1
|
Sołtys K, Tarczewska A, Bystranowska D. Modulation of biomolecular phase behavior by metal ions. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119567. [PMID: 37582439 DOI: 10.1016/j.bbamcr.2023.119567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 08/04/2023] [Accepted: 08/08/2023] [Indexed: 08/17/2023]
Abstract
Liquid-liquid phase separation (LLPS) appears to be a newly appreciated aspect of the cellular organization of biomolecules that leads to the formation of membraneless organelles (MLOs). MLOs generate distinct microenvironments where particular biomolecules are highly concentrated compared to those in the surrounding environment. Their thermodynamically driven formation is reversible, and their liquid nature allows them to fuse with each other. Dysfunctional biomolecular condensation is associated with human diseases. Pathological states of MLOs may originate from the mutation of proteins or may be induced by other factors. In most aberrant MLOs, transient interactions are replaced by stronger and more rigid interactions, preventing their dissolution, and causing their uncontrolled growth and dysfunction. For these reasons, there is great interest in identifying factors that modulate LLPS. In this review, we discuss an enigmatic and mostly unexplored aspect of this process, namely, the regulatory effects of metal ions on the phase behavior of biomolecules.
Collapse
Affiliation(s)
- Katarzyna Sołtys
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
| | - Aneta Tarczewska
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Dominika Bystranowska
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| |
Collapse
|
2
|
Lehne F, Bogdan S. Swip-1 promotes exocytosis of glue granules in the exocrine Drosophila salivary gland. J Cell Sci 2023; 136:286884. [PMID: 36727484 PMCID: PMC10038153 DOI: 10.1242/jcs.260366] [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: 06/22/2022] [Accepted: 01/27/2023] [Indexed: 02/03/2023] Open
Abstract
Exocytosis is a fundamental cellular process by which cells secrete cargos from their apical membrane into the extracellular lumen. Cargo release proceeds in sequential steps that depend on coordinated assembly and organization of an actin cytoskeletal network. Here, we identified the conserved actin-crosslinking protein Swip-1 as a novel regulator controlling exocytosis of glue granules in the Drosophila salivary gland. Real-time imaging revealed that Swip-1 is simultaneously recruited with F-actin onto secreting granules in proximity to the apical membrane. We observed that Swip-1 is rapidly cleared at the point of secretory vesicle fusion and colocalizes with actomyosin network around the fused vesicles. Loss of Swip-1 function impairs secretory cargo expulsion, resulting in strongly delayed secretion. Thus, our results uncover a novel role of Swip-1 in secretory vesicle compression and expulsion of cargo during regulated exocytosis. Remarkably, this function neither requires Ca2+ binding nor dimerization of Swip-1. Our data rather suggest that Swip-1 regulates actomyosin activity upstream of Rho-GTPase signaling to drive proper vesicle membrane crumpling and expulsion of cargo.
Collapse
Affiliation(s)
- Franziska Lehne
- Institute of Physiology and Pathophysiology, Department of Molecular Cell Physiology, Philipps-University Marburg, 35037 Marburg, Germany
| | - Sven Bogdan
- Institute of Physiology and Pathophysiology, Department of Molecular Cell Physiology, Philipps-University Marburg, 35037 Marburg, Germany
| |
Collapse
|
3
|
Lehne F, Bogdan S. Getting cells into shape by calcium-dependent actin cross-linking proteins. Front Cell Dev Biol 2023; 11:1171930. [PMID: 37025173 PMCID: PMC10070769 DOI: 10.3389/fcell.2023.1171930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 03/09/2023] [Indexed: 04/08/2023] Open
Abstract
The actin cytoskeleton represents a highly dynamic filament system providing cell structure and mechanical forces to drive a variety of cellular processes. The dynamics of the actin cytoskeleton are controlled by a number of conserved proteins that maintain the pool of actin monomers, promote actin nucleation, restrict the length of actin filaments and cross-link filaments into networks or bundles. Previous work has been established that cytoplasmic calcium is an important signal to rapidly relay information to the actin cytoskeleton, but the underlying mechanisms remain poorly understood. Here, we summarize new recent perspectives on how calcium fluxes are transduced to the actin cytoskeleton in a physiological context. In this mini-review we will focus on three calcium-binding EF-hand-containing actin cross-linking proteins, α-actinin, plastin and EFHD2/Swiprosin-1, and how these conserved proteins affect the cell's actin reorganization in the context of cell migration and wound closure in response to calcium.
