1
|
Whitsitt Q, Saxena A, Patel B, Evans BM, Hunt B, Purcell EK. Spatial transcriptomics at the brain-electrode interface in rat motor cortex and the relationship to recording quality. J Neural Eng 2024; 21:046033. [PMID: 38885679 PMCID: PMC11289622 DOI: 10.1088/1741-2552/ad5936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 04/15/2024] [Accepted: 06/17/2024] [Indexed: 06/20/2024]
Abstract
Study of the foreign body reaction to implanted electrodes in the brain is an important area of research for the future development of neuroprostheses and experimental electrophysiology. After electrode implantation in the brain, microglial activation, reactive astrogliosis, and neuronal cell death create an environment immediately surrounding the electrode that is significantly altered from its homeostatic state.Objective.To uncover physiological changes potentially affecting device function and longevity, spatial transcriptomics (ST) was implemented to identify changes in gene expression driven by electrode implantation and compare this differential gene expression to traditional metrics of glial reactivity, neuronal loss, and electrophysiological recording quality.Approach.For these experiments, rats were chronically implanted with functional Michigan-style microelectrode arrays, from which electrophysiological recordings (multi-unit activity, local field potential) were taken over a six-week time course. Brain tissue cryosections surrounding each electrode were then mounted for ST processing. The tissue was immunolabeled for neurons and astrocytes, which provided both a spatial reference for ST and a quantitative measure of glial fibrillary acidic protein and neuronal nuclei immunolabeling surrounding each implant.Main results. Results from rat motor cortex within 300µm of the implanted electrodes at 24 h, 1 week, and 6 weeks post-implantation showed up to 553 significantly differentially expressed (DE) genes between implanted and non-implanted tissue sections. Regression on the significant DE genes identified the 6-7 genes that had the strongest relationship to histological and electrophysiological metrics, revealing potential candidate biomarkers of recording quality and the tissue response to implanted electrodes.Significance. Our analysis has shed new light onto the potential mechanisms involved in the tissue response to implanted electrodes while generating hypotheses regarding potential biomarkers related to recorded signal quality. A new approach has been developed to understand the tissue response to electrodes implanted in the brain using genes identified through transcriptomics, and to screen those results for potential relationships with functional outcomes.
Collapse
Affiliation(s)
- Quentin Whitsitt
- Department of Biomedical Engineering and Institute of Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI 48824, United States of America
| | - Akash Saxena
- Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI 48824, United States of America
| | - Bella Patel
- Department of Biomedical Engineering and Institute of Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI 48824, United States of America
| | - Blake M Evans
- Department of Biomedical Engineering and Institute of Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI 48824, United States of America
| | - Bradley Hunt
- Department of Biomedical Engineering and Institute of Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI 48824, United States of America
| | - Erin K Purcell
- Department of Biomedical Engineering and Institute of Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI 48824, United States of America
- Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI 48824, United States of America
| |
Collapse
|
2
|
Shoyer TC, Collins KL, Ham TR, Blanchard AT, Malavade JN, Johns BA, West JL, Hoffman BD. Detection of fluorescent protein mechanical switching in cellulo. CELL REPORTS METHODS 2024; 4:100815. [PMID: 38986612 PMCID: PMC11294842 DOI: 10.1016/j.crmeth.2024.100815] [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: 01/11/2024] [Revised: 05/03/2024] [Accepted: 06/17/2024] [Indexed: 07/12/2024]
Abstract
The ability of cells to sense and respond to mechanical forces is critical in many physiological and pathological processes. However, determining the mechanisms by which forces affect protein function inside cells remains challenging. Motivated by in vitro demonstrations of fluorescent proteins (FPs) undergoing reversible mechanical switching of fluorescence, we investigated whether force-sensitive changes in FP function could be visualized in cells. Guided by a computational model of FP mechanical switching, we develop a formalism for its detection in Förster resonance energy transfer (FRET)-based biosensors and demonstrate its occurrence in cellulo within a synthetic actin crosslinker and the mechanical linker protein vinculin. We find that in cellulo mechanical switching is reversible and altered by manipulation of cell force generation, external stiffness, and force-sensitive bond dynamics of the biosensor. This work describes a framework for assessing FP mechanical stability and provides a means of probing force-sensitive protein function inside cells.
Collapse
Affiliation(s)
- T Curtis Shoyer
- Department of Biomedical Engineering, Duke University, Durham NC 27708, USA
| | - Kasie L Collins
- Department of Chemistry, Duke University, Durham NC 27708, USA
| | - Trevor R Ham
- Department of Biomedical Engineering, Duke University, Durham NC 27708, USA
| | - Aaron T Blanchard
- Department of Biomedical Engineering, Duke University, Durham NC 27708, USA
| | - Juilee N Malavade
- Department of Biomedical Engineering, Duke University, Durham NC 27708, USA
| | - Benjamin A Johns
- Department of Biomedical Engineering, Duke University, Durham NC 27708, USA
| | - Jennifer L West
- Department of Biomedical Engineering, Duke University, Durham NC 27708, USA; Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA
| | - Brenton D Hoffman
- Department of Biomedical Engineering, Duke University, Durham NC 27708, USA.
| |
Collapse
|
3
|
Ilnitskaya AS, Litovka NI, Rubtsova SN, Zhitnyak IY, Gloushankova NA. Actin Cytoskeleton Remodeling Accompanied by Redistribution of Adhesion Proteins Drives Migration of Cells in Different EMT States. Cells 2024; 13:780. [PMID: 38727316 PMCID: PMC11083118 DOI: 10.3390/cells13090780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 04/23/2024] [Accepted: 04/29/2024] [Indexed: 05/13/2024] Open
Abstract
Epithelial-mesenchymal transition (EMT) is a process during which epithelial cells lose epithelial characteristics and gain mesenchymal features. Here, we used several cell models to study migratory activity and redistribution of cell-cell adhesion proteins in cells in different EMT states: EGF-induced EMT of epithelial IAR-20 cells; IAR-6-1 cells with a hybrid epithelial-mesenchymal phenotype; and their more mesenchymal derivatives, IAR-6-1-DNE cells lacking adherens junctions. In migrating cells, the cell-cell adhesion protein α-catenin accumulated at the leading edges along with ArpC2/p34 and α-actinin. Suppression of α-catenin shifted cell morphology from fibroblast-like to discoid and attenuated cell migration. Expression of exogenous α-catenin in MDA-MB-468 cells devoid of α-catenin drastically increased their migratory capabilities. The Y654 phosphorylated form of β-catenin was detected at integrin adhesion complexes (IACs). Co-immunoprecipitation studies indicated that α-catenin and pY654-β-catenin were associated with IAC proteins: vinculin, zyxin, and α-actinin. Taken together, these data suggest that in cells undergoing EMT, catenins not participating in assembly of adherens junctions may affect cell migration.
Collapse
Affiliation(s)
- Alla S. Ilnitskaya
- Institute of Carcinogenesis, N.N. Blokhin National Medical Research Center of Oncology, 24 Kashirskoye Shosse, 115478 Moscow, Russia; (A.S.I.); (N.I.L.); (S.N.R.); (I.Y.Z.)
| | - Nikita I. Litovka
- Institute of Carcinogenesis, N.N. Blokhin National Medical Research Center of Oncology, 24 Kashirskoye Shosse, 115478 Moscow, Russia; (A.S.I.); (N.I.L.); (S.N.R.); (I.Y.Z.)
| | - Svetlana N. Rubtsova
- Institute of Carcinogenesis, N.N. Blokhin National Medical Research Center of Oncology, 24 Kashirskoye Shosse, 115478 Moscow, Russia; (A.S.I.); (N.I.L.); (S.N.R.); (I.Y.Z.)
| | - Irina Y. Zhitnyak
- Institute of Carcinogenesis, N.N. Blokhin National Medical Research Center of Oncology, 24 Kashirskoye Shosse, 115478 Moscow, Russia; (A.S.I.); (N.I.L.); (S.N.R.); (I.Y.Z.)
- Department of Molecular Genetics, University of Toronto, 661 University Ave, MaRS West, Toronto, ON 5MG 1M1, Canada
| | - Natalya A. Gloushankova
- Institute of Carcinogenesis, N.N. Blokhin National Medical Research Center of Oncology, 24 Kashirskoye Shosse, 115478 Moscow, Russia; (A.S.I.); (N.I.L.); (S.N.R.); (I.Y.Z.)
| |
Collapse
|
4
|
Xiong T, Zhang Z, Fan T, Ye F, Ye Z. Origin, evolution, and diversification of inositol 1,4,5-trisphosphate 3-kinases in plants and animals. BMC Genomics 2024; 25:350. [PMID: 38589807 PMCID: PMC11000326 DOI: 10.1186/s12864-024-10257-7] [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: 01/25/2024] [Accepted: 03/26/2024] [Indexed: 04/10/2024] Open
Abstract
BACKGROUND In Eukaryotes, inositol polyphosphates (InsPs) represent a large family of secondary messengers and play crucial roes in various cellular processes. InsPs are synthesized through a series of pohophorylation reactions catalyzed by various InsP kinases in a sequential manner. Inositol 1,4,5-trisphosphate 3-kinase (IP3 3-kinase/IP3K), one member of InsP kinase, plays important regulation roles in InsPs metabolism by specifically phosphorylating inositol 1,4,5-trisphosphate (IP3) to inositol 1,3,4,5-tetrakisphosphate (IP4) in animal cells. IP3Ks were widespread in fungi, plants and animals. However, its evolutionary history and patterns have not been examined systematically. RESULTS A total of 104 and 31 IP3K orthologues were identified across 57 plant genomes and 13 animal genomes, respectively. Phylogenetic analyses indicate that IP3K originated in the common ancestor before the divergence of fungi, plants and animals. In most plants and animals, IP3K maintained low-copy numbers suggesting functional conservation during plant and animal evolution. In Brassicaceae and vertebrate, IP3K underwent one and two duplication events, respectively, resulting in multiple gene copies. Whole-genome duplication (WGD) was the main mechanism for IP3K duplications, and the IP3K duplicates have experienced functional divergence. Finally, a hypothetical evolutionary model for the IP3K proteins is proposed based on phylogenetic theory. CONCLUSION Our study reveals the evolutionary history of IP3K proteins and guides the future functions of animal, plant, and fungal IP3K proteins.
