originated neurodegenerative diseases may alter the kinetics of single-vesicle exocytotic events in peripheral adrenal medullary CCs.
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Affiliation(s)
- A. M. García de Diego
- Instituto Teófilo Hernando; Universidad Autónoma de Madrid; Madrid Spain
- Instituto de Investigación Sanitaria; Hospital Universitario de la Princesa; Universidad Autónoma de Madrid; Madrid Spain
- DNS Neuroscience; Parque Científico de Madrid; Madrid Spain
| | - A. García García
- Instituto Teófilo Hernando; Universidad Autónoma de Madrid; Madrid Spain
- Instituto de Investigación Sanitaria; Hospital Universitario de la Princesa; Universidad Autónoma de Madrid; Madrid Spain
- DNS Neuroscience; Parque Científico de Madrid; Madrid Spain
- Departamento de Farmacología y Terapéutica; Facultad de Medicina; Universidad Autónoma de Madrid; Madrid Spain
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20
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Actin Remodeling in Regulated Exocytosis: Toward a Mesoscopic View. Trends Cell Biol 2018; 28:685-697. [DOI: 10.1016/j.tcb.2018.04.004] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 04/05/2018] [Accepted: 04/13/2018] [Indexed: 01/10/2023]
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21
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Wang G, Galli T. Reciprocal link between cell biomechanics and exocytosis. Traffic 2018; 19:741-749. [PMID: 29943478 DOI: 10.1111/tra.12584] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 06/03/2018] [Accepted: 06/03/2018] [Indexed: 12/16/2022]
Abstract
A cell is able to sense the biomechanical properties of the environment such as the rigidity of the extracellular matrix and adapt its tension via regulation of plasma membrane and underlying actomyosin meshwork properties. The cell's ability to adapt to the changing biomechanical environment is important for cellular homeostasis and also cell dynamics such as cell growth and motility. Membrane trafficking has emerged as an important mechanism to regulate cell biomechanics. In this review, we summarize the current understanding of the role of cell mechanics in exocytosis, and reciprocally, the role of exocytosis in regulating cell mechanics. We also discuss how cell mechanics and membrane trafficking, particularly exocytosis, can work together to regulate cell polarity and motility.
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Affiliation(s)
- Guan Wang
- Membrane Traffic in Healthy & Diseased Brain, Center of Psychiatry and Neurosciences, INSERM U894, Sorbonne Paris-Cité, Université Paris Descartes, Paris, France
| | - Thierry Galli
- Membrane Traffic in Healthy & Diseased Brain, Center of Psychiatry and Neurosciences, INSERM U894, Sorbonne Paris-Cité, Université Paris Descartes, Paris, France
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22
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Knabbe J, Nassal JP, Verhage M, Kuner T. Secretory vesicle trafficking in awake and anaesthetized mice: differential speeds in axons versus synapses. J Physiol 2018; 596:3759-3773. [PMID: 29873393 DOI: 10.1113/jp276022] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Accepted: 05/24/2018] [Indexed: 12/11/2022] Open
Abstract
KEY POINTS Despite their immense physiological and pathophysiological importance, we know very little about the biology of dense core vesicle (DCV) trafficking in the intact mammalian brain. DCVs are transported at similar average speeds in the anaesthetized and awake mouse brain compared to neurons in culture, yet maximal speed and pausing fraction of transport were higher. Microtubule plus (+)-end extension imaging visualized microtubular growth at 0.12 μm/s and revealed that DCVs were transported faster in the anterograde direction. DCV transport slowed down upon presynaptic bouton approach, possibly promoting synaptic localization and cargo release. Our work provides a basis to extrapolate DCV transport properties determined in cultured neurons to the intact mouse brain and reveals novel features such as slowing upon bouton approach and brain state-dependent trafficking directionality. ABSTRACT Neuronal dense core vesicles (DCVs) transport many cargo molecules like neuropeptides and neurotrophins to their release sites in dendrites or axons. The transport properties of DCVs in axons of the intact mammalian brain are unknown. We used viral expression of a DCV cargo reporter (NPY-Venus/Cherry) in the thalamus and two-photon in vivo imaging to visualize axonal DCV trafficking in thalamocortical projections of anaesthetized and awake mice. We found an average speed of 1 μm/s, maximal speeds of up to 5 μm/s and a pausing fraction of ∼11%. Directionality of transport differed between anaesthetized and awake mice. In vivo microtubule +-end extension imaging using MACF18-GFP revealed microtubular growth at 0.12 μm/s and provided positive identification of antero- and retrograde axonal transport. Consistent with previous reports, anterograde transport was faster (∼2.1 μm/s) than retrograde transport (∼1.4 μm/s). In summary, DCVs are transported with faster maximal speeds and lower pausing fraction in vivo compared to previous results obtained in vitro. Finally, we found that DCVs slowed down upon presynaptic bouton approach. We propose that this mechanism promotes synaptic localization and cargo release.
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Affiliation(s)
- Johannes Knabbe
- Department of Functional Neuroanatomy, Institute for Anatomy and Cell Biology, Heidelberg University, Im Neuenheimer Feld 307, 69120, Heidelberg, Germany
| | - Joris Paul Nassal
- Department of Functional Neuroanatomy, Institute for Anatomy and Cell Biology, Heidelberg University, Im Neuenheimer Feld 307, 69120, Heidelberg, Germany.,Departments of Functional Genomics and Clinical Genetics, Center for Neurogenomics and Cognitive Research (CNCR), VU University Amsterdam and VU University Medical Center, De Boelelaan, 1087, 1081 HV Amsterdam, The Netherlands
| | - Matthijs Verhage
- Departments of Functional Genomics and Clinical Genetics, Center for Neurogenomics and Cognitive Research (CNCR), VU University Amsterdam and VU University Medical Center, De Boelelaan, 1087, 1081 HV Amsterdam, The Netherlands
| | - Thomas Kuner
- Department of Functional Neuroanatomy, Institute for Anatomy and Cell Biology, Heidelberg University, Im Neuenheimer Feld 307, 69120, Heidelberg, Germany
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23
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Wang G, Nola S, Bovio S, Bun P, Coppey-Moisan M, Lafont F, Galli T. Biomechanical Control of Lysosomal Secretion Via the VAMP7 Hub: A Tug-of-War between VARP and LRRK1. iScience 2018; 4:127-143. [PMID: 30240735 PMCID: PMC6147023 DOI: 10.1016/j.isci.2018.05.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 02/05/2018] [Accepted: 05/23/2018] [Indexed: 12/21/2022] Open
Abstract
The rigidity of the cell environment can vary tremendously between tissues and in pathological conditions. How this property may affect intracellular membrane dynamics is still largely unknown. Here, using atomic force microscopy, we show that cells deficient in the secretory lysosome v-SNARE VAMP7 are impaired in adaptation to substrate rigidity. Conversely, VAMP7-mediated secretion is stimulated by more rigid substrate and this regulation depends on the Longin domain of VAMP7. We further find that the Longin domain binds the kinase and retrograde trafficking adaptor LRRK1 and that LRRK1 negatively regulates VAMP7-mediated exocytosis. Conversely, VARP, a VAMP7- and kinesin 1-interacting protein, further controls the availability for secretion of peripheral VAMP7 vesicles and response of cells to mechanical constraints. LRRK1 and VARP interact with VAMP7 in a competitive manner. We propose a mechanism whereby biomechanical constraints regulate VAMP7-dependent lysosomal secretion via LRRK1 and VARP tug-of-war control of the peripheral pool of secretory lysosomes.