Collapse
|
4
|
Lehne F, Pokrant T, Parbin S, Salinas G, Großhans J, Rust K, Faix J, Bogdan S. Calcium bursts allow rapid reorganization of EFhD2/Swip-1 cross-linked actin networks in epithelial wound closure. Nat Commun 2022; 13:2492. [PMID: 35524157 PMCID: PMC9076686 DOI: 10.1038/s41467-022-30167-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 04/19/2022] [Indexed: 02/01/2023] Open
Abstract
Changes in cell morphology require the dynamic remodeling of the actin cytoskeleton. Calcium fluxes have been suggested as an important signal to rapidly relay information to the actin cytoskeleton, but the underlying mechanisms remain poorly understood. Here, we identify the EF-hand domain containing protein EFhD2/Swip-1 as a conserved lamellipodial protein strongly upregulated in Drosophila macrophages at the onset of metamorphosis when macrophage behavior shifts from quiescent to migratory state. Loss- and gain-of-function analysis confirm a critical function of EFhD2/Swip-1 in lamellipodial cell migration in fly and mouse melanoma cells. Contrary to previous assumptions, TIRF-analyses unambiguously demonstrate that EFhD2/Swip-1 proteins efficiently cross-link actin filaments in a calcium-dependent manner. Using a single-cell wounding model, we show that EFhD2/Swip-1 promotes wound closure in a calcium-dependent manner. Mechanistically, our data suggest that transient calcium bursts reduce EFhD2/Swip-1 cross-linking activity and thereby promote rapid reorganization of existing actin networks to drive epithelial wound closure.
Collapse
Affiliation(s)
- Franziska Lehne
- Institute of Physiology and Pathophysiology, Department of Molecular Cell Physiology, Philipps-University Marburg, Marburg, Germany
| | - Thomas Pokrant
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - Sabnam Parbin
- NGS-Integrative Genomics Core Unit, Department of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
| | - Gabriela Salinas
- NGS-Integrative Genomics Core Unit, Department of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
| | - Jörg Großhans
- Department of Biology, Philipps-University Marburg, Marburg, Germany
| | - Katja Rust
- Institute of Physiology and Pathophysiology, Department of Molecular Cell Physiology, Philipps-University Marburg, Marburg, Germany
| | - Jan Faix
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - Sven Bogdan
- Institute of Physiology and Pathophysiology, Department of Molecular Cell Physiology, Philipps-University Marburg, Marburg, Germany.
| |
Collapse
|
5
|
Drosophila melanogaster: A Model System to Study Distinct Genetic Programs in Myoblast Fusion. Cells 2022; 11:cells11030321. [PMID: 35159130 PMCID: PMC8834112 DOI: 10.3390/cells11030321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Revised: 01/04/2022] [Accepted: 01/05/2022] [Indexed: 11/25/2022] Open
Abstract
Muscle fibers are multinucleated cells that arise during embryogenesis through the fusion of mononucleated myoblasts. Myoblast fusion is a lifelong process that is crucial for the growth and regeneration of muscles. Understanding the molecular mechanism of myoblast fusion may open the way for novel therapies in muscle wasting and weakness. Recent reports in Drosophila and mammals have provided new mechanistic insights into myoblast fusion. In Drosophila, muscle formation occurs twice: during embryogenesis and metamorphosis. A fundamental feature is the formation of a cell–cell communication structure that brings the apposing membranes into close proximity and recruits possible fusogenic proteins. However, genetic studies suggest that myoblast fusion in Drosophila is not a uniform process. The complexity of the players involved in myoblast fusion can be modulated depending on the type of muscle that is formed. In this review, we introduce the different types of multinucleated muscles that form during Drosophila development and provide an overview in advances that have been made to understand the mechanism of myoblast fusion. Finally, we will discuss conceptual frameworks in cell–cell fusion in Drosophila and mammals.