Collapse
Affiliation(s)
- Tao Xiong
- School of Life and Health Science, Huzhou College, Huzhou, Zhejiang, China
- College of Life Science, Xinyang Normal University, Xinyang, Henan, China
| | - Zaibao Zhang
- School of Life and Health Science, Huzhou College, Huzhou, Zhejiang, China.
- College of Life Science, Xinyang Normal University, Xinyang, Henan, China.
| | - Tianyu Fan
- School of Life and Health Science, Huzhou College, Huzhou, Zhejiang, China
| | - Fan Ye
- College of Forestry and Biotechnology, Zhejiang A & F University, Hangzhou, Zhejiang, China
| | - Ziyi Ye
- School of Life and Health Science, Huzhou College, Huzhou, Zhejiang, China
| |
Collapse
|
5
|
Quintanilla MA, Patel H, Wu H, Sochacki KA, Chandrasekar S, Akamatsu M, Rotty JD, Korobova F, Bear JE, Taraska JW, Oakes PW, Beach JR. Local monomer levels and established filaments potentiate non-muscle myosin 2 assembly. J Cell Biol 2024; 223:e202305023. [PMID: 38353656 PMCID: PMC10866686 DOI: 10.1083/jcb.202305023] [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: 05/05/2023] [Revised: 01/02/2024] [Accepted: 01/26/2024] [Indexed: 02/16/2024] Open
Abstract
The ability to dynamically assemble contractile networks is required throughout cell physiology, yet direct biophysical mechanisms regulating non-muscle myosin 2 filament assembly in living cells are lacking. Here, we use a suite of dynamic, quantitative imaging approaches to identify deterministic factors that drive myosin filament appearance and amplification. We find that actin dynamics regulate myosin assembly, but that the static actin architecture plays a less clear role. Instead, remodeling of actin networks modulates the local myosin monomer levels and facilitates assembly through myosin:myosin-driven interactions. Using optogenetically controlled myosin, we demonstrate that locally concentrating myosin is sufficient to both form filaments and jump-start filament amplification and partitioning. By counting myosin monomers within filaments, we demonstrate a myosin-facilitated assembly process that establishes filament stacks prior to partitioning into clusters that feed higher-order networks. Together, these findings establish the biophysical mechanisms regulating the assembly of non-muscle contractile structures that are ubiquitous throughout cell biology.
Collapse
Affiliation(s)
- Melissa A. Quintanilla
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Hiral Patel
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Huini Wu
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Kem A. Sochacki
- Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Shreya Chandrasekar
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Matthew Akamatsu
- Department of Biology, University of Washington, Seattle, WA, USA
| | - Jeremy D. Rotty
- Department of Biochemistry, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Farida Korobova
- Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - James E. Bear
- Department of Cell Biology and Physiology, University of North Carolina-Chapel Hill, Chapel Hill, NC, USA
| | - Justin W. Taraska
- Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Patrick W. Oakes
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Jordan R. Beach
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| |
Collapse
|
6
|
Bedi A, Choi K, Keane C, Bolger-Munro M, Ambrose AR, Gold MR. WAVE2 Regulates Actin-Dependent Processes Induced by the B Cell Antigen Receptor and Integrins. Cells 2023; 12:2704. [PMID: 38067132 PMCID: PMC10705906 DOI: 10.3390/cells12232704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 11/22/2023] [Accepted: 11/22/2023] [Indexed: 12/18/2023] Open
Abstract
B cell antigen receptor (BCR) signaling induces actin cytoskeleton remodeling by stimulating actin severing, actin polymerization, and the nucleation of branched actin networks via the Arp2/3 complex. This enables B cells to spread on antigen-bearing surfaces in order to increase antigen encounters and to form an immune synapse (IS) when interacting with antigen-presenting cells (APCs). Although the WASp, N-WASp, and WAVE nucleation-promoting factors activate the Arp2/3 complex, the role of WAVE2 in B cells has not been directly assessed. We now show that both WAVE2 and the Arp2/3 complex localize to the peripheral ring of branched F-actin when B cells spread on immobilized anti-Ig antibodies. The siRNA-mediated depletion of WAVE2 reduced and delayed B cell spreading on immobilized anti-Ig, and this was associated with a thinner peripheral F-actin ring and reduced actin retrograde flow compared to control cells. Depleting WAVE2 also impaired integrin-mediated B cell spreading on fibronectin and the LFA-1-induced formation of actomyosin arcs. Actin retrograde flow amplifies BCR signaling at the IS, and we found that depleting WAVE2 reduced microcluster-based BCR signaling and signal amplification at the IS, as well as B cell activation in response to antigen-bearing cells. Hence, WAVE2 contributes to multiple actin-dependent processes in B lymphocytes.
Collapse
Affiliation(s)
- Abhishek Bedi
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T1Z3, Canada
| | - Kate Choi
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T1Z3, Canada
| | - Connor Keane
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T1Z3, Canada
| | - Madison Bolger-Munro
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T1Z3, Canada
| | - Ashley R Ambrose
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T1Z3, Canada
| | - Michael R Gold
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T1Z3, Canada
| |
Collapse
|
7
|
Dahlstroem C, Paraschiakos T, Sun H, Windhorst S. Cryo-EM structures of actin binding proteins as tool for drug discovery. Biochem Pharmacol 2023:115680. [PMID: 37399949 DOI: 10.1016/j.bcp.2023.115680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 06/29/2023] [Accepted: 06/29/2023] [Indexed: 07/05/2023]
Abstract
Cellular actin dynamic is controlled by a plethora of actin binding proteins (ABPs), including actin nucleating, bundling, cross-linking, capping, and severing proteins. In this review, regulation of actin dynamics by ABPs will be introduced, and the role of the F-actin severing protein cofilin-1 and the F-actin bundling protein L-plastin in actin dynamics discussed in more detail. Since up-regulation of these proteins in different kinds of cancers is associated with malignant progression of cancer cells, we suggest the cryogenic electron microscopy (Cryo-EM) structure of F- actin with the respective ABP as template for in silico drug design to specifically disrupt the interaction of these ABPs with F-actin.
Collapse
Affiliation(s)
- Christian Dahlstroem
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg
| | - Themistoklis Paraschiakos
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg
| | - Han Sun
- Structural Chemistry and Computational Biophysics Group, Leipniz-Forschungsinstitut für Moekulare Pharmakologie, Robert-Rössle-Strasse 10, D-13125, Berlin; Institute of Chemistry, Technical University of Berlin, D-10623, Berlin
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg.
| |
Collapse
|
8
|
Ignácz A, Nagy-Herczeg D, Hausser A, Schlett K. Dendritic effects of genetically encoded actin-labeling probes in cultured hippocampal neurons. Mol Biol Cell 2023; 34:br8. [PMID: 36989034 PMCID: PMC10295473 DOI: 10.1091/mbc.e22-08-0331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 03/14/2023] [Accepted: 03/20/2023] [Indexed: 03/30/2023] Open
Abstract
Actin cytoskeleton predominantly regulates the formation and maintenance of synapses by controlling dendritic spine morphology and motility. To visualize actin dynamics, actin molecules can be labeled by genetically fusing fluorescent proteins to actin monomers, actin-binding proteins, or single-chain anti-actin antibodies. In the present study, we compared the dendritic effect of EGFP-actin, LifeAct-TagGFP2 (LifeAct-GFP), and Actin-Chromobody-TagGFP2 (AC-GFP) in mouse cultured hippocampal neurons using unbiased quantitative methods. The actin-binding probes LifeAct-GFP and AC-GFP showed similar affinity to F-actin, but in contrast to EGFP-actin, they did not reveal subtle changes in actin remodeling between mushroom-shaped spines and filopodia. All tested actin probes colocalized with phalloidin similarly; however, the enrichment of LifeAct-GFP in dendritic spines was remarkably lower compared with the other constructs. LifeAct-GFP expression was tolerated at a higher expression level compared with EGFP-actin and AC-GFP with only subtle differences identified in dendritic spine morphology and protrusion density. While EGFP-actin and LifeAct-GFP expression did not alter dendritic arborization, AC-GFP-expressing neurons displayed a reduced dendritic tree. Thus, although all tested actin probes may be suitable for actin imaging studies, certain limitations should be considered before performing experiments with a particular actin-labeling probe in primary neurons.
Collapse
Affiliation(s)
- Attila Ignácz
- Department of Physiology and Neurobiology, Eötvös Loránd University, Budapest, Hungary
| | - Domonkos Nagy-Herczeg
- Department of Physiology and Neurobiology, Eötvös Loránd University, Budapest, Hungary
| | - Angelika Hausser
- Institute of Cell Biology and Immunology, University of Stuttgart, Stuttgart, Germany
- Stuttgart Research Center Systems Biology, University of Stuttgart, Stuttgart, Germany
| | - Katalin Schlett
- Department of Physiology and Neurobiology, Eötvös Loránd University, Budapest, Hungary
| |
Collapse
|
9
|
Quintanilla MA, Patel H, Wu H, Sochacki KA, Akamatsu M, Rotty JD, Korobova F, Bear JE, Taraska JW, Oakes PW, Beach JR. Local Monomer Levels and Established Filaments Potentiate Non-Muscle Myosin 2 Assembly. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.26.538303. [PMID: 37162845 PMCID: PMC10168331 DOI: 10.1101/2023.04.26.538303] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The ability to dynamically assemble contractile networks is required throughout cell physiology, yet the biophysical mechanisms regulating non-muscle myosin 2 filament assembly in living cells are lacking. Here we use a suite of dynamic, quantitative imaging approaches to identify deterministic factors that drive myosin filament appearance and amplification. We find that actin dynamics regulate myosin assembly, but that the actin architecture plays a minimal direct role. Instead, remodeling of actin networks modulates the local myosin monomer levels and facilitates assembly through myosin:myosin driven interactions. Using optogenetically controlled myosin, we demonstrate that locally concentrating myosin is sufficient to both form filaments and jump-start filament amplification and partitioning. By counting myosin monomers within filaments, we demonstrate a myosin-facilitated assembly process that establishes sub-resolution filament stacks prior to partitioning into clusters that feed higher-order networks. Together these findings establish the biophysical mechanisms regulating the assembly of non-muscle contractile structures that are ubiquitous throughout cell biology.