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Affiliation(s)
- Guan Wang
- Membrane Traffic in Health & Disease, Institut Jacques Monod, CNRS UMR7592, INSERM U950, Sorbonne Paris-Cité, Université Paris Diderot, Paris 75205, France; Membrane Traffic in Healthy & Diseased Brain, Center of Psychiatry and Neurosciences, INSERM U894, Sorbonne Paris-Cité, Université Paris Descartes, 102-108 rue de la Santé, Paris 75014, France
| | - Sébastien Nola
- Membrane Traffic in Health & Disease, Institut Jacques Monod, CNRS UMR7592, INSERM U950, Sorbonne Paris-Cité, Université Paris Diderot, Paris 75205, France; Membrane Traffic in Healthy & Diseased Brain, Center of Psychiatry and Neurosciences, INSERM U894, Sorbonne Paris-Cité, Université Paris Descartes, 102-108 rue de la Santé, Paris 75014, France
| | - Simone Bovio
- Cellular Microbiology and Physics of Infection Group, Center for Infection and Immunity of Lille, CNRS UMR 8204, INSERM U1019, Institut Pasteur de Lille, Centre Hospitalier Régional de Lille, Université de Lille, Lille, France
| | - Philippe Bun
- NeurImag Tech Core Facility, Center of Psychiatry and Neurosciences, INSERM U894, Sorbonne Paris-Cité, Université Paris Descartes, Paris 75014, France
| | - Maïté Coppey-Moisan
- Mechanotransduction: from Cell Surface to Nucleus, Institut Jacques Monod, CNRS UMR7592, Sorbonne Paris-Cité, Université Paris-Diderot, Paris, France
| | - Frank Lafont
- Cellular Microbiology and Physics of Infection Group, Center for Infection and Immunity of Lille, CNRS UMR 8204, INSERM U1019, Institut Pasteur de Lille, Centre Hospitalier Régional de Lille, Université de Lille, Lille, France
| | - Thierry Galli
- Membrane Traffic in Health & Disease, Institut Jacques Monod, CNRS UMR7592, INSERM U950, Sorbonne Paris-Cité, Université Paris Diderot, Paris 75205, France; Membrane Traffic in Healthy & Diseased Brain, Center of Psychiatry and Neurosciences, INSERM U894, Sorbonne Paris-Cité, Université Paris Descartes, 102-108 rue de la Santé, Paris 75014, France.
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24
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Yoshida A, Sakai N, Uekusa Y, Imaoka Y, Itagaki Y, Suzuki Y, Yoshimura SH. Morphological changes of plasma membrane and protein assembly during clathrin-mediated endocytosis. PLoS Biol 2018; 16:e2004786. [PMID: 29723197 PMCID: PMC5953504 DOI: 10.1371/journal.pbio.2004786] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Revised: 05/15/2018] [Accepted: 03/29/2018] [Indexed: 12/21/2022] Open
Abstract
Clathrin-mediated endocytosis (CME) proceeds through a series of morphological changes of the plasma membrane induced by a number of protein components. Although the spatiotemporal assembly of these proteins has been elucidated by fluorescence-based techniques, the protein-induced morphological changes of the plasma membrane have not been fully clarified in living cells. Here, we visualize membrane morphology together with protein localizations during CME by utilizing high-speed atomic force microscopy (HS-AFM) combined with a confocal laser scanning unit. The plasma membrane starts to invaginate approximately 30 s after clathrin starts to assemble, and the aperture diameter increases as clathrin accumulates. Actin rapidly accumulates around the pit and induces a small membrane swelling, which, within 30 s, rapidly covers the pit irreversibly. Inhibition of actin turnover abolishes the swelling and induces a reversible open–close motion of the pit, indicating that actin dynamics are necessary for efficient and irreversible pit closure at the end of CME. Cells communicate with their environments via the plasma membrane and various membrane proteins. Clathrin-mediated endocytosis (CME) plays a central role in such communication and proceeds with a series of multiprotein assembly, deformation of the plasma membrane, and production of a membrane vesicle that delivers extracellular signaling molecules into the cytoplasm. In this study, we utilized our home-built correlative imaging system comprising high-speed atomic force microscopy (HS-AFM) and confocal fluorescence microscopy to simultaneously image morphological changes of the plasma membrane and protein localization during CME in a living cell. The results revealed a tight correlation between the size of the pit and the amount of clathrin assembled. Actin dynamics play multiple roles in the assembly, maturation, and closing phases of the process, and affects membrane morphology, suggesting a close relationship between endocytosis and dynamic events at the cell cortex. Knock down of dynamin also affected the closing motion of the pit and showed functional correlation with actin.