Collapse
|
6
|
Moreno-Layseca P, Jäntti NZ, Godbole R, Sommer C, Jacquemet G, Al-Akhrass H, Conway JRW, Kronqvist P, Kallionpää RE, Oliveira-Ferrer L, Cervero P, Linder S, Aepfelbacher M, Zauber H, Rae J, Parton RG, Disanza A, Scita G, Mayor S, Selbach M, Veltel S, Ivaska J. Cargo-specific recruitment in clathrin- and dynamin-independent endocytosis. Nat Cell Biol 2021; 23:1073-1084. [PMID: 34616024 DOI: 10.1038/s41556-021-00767-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 09/01/2021] [Indexed: 12/12/2022]
Abstract
Spatially controlled, cargo-specific endocytosis is essential for development, tissue homeostasis and cancer invasion. Unlike cargo-specific clathrin-mediated endocytosis, the clathrin- and dynamin-independent endocytic pathway (CLIC-GEEC, CG pathway) is considered a bulk internalization route for the fluid phase, glycosylated membrane proteins and lipids. While the core molecular players of CG-endocytosis have been recently defined, evidence of cargo-specific adaptors or selective uptake of proteins for the pathway are lacking. Here we identify the actin-binding protein Swiprosin-1 (Swip1, EFHD2) as a cargo-specific adaptor for CG-endocytosis. Swip1 couples active Rab21-associated integrins with key components of the CG-endocytic machinery-Arf1, IRSp53 and actin-and is critical for integrin endocytosis. Through this function, Swip1 supports integrin-dependent cancer-cell migration and invasion, and is a negative prognostic marker in breast cancer. Our results demonstrate a previously unknown cargo selectivity for the CG pathway and a role for specific adaptors in recruitment into this endocytic route.
Collapse
Affiliation(s)
- Paulina Moreno-Layseca
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland.,University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Niklas Z Jäntti
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | - Rashmi Godbole
- National Centre for Biological Science (TIFR), Bangalore, India.,The University of Trans-Disciplinary Health Sciences and Technology (TDU), Bangalore, India
| | - Christian Sommer
- Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany
| | - Guillaume Jacquemet
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland.,Faculty of Science and Engineering, Cell Biology, Åbo Akademi University, Turku, Finland
| | - Hussein Al-Akhrass
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | - James R W Conway
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | - Pauliina Kronqvist
- Institute of Biomedicine, Faculty of Medicine, University of Turku, Turku, Finland
| | - Roosa E Kallionpää
- Auria Biobank, Turku University Hospital and University of Turku, Turku, Finland
| | | | - Pasquale Cervero
- University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Stefan Linder
- University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | | | - Henrik Zauber
- Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany
| | - James Rae
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland, Australia
| | - Robert G Parton
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland, Australia.,Centre for Microscopy and Microanalysis, University of Queensland, Brisbane, Queensland, Australia
| | - Andrea Disanza
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare and University of Milan, Milan, Italy
| | - Giorgio Scita
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare and University of Milan, Milan, Italy
| | - Satyajit Mayor
- National Centre for Biological Science (TIFR), Bangalore, India
| | - Matthias Selbach
- Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany
| | - Stefan Veltel
- University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany. .,Hochschule Bremen, City University of Applied Sciences, Bremen, Germany.
| | - Johanna Ivaska
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland. .,Department of Life Sciences, University of Turku, Turku, Finland. .,InFLAMES Research Flagship Center, University of Turku, Turku, Finland.