Collapse
Affiliation(s)
- Melissa A Quintanilla
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL
| | - Hiral Patel
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL
| | - Huini Wu
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL
| | - Kem A Sochacki
- Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD, USA
| | | | - Jeremy D Rotty
- Department of Biochemistry, Uniformed Services University of the Health Sciences, Bethesda, MD
| | - Farida Korobova
- Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - James E Bear
- Department of Cell Biology and Physiology, University of North Carolina-Chapel Hill, Chapel Hill, NC
| | - Justin W Taraska
- Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD, USA
| | - Patrick W Oakes
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL
| | - Jordan R Beach
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL
| |
Collapse
|
10
|
Umapathy A, Torten G, Paniagua AE, Chung J, Tomlinson M, Lim C, Williams DS. Spatiotemporal Live-Cell Analysis of Photoreceptor Outer Segment Membrane Ingestion by the Retinal Pigment Epithelium Reveals Actin-Regulated Scission. J Neurosci 2023; 43:2653-2664. [PMID: 36878726 PMCID: PMC10089248 DOI: 10.1523/jneurosci.1726-22.2023] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 01/16/2023] [Accepted: 01/18/2023] [Indexed: 03/08/2023] Open
Abstract
The photoreceptor outer segment (OS) is the phototransductive organelle in the vertebrate retina. OS tips are regularly ingested and degraded by the adjacent retinal pigment epithelium (RPE), offsetting the addition of new disk membrane at the base of the OS. This catabolic role of the RPE is essential for photoreceptor health, with defects in ingestion or degradation underlying different forms of retinal degeneration and blindness. Although proteins required for OS tip ingestion have been identified, spatiotemporal analysis of the ingestion process in live RPE cells is lacking; hence, the literature reflects no common understanding of the cellular mechanisms that affect ingestion. We imaged live RPE cells from mice (both sexes) to elucidate the ingestion events in real time. Our imaging revealed roles for f-actin dynamics and specific dynamic localizations of two BAR (Bin-Amphiphysin-Rvs) proteins, FBP17 and AMPH1-BAR, in shaping the RPE apical membrane as it surrounds the OS tip. Completion of ingestion was observed to occur by scission of the OS tip from the remainder of the OS, with a transient concentration of f-actin forming around the site of imminent scission. Actin dynamics were also required for regulating the size of the ingested OS tip, and the time course of the overall ingestion process. The size of the ingested tip is consistent with the term "phagocytosis." However, phagocytosis usually refers to engulfment of an entire particle or cell, whereas our observations of OS tip scission indicate a process that is more specifically described as "trogocytosis," in which one cell "nibbles" another cell.SIGNIFICANCE STATEMENT The ingestion of the photoreceptor outer segment (OS) tips by the retinal pigment epithelium (RPE) is a dynamic cellular process that has fascinated scientists for 60 years. Yet its molecular mechanisms had not been addressed in living cells. We developed a live-cell imaging approach to investigate OS tip ingestion, and focused on the dynamic participation of actin filaments and membrane-shaping BAR proteins. We observed scission of OS tips for the first time, and were able to monitor local changes in protein concentration preceding, during, and following scission. Our approach revealed that actin filaments were concentrated at the site of OS scission and were required for regulating the size of the ingested OS tip and the time course of the ingestion process.
Collapse
Affiliation(s)
- Ankita Umapathy
- Department of Ophthalmology and Stein Eye Institute, and Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095
| | - Gil Torten
- Department of Ophthalmology and Stein Eye Institute, and Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095
| | - Antonio E Paniagua
- Department of Ophthalmology and Stein Eye Institute, and Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095
| | - Julie Chung
- Department of Ophthalmology and Stein Eye Institute, and Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095
| | - Madeline Tomlinson
- Department of Ophthalmology and Stein Eye Institute, and Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095
| | - Caleb Lim
- Department of Ophthalmology and Stein Eye Institute, and Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095
| | - David S Williams
- Department of Ophthalmology and Stein Eye Institute, and Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095
| |
Collapse
|
11
|
Ebrahimkutty M, Duan J, Nüsse H, Klingauf J, Galic M. Negatively curved cellular membranes promote BAIAP2 signaling hub assembly. NANOSCALE 2023; 15:6759-6769. [PMID: 36943331 DOI: 10.1039/d2nr05719k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Plasma membrane deformations are associated with curvature-dependent protein enrichment that contributes to a wide array of cellular functions. While the spatio-temporal protein dynamics at membrane indentations is well characterized, relatively little is known about protein kinetics at outwardly deforming membrane sites. This is in part due to the lack of high throughput approaches to systematically probe the curvature-dependence of protein-membrane interactions. Here, we developed a nanopatterned array for multiplexed analysis of protein dynamics at negatively curved cellular membranes. Taking advantage of this robust and versatile platform, we explored how membrane shape influences the prototypic negative curvature sensing protein BAIAP2 and its effector proteins. We find assembly of multi-protein signaling hubs and increased actin polymerization at outwardly deformed membrane sections, indicative of curvature-dependent BAIAP2 activation. Collectively, this study presents technical and conceptual advancements towards a quantitative understanding of spatio-temporal protein dynamics at negatively curved membranes.
Collapse
Affiliation(s)
- Mirsana Ebrahimkutty
- Institute of Medical Physics and Biophysics, University of Muenster, Germany.
- 'Cells in Motion' Interfaculty Centre, University of Muenster, Germany
- CIM-IMPRS Graduate School, Muenster, Germany
| | - Junxiu Duan
- Institute of Medical Physics and Biophysics, University of Muenster, Germany.
- 'Cells in Motion' Interfaculty Centre, University of Muenster, Germany
- CIM-IMPRS Graduate School, Muenster, Germany
| | - Harald Nüsse
- Institute of Medical Physics and Biophysics, University of Muenster, Germany.
| | - Jürgen Klingauf
- Institute of Medical Physics and Biophysics, University of Muenster, Germany.
- 'Cells in Motion' Interfaculty Centre, University of Muenster, Germany
| | - Milos Galic
- Institute of Medical Physics and Biophysics, University of Muenster, Germany.
- 'Cells in Motion' Interfaculty Centre, University of Muenster, Germany
| |
Collapse
|
12
|
Urrutia PJ, González-Billault C. A Role for Second Messengers in Axodendritic Neuronal Polarity. J Neurosci 2023; 43:2037-2052. [PMID: 36948585 PMCID: PMC10039749 DOI: 10.1523/jneurosci.1065-19.2023] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 02/07/2023] [Accepted: 02/10/2023] [Indexed: 03/24/2023] Open
Abstract
Neuronal polarization is a complex molecular process regulated by intrinsic and extrinsic mechanisms. Nerve cells integrate multiple extracellular cues to generate intracellular messengers that ultimately control cell morphology, metabolism, and gene expression. Therefore, second messengers' local concentration and temporal regulation are crucial elements for acquiring a polarized morphology in neurons. This review article summarizes the main findings and current understanding of how Ca2+, IP3, cAMP, cGMP, and hydrogen peroxide control different aspects of neuronal polarization, and highlights questions that still need to be resolved to fully understand the fascinating cellular processes involved in axodendritic polarization.
Collapse
Affiliation(s)
- Pamela J Urrutia
- Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile 7800003
- School of Medical Technology, Faculty of Medicine and Science, Universidad San Sebastián, Santiago, Chile 7510157
| | - Christian González-Billault
- Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile 7800003
- Department of Neurosciences, Faculty of Medicine, Universidad de Chile, Santiago, Chile 8380453
- Geroscience Center for Brain Health and Metabolism, Santiago, Chile 7800003
- Buck Institute for Research on Aging, Novato, California 94945
| |
Collapse
|
13
|
Schäfer P, Muhs S, Turnbull L, Garwal P, Maar H, Yorgan TA, Tolosa E, Lange T, Windhorst S. Ex Vivo Model of Neuroblastoma Plasticity. Cancers (Basel) 2023; 15:cancers15041274. [PMID: 36831616 PMCID: PMC9954615 DOI: 10.3390/cancers15041274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 02/10/2023] [Accepted: 02/11/2023] [Indexed: 02/19/2023] Open
Abstract
Tumor plasticity is essential for adaptation to changing environmental conditions, in particular during the process of metastasis. In this study, we compared morphological and biochemical differences between LAN-1 neuroblastoma (NB) cells recovered from a subcutaneous xenograft primary tumor (PT) and the corresponding three generations of bone metastasis (BM I-III). Moreover, growth behavior, as well as the response to chemotherapy and immune cells were assessed. For this purpose, F-actin was stained, mRNA and protein expression assessed, and lactate secretion analyzed. Further, we measured adhesion to collagen I, the growth rate of spheroids in the presence and absence of vincristine, and the production of IL-6 by peripheral blood mononuclear cells (PBMCs) co-incubated with PT or BM I-III. Analysis of PT and the three BM generations revealed that their growth rate decreased from PT to BM III, and accordingly, PT cells reacted most sensitively to vincristine. In addition, morphology, adaption to hypoxic conditions, as well as transcriptomes showed strong differences between the cell lines. Moreover, BM I and BM II cells exhibited a significantly different ability to stimulate human immune cells compared to PT and BM III cells. Interestingly, the differences in immune cell stimulation corresponded to the expression level of the cancer-testis antigen MAGE-A3. In conclusion, our ex vivo model allows to analyze the adaption of tumor populations to different microenvironments and clearly demonstrates the strong alteration of tumor cell populations during this process.