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Affiliation(s)
- Aiko Yoshida
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | | | | | - Yuka Imaoka
- R&D Group, Olympus Corporation, Hachioji, Japan
| | | | - Yuki Suzuki
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai, Japan
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25
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Chhabra Y, Wong HY, Nikolajsen LF, Steinocher H, Papadopulos A, Tunny KA, Meunier FA, Smith AG, Kragelund BB, Brooks AJ, Waters MJ. A growth hormone receptor SNP promotes lung cancer by impairment of SOCS2-mediated degradation. Oncogene 2018; 37:489-501. [PMID: 28967904 PMCID: PMC5799715 DOI: 10.1038/onc.2017.352] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 08/13/2017] [Accepted: 08/16/2017] [Indexed: 02/07/2023]
Abstract
Both humans and mice lacking functional growth hormone (GH) receptors are known to be resistant to cancer. Further, autocrine GH has been reported to act as a cancer promoter. Here we present the first example of a variant of the GH receptor (GHR) associated with cancer promotion, in this case lung cancer. We show that the GHRP495T variant located in the receptor intracellular domain is able to prolong the GH signal in vitro using stably expressing mouse pro-B-cell and human lung cell lines. This is relevant because GH secretion is pulsatile, and extending the signal duration makes it resemble autocrine GH action. Signal duration for the activated GHR is primarily controlled by suppressor of cytokine signalling 2 (SOCS2), the substrate recognition component of the E3 protein ligase responsible for ubiquitinylation and degradation of the GHR. SOCS2 is induced by a GH pulse and we show that SOCS2 binding to the GHR is impaired by a threonine substitution at Pro 495. This results in decreased internalisation and degradation of the receptor evident in TIRF microscopy and by measurement of mature (surface) receptor expression. Mutational analysis showed that the residue at position 495 impairs SOCS2 binding only when a threonine is present, consistent with interference with the adjacent Thr494. The latter is key for SOCS2 binding, together with nearby Tyr487, which must be phosphorylated for SOCS2 binding. We also undertook nuclear magnetic resonance spectroscopy approach for structural comparison of the SOCS2 binding scaffold Ile455-Ser588, and concluded that this single substitution has altered the structure of the SOCS2 binding site. Importantly, we find that lung BEAS-2B cells expressing GHRP495T display increased expression of transcripts associated with tumour proliferation, epithelial-mesenchymal transition and metastases (TWIST1, SNAI2, EGFR, MYC and CCND1) at 2 h after a GH pulse. This is consistent with prolonged GH signalling acting to promote cancer progression in lung cancer.
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Affiliation(s)
- Y Chhabra
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
- The University of Queensland Diamantina Institute, The University of Queensland, Translational Research Institute, Woolloongabba, Queensland, Australia
| | - H Y Wong
- University of Queensland Centre for Clinical Research, The University of Queensland, Herston, Queensland, Australia
| | - L F Nikolajsen
- Structural Biology and NMR Laboratory (SBiNLab), Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - H Steinocher
- Structural Biology and NMR Laboratory (SBiNLab), Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - A Papadopulos
- The Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia
| | - K A Tunny
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
- The University of Queensland Diamantina Institute, The University of Queensland, Translational Research Institute, Woolloongabba, Queensland, Australia
| | - F A Meunier
- The Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia
| | - A G Smith
- School of Biomedical Sciences, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Woolloongabba, Queensland, Australia
| | - B B Kragelund
- Structural Biology and NMR Laboratory (SBiNLab), Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - A J Brooks
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
- The University of Queensland Diamantina Institute, The University of Queensland, Translational Research Institute, Woolloongabba, Queensland, Australia
| | - M J Waters
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
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26
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Bademosi AT, Lauwers E, Amor R, Verstreken P, van Swinderen B, Meunier FA. In Vivo Single-Molecule Tracking at the Drosophila Presynaptic Motor Nerve Terminal. J Vis Exp 2018. [PMID: 29364242 PMCID: PMC5908646 DOI: 10.3791/56952] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
An increasing number of super-resolution microscopy techniques are helping to uncover the mechanisms that govern the nanoscale cellular world. Single-molecule imaging is gaining momentum as it provides exceptional access to the visualization of individual molecules in living cells. Here, we describe a technique that we developed to perform single-particle tracking photo-activated localization microscopy (sptPALM) in Drosophila larvae. Synaptic communication relies on key presynaptic proteins that act by docking, priming, and promoting the fusion of neurotransmitter-containing vesicles with the plasma membrane. A range of protein-protein and protein-lipid interactions tightly regulates these processes and the presynaptic proteins therefore exhibit changes in mobility associated with each of these key events. Investigating how mobility of these proteins correlates with their physiological function in an intact live animal is essential to understanding their precise mechanism of action. Extracting protein mobility with high resolution in vivo requires overcoming limitations such as optical transparency, accessibility, and penetration depth. We describe how photoconvertible fluorescent proteins tagged to the presynaptic protein Syntaxin-1A can be visualized via slight oblique illumination and tracked at the motor nerve terminal or along the motor neuron axon of the third instar Drosophila larva.
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Affiliation(s)
- Adekunle T Bademosi
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland
| | - Elsa Lauwers
- VIB Centre for Brain and Disease Research, KU Leuven Department of Neurosciences, Leuven Institute for Neurodegenerative Disease (LIND)
| | - Rumelo Amor
- Queensland Brain Institute, The University of Queensland
| | - Patrik Verstreken
- VIB Centre for Brain and Disease Research, KU Leuven Department of Neurosciences, Leuven Institute for Neurodegenerative Disease (LIND)
| | | | - Frédéric A Meunier
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland;
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27
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Peiris H, Keating DJ. The neuronal and endocrine roles of RCAN1 in health and disease. Clin Exp Pharmacol Physiol 2017; 45:377-383. [PMID: 29094385 DOI: 10.1111/1440-1681.12884] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 10/18/2017] [Accepted: 10/24/2017] [Indexed: 01/15/2023]
Abstract
The regulator of calcineurin 1 (RCAN1) was first discovered as a gene located on human chromosome 21, expressed in neurons and overexpressed in the brains of Down syndrome individuals. Increased expression of RCAN1 has been linked with not only Down syndrome-associated pathology but also an associated neurological disorder, Alzheimer's Disease, in which neuronal RCAN1 expression is also increased. RCAN1 has additionally been demonstrated to affect other cell types including endocrine cells, with links to the pathogenesis of β-cell dysfunction in type 2 diabetes. The primary functions of RCAN1 relate to the inhibition of the phosphatase calcineurin, and to the regulation of mitochondrial function. Various forms of cellular stress such as reactive oxygen species and hyperglycaemia cause transient increases in RCAN1 expression. The short term (hours to days) induction of RCAN1 expression is generally thought to have a protective effect by regulating the expression of pro-survival genes in multiple cell types, many of which are mediated via the calcineurin/NFAT transcriptional pathway. However, strong evidence also supports the notion that chronic (weeks-years) overexpression of RCAN1 has a detrimental effect on cells and that this may drive pathophysiological changes in neurons and endocrine cells linked to Down syndrome, Alzheimer's Disease and type 2 diabetes. Here we review the evidence related to these roles of RCAN1 in neurons and endocrine cells and their relationship to these human health disorders.