| |
Collapse
|
7
|
Swiprosin-1/EFhD-2 Expression in Cardiac Remodeling and Post-Infarct Repair: Effect of Ischemic Conditioning. Int J Mol Sci 2020; 21:ijms21093359. [PMID: 32397496 PMCID: PMC7247556 DOI: 10.3390/ijms21093359] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 04/30/2020] [Accepted: 05/04/2020] [Indexed: 02/08/2023] Open
Abstract
Swiprosin-1 (EFhD2) is a molecule that triggers structural adaptation of isolated adult rat cardiomyocytes to cell culture conditions by initiating a process known as cell spreading. This process mimics central aspects of cardiac remodeling, as it occurs subsequent to myocardial infarction. However, expression of swiprosin-1 in cardiac tissue and its regulation in vivo has not yet been addressed. The expression of swiprosin-1 was analyzed in mice, rat, and pig hearts undergoing myocardial infarction or ischemia/reperfusion with or without cardiac protection by ischemic pre- and postconditioning. In mouse hearts, swiprosin-1 protein expression was increased after 4 and 7 days in myocardial infarct areas specifically in cardiomyocytes as verified by immunoblotting and histology. In rat hearts, swiprosin-1 mRNA expression was induced within 7 days after ischemia/reperfusion but this induction was abrogated by conditioning. As in cultured cardiomyocytes, the expression of swiprosin-1 was associated with a coinduction of arrestin-2, suggesting a common mechanism of regulation. Rno-miR-32-3p and rno-miR-34c-3p were associated with the regulation pattern of both molecules. Moreover, induction of swiprosin-1 and ssc-miR-34c was also confirmed in the infarct zone of pigs. In summary, our data show that up-regulation of swiprosin-1 appears in the postischemic heart during cardiac remodeling and repair in different species.
Collapse
|
8
|
Kogias G, Zheng F, Kalinichenko LS, Kornhuber J, Alzheimer C, Mielenz D, Müller CP. Swiprosin1/EFhd2 is involved in the monoaminergic and locomotor responses of psychostimulant drugs. J Neurochem 2020; 154:424-440. [DOI: 10.1111/jnc.14959] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 01/08/2020] [Accepted: 01/10/2020] [Indexed: 12/13/2022]
Affiliation(s)
- Georgios Kogias
- Department of Psychiatry and Psychotherapy Friedrich‐Alexander University Erlangen‐Nürnberg Erlangen Germany
| | - Fang Zheng
- Institute of Physiology and Pathophysiology Friedrich‐Alexander University Erlangen‐Nürnberg Erlangen Germany
| | - Liubov S. Kalinichenko
- Department of Psychiatry and Psychotherapy Friedrich‐Alexander University Erlangen‐Nürnberg Erlangen Germany
| | - Johannes Kornhuber
- Department of Psychiatry and Psychotherapy Friedrich‐Alexander University Erlangen‐Nürnberg Erlangen Germany
| | - Christian Alzheimer
- Institute of Physiology and Pathophysiology Friedrich‐Alexander University Erlangen‐Nürnberg Erlangen Germany
| | - Dirk Mielenz
- Division of Molecular Immunology Department of Internal Medicine III Nikolaus‐Fiebiger‐Center University Clinic Friedrich‐Alexander University Erlangen‐Nürnberg Erlangen Germany
| | - Christian P. Müller
- Department of Psychiatry and Psychotherapy Friedrich‐Alexander University Erlangen‐Nürnberg Erlangen Germany
| |
Collapse
|
9
|
Geisbrecht ER, Baylies MK. In memoriam: Susan Abmayr (1956–2019) – “What do we do? Whatever it takes!”. Skelet Muscle 2019. [PMCID: PMC6882191 DOI: 10.1186/s13395-019-0215-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|
10
|
Kuckwa J, Fritzen K, Buttgereit D, Rothenbusch-Fender S, Renkawitz-Pohl R. A new level of plasticity: Drosophila smooth-like testes muscles compensate failure of myoblast fusion. Development 2015; 143:329-38. [PMID: 26657767 PMCID: PMC4725342 DOI: 10.1242/dev.126730] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 11/28/2015] [Indexed: 12/26/2022]
Abstract