Collapse
Affiliation(s)
- Paula Schäfer
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Stefanie Muhs
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Lucas Turnbull
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Palwasha Garwal
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Hanna Maar
- Institute of Anatomy and Experimental Morphology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Timur A. Yorgan
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Eva Tolosa
- Department of Immunology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Tobias Lange
- Institute of Anatomy and Experimental Morphology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
- Institute of Anatomy I, Jena University Hospital, Teichgraben 7, D-07743 Jena, Germany
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
- Correspondence: ; Tel.: +49-40-7410-56013
| |
Collapse
|
14
|
The actin bundling activity of ITPKA mainly accounts for its migration-promoting effect in lung cancer cells. Biosci Rep 2023; 43:232487. [PMID: 36688944 PMCID: PMC9912108 DOI: 10.1042/bsr20222150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 12/29/2022] [Accepted: 01/09/2023] [Indexed: 01/24/2023] Open
Abstract
Expression of Ins(1,4,5)P3-kinase-A (ITPKA), the neuronal isoform of Ins(1,4,5)P3-kinases, is up-regulated in many tumor types. In particular, in lung cancer cells this up-regulation is associated with bad prognosis and it has been shown that a high level of ITPKA increases migration and invasion of lung cancer cell lines. However, since ITPKA exhibits actin bundling and Ins(1,4,5)P3-kinase activity, it was not clear which of these activities account for ITPKA-promoted migration and invasion of cancer cells. To address this issue, we inhibited endogenous actin bundling activity of ITPKA in lung cancer H1299 cells by overexpressing the dominant negative mutant ITPKAL34P. Analysis of actin dynamics in filopodia as well as wound-healing migration revealed that ITPKAL34P inhibited both processes. Moreover, the formation of invasive protrusions into collagen I was strongly blocked in cells overexpressing ITPKAL34P. Furthermore, we found that ATP stimulation slightly but significantly (by 13%) increased migration of cells overexpressing ITPKA while under basal conditions up-regulation of ITPKA had no effect. In accordance with these results, overexpression of a catalytic inactive ITPKA mutant did not affect migration, and the Ins(1,4,5)P3-kinase-inhibitor GNF362 reversed the stimulating effect of ITPKA overexpression on migration. In summary, we demonstrate that under basal conditions the actin bundling activity controls ITPKA-facilitated migration and invasion and in presence of ATP the Ins(1,4,5)P3-kinase activity slightly enhances this effect.
Collapse
|
15
|
Radler MR, Liu X, Peng M, Doyle B, Toyo-Oka K, Spiliotis ET. Pyramidal neuron morphogenesis requires a septin network that stabilizes filopodia and suppresses lamellipodia during neurite initiation. Curr Biol 2023; 33:434-448.e8. [PMID: 36538929 PMCID: PMC9905282 DOI: 10.1016/j.cub.2022.11.043] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 10/31/2022] [Accepted: 11/18/2022] [Indexed: 12/23/2022]
Abstract
Pyramidal neurons are a major cell type of the forebrain, consisting of a pyramidally shaped soma with axonal and apicobasal dendritic processes. It is poorly understood how the neuronal soma develops its pyramidal morphology, while generating neurites of the proper shape and orientation. Here, we discovered that the spherical somata of immature neurite-less neurons possess a circumferential wreath-like network of septin filaments, which promotes neuritogenesis by balancing the protrusive activity of lamellipodia and filopodia. In embryonic rat hippocampal and mouse cortical neurons, the septin wreath network consists of curvilinear filaments that contain septins 5, 7, and 11 (Sept5/7/11). The Sept5/7/11 wreath network demarcates a zone of myosin II enrichment and Arp2/3 diminution at the base of filopodial actin bundles. In Sept7-depleted neurons, cell bodies are enlarged with hyperextended lamellae and abnormally shaped neurites that originate from lamellipodia. This phenotype is accompanied by diminished myosin II and filopodia lifetimes and increased Arp2/3 and lamellipodial activity. Inhibition of Arp2/3 rescues soma and neurite phenotypes, indicating that the septin wreath network suppresses the extension of lamellipodia, facilitating the formation of neurites from the filopodia of a consolidated soma. We show that this septin function is critical for developing a pyramidally shaped soma with properly distributed and oriented dendrites in cultured rat hippocampal neurons and in vivo in mouse perinatal cortical neurons. Therefore, the somatic septin cytoskeleton provides a key morphogenetic mechanism for neuritogenesis and the development of pyramidal neurons.
Collapse
Affiliation(s)
- Megan R Radler
- Department of Biology, Drexel University, 3245 Chestnut Street, Philadelphia, PA 19104, USA
| | - Xiaonan Liu
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA
| | - Megan Peng
- Department of Biology, Drexel University, 3245 Chestnut Street, Philadelphia, PA 19104, USA
| | - Brenna Doyle
- Department of Biology, Drexel University, 3245 Chestnut Street, Philadelphia, PA 19104, USA
| | - Kazuhito Toyo-Oka
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA
| | - Elias T Spiliotis
- Department of Biology, Drexel University, 3245 Chestnut Street, Philadelphia, PA 19104, USA.
| |
Collapse
|
16
|
Cho IS, Gupta P, Mostafazadeh N, Wong SW, Saichellappa S, Lenzini S, Peng Z, Shin J. Deterministic Single Cell Encapsulation in Asymmetric Microenvironments to Direct Cell Polarity. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2206014. [PMID: 36453581 PMCID: PMC9875620 DOI: 10.1002/advs.202206014] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Indexed: 06/17/2023]
Abstract
Various signals in tissue microenvironments are often unevenly distributed around cells. Cellular responses to asymmetric cell-matrix adhesion in a 3D space remain generally unclear and are to be studied at the single-cell resolution. Here, the authors developed a droplet-based microfluidic approach to manufacture a pure population of single cells in a microscale layer of compartmentalized 3D hydrogel matrices with a tunable spatial presentation of ligands at the subcellular level. Cells elongate with an asymmetric presentation of the integrin adhesion ligand Arg-Gly-Asp (RGD), while cells expand isotropically with a symmetric presentation of RGD. Membrane tension is higher on the side of single cells interacting with RGD than on the side without RGD. Finite element analysis shows that a non-uniform isotropic cell volume expansion model is sufficient to recapitulate the experimental results. At a longer timescale, asymmetric ligand presentation commits mesenchymal stem cells to the osteogenic lineage. Cdc42 is an essential mediator of cell polarization and lineage specification in response to asymmetric cell-matrix adhesion. This study highlights the utility of precisely controlling 3D ligand presentation around single cells to direct cell polarity for regenerative engineering and medicine.
Collapse
Affiliation(s)
- Ik Sung Cho
- Department of Pharmacology and Regenerative MedicineUniversity of Illinois at Chicago College of MedicineChicagoIL60612USA
- Department of Biomedical EngineeringUniversity of Illinois at ChicagoChicagoIL60607USA
| | - Prerak Gupta
- Department of Pharmacology and Regenerative MedicineUniversity of Illinois at Chicago College of MedicineChicagoIL60612USA
- Department of Biomedical EngineeringUniversity of Illinois at ChicagoChicagoIL60607USA
| | - Nima Mostafazadeh
- Department of Biomedical EngineeringUniversity of Illinois at ChicagoChicagoIL60607USA
| | - Sing Wan Wong
- Department of Pharmacology and Regenerative MedicineUniversity of Illinois at Chicago College of MedicineChicagoIL60612USA
- Department of Biomedical EngineeringUniversity of Illinois at ChicagoChicagoIL60607USA
| | - Saiumamaheswari Saichellappa
- Department of Pharmacology and Regenerative MedicineUniversity of Illinois at Chicago College of MedicineChicagoIL60612USA
- Department of Biomedical EngineeringUniversity of Illinois at ChicagoChicagoIL60607USA
| | - Stephen Lenzini
- Department of Pharmacology and Regenerative MedicineUniversity of Illinois at Chicago College of MedicineChicagoIL60612USA
- Department of Biomedical EngineeringUniversity of Illinois at ChicagoChicagoIL60607USA
| | - Zhangli Peng
- Department of Biomedical EngineeringUniversity of Illinois at ChicagoChicagoIL60607USA
| | - Jae‐Won Shin
- Department of Pharmacology and Regenerative MedicineUniversity of Illinois at Chicago College of MedicineChicagoIL60612USA
- Department of Biomedical EngineeringUniversity of Illinois at ChicagoChicagoIL60607USA
| |
Collapse
|
17
|
Chakrabarti R, Fung TS, Kang T, Elonkirjo PW, Suomalainen A, Usherwood EJ, Higgs HN. Mitochondrial dysfunction triggers actin polymerization necessary for rapid glycolytic activation. J Cell Biol 2022; 221:213462. [PMID: 36102863 PMCID: PMC9477750 DOI: 10.1083/jcb.202201160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 06/02/2022] [Accepted: 08/25/2022] [Indexed: 11/22/2022] Open
Abstract
Mitochondrial damage represents a dramatic change in cellular homeostasis. One rapid response is perimitochondrial actin polymerization, termed acute damage-induced actin (ADA). The consequences of ADA are not understood. In this study, we show evidence suggesting that ADA is linked to rapid glycolytic activation upon mitochondrial damage in multiple cells, including mouse embryonic fibroblasts and effector CD8+ T lymphocytes. ADA-inducing treatments include CCCP, antimycin, rotenone, oligomycin, and hypoxia. The Arp2/3 complex inhibitor CK666 or the mitochondrial sodium-calcium exchanger (NCLX) inhibitor CGP37157 inhibits both ADA and the glycolytic increase within 5 min, supporting ADA's role in glycolytic stimulation. Two situations causing chronic reductions in mitochondrial ATP production, mitochondrial DNA depletion and mutation to the NDUFS4 subunit of complex 1 of the electron transport chain, cause persistent perimitochondrial actin filaments similar to ADA. CK666 treatment causes rapid mitochondrial actin loss and a drop in ATP in NDUFS4 knock-out cells. We propose that ADA is necessary for rapid glycolytic activation upon mitochondrial impairment, to re-establish ATP production.