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Affiliation(s)
- Heshan Peiris
- College of Medicine and Public Health and Centre for Neuroscience, Flinders University, Adelaide, SA, Australia
| | - Damien J Keating
- College of Medicine and Public Health and Centre for Neuroscience, Flinders University, Adelaide, SA, Australia
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28
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How does the stimulus define exocytosis in adrenal chromaffin cells? Pflugers Arch 2017; 470:155-167. [DOI: 10.1007/s00424-017-2052-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 07/28/2017] [Accepted: 08/01/2017] [Indexed: 12/28/2022]
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29
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Tomatis VM, Josh P, Papadopulos A, Gormal RS, Lanoue V, Martin S, Meunier FA. ENA/VASP proteins regulate exocytosis by mediating myosin VI-dependent recruitment of secretory granules to the cortical actin network. Mol Cell Neurosci 2017; 84:100-111. [PMID: 28784263 DOI: 10.1016/j.mcn.2017.07.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 07/17/2017] [Accepted: 07/27/2017] [Indexed: 10/24/2022] Open
Abstract
In neurosecretory cells, myosin VI associated with secretory granules (SGs) mediates their activity-dependent recruitment to the cortical actin network and is necessary to sustain exocytosis. The mechanism by which myosin VI interacts with SGs is unknown. Using a myosin VI pull-down assay and mass spectrometry we identified Mena, a member of the ENA/VASP family, as a myosin VI binding partner in PC12 cells, and confirmed that Mena colocalized with myosin VI on SGs. Using a knock-sideways approach to inactivate the ENA/VASP family members by mitochondrial relocation, we revealed a concomitant redistribution of myosin VI. This was ensued by a reduction in the association of myosin VI with SGs, a decreased SG mobility and density in proximity to the plasma membrane as well as decreased evoked exocytosis. These data demonstrate that ENA/VASP proteins regulate SG exocytosis through modulating the activity of myosin VI.
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Affiliation(s)
- Vanesa M Tomatis
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Peter Josh
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Andreas Papadopulos
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Rachel S Gormal
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Vanessa Lanoue
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Sally Martin
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Frédéric A Meunier
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia.
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30
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Gutiérrez LM, Villanueva J. The role of F-actin in the transport and secretion of chromaffin granules: an historic perspective. Pflugers Arch 2017; 470:181-186. [PMID: 28730385 PMCID: PMC5748413 DOI: 10.1007/s00424-017-2040-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 07/13/2017] [Accepted: 07/14/2017] [Indexed: 12/23/2022]
Abstract
Actin is one of the most ubiquitous protein playing fundamental roles in a variety of cellular processes. Since early in the 1980s, it was evident that filamentous actin (F-actin) formed a peripheral cortical barrier that prevented vesicles to access secretory sites in chromaffin cells in culture. Later, around 2000, it was described that the F-actin structure accomplishes a dual role serving both vesicle transport and retentive purposes and undergoing dynamic transient changes during cell stimulation. The complex role of the F-actin cytoskeleton in neuroendocrine secretion was further evidenced when it has been proved to participate in the scaffold structure holding together the secretory machinery at active sites and participate in the generation of mechanical forces that drive the opening of the fusion pore, during the first decade of the present century. The complex vision of the multiple roles of F-actin in secretion we have acquired to date comes largely from studies performed on traditional 2D cultures of primary cells; however, recent evidences suggest that these may not accurately mimic the 3D in vivo environment, and thus, more work is now needed on adrenomedullary cells kept in a more “native” configuration to fully understand the role of F-actin in regulating chromaffin granule transport and secretion under physiological conditions.
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Affiliation(s)
- Luis M Gutiérrez
- Instituto de Neurociencias de Alicante, Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández, Sant Joan d'Alacant, 03550, Alicante, Spain.
| | - José Villanueva
- Instituto de Neurociencias de Alicante, Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández, Sant Joan d'Alacant, 03550, Alicante, Spain
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31
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Fan F, Matsunaga K, Wang H, Ishizaki R, Kobayashi E, Kiyonari H, Mukumoto Y, Okunishi K, Izumi T. Exophilin-8 assembles secretory granules for exocytosis in the actin cortex via interaction with RIM-BP2 and myosin-VIIa. eLife 2017; 6. [PMID: 28673385 PMCID: PMC5496739 DOI: 10.7554/elife.26174] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 06/04/2017] [Indexed: 12/15/2022] Open
Abstract
Exophilin-8 has been reported to play a role in anchoring secretory granules within the actin cortex, due to its direct binding activities to Rab27 on the granule membrane and to F-actin and its motor protein, myosin-Va. Here, we show that exophilin-8 accumulates granules in the cortical F-actin network not by direct interaction with myosin-Va, but by indirect interaction with a specific form of myosin-VIIa through its previously unknown binding partner, RIM-BP2. RIM-BP2 also associates with exocytic machinery, Cav1.3, RIM, and Munc13-1. Disruption of the exophilin-8-RIM-BP2-myosin-VIIa complex by ablation or knockdown of each component markedly decreases both the peripheral accumulation and exocytosis of granules. Furthermore, exophilin-8-null mouse pancreatic islets lose polarized granule localization at the β-cell periphery and exhibit impaired insulin secretion. This newly identified complex acts as a physical and functional scaffold and provides a mechanism supporting a releasable pool of granules within the F-actin network beneath the plasma membrane.