The testis of Drosophila resembles an individual testis tubule of mammals. Both are surrounded by a sheath of smooth muscles, which in Drosophila are multinuclear and originate from a pool of myoblasts that are set aside in the embryo and accumulate on the genital disc later in development. These muscle stem cells start to differentiate early during metamorphosis and give rise to all muscles of the inner male reproductive system. Shortly before the genital disc and the developing testes connect, multinuclear nascent myotubes appear on the anterior tips of the seminal vesicles. Here, we show that adhesion molecules are distinctly localized on the seminal vesicles; founder cell (FC)-like myoblasts express Dumbfounded (Duf) and Roughest (Rst), and fusion-competent myoblast (FCM)-like cells mainly express Sticks and stones (Sns). The smooth but multinuclear myotubes of the testes arose by myoblast fusion. RNAi-mediated attenuation of Sns or both Duf and Rst severely reduced the number of nuclei in the testes muscles. Duf and Rst probably act independently in this context. Despite reduced fusion in all of these RNAi-treated animals, myotubes migrated onto the testes, testes were shaped and coiled, muscle filaments were arranged as in the wild type and spermatogenesis proceeded normally. Hence, the testes muscles compensate for fusion defects so that the myofibres encircling the adult testes are indistinguishable from those of the wild type and male fertility is guaranteed. Summary:Drosophila testes muscles arise from stem cells and can compensate for fusion defects to safeguard fertility; this plasticity may compensate for the observed lack of satellite cells in Drosophila.
Collapse
Affiliation(s)
- Jessica Kuckwa
- Philipps-Universität Marburg, Fachbereich Biologie, Entwicklungsbiologie, Karl-von-Frisch Strasse 8, Marburg 35043, Germany
| | - Katharina Fritzen
- Philipps-Universität Marburg, Fachbereich Biologie, Entwicklungsbiologie, Karl-von-Frisch Strasse 8, Marburg 35043, Germany
| | - Detlev Buttgereit
- Philipps-Universität Marburg, Fachbereich Biologie, Entwicklungsbiologie, Karl-von-Frisch Strasse 8, Marburg 35043, Germany
| | - Silke Rothenbusch-Fender
- Philipps-Universität Marburg, Fachbereich Biologie, Entwicklungsbiologie, Karl-von-Frisch Strasse 8, Marburg 35043, Germany
| | - Renate Renkawitz-Pohl
- Philipps-Universität Marburg, Fachbereich Biologie, Entwicklungsbiologie, Karl-von-Frisch Strasse 8, Marburg 35043, Germany
| |
Collapse
|
11
|
The calcium-binding protein EFhd2 modulates synapse formation in vitro and is linked to human dementia. J Neuropathol Exp Neurol 2015; 73:1166-82. [PMID: 25383639 PMCID: PMC4238966 DOI: 10.1097/nen.0000000000000138] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
EFhd2 is a calcium-binding adaptor protein that has been found to be associated with pathologically aggregated tau in the brain in Alzheimer disease and in a mouse model of frontotemporal dementia. EFhd2 has cell type-specific functions, including the modulation of intracellular calcium responses, actin dynamics, and microtubule transport. Here we report that EFhd2 protein and mRNA levels are reduced in human frontal cortex tissue affected by different types of dementia with and without tau pathology. We show that EFhd2 is mainly a neuronal protein in the brain and is abundant in the forebrain. Using short hairpin RNA-mediated knockdown of EFhd2 expression in cultured cortical neurons, we demonstrate that loss of EFhd2 affects the number of synapses developed in vitro whereas it does not alter neurite outgrowth per se. Our data suggest that EFhd2 is involved in the control of synapse development and maintenance through means other than affecting neurite development. The changes in expression levels observed in human dementias might, therefore, play a significant role in disease onset and progression of dementia, which is characterized by the loss of synapses.