Collapse
Affiliation(s)
- Rajarshi Chakrabarti
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH
| | - Tak Shun Fung
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH
| | - Taewook Kang
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH
| | - Pieti W Elonkirjo
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Anu Suomalainen
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Edward J Usherwood
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth College, Hanover, NH
| | - Henry N Higgs
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH
| |
Collapse
|
18
|
Hill NS, Welch MD. A glycine-rich PE_PGRS protein governs mycobacterial actin-based motility. Nat Commun 2022; 13:3608. [PMID: 35750685 PMCID: PMC9232537 DOI: 10.1038/s41467-022-31333-0] [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: 09/27/2021] [Accepted: 06/14/2022] [Indexed: 11/09/2022] Open
Abstract
Many key insights into actin regulation have been derived through examining how microbial pathogens intercept the actin cytoskeleton during infection. Mycobacterium marinum, a close relative of the human pathogen Mycobacterium tuberculosis, polymerizes host actin at the bacterial surface to drive intracellular movement and cell-to-cell spread during infection. However, the mycobacterial factor that commandeers actin polymerization has remained elusive. Here, we report the identification and characterization of the M. marinum actin-based motility factor designated mycobacterial intracellular rockets A (MirA), which is a member of the glycine-rich PE_PGRS protein family. MirA contains an amphipathic helix to anchor into the mycobacterial outer membrane and, surprisingly, also the surface of host lipid droplet organelles. MirA directly binds to and activates the host protein N-WASP to stimulate actin polymerization through the Arp2/3 complex, directing both bacterial and lipid droplet actin-based motility. MirA is dissimilar to known N-WASP activating ligands and may represent a new class of microbial and host actin regulator. Additionally, the MirA-N-WASP interaction represents a model to understand how the enigmatic PE_PGRS proteins contribute to mycobacterial pathogenesis.
Collapse
Affiliation(s)
- Norbert S Hill
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA.
| | - Matthew D Welch
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA.
| |
Collapse
|
19
|
Kage F, Vicente-Manzanares M, McEwan BC, Kettenbach AN, Higgs HN. Myosin II proteins are required for organization of calcium-induced actin networks upstream of mitochondrial division. Mol Biol Cell 2022; 33:ar63. [PMID: 35427150 PMCID: PMC9561854 DOI: 10.1091/mbc.e22-01-0005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The formin INF2 polymerizes a calcium-activated cytoplasmic network of actin filaments, which we refer to as calcium-induced actin polymerization (CIA). CIA plays important roles in multiple cellular processes, including mitochondrial dynamics and vesicle transport. Here, we show that nonmuscle myosin II (NMII) is activated within 60 s of calcium stimulation and rapidly recruited to the CIA network. Knockout of any individual NMII in U2OS cells affects the organization of the CIA network, as well as three downstream effects: endoplasmic-reticulum-to-mitochondrial calcium transfer, mitochondrial Drp1 recruitment, and mitochondrial division. Interestingly, while NMIIC is the least abundant NMII in U2OS cells (>200-fold less than NMIIA and >10-fold less than NMIIB), its knockout is equally deleterious to CIA. On the basis of these results, we propose that myosin II filaments containing all three NMII heavy chains exert organizational and contractile roles in the CIA network. In addition, NMIIA knockout causes a significant decrease in myosin regulatory light chain levels, which might have additional effects.
Collapse
Affiliation(s)
- Frieda Kage
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover NH 03755, USA
| | - Miguel Vicente-Manzanares
- Centro de Investigacion del Cancer/Instituto de Biologia Molecular y Celular del Cancer, Centro Mixto Universidad de Salamanca, 37007 Salamanca, Spain
| | - Brennan C. McEwan
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover NH 03755, USA
- Program in Cancer Biology, Geisel School of Medicine at Dartmouth College, Hanover NH 03755, USA
| | - Arminja N. Kettenbach
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover NH 03755, USA
- Program in Cancer Biology, Geisel School of Medicine at Dartmouth College, Hanover NH 03755, USA
| | - Henry N. Higgs
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover NH 03755, USA
| |
Collapse
|
20
|
Fung TS, Chakrabarti R, Kollasser J, Rottner K, Stradal TE, Kage F, Higgs HN. Parallel kinase pathways stimulate actin polymerization at depolarized mitochondria. Curr Biol 2022; 32:1577-1592.e8. [PMID: 35290799 PMCID: PMC9078333 DOI: 10.1016/j.cub.2022.02.058] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 02/04/2022] [Accepted: 02/21/2022] [Indexed: 12/31/2022]
Abstract
Mitochondrial damage (MtD) represents a dramatic change in cellular homeostasis, necessitating metabolic changes and stimulating mitophagy. One rapid response to MtD is a rapid peri-mitochondrial actin polymerization termed ADA (acute damage-induced actin). The activation mechanism for ADA is unknown. Here, we use mitochondrial depolarization or the complex I inhibitor metformin to induce ADA. We show that two parallel signaling pathways are required for ADA. In one pathway, increased cytosolic calcium in turn activates PKC-β, Rac, WAVE regulatory complex, and Arp2/3 complex. In the other pathway, a drop in cellular ATP in turn activates AMPK (through LKB1), Cdc42, and FMNL formins. We also identify putative guanine nucleotide exchange factors for Rac and Cdc42, Trio and Fgd1, respectively, whose phosphorylation states increase upon mitochondrial depolarization and whose suppression inhibits ADA. The depolarization-induced calcium increase is dependent on the mitochondrial sodium-calcium exchanger NCLX, suggesting initial mitochondrial calcium efflux. We also show that ADA inhibition results in enhanced mitochondrial shape changes upon mitochondrial depolarization, suggesting that ADA inhibits these shape changes. These depolarization-induced shape changes are not fragmentation but a circularization of the inner mitochondrial membrane, which is dependent on the inner mitochondrial membrane protease Oma1. ADA inhibition increases the proteolytic processing of an Oma1 substrate, the dynamin GTPase Opa1. These results show that ADA requires the combined action of the Arp2/3 complex and formin proteins to polymerize a network of actin filaments around mitochondria and that the ADA network inhibits the rapid mitochondrial shape changes that occur upon mitochondrial depolarization.
Collapse
|
21
|
Lu W, Lakonishok M, Serpinskaya AS, Gelfand VI. A novel mechanism of bulk cytoplasmic transport by cortical dynein in Drosophila ovary. eLife 2022; 11:75538. [PMID: 35170428 PMCID: PMC8896832 DOI: 10.7554/elife.75538] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 02/16/2022] [Indexed: 11/22/2022] Open
Abstract
Cytoplasmic dynein, a major minus-end directed microtubule motor, plays essential roles in eukaryotic cells. Drosophila oocyte growth is mainly dependent on the contribution of cytoplasmic contents from the interconnected sister cells, nurse cells. We have previously shown that cytoplasmic dynein is required for Drosophila oocyte growth and assumed that it simply transports cargoes along microtubule tracks from nurse cells to the oocyte. Here, we report that instead of transporting individual cargoes along stationary microtubules into the oocyte, cortical dynein actively moves microtubules within nurse cells and from nurse cells to the oocyte via the cytoplasmic bridges, the ring canals. This robust microtubule movement is sufficient to drag even inert cytoplasmic particles through the ring canals to the oocyte. Furthermore, replacing dynein with a minus-end directed plant kinesin linked to the actin cortex is sufficient for transporting organelles and cytoplasm to the oocyte and driving its growth. These experiments show that cortical dynein performs bulk cytoplasmic transport by gliding microtubules along the cell cortex and through the ring canals to the oocyte. We propose that the dynein-driven microtubule flow could serve as a novel mode of fast cytoplasmic transport.
Collapse
Affiliation(s)
- Wen Lu
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Margot Lakonishok
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Anna S Serpinskaya
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Vladimir I Gelfand
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| |
Collapse
|
22
|
Rear traction forces drive adherent tissue migration in vivo. Nat Cell Biol 2022; 24:194-204. [PMID: 35165417 PMCID: PMC8868490 DOI: 10.1038/s41556-022-00844-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 01/06/2022] [Indexed: 12/16/2022]
|
23
|
Li C, Liu K, Dai J, Li X, Liu X, Ni W, Li H, Wang D, Qiao J, Wang Y, Cui Y, Xia X, Hu S. Whole-genome resequencing to investigate the determinants of the multi-lumbar vertebrae trait in sheep. Gene 2022; 809:146020. [PMID: 34656743 DOI: 10.1016/j.gene.2021.146020] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 10/03/2021] [Accepted: 10/11/2021] [Indexed: 12/25/2022]
Abstract
Multi-lumbar vertebrae trait is a beneficial mutation that can significantly improve livestock meat production. However, the genetic basis of the multi-lumbar vertebrae in sheep is still unclear. Here, we analysed the number of lumbar vertebrae of Duolang sheep and found three different traits of lumbar vertebrae number. Compared with the normal sheep, the length and weight of animal carcass from the multi-lumbar vertebrae sheep increased by 2.21 cm and 0.78 kg, respectively. We performed high-throughput genome resequencing on multi-lumbar vertebrae (n = 18) and normal (n = 11) Duolang sheep and obtained a total of more than 528.87 GB data. We found that the most significantly selective region were located in the 49.68-49.74 MB of chromosome 4 by selective-sweep analysis. We annotated this region and found that it contains SFRP4 which is known to regulate bone development. We further used the PCR-SSCP technology to detect the single nucleotide polymorphism (SNP) of the putative candidate SFRP4 and found that the two SNPs (rs600370085:C > T and rs415133338: A > G) of this gene were significantly associated with the multi-lumbar vertebrae of Duolang sheep. Our study indicates that the SFRP4 may be a potential major gene that affects the number of lumbar vertebrae in Duolang sheep, and has the potential to be utilized for sheep breeding in the future.