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Affiliation(s)
- Fushun Fan
- Laboratory of Molecular Endocrinology and Metabolism, Department of Molecular Medicine, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan
| | - Kohichi Matsunaga
- Laboratory of Molecular Endocrinology and Metabolism, Department of Molecular Medicine, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan
| | - Hao Wang
- Laboratory of Molecular Endocrinology and Metabolism, Department of Molecular Medicine, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan
| | - Ray Ishizaki
- Laboratory of Molecular Endocrinology and Metabolism, Department of Molecular Medicine, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan
| | - Eri Kobayashi
- Laboratory of Molecular Endocrinology and Metabolism, Department of Molecular Medicine, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan
| | - Hiroshi Kiyonari
- Animal Resource Development Unit, RIKEN Center for Life Science Technologies, Kobe, Japan.,Genetic Engineering Team, RIKEN Center for Life Science Technologies, Kobe, Japan
| | - Yoshiko Mukumoto
- Genetic Engineering Team, RIKEN Center for Life Science Technologies, Kobe, Japan
| | - Katsuhide Okunishi
- Laboratory of Molecular Endocrinology and Metabolism, Department of Molecular Medicine, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan
| | - Tetsuro Izumi
- Laboratory of Molecular Endocrinology and Metabolism, Department of Molecular Medicine, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan.,Research Program for Signal Transduction, Division of Endocrinology, Metabolism and Signal Research, Gunma University Initiative for Advanced Research, Maebashi, Japan
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32
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Papadopulos A. Membrane shaping by actin and myosin during regulated exocytosis. Mol Cell Neurosci 2017; 84:93-99. [PMID: 28536001 DOI: 10.1016/j.mcn.2017.05.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 04/21/2017] [Accepted: 05/19/2017] [Indexed: 12/01/2022] Open
Abstract
The cortical actin network in neurosecretory cells is a dense mesh of actin filaments underlying the plasma membrane. Interaction of actomyosin with vesicular membranes or the plasma membrane is vital for tethering, retention, transport as well as fusion and fission of exo- and endocytic membrane structures. During regulated exocytosis the cortical actin network undergoes dramatic changes in morphology to accommodate vesicle docking, fusion and replenishment. Most of these processes involve plasma membrane Phosphoinositides (PIP) and investigating the interactions between the actin cortex and secretory structures has become a hotbed for research in recent years. Actin remodelling leads to filopodia outgrowth and the creation of new fusion sites in neurosecretory cells and actin, myosin and dynamin actively shape and maintain the fusion pore of secretory vesicles. Changes in viscoelastic properties of the actin cortex can facilitate vesicular transport and lead to docking and priming of vesicle at the plasma membrane. Small GTPase actin mediators control the state of the cortical actin network and influence vesicular access to their docking and fusion sites. These changes potentially affect membrane properties such as tension and fluidity as well as the mobility of embedded proteins and could influence the processes leading to both exo- and endocytosis. Here we discuss the multitudes of actin and membrane interactions that control successive steps underpinning regulated exocytosis.
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Affiliation(s)
- Andreas Papadopulos
- The Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia.
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33
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González-Jamett AM, Guerra MJ, Olivares MJ, Haro-Acuña V, Baéz-Matus X, Vásquez-Navarrete J, Momboisse F, Martinez-Quiles N, Cárdenas AM. The F-Actin Binding Protein Cortactin Regulates the Dynamics of the Exocytotic Fusion Pore through its SH3 Domain. Front Cell Neurosci 2017; 11:130. [PMID: 28522963 PMCID: PMC5415606 DOI: 10.3389/fncel.2017.00130] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 04/18/2017] [Indexed: 11/20/2022] Open
Abstract
Upon cell stimulation, the network of cortical actin filaments is rearranged to facilitate the neurosecretory process. This actin rearrangement includes both disruption of the preexisting actin network and de novo actin polymerization. However, the mechanism by which a Ca2+ signal elicits the formation of new actin filaments remains uncertain. Cortactin, an actin-binding protein that promotes actin polymerization in synergy with the nucleation promoting factor N-WASP, could play a key role in this mechanism. We addressed this hypothesis by analyzing de novo actin polymerization and exocytosis in bovine adrenal chromaffin cells expressing different cortactin or N-WASP domains, or cortactin mutants that fail to interact with proline-rich domain (PRD)-containing proteins, including N-WASP, or to be phosphorylated by Ca2+-dependent kinases, such as ERK1/2 and Src. Our results show that the activation of nicotinic receptors in chromaffin cells promotes cortactin translocation to the cell cortex, where it colocalizes with actin filaments. We further found that, in association with PRD-containing proteins, cortactin contributes to the Ca2+-dependent formation of F-actin, and regulates fusion pore dynamics and the number of exocytotic events induced by activation of nicotinic receptors. However, whereas the actions of cortactin on the fusion pore dynamics seems to depend on the availability of monomeric actin and its phosphorylation by ERK1/2 and Src kinases, cortactin regulates the extent of exocytosis by a mechanism independent of actin polymerization. Together our findings point out a role for cortactin as a critical modulator of actin filament formation and exocytosis in neuroendocrine cells.
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Affiliation(s)
- Arlek M González-Jamett
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de ValparaísoValparaíso, Chile
| | - María J Guerra
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de ValparaísoValparaíso, Chile
| | - María J Olivares
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de ValparaísoValparaíso, Chile
| | - Valentina Haro-Acuña
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de ValparaísoValparaíso, Chile
| | - Ximena Baéz-Matus
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de ValparaísoValparaíso, Chile
| | - Jacqueline Vásquez-Navarrete
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de ValparaísoValparaíso, Chile
| | - Fanny Momboisse
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de ValparaísoValparaíso, Chile
| | - Narcisa Martinez-Quiles
- Departamento de Microbiología (Inmunología), Facultad de Medicina, Universidad Complutense de MadridMadrid, Spain
| | - Ana M Cárdenas
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de ValparaísoValparaíso, Chile
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34
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Zyxin regulates endothelial von Willebrand factor secretion by reorganizing actin filaments around exocytic granules. Nat Commun 2017; 8:14639. [PMID: 28256511 PMCID: PMC5338022 DOI: 10.1038/ncomms14639] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 01/17/2017] [Indexed: 12/13/2022] Open
Abstract
Endothelial exocytosis of Weibel-Palade body (WPB) is one of the first lines of defence against vascular injury. However, the mechanisms that control WPB exocytosis in the final stages (including the docking, priming and fusion of granules) are poorly understood. Here we show that the focal adhesion protein zyxin is crucial in this process. Zyxin downregulation inhibits the secretion of von Willebrand factor (VWF), the most abundant cargo in WPBs, from human primary endothelial cells (ECs) induced by cAMP agonists. Zyxin-deficient mice exhibit impaired epinephrine-stimulated VWF release, prolonged bleeding time and thrombosis, largely due to defective endothelial secretion of VWF. Using live-cell super-resolution microscopy, we visualize previously unappreciated reorganization of pre-existing actin filaments around WPBs before fusion, dependent on zyxin and an interaction with the actin crosslinker α-actinin. Our findings identify zyxin as a physiological regulator of endothelial exocytosis through reorganizing local actin network in the final stage of exocytosis.