Collapse
|
12
|
The Ca2+ sensor protein swiprosin-1/EFhd2 is present in neurites and involved in kinesin-mediated transport in neurons. PLoS One 2014; 9:e103976. [PMID: 25133820 PMCID: PMC4136728 DOI: 10.1371/journal.pone.0103976] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 07/08/2014] [Indexed: 01/10/2023] Open
Abstract
Swiprosin-1/EFhd2 (EFhd2) is a cytoskeletal Ca2+ sensor protein strongly expressed in the brain. It has been shown to interact with mutant tau, which can promote neurodegeneration, but nothing is known about the physiological function of EFhd2 in the nervous system. To elucidate this question, we analyzed EFhd2−/−/lacZ reporter mice and showed that lacZ was strongly expressed in the cortex, the dentate gyrus, the CA1 and CA2 regions of the hippocampus, the thalamus, and the olfactory bulb. Immunohistochemistry and western blotting confirmed this pattern and revealed expression of EFhd2 during neuronal maturation. In cortical neurons, EFhd2 was detected in neurites marked by MAP2 and co-localized with pre- and post-synaptic markers. Approximately one third of EFhd2 associated with a biochemically isolated synaptosome preparation. There, EFhd2 was mostly confined to the cytosolic and plasma membrane fractions. Both synaptic endocytosis and exocytosis in primary hippocampal EFhd2−/− neurons were unaltered but transport of synaptophysin-GFP containing vesicles was enhanced in EFhd2−/− primary hippocampal neurons, and notably, EFhd2 inhibited kinesin mediated microtubule gliding. Therefore, we found that EFhd2 is a neuronal protein that interferes with kinesin-mediated transport.
Collapse
|
13
|
Önel SF, Rust MB, Jacob R, Renkawitz-Pohl R. Tethering membrane fusion: common and different players in myoblasts and at the synapse. J Neurogenet 2014; 28:302-15. [PMID: 24957080 PMCID: PMC4245166 DOI: 10.3109/01677063.2014.936014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Drosophila Membrane fusion is essential for the communication of membrane-defined compartments, development of multicellular organisms and tissue homeostasis. Although membrane fusion has been studied extensively, still little is known about the molecular mechanisms. Especially the intercellular fusion of cells during development and tissue homeostasis is poorly understood. Somatic muscle formation in Drosophila depends on the intercellular fusion of myoblasts. In this process, myoblasts recognize each other and adhere, thereby triggering a protein machinery that leads to electron-dense plaques, vesicles and F-actin formation at apposing membranes. Two models of how local membrane stress is achieved to induce the merging of the myoblast membranes have been proposed: the electron-dense vesicles transport and release a fusogen and F-actin bends the plasma membrane. In this review, we highlight cell-adhesion molecules and intracellular proteins known to be involved in myoblast fusion. The cell-adhesion proteins also mediate the recognition and adhesion of other cell types, such as neurons that communicate with each other via special intercellular junctions, termed chemical synapses. At these synapses, neurotransmitters are released through the intracellular fusion of synaptic vesicles with the plasma membrane. As the targeting of electron-dense vesicles in myoblasts shares some similarities with the targeting of synaptic vesicle fusion, we compare molecules required for synaptic vesicle fusion to recently identified molecules involved in myoblast fusion.
Collapse
Affiliation(s)
- Susanne Filiz Önel
- Developmental Biology, Philipps University of Marburg , 35043 Marburg , Germany
| | | | | | | |
Collapse
|
14
|
Brachs S, Lang C, Buslei R, Purohit P, Fürnrohr B, Kalbacher H, Jäck HM, Mielenz D. Monoclonal antibodies to discriminate the EF hand containing calcium binding adaptor proteins EFhd1 and EFhd2. Monoclon Antib Immunodiagn Immunother 2014; 32:237-45. [PMID: 23909416 DOI: 10.1089/mab.2013.0014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Small Ca(2+) binding adaptor proteins of the EF hand family play important roles in neuronal and immune cell Ca(2+) signaling. Swiprosin-1/EFhd2 (EFhd2) and Swiprosin-2/EFhd1 (EFhd1) are conserved and very homologous Ca(2+) binding adaptor proteins of the EF hand family, with possibly redundant functions. In particular, EFhd2 has been proposed to be involved in B cell signaling and neuropathological disorders. Little is known thus far about the expression of EFhd2 on the single cell level in tissue sections or blood cells. Here we describe the generation of four specific anti-EFhd2 monoclonal antibodies. These recognize murine and human EFhd2, but not murine EFhd1, and their binding site maps to a region in the N-terminal part of EFhd2, where EFhd2 and EFhd1 differ most. Moreover, to detect EFhd1 specifically, we also generated anti-EFhd1 polyclonal antibodies, making use of a singular peptide of the N-terminal part of the protein. Using anti-EFhd2 MAb, we reveal two EFhd2 pools in B cells, one at the membrane and one cytoplasmic pool. Staining of human peripheral blood mononuclear cells shows EFhd2 expression in B cells but a ∼5 fold higher expression in monocytes. Taken together, EFhd2 monoclonal antibodies will be valuable to assess the real subcellular localization and expression level of EFhd2 in healthy and diseased primary cells and tissues.