Collapse
Affiliation(s)
- Cunyuan Li
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang 832003, China; College of Life Science, Shihezi University, Shihezi, Xinjiang 832003, China
| | - Kaiping Liu
- College of Life Science, Shihezi University, Shihezi, Xinjiang 832003, China
| | - Jihong Dai
- College of Life Science, Shihezi University, Shihezi, Xinjiang 832003, China
| | - Xiaoyue Li
- College of Life Science, Shihezi University, Shihezi, Xinjiang 832003, China
| | - Xia Liu
- College of Life Science, Shihezi University, Shihezi, Xinjiang 832003, China
| | - Wei Ni
- College of Life Science, Shihezi University, Shihezi, Xinjiang 832003, China
| | - Hui Li
- College of Life Science, Shihezi University, Shihezi, Xinjiang 832003, China
| | - Dawei Wang
- College of Life Science, Shihezi University, Shihezi, Xinjiang 832003, China
| | - Jun Qiao
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang 832003, China.
| | - Yue Wang
- College of Life Science, Shihezi University, Shihezi, Xinjiang 832003, China
| | - Yuying Cui
- College of Life Science, Shihezi University, Shihezi, Xinjiang 832003, China
| | - Xianzhu Xia
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang 832003, China.
| | - Shengwei Hu
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang 832003, China; College of Life Science, Shihezi University, Shihezi, Xinjiang 832003, China.
| |
Collapse
|
24
|
Liu T, Song J, Zhou Q, Chu S, Liu Y, Zhao X, Ma Z, Xia T, Gu X. The role of 5-HT 7R in the memory impairment of mice induced by long-term isoflurane anesthesia. Neurobiol Learn Mem 2022; 188:107584. [PMID: 35032676 DOI: 10.1016/j.nlm.2022.107584] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 12/21/2021] [Accepted: 01/04/2022] [Indexed: 10/19/2022]
Abstract
General anesthesia is widely utilized in the clinic for surgical and diagnostic procedures. However, growing evidence suggests that anesthetic exposure may affect cognitive function negatively. Unfortunately, little is known about the underlying mechanisms and efficient prevention and therapeutic strategies for the anesthesia-induced cognitive dysfunction. 5-HT7R, a serotonin receptor family member, is functionally associated with learning and memory. It has recently become a potential therapeutic target in various neurological diseases as its ligands have a wide range of neuropharmacological effects. However, it remains unknown the role of 5-HT7R in the long-term isoflurane anesthesia-induced memory impairment and whether prior activation or blockade of 5-HT7R before anesthesia has modulating effects on this memory impairment. In this study, 5-HT7R selective agonist LP-211 and 5-HT7R selective antagonist SB-269970 were pretreated intraperitoneally to mice before anesthesia; their effects on the cognitive performance of mice were assessed using fear conditioning test and novel object recognition test. Furthermore, the transcriptional level of 5-HT7R in the hippocampus was detected using qRT-PCR, and proteomics was conducted to probe the underlying mechanisms. As a result, long-term exposure to isoflurane anesthesia caused memory impairment and an increase in hippocampal 5-HT7R mRNA expression, which could be attenuated by SB-269970 pretreatment but not LP-211pretreatment. According to the proteomics results, the antiamnestic effect of SB-269970 pretreatment was probably attributed to its action on the gene expression of Slc6a11, Itpka, Arf3, Srcin1, and Epb41l2, and synapse organization in the hippocampus. In conclusion, 5-HT7R is involved in the memory impairment induced by long-term isoflurane anesthesia, and the prior blockade of 5-HT7R with SB-269970 protects the memory impairment. This finding may help to improve the understanding of the long-term isoflurane anesthesia-induced memory impairment and to construct potential preventive and therapeutic strategies for the adverse effects after long-term isoflurane exposure.
Collapse
Affiliation(s)
- Tiantian Liu
- Department of Anesthesiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu Province, China
| | - Jia Song
- Department of Anesthesiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu Province, China
| | - Qingyun Zhou
- Department of Anesthesiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu Province, China
| | - Shuaishuai Chu
- Department of Anesthesiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu Province, China
| | - Yujia Liu
- Department of Anesthesiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu Province, China
| | - Xin Zhao
- Nanjing Stomatology Hospital, Medical School of Nanjing University, Nanjing, Jiangsu Province, China
| | - Zhengliang Ma
- Department of Anesthesiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu Province, China.
| | - Tianjiao Xia
- Department of Anesthesiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu Province, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu Province, China.
| | - Xiaoping Gu
- Department of Anesthesiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu Province, China.
| |
Collapse
|
25
|
Pal D, Visconti F, Sepúlveda-Ramírez SP, Swartz SZ, Shuster CB. Use of Echinoderm Gametes and Early Embryos for Studying Meiosis and Mitosis. Methods Mol Biol 2022; 2415:1-17. [PMID: 34972942 DOI: 10.1007/978-1-0716-1904-9_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The early embryos of sea urchins and other echinoderms have served as experimental models for the study of cell division since the nineteenth century. Their rapid development, optical clarity, and ease of manipulation continue to offer advantages for studying spindle assembly and cytokinesis. In the absence of transgenic lines, alternative strategies must be employed to visualize microtubules and actin. Here, we describe methods to visualize actin and microtubule using either purified, recombinant proteins, or probes in in vitro-transcribed mRNAs.
Collapse
Affiliation(s)
- Debadrita Pal
- Department of Biology, New Mexico State University, Las Cruces, NM, USA
| | | | | | | | - Charles B Shuster
- Department of Biology, New Mexico State University, Las Cruces, NM, USA.
| |
Collapse
|
26
|
Lin H, Ho A, Huang H, Yang B, Shih B, Lin H, Yeh C, Hsu C, Cheng C. STAT3‐mediated gene expression in colorectal cancer cells‐derived cancer stem‐like tumorspheres. ADVANCES IN DIGESTIVE MEDICINE 2021. [DOI: 10.1002/aid2.13223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Hua‐Ching Lin
- Division of Colorectal Surgery Chen Hsin General Hospital Taipei Taiwan
- Department of Healthcare Information and Management Ming Chuan University Taoyuan Taiwan
| | - Ai‐Sheng Ho
- Division of Gastroenterology Cheng Hsin General Hospital Taipei Taiwan
| | - Hsin‐Hung Huang
- Division of Gastroenterology Cheng Hsin General Hospital Taipei Taiwan
| | - Bi‐Ling Yang
- Division of Gastroenterology Cheng Hsin General Hospital Taipei Taiwan
| | - Bin‐Bin Shih
- Division of Gastroenterology Cheng Hsin General Hospital Taipei Taiwan
| | - Hsin‐Chi Lin
- Division of Gastroenterology Cheng Hsin General Hospital Taipei Taiwan
| | - Chun Yeh
- Division of Gastroenterology Cheng Hsin General Hospital Taipei Taiwan
| | - Chung‐Te Hsu
- Division of Gastroenterology Cheng Hsin General Hospital Taipei Taiwan
| | - Chun‐Chia Cheng
- Radiation Biology Research Center Institute for Radiological Research, Chang Gung University/Chang Gung Memorial Hospital at Linkou Taoyuan Taiwan
| |
Collapse
|
27
|
Dendrite tapering actuates a self-organizing signaling circuit for stochastic filopodia initiation in neurons. Proc Natl Acad Sci U S A 2021; 118:2106921118. [PMID: 34686599 DOI: 10.1073/pnas.2106921118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/01/2021] [Indexed: 01/09/2023] Open
Abstract
How signaling units spontaneously arise from a noisy cellular background is not well understood. Here, we show that stochastic membrane deformations can nucleate exploratory dendritic filopodia, dynamic actin-rich structures used by neurons to sample its surroundings for compatible transcellular contacts. A theoretical analysis demonstrates that corecruitment of positive and negative curvature-sensitive proteins to deformed membranes minimizes the free energy of the system, allowing the formation of long-lived curved membrane sections from stochastic membrane fluctuations. Quantitative experiments show that once recruited, curvature-sensitive proteins form a signaling circuit composed of interlinked positive and negative actin-regulatory feedback loops. As the positive but not the negative feedback loop can sense the dendrite diameter, this self-organizing circuit determines filopodia initiation frequency along tapering dendrites. Together, our findings identify a receptor-independent signaling circuit that employs random membrane deformations to simultaneously elicit and limit formation of exploratory filopodia to distal dendritic sites of developing neurons.
Collapse
|
28
|
An In Vitro Model System to Test Mechano-Microbiological Interactions Between Bacteria and Host Cells. Methods Mol Biol 2021. [PMID: 34542856 DOI: 10.1007/978-1-0716-1661-1_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
The aim of this chapter is to present an innovative technique to visualize changes of the F-actin cytoskeleton in response to locally applied force. We developed an in vitro system that combines micromanipulation of force by magnetic tweezers with simultaneous live cell fluorescence microscopy. We applied pulling forces to magnetic beads coated with the Neisseria gonorrhoeae Type IV pili in the same order of magnitude than the forces generated by live bacteria. We saw quick and robust F-actin accumulation in individual cells at the sites where pulling forces were applied. Using the magnetic tweezers, we were able to mimic the local response of the F-actin cytoskeleton to bacteria-generated forces. In this chapter, we describe our magnetic tweezers system and show how to control it in order to study cellular responses to force.
Collapse
|
29
|
Deretic N, Bolger-Munro M, Choi K, Abraham L, Gold MR. The Actin-Disassembly Protein Glia Maturation Factor γ Enhances Actin Remodeling and B Cell Antigen Receptor Signaling at the Immune Synapse. Front Cell Dev Biol 2021; 9:647063. [PMID: 34336818 PMCID: PMC8318000 DOI: 10.3389/fcell.2021.647063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 06/07/2021] [Indexed: 11/16/2022] Open
Abstract
Signaling by the B cell antigen receptor (BCR) initiates actin remodeling. The assembly of branched actin networks that are nucleated by the Arp2/3 complex exert outward force on the plasma membrane, allowing B cells to form membrane protrusions that can scan the surface of antigen-presenting cells (APCs). The resulting Arp2/3 complex-dependent actin retrograde flow promotes the centripetal movement and progressive coalescence of BCR microclusters, which amplifies BCR signaling. Glia maturation factor γ (GMFγ) is an actin disassembly-protein that releases Arp2/3 complex-nucleated actin filaments from actin networks. By doing so, GMFγ could either oppose the actions of the Arp2/3 complex or support Arp2/3 complex-nucleated actin polymerization by contributing to the recycling of actin monomers and Arp2/3 complexes. We now show that reducing the levels of GMFγ in human B cell lines via transfection with a specific siRNA impairs the ability of B cells to spread on antigen-coated surfaces, decreases the velocity of actin retrograde flow, diminishes the coalescence of BCR microclusters into a central cluster at the B cell-APC contact site, and decreases APC-induced BCR signaling. These effects of depleting GMFγ are similar to what occurs when the Arp2/3 complex is inhibited. This suggests that GMFγ cooperates with the Arp2/3 complex to support BCR-induced actin remodeling and amplify BCR signaling at the immune synapse.