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35
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Bademosi AT, Lauwers E, Padmanabhan P, Odierna L, Chai YJ, Papadopulos A, Goodhill GJ, Verstreken P, van Swinderen B, Meunier FA. In vivo single-molecule imaging of syntaxin1A reveals polyphosphoinositide- and activity-dependent trapping in presynaptic nanoclusters. Nat Commun 2017; 8:13660. [PMID: 28045048 PMCID: PMC5171881 DOI: 10.1038/ncomms13660] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 10/21/2016] [Indexed: 01/03/2023] Open
Abstract
Syntaxin1A is organized in nanoclusters that are critical for the docking and priming of secretory vesicles from neurosecretory cells. Whether and how these nanoclusters are affected by neurotransmitter release in nerve terminals from a living organism is unknown. Here we imaged photoconvertible syntaxin1A-mEos2 in the motor nerve terminal of Drosophila larvae by single-particle tracking photoactivation localization microscopy. Opto- and thermo-genetic neuronal stimulation increased syntaxin1A-mEos2 mobility, and reduced the size and molecular density of nanoclusters, suggesting an activity-dependent release of syntaxin1A from the confinement of nanoclusters. Syntaxin1A mobility was increased by mutating its polyphosphoinositide-binding site or preventing SNARE complex assembly via co-expression of tetanus toxin light chain. In contrast, syntaxin1A mobility was reduced by preventing SNARE complex disassembly. Our data demonstrate that polyphosphoinositide favours syntaxin1A trapping, and show that SNARE complex disassembly leads to syntaxin1A dissociation from nanoclusters. Lateral diffusion and trapping of syntaxin1A in nanoclusters therefore dynamically regulate neurotransmitter release. Syntaxin1A (Sx1A) is organized in nanoclusters in neurosecretory cells but how these nanoclusters are affected by neurotransmitter release in a living organism is unknown. Here the authors perform single molecule imaging analysis in live fly larvae and show that the lateral diffusion and trapping of Sx1A in nanoclusters are altered by synaptic activity.
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Affiliation(s)
- Adekunle T Bademosi
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Elsa Lauwers
- VIB Center for the Biology of Disease, 3000 Leuven, Belgium.,KU Leuven Department of Human Genetics, Leuven Institute for Neurodegenerative Disease (LIND), 3000 Leuven, Belgium
| | - Pranesh Padmanabhan
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Lorenzo Odierna
- School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Ye Jin Chai
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Andreas Papadopulos
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Geoffrey J Goodhill
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia.,School of Mathematics and Physics, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Patrik Verstreken
- VIB Center for the Biology of Disease, 3000 Leuven, Belgium.,KU Leuven Department of Human Genetics, Leuven Institute for Neurodegenerative Disease (LIND), 3000 Leuven, Belgium
| | - Bruno van Swinderen
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Frédéric A Meunier
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
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Kasula R, Chai YJ, Bademosi AT, Harper CB, Gormal RS, Morrow IC, Hosy E, Collins BM, Choquet D, Papadopulos A, Meunier FA. The Munc18-1 domain 3a hinge-loop controls syntaxin-1A nanodomain assembly and engagement with the SNARE complex during secretory vesicle priming. J Cell Biol 2016; 214:847-58. [PMID: 27646276 PMCID: PMC5037406 DOI: 10.1083/jcb.201508118] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Accepted: 08/24/2016] [Indexed: 12/12/2022] Open
Abstract
Kasula et al. use single-molecule imaging to reveal the diffusional signature for the SNARE proteins Munc18-1 and syntaxin-1A during secretory vesicle priming. The authors show that a conformational change in the Munc18-1 domain 3a hinge-loop regulates engagement of syntaxin-1A in the SNARE complex. Munc18-1 and syntaxin-1A control SNARE-dependent neuroexocytosis and are organized in nanodomains on the plasma membrane of neurons and neurosecretory cells. Deciphering the intra- and intermolecular steps via which they prepare secretory vesicles (SVs) for fusion is key to understanding neuronal and hormonal communication. Here, we demonstrate that expression of a priming-deficient mutant lacking 17 residues of the domain 3a hinge-loop (Munc18-1Δ317-333) in PC12 cells engineered to knockdown Munc18-1/2 markedly prolonged SV docking. Single-molecule analysis revealed nonhomogeneous diffusion of Munc18-1 and syntaxin-1A in and out of partially overlapping nanodomains. Whereas Munc18-1WT mobility increased in response to stimulation, syntaxin-1A became less mobile. These Munc18-1 and syntaxin-1A diffusional switches were blocked by the expression of Munc18-1Δ317-333, suggesting that a conformational change in the Munc18-1 hinge-loop controls syntaxin-1A and subsequent SNARE complex assembly. Accordingly, syntaxin-1A confinement was prevented by expression of botulinum neurotoxin type E. The Munc18-1 domain 3a hinge-loop therefore controls syntaxin-1A engagement into SNARE complex formation during priming.