Collapse
Affiliation(s)
- Sebastian Brachs
- Division of Molecular Immunology, Department of Medicine III, University of Erlangen-Nürnberg, Nikolaus Fiebiger Center, Erlangen, Germany
| | | | | | | | | | | | | | | |
Collapse
|
15
|
Kwon MS, Park KR, Kim YD, Na BR, Kim HR, Choi HJ, Piragyte I, Jeon H, Chung KH, Song WK, Eom SH, Jun CD. Swiprosin-1 is a novel actin bundling protein that regulates cell spreading and migration. PLoS One 2013; 8:e71626. [PMID: 23977092 PMCID: PMC3744483 DOI: 10.1371/journal.pone.0071626] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 06/28/2013] [Indexed: 11/18/2022] Open
Abstract
Protein functions are often revealed by their localization to specialized cellular sites. Recent reports demonstrated that swiprosin-1 is found together with actin and actin-binding proteins in the cytoskeleton fraction of human mast cells and NK-like cells. However, direct evidence of whether swiprosin-1 regulates actin dynamics is currently lacking. We found that swiprosin-1 localizes to microvilli-like membrane protrusions and lamellipodia and exhibits actin-binding activity. Overexpression of swiprosin-1 enhanced lamellipodia formation and cell spreading. In contrast, swiprosin-1 knockdown showed reduced cell spreading and migration. Swiprosin-1 induced actin bundling in the presence of Ca(2+), and deletion of the EF-hand motifs partially reduced bundling activity. Swiprosin-1 dimerized in the presence of Ca(2+) via its coiled-coil domain, and a lysine (Lys)-rich region in the coiled-coil domain was essential for regulation of actin bundling. Consistent with these observations, mutations of the EF-hand motifs and coiled-coil region significantly reduced cell spreading and lamellipodia formation. We provide new evidence of how swiprosin-1 influences cytoskeleton reorganization and cell spreading.
Collapse
Affiliation(s)
- Min-Sung Kwon
- School of Life Sciences, Immune Synapse Research Center and Cell Dynamics Research Center, Gwangju Institute of Science and Technology, Gwangju, Korea
| | - Kyoung Ryoung Park
- School of Life Sciences, Immune Synapse Research Center and Cell Dynamics Research Center, Gwangju Institute of Science and Technology, Gwangju, Korea
| | - Young-Dae Kim
- School of Life Sciences, Immune Synapse Research Center and Cell Dynamics Research Center, Gwangju Institute of Science and Technology, Gwangju, Korea
| | - Bo-Ra Na
- School of Life Sciences, Immune Synapse Research Center and Cell Dynamics Research Center, Gwangju Institute of Science and Technology, Gwangju, Korea
| | - Hye-Ran Kim
- School of Life Sciences, Immune Synapse Research Center and Cell Dynamics Research Center, Gwangju Institute of Science and Technology, Gwangju, Korea
| | - Hak-Jong Choi
- School of Life Sciences, Immune Synapse Research Center and Cell Dynamics Research Center, Gwangju Institute of Science and Technology, Gwangju, Korea
| | - Indre Piragyte
- School of Life Sciences, Immune Synapse Research Center and Cell Dynamics Research Center, Gwangju Institute of Science and Technology, Gwangju, Korea
| | - Hyesung Jeon
- Biomedical Research Center, Korea Institute of Science and Technology, Seongbuk-gu, Seoul, Korea
| | - Kyung Hwun Chung
- School of Life Sciences, Immune Synapse Research Center and Cell Dynamics Research Center, Gwangju Institute of Science and Technology, Gwangju, Korea
| | - Woo Keun Song
- School of Life Sciences, Immune Synapse Research Center and Cell Dynamics Research Center, Gwangju Institute of Science and Technology, Gwangju, Korea