Collapse
Affiliation(s)
- Nikola Deretic
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Madison Bolger-Munro
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Kate Choi
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Libin Abraham
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Michael R Gold
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
30
|
Mechanism of BIP-4 mediated inhibition of InsP3Kinase-A. Biosci Rep 2021; 41:229216. [PMID: 34232294 PMCID: PMC8292763 DOI: 10.1042/bsr20211259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/02/2021] [Accepted: 07/02/2021] [Indexed: 11/17/2022] Open
Abstract
Overexpression of the neuronal InsP3kinase-A increases malignancy of different tumor types. Since InsP3kinase-A highly selectively binds Ins(1,4,5)P3, small molecules competing with Ins(1,4,5)P3 provide a promising approach for the therapeutic targeting of InsP3kinase-A. Based on this consideration, we analyzed the binding mechanism of BIP-4 (2-[3,5-dimethyl-1-(4-nitrophenyl)-1H-pyrazol-4-yl]-5, 8-dinitro-1H-benzo[de]isoquinoline-1,3(2H)-dione), a known competitive small-molecule inhibitor of Ins(1,4,5)P3. We tested a total of 80 BIP-4 related compounds in biochemical assays. The results of these experiments revealed that neither the nitrophenyl nor the benzisochinoline group inhibited InsP3kinase-A activity. Moreover, none of the BIP-4 related compounds competed for Ins(1,4,5)P3, demonstrating the high selectivity of BIP-4. To analyze the inhibition mechanism of BIP-4, mutagenesis experiments were performed. The results of these experiments suggest that the nitro groups attached to the benzisochinoline ring compete for binding of Ins(1,4,5)P3 while the nitrophenyl group is associated with amino acids of the ATP-binding pocket. Our results now offer the possibility to optimize BIP-4 to design specific InsP3Kinase-A inhibitors suitable for therapeutic targeting of the enzyme.
Collapse
|
31
|
Bolger-Munro M, Choi K, Cheung F, Liu YT, Dang-Lawson M, Deretic N, Keane C, Gold MR. The Wdr1-LIMK-Cofilin Axis Controls B Cell Antigen Receptor-Induced Actin Remodeling and Signaling at the Immune Synapse. Front Cell Dev Biol 2021; 9:649433. [PMID: 33928084 PMCID: PMC8076898 DOI: 10.3389/fcell.2021.649433] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 03/12/2021] [Indexed: 12/27/2022] Open
Abstract
When B cells encounter membrane-bound antigens, the formation and coalescence of B cell antigen receptor (BCR) microclusters amplifies BCR signaling. The ability of B cells to probe the surface of antigen-presenting cells (APCs) and respond to APC-bound antigens requires remodeling of the actin cytoskeleton. Initial BCR signaling stimulates actin-related protein (Arp) 2/3 complex-dependent actin polymerization, which drives B cell spreading as well as the centripetal movement and coalescence of BCR microclusters at the B cell-APC synapse. Sustained actin polymerization depends on concomitant actin filament depolymerization, which enables the recycling of actin monomers and Arp2/3 complexes. Cofilin-mediated severing of actin filaments is a rate-limiting step in the morphological changes that occur during immune synapse formation. Hence, regulators of cofilin activity such as WD repeat-containing protein 1 (Wdr1), LIM domain kinase (LIMK), and coactosin-like 1 (Cotl1) may also be essential for actin-dependent processes in B cells. Wdr1 enhances cofilin-mediated actin disassembly. Conversely, Cotl1 competes with cofilin for binding to actin and LIMK phosphorylates cofilin and prevents it from binding to actin filaments. We now show that Wdr1 and LIMK have distinct roles in BCR-induced assembly of the peripheral actin structures that drive B cell spreading, and that cofilin, Wdr1, and LIMK all contribute to the actin-dependent amplification of BCR signaling at the immune synapse. Depleting Cotl1 had no effect on these processes. Thus, the Wdr1-LIMK-cofilin axis is critical for BCR-induced actin remodeling and for B cell responses to APC-bound antigens.
Collapse
Affiliation(s)
- Madison Bolger-Munro
- Department of Microbiology & Immunology and Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Kate Choi
- Department of Microbiology & Immunology and Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Faith Cheung
- Department of Microbiology & Immunology and Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Yi Tian Liu
- Department of Microbiology & Immunology and Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - May Dang-Lawson
- Department of Microbiology & Immunology and Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Nikola Deretic
- Department of Microbiology & Immunology and Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Connor Keane
- Department of Microbiology & Immunology and Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Michael R Gold
- Department of Microbiology & Immunology and Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
32
|
Efimova N, Yang C, Chia JX, Li N, Lengner CJ, Neufeld KL, Svitkina TM. Branched actin networks are assembled on microtubules by adenomatous polyposis coli for targeted membrane protrusion. J Cell Biol 2021; 219:151902. [PMID: 32597939 PMCID: PMC7480092 DOI: 10.1083/jcb.202003091] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 05/26/2020] [Accepted: 05/28/2020] [Indexed: 12/26/2022] Open
Abstract
Cell migration is driven by pushing and pulling activities of the actin cytoskeleton, but migration directionality is largely controlled by microtubules. This function of microtubules is especially critical for neuron navigation. However, the underlying mechanisms are poorly understood. Here we show that branched actin filament networks, the main pushing machinery in cells, grow directly from microtubule tips toward the leading edge in growth cones of hippocampal neurons. Adenomatous polyposis coli (APC), a protein with both tumor suppressor and cytoskeletal functions, concentrates at the microtubule-branched network interface, whereas APC knockdown nearly eliminates branched actin in growth cones and prevents growth cone recovery after repellent-induced collapse. Conversely, encounters of dynamic APC-positive microtubule tips with the cell edge induce local actin-rich protrusions. Together, we reveal a novel mechanism of cell navigation involving APC-dependent assembly of branched actin networks on microtubule tips.
Collapse
Affiliation(s)
- Nadia Efimova
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA
| | - Changsong Yang
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA
| | - Jonathan X Chia
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA
| | - Ning Li
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
| | - Christopher J Lengner
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA.,Department of Cell and Developmental Biology, Perelman School of Medicine and Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA
| | - Kristi L Neufeld
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS
| | - Tatyana M Svitkina
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA
| |
Collapse
|
33
|
Zhang J, Zhang S, Li X, Pi H. Relationship of ITPKA expression with the prognosis of breast cancer. Mol Genet Genomic Med 2021; 9:e1598. [PMID: 33624455 PMCID: PMC8123748 DOI: 10.1002/mgg3.1598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 11/06/2020] [Accepted: 12/15/2020] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Breast cancer (BC) represents a most common cancer among women worldwide. The outcomes of this disease remain dismal due to frequent recurrence and metastasis. Inositol-1,4,5-trisphosphate-3-kinase-A (ITPKA) plays an important role in regulating calcium signaling and actin dynamics. The dysregulation of ITPKA has been observed in several human cancers. The present study aimed to assess ITPKA expression and its prognostic value in BC. METHODS ITPKA expression was examined via quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) methods. In addition, Kaplan-Meier survival analysis and Cox regression analysis were performed to evaluate prognostic value of ITPKA in BC. RESULTS Upregulated ITPKA expression was found in BC samples, according to both qRT-PCR and IHC analyses (all p < .05). ITPKA expression was positively correlated with lymph node metastasis (p = .021) and TNM stage (p = .009). Moreover, BC patients with high expression of ITPKA had poor overall survival compared with those with low expression (log-rank p < .05). Cox analysis verified that ITPKA expression was an independent prognostic factor for BC patients (HR = 4.239, 95%CI = 2.221-8.093 and p = .000). CONCLUSION BC cases show increased expression of ITPKA. ITPKA may act as an independent prognostic biomarker in BC.
Collapse
Affiliation(s)
- Jie Zhang
- Nursing Department, Sixth Medical Center of Chinese PLA Hospital, Medical School of Chinese PLA, Beijing, China
| | - Sujie Zhang
- Department of Oncology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Xiaoyan Li
- Department of Oncology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China
| | - Hongying Pi
- Nursing Department, Sixth Medical Center of Chinese PLA Hospital, Medical School of Chinese PLA, Beijing, China
| |
Collapse
|
34
|
Schneider F, Colin-York H, Fritzsche M. Quantitative Bio-Imaging Tools to Dissect the Interplay of Membrane and Cytoskeletal Actin Dynamics in Immune Cells. Front Immunol 2021; 11:612542. [PMID: 33505401 PMCID: PMC7829180 DOI: 10.3389/fimmu.2020.612542] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 11/23/2020] [Indexed: 12/13/2022] Open
Abstract
Cellular function is reliant on the dynamic interplay between the plasma membrane and the actin cytoskeleton. This critical relationship is of particular importance in immune cells, where both the cytoskeleton and the plasma membrane work in concert to organize and potentiate immune signaling events. Despite their importance, there remains a critical gap in understanding how these respective dynamics are coupled, and how this coupling in turn may influence immune cell function from the bottom up. In this review, we highlight recent optical technologies that could provide strategies to investigate the simultaneous dynamics of both the cytoskeleton and membrane as well as their interplay, focusing on current and future applications in immune cells. We provide a guide of the spatio-temporal scale of each technique as well as highlighting novel probes and labels that have the potential to provide insights into membrane and cytoskeletal dynamics. The quantitative biophysical tools presented here provide a new and exciting route to uncover the relationship between plasma membrane and cytoskeletal dynamics that underlies immune cell function.