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Affiliation(s)
- Ravikiran Kasula
- Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Ye Jin Chai
- Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Adekunle T Bademosi
- Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Callista B Harper
- Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Rachel S Gormal
- Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Isabel C Morrow
- Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, Queensland 4072, Australia Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Eric Hosy
- Interdisciplinary Institute for Neuroscience, University of Bordeaux, 33077 Bordeaux, France Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5297, 33077 Bordeaux, France
| | - Brett M Collins
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Daniel Choquet
- Interdisciplinary Institute for Neuroscience, University of Bordeaux, 33077 Bordeaux, France Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5297, 33077 Bordeaux, France Bordeaux Imaging Center, Unité Mixte de Service 3420, Centre National de la Recherche Scientifique, US4 Institut National de la Santé et de la Recherche Médicale, University of Bordeaux, 33077 Bordeaux, France
| | - Andreas Papadopulos
- Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Frédéric A Meunier
- Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, Queensland 4072, Australia
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37
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Meunier FA, Gutiérrez LM. Captivating New Roles of F-Actin Cortex in Exocytosis and Bulk Endocytosis in Neurosecretory Cells. Trends Neurosci 2016; 39:605-613. [DOI: 10.1016/j.tins.2016.07.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 07/01/2016] [Accepted: 07/06/2016] [Indexed: 12/01/2022]
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38
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Gabel M, Chasserot-Golaz S. Annexin A2, an essential partner of the exocytotic process in chromaffin cells. J Neurochem 2016; 137:890-6. [DOI: 10.1111/jnc.13628] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 03/09/2016] [Accepted: 03/30/2016] [Indexed: 12/30/2022]
Affiliation(s)
- Marion Gabel
- INCI; UPR3212 CNRS; Université de Strasbourg; Strasbourg France
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39
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Villanueva J, Gimenez-Molina Y, Viniegra S, Gutiérrez LM. F-actin cytoskeleton and the fate of organelles in chromaffin cells. J Neurochem 2016; 137:860-6. [PMID: 26843469 DOI: 10.1111/jnc.13560] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 01/21/2016] [Accepted: 01/22/2016] [Indexed: 12/31/2022]
Abstract
In addition to playing a fundamental structural role, the F-actin cytoskeleton in neuroendocrine chromaffin cells has a prominent influence on governing the molecular mechanism and regulating the secretory process. Performing such roles, the F-actin network might be essential to first transport, and later locate the cellular organelles participating in the secretory cycle. Chromaffin granules are transported from the internal cytosolic regions to the cell periphery along microtubular and F-actin structures. Once in the cortical region, they are embedded in the F-actin network where these vesicles experience restrictions in motility. Similarly, mitochondria transport is affected by both microtubule and F-actin inhibitors and suffers increasing motion restrictions when they are located in the cortical region. Therefore, the F-actin cortex is a key factor in defining the existence of two populations of cortical and perinuclear granules and mitochondria which could be distinguished by their different location and mobility. Interestingly, other important organelles for controlling intracellular calcium levels, such as the endoplasmic reticulum network, present clear differences in distribution and much lower mobility than chromaffin vesicles and mitochondria. Nevertheless, both mitochondria and the endoplasmic reticulum appear to distribute in the proximity of secretory sites to fulfill a pivotal role, forming triads with calcium channels ensuring the fine tuning of the secretory response. This review presents the contributions that provide the basis for our current view regarding the influence that F-actin has on the distribution of organelles participating in the release of catecholamines in chromaffin cells, and summarizes this knowledge in simple models. In chromaffin cells, organelles such as granules and mitochondria distribute forming cortical and perinuclear populations whereas others like the ER present homogenous distributions. In the present review we discuss the role of transport systems and the existence of an F-actin cortical structure as the main factors behind the formation of organelle subpopulations in this neuroendocrine cell model. This article is part of a mini review series on Chromaffin cells (ISCCB Meeting, 2015). Cover image for this issue: doi: 10.1111/jnc.13322.
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Affiliation(s)
- José Villanueva
- Instituto de Neurociencias, Centro Mixto Universidad Miguel Hernández-CSIC, Sant Joan d'Alacant (Alicante), Spain
| | - Yolanda Gimenez-Molina
- Instituto de Neurociencias, Centro Mixto Universidad Miguel Hernández-CSIC, Sant Joan d'Alacant (Alicante), Spain
| | - Salvador Viniegra
- Instituto de Neurociencias, Centro Mixto Universidad Miguel Hernández-CSIC, Sant Joan d'Alacant (Alicante), Spain
| | - Luis M Gutiérrez
- Instituto de Neurociencias, Centro Mixto Universidad Miguel Hernández-CSIC, Sant Joan d'Alacant (Alicante), Spain
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40
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Brenner MD, Zhou R, Conway DE, Lanzano L, Gratton E, Schwartz MA, Ha T. Spider Silk Peptide Is a Compact, Linear Nanospring Ideal for Intracellular Tension Sensing. NANO LETTERS 2016; 16:2096-102. [PMID: 26824190 PMCID: PMC4851340 DOI: 10.1021/acs.nanolett.6b00305] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Recent development and applications of calibrated, fluorescence resonance energy transfer (FRET)-based tension sensors have led to a new understanding of single molecule mechanotransduction in a number of biological systems. To expand the range of accessible forces, we systematically measured FRET versus force trajectories for 25, 40, and 50 amino acid peptide repeats derived from spider silk. Single molecule fluorescence-force spectroscopy showed that the peptides behaved as linear springs instead of the nonlinear behavior expected for a disordered polymer. Our data are consistent with a compact, rodlike structure that measures 0.26 nm per 5 amino acid repeat that can stretch by 500% while maintaining linearity, suggesting that the remarkable elasticity of spider silk proteins may in part derive from the properties of individual chains. We found the shortest peptide to have the widest range of force sensitivity: between 2 pN and 11 pN. Live cell imaging of the three tension sensor constructs inserted into vinculin showed similar force values around 2.4 pN. We also provide a lookup table for force versus intracellular FRET for all three constructs.