| | - Soo Hyun Eom
- School of Life Sciences, Immune Synapse Research Center and Cell Dynamics Research Center, Gwangju Institute of Science and Technology, Gwangju, Korea
| | - Chang-Duk Jun
- School of Life Sciences, Immune Synapse Research Center and Cell Dynamics Research Center, Gwangju Institute of Science and Technology, Gwangju, Korea
| |
Collapse
|
16
|
Bonn BR, Rudolf A, Hornbruch-Freitag C, Daum G, Kuckwa J, Kastl L, Buttgereit D, Renkawitz-Pohl R. Myosin heavy chain-like localizes at cell contact sites during Drosophila myoblast fusion and interacts in vitro with Rolling pebbles 7. Exp Cell Res 2012; 319:402-16. [PMID: 23246571 DOI: 10.1016/j.yexcr.2012.12.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 12/04/2012] [Accepted: 12/05/2012] [Indexed: 11/29/2022]
Abstract
Besides representing the sarcomeric thick filaments, myosins are involved in many cellular transport and motility processes. Myosin heavy chains are grouped into 18 classes. Here we show that in Drosophila, the unconventional group XVIII myosin heavy chain-like (Mhcl) is transcribed in the mesoderm of embryos, most prominently in founder cells (FCs). An ectopically expressed GFP-tagged Mhcl localizes in the growing muscle at cell-cell contacts towards the attached fusion competent myoblast (FCM). We further show that Mhcl interacts in vitro with the essential fusion protein Rolling pebbles 7 (Rols7), which is part of a protein complex established at cell contact sites (Fusion-restricted Myogenic-Adhesive Structure or FuRMAS). Here, branched F-actin is likely needed to widen the fusion pore and to integrate the myoblast into the growing muscle. We show that the localization of Mhcl is dependent on the presence of Rols7, and we postulate that Mhcl acts at the FuRMAS as an actin motor protein. We further show that Mhcl deficient embryos develop a wild-type musculature. We thus propose that Mhcl functions redundantly to other myosin heavy chains in myoblasts. Lastly, we found that the protein is detectable adjacent to the sarcomeric Z-discs, suggesting an additional function in mature muscles.
Collapse
Affiliation(s)
- Bettina R Bonn
- Developmental Biology, Department of Biology, Philipps-Universität Marburg, Karl-von-Frisch-Strasse 8, 35037 Marburg, Germany
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Hagen S, Brachs S, Kroczek C, Fürnrohr BG, Lang C, Mielenz D. The B cell receptor-induced calcium flux involves a calcium mediated positive feedback loop. Cell Calcium 2012; 51:411-7. [DOI: 10.1016/j.ceca.2012.01.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Revised: 01/09/2012] [Accepted: 01/10/2012] [Indexed: 01/10/2023]
|
18
|
Rudolf A, Buttgereit D, Rexer KH, Renkawitz-Pohl R. The syncytial visceral and somatic musculature develops independently of β3-Tubulin during Drosophila embryogenesis, while maternally supplied β1-Tubulin is stable until the early steps of myoblast fusion. Eur J Cell Biol 2012; 91:192-203. [DOI: 10.1016/j.ejcb.2011.11.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Revised: 11/15/2011] [Accepted: 11/16/2011] [Indexed: 12/11/2022] Open
|
19
|
Hornbruch-Freitag C, Griemert B, Buttgereit D, Renkawitz-Pohl R. Drosophila Swiprosin-1/EFHD2 accumulates at the prefusion complex stage during Drosophila myoblast fusion. Development 2011. [DOI: 10.1242/dev.074682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|