Collapse
Affiliation(s)
- Falk Schneider
- Medical Research Council (MRC) Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Huw Colin-York
- Medical Research Council (MRC) Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
- Kennedy Institute for Rheumatology, University of Oxford, Oxford, United Kingdom
| | - Marco Fritzsche
- Medical Research Council (MRC) Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
- Kennedy Institute for Rheumatology, University of Oxford, Oxford, United Kingdom
- Rosalind Franklin Institute, Harwell Campus, Didcot, United Kingdom
| |
Collapse
|
35
|
See C, Arya D, Lin E, Chiolo I. Live Cell Imaging of Nuclear Actin Filaments and Heterochromatic Repair foci in Drosophila and Mouse Cells. Methods Mol Biol 2021; 2153:459-482. [PMID: 32840799 DOI: 10.1007/978-1-0716-0644-5_32] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Pericentromeric heterochromatin is mostly composed of repeated DNA sequences, which are prone to aberrant recombination during double-strand break (DSB) repair. Studies in Drosophila and mouse cells revealed that 'safe' homologous recombination (HR) repair of these sequences relies on the relocalization of repair sites to outside the heterochromatin domain before Rad51 recruitment. Relocalization requires a striking network of nuclear actin filaments (F-actin) and myosins that drive directed motions. Understanding this pathway requires the detection of nuclear actin filaments that are significantly less abundant than those in the cytoplasm, and the imaging and tracking of repair sites for long time periods. Here, we describe an optimized protocol for live cell imaging of nuclear F-actin in Drosophila cells, and for repair focus tracking in mouse cells, including: imaging setup, image processing approaches, and analysis methods. We emphasize approaches that can be applied to identify the most effective fluorescent markers for live cell imaging, strategies to minimize photobleaching and phototoxicity with a DeltaVision deconvolution microscope, and image processing and analysis methods using SoftWoRx and Imaris software. These approaches enable a deeper understanding of the spatial and temporal dynamics of heterochromatin repair and have broad applicability in the fields of nuclear architecture, nuclear dynamics, and DNA repair.
Collapse
Affiliation(s)
- Colby See
- Molecular and Computational Biology Department, University of Southern California, Los Angeles, CA, USA
| | - Deepak Arya
- Molecular and Computational Biology Department, University of Southern California, Los Angeles, CA, USA
| | - Emily Lin
- Molecular and Computational Biology Department, University of Southern California, Los Angeles, CA, USA
| | - Irene Chiolo
- Molecular and Computational Biology Department, University of Southern California, Los Angeles, CA, USA.
| |
Collapse
|
36
|
Smith CEL, Lake AVR, Johnson CA. Primary Cilia, Ciliogenesis and the Actin Cytoskeleton: A Little Less Resorption, A Little More Actin Please. Front Cell Dev Biol 2020; 8:622822. [PMID: 33392209 PMCID: PMC7773788 DOI: 10.3389/fcell.2020.622822] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 11/24/2020] [Indexed: 12/13/2022] Open
Abstract
Primary cilia are microtubule-based organelles that extend from the apical surface of most mammalian cells, forming when the basal body (derived from the mother centriole) docks at the apical cell membrane. They act as universal cellular "antennae" in vertebrates that receive and integrate mechanical and chemical signals from the extracellular environment, serving diverse roles in chemo-, mechano- and photo-sensation that control developmental signaling, cell polarity and cell proliferation. Mutations in ciliary genes cause a major group of inherited developmental disorders called ciliopathies. There are very few preventative treatments or new therapeutic interventions that modify disease progression or the long-term outlook of patients with these conditions. Recent work has identified at least four distinct but interrelated cellular processes that regulate cilia formation and maintenance, comprising the cell cycle, cellular proteostasis, signaling pathways and structural influences of the actin cytoskeleton. The actin cytoskeleton is composed of microfilaments that are formed from filamentous (F) polymers of globular G-actin subunits. Actin filaments are organized into bundles and networks, and are attached to the cell membrane, by diverse cross-linking proteins. During cell migration, actin filament bundles form either radially at the leading edge or as axial stress fibers. Early studies demonstrated that loss-of-function mutations in ciliopathy genes increased stress fiber formation and impaired ciliogenesis whereas pharmacological inhibition of actin polymerization promoted ciliogenesis. These studies suggest that polymerization of the actin cytoskeleton, F-actin branching and the formation of stress fibers all inhibit primary cilium formation, whereas depolymerization or depletion of actin enhance ciliogenesis. Here, we review the mechanistic basis for these effects on ciliogenesis, which comprise several cellular processes acting in concert at different timescales. Actin polymerization is both a physical barrier to both cilia-targeted vesicle transport and to the membrane remodeling required for ciliogenesis. In contrast, actin may cause cilia loss by localizing disassembly factors at the ciliary base, and F-actin branching may itself activate the YAP/TAZ pathway to promote cilia disassembly. The fundamental role of actin polymerization in the control of ciliogenesis may present potential new targets for disease-modifying therapeutic approaches in treating ciliopathies.
Collapse
Affiliation(s)
| | | | - Colin A. Johnson
- Leeds Institute of Medical Research at St. James’s, University of Leeds, Leeds, United Kingdom
| |
Collapse
|
37
|
Blechner C, Becker L, Fuchs H, Rathkolb B, Prehn C, Adler T, Calzada-Wack J, Garrett L, Gailus-Durner V, Morellini F, Conrad S, Hölter SM, Wolf E, Klopstock T, Adamski J, Busch D, de Angelis MH, Schmeisser MJ, Windhorst S. Physiological relevance of the neuronal isoform of inositol-1,4,5-trisphosphate 3-kinases in mice. Neurosci Lett 2020; 735:135206. [PMID: 32593773 DOI: 10.1016/j.neulet.2020.135206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 06/09/2020] [Accepted: 06/23/2020] [Indexed: 10/24/2022]
Abstract
Inositol-1,4,5-trisphosphate 3-kinase-A (ITPKA) is the neuronal isoform of ITPKs and exhibits both actin bundling and InsP3kinase activity. In addition to neurons, ITPKA is ectopically expressed in tumor cells, where its oncogenic activity increases tumor cell malignancy. In order to analyze the physiological relevance of ITPKA, here we performed a broad phenotypic screening of itpka deficient mice. Our data show that among the neurobehavioral tests analyzed, itpka deficient mice reacted faster to a hotplate, prepulse inhibition was impaired and the accelerating rotarod test showed decreased latency of itpka deficient mice to fall. These data indicate that ITPKA is involved in the regulation of nociceptive pathways, sensorimotor gating and motor learning. Analysis of extracerebral functions in control and itpka deficient mice revealed significantly reduced glucose, lactate, and triglyceride plasma concentrations in itpka deficient mice. Based on this finding, expression of ITPKA was analyzed in extracerebral tissues and the highest level was found in the small intestine. However, functional studies on CaCo-2 control and ITPKA depleted cells showed that glucose, as well as triglyceride uptake, were not significantly different between the cell lines. Altogether, these data show that ITPKA exhibits distinct functions in the central nervous system and reveal an involvement of ITPKA in energy metabolism.
Collapse
Affiliation(s)
- Christine Blechner
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246, Hamburg, Germany
| | - Lore Becker
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
| | - Helmut Fuchs
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
| | - Birgit Rathkolb
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany; Geman Center for Diabetes Research (DZD), Ingolstädter Landstr. 1, 85764, Neuherberg, Germany; Institute of Molecular Animal Breeding and Biotechnology, Gene Center, Ludwig-Maximilians-University München, Feodor-Lynen Str. 25, 81377, Munich, Germany
| | - Cornelia Prehn
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
| | - Thure Adler
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
| | - Julia Calzada-Wack
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
| | - Lillian Garrett
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany; Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
| | - Valerie Gailus-Durner
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
| | - Fabio Morellini
- Behavioral Biology, Center for Molecular Neurobiology Hamburg, Falkenried 94, D-20251 Hamburg, Germany
| | - Susanne Conrad
- Forschungstierhaltung University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246, Hamburg, Germany
| | - Sabine M Hölter
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany; Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
| | - Eckhard Wolf
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center, Ludwig-Maximilians-University München, Feodor-Lynen Str. 25, 81377, Munich, Germany
| | - Thomas Klopstock
- Dept. of Neurology, Friedrich-Baur-Institute, Klinikum der Ludwig-Maximilians-Universität München, Ziemssenstr. 1a, 80336, Munich, Germany; Deutsches Institut für Neurodegenerative Erkrankungen (DZNE), Site Munich, 80336, München, Germany; Munich Cluster for Systems Neurology (SyNergy), Adolf-Butenandt-Institut, Ludwig-Maximilians-Universität München, Schillerstr. 44, 80336, Munich, Germany
| | - Jerzy Adamski
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany; Chair of Experimental Genetics, School of Life Science Weihenstephan, Technische Universität München, Alte Akademie 8, 85354, Freising, Germany
| | - Dirk Busch
- Institute for Medical Microbiology, Immunology and Hygiene, Technische Universität München, Trogerstrasse 30, 81675, Munich, Germany
| | - Martin Hrabe de Angelis
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany; Geman Center for Diabetes Research (DZD), Ingolstädter Landstr. 1, 85764, Neuherberg, Germany; Chair of Experimental Genetics, School of Life Science Weihenstephan, Technische Universität München, Alte Akademie 8, 85354, Freising, Germany
| | - Michael J Schmeisser
- Institute for Microscopic Anatomy and Neurobiology, University Medical Center of the Johannes Gutenberg-University Mainz, Langenbeckstr. 1, 55131, Mainz, Germany; Focus Program Translational Neurosciences (FTN), University Medical Center of the Johannes Gutenberg-University Mainz, Langenbeckstr. 1, 55131, Mainz, Germany; Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246, Hamburg, Germany.
| |
Collapse
|
38
|
Jiang M, Paniagua AE, Volland S, Wang H, Balaji A, Li DG, Lopes VS, Burgess BL, Williams DS. Microtubule motor transport in the delivery of melanosomes to the actin-rich apical domain of the retinal pigment epithelium. J Cell Sci 2020; 133:jcs242214. [PMID: 32661088 PMCID: PMC7420818 DOI: 10.1242/jcs.242214] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 06/25/2020] [Indexed: 12/20/2022] Open
Abstract
Melanosomes are motile, light-absorbing organelles that are present in pigment cells of the skin and eye. It has been proposed that melanosome localization, in both skin melanocytes and the retinal pigment epithelium (RPE), involves melanosome capture from microtubule motors by an unconventional myosin, which dynamically tethers the melanosomes to actin filaments. Recent studies with melanocytes have questioned this cooperative capture model. Here, we test the model in RPE cells by imaging melanosomes associated with labeled actin filaments and microtubules, and by investigating the roles of different motor proteins