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Affiliation(s)
- Michael D. Brenner
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Physics and Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Ruobo Zhou
- Department of Physics and Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Daniel E. Conway
- Cardiovascular Research Center, University of Virginia, Charlottesville, VA 22908, USA
| | - Luca Lanzano
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, CA 92697, USA
| | - E. Gratton
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, CA 92697, USA
| | - Martin A. Schwartz
- Cardiovascular Research Center, University of Virginia, Charlottesville, VA 22908, USA
- Yale Cardiovascular Research Center, Departments of Internal Medicine (Section of Cardiovascular Medicine) and Cell Biology, Yale University, New Haven, CT 06511, USA
| | - Taekjip Ha
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Department of Physics and Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Howard Hughes Medical Institute, Urbana, IL 61801, USA
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41
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Raghupathi R, Jessup CF, Lumsden AL, Keating DJ. Fusion Pore Size Limits 5-HT Release From Single Enterochromaffin Cell Vesicles. J Cell Physiol 2015; 231:1593-600. [PMID: 26574734 DOI: 10.1002/jcp.25256] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 11/13/2015] [Indexed: 12/15/2022]
Abstract
Enterochromaffin cells are the major site of serotonin (5-HT) synthesis and secretion providing ∼95% of the body's total 5-HT. 5-HT can act as a neurotransmitter or hormone and has several important endocrine and paracrine roles. We have previously demonstrated that EC cells release small amounts of 5-HT per exocytosis event compared to other endocrine cells. We utilized a recently developed method to purify EC cells to demonstrate the mechanisms underlying 5-HT packaging and release. Using the fluorescent probe FFN511, we demonstrate that EC cells express VMAT and that VMAT plays a functional role in 5-HT loading into vesicles. Carbon fiber amperometry studies illustrate that the amount of 5-HT released per exocytosis event from EC cells is dependent on both VMAT and the H(+)-ATPase pump, as demonstrated with reserpine or bafilomycin, respectively. We also demonstrate that increasing the amount of 5-HT loaded into EC cell vesicles does not result in an increase in quantal release. As this indicates that fusion pore size may be a limiting factor involved, we compared pore diameter in EC and chromaffin cells by assessing the vesicle capture of different-sized fluorescent probes to measure the extent of fusion pore dilation. This identified that EC cells have a reduced fusion pore expansion that does not exceed 9 nm in diameter. These results demonstrate that the small amounts of 5-HT released per fusion event in EC cells can be explained by a smaller fusion pore that limits 5-HT release capacity from individual vesicles.
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Affiliation(s)
- Ravinarayan Raghupathi
- Department of Human Physiology and Centre for Neuroscience, Flinders University, Adelaide, Australia
| | - Claire F Jessup
- Department of Anatomy and Histology and Centre for Neuroscience, Flinders University, Adelaide, Australia.,Discipline of Medicine, University of Adelaide, Adelaide, Australia
| | - Amanda L Lumsden
- Department of Human Physiology and Centre for Neuroscience, Flinders University, Adelaide, Australia
| | - Damien J Keating
- Department of Human Physiology and Centre for Neuroscience, Flinders University, Adelaide, Australia.,South Australian Health and Medical Research Institute, Adelaide, Australia
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42
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Abstract
Cells generate and experience mechanical forces that may shape tissues and regulate signaling pathways in a variety of physiological or pathological situations. How forces propagate and transduce signals at the molecular level is poorly understood. The advent of FRET-based Molecular Tension Microscopy now allows to achieve mechanical force measurements at a molecular scale with molecular specificity in situ, and thereby better understand the mechanical architecture of cells and tissues, and mechanotransduction pathways. In this review, we will first expose the basic principles of FRET-based MTM and its various incarnations. We will describe different ways of measuring FRET, their advantages and drawbacks. Then, throughout the range of proteins of interest, cells and organisms to which it has been applied, we will review the tests developed to validate the approach, how molecular tension was related to cell functions, and conclude with possible developments and offshoots.
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Affiliation(s)
- Charlène Gayrard
- Institut Jacques Monod, Unité Mixe de Recherche 7592, Centre national de la recherche scientifique, Université Paris-Diderot, Paris 75013, France
| | - Nicolas Borghi
- Institut Jacques Monod, Unité Mixe de Recherche 7592, Centre national de la recherche scientifique, Université Paris-Diderot, Paris 75013, France.
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43
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Jackson J, Papadopulos A, Meunier FA, McCluskey A, Robinson PJ, Keating DJ. Small molecules demonstrate the role of dynamin as a bi-directional regulator of the exocytosis fusion pore and vesicle release. Mol Psychiatry 2015; 20:810-9. [PMID: 25939402 DOI: 10.1038/mp.2015.56] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 03/14/2015] [Accepted: 03/24/2015] [Indexed: 12/18/2022]
Abstract
Hormones and neurotransmitters are stored in specialised vesicles and released from excitable cells through exocytosis. During vesicle fusion with the plasma membrane, a transient fusion pore is created that enables transmitter release. The protein dynamin is known to regulate fusion pore expansion (FPE). The mechanism is unknown, but requires its oligomerisation-stimulated GTPase activity. We used a palette of small molecule dynamin modulators to reveal bi-directional regulation of FPE by dynamin and vesicle release in chromaffin cells. The dynamin inhibitors Dynole 34-2 and Dyngo 4a and the dynamin activator Ryngo 1-23 reduced or increased catecholamine released from single vesicles, respectively. Total internal reflection fluorescence (TIRF) microscopy demonstrated that dynamin stimulation with Ryngo 1-23 reduced the number of neuropeptide Y (NPY) kiss-and-run events, but not full fusion events, and slowed full fusion release kinetics. Amperometric stand-alone foot signals, representing transient kiss-and-run events, were less frequent but were of longer duration, similarly to full amperometric spikes and pre-spike foot signals. These effects are not due to alterations in vesicle size. Ryngo 1-23 action was blocked by inhibitors of actin polymerisation or myosin II. Therefore, we demonstrate using a novel pharmacological approach that dynamin not only controls FPE during exocytosis, but is a bi-directional modulator of the fusion pore that increases or decreases the amount released from a vesicle during exocytosis if it is activated or inhibited, respectively. As such, dynamin has the ability to exquisitely fine-tune transmitter release.
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Affiliation(s)
- J Jackson
- Discipline of Human Physiology, Centre for Neuroscience, Flinders University, Adelaide, Australia
| | - A Papadopulos
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia
| | - F A Meunier
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia
| | - A McCluskey
- Centre for Chemical Biology and Chemistry, School of Environmental and Life Sciences, The University of Newcastle, Callaghan, New South Wales, Australia
| | - P J Robinson
- Children's Medical Research Institute, University of Sydney, Westmead, New South Wales, Australia
| | - D J Keating
- 1] Discipline of Human Physiology, Centre for Neuroscience, Flinders University, Adelaide, Australia [2] South Australian Health and Medical Research Institute (SAHMRI), Adelaide, Australia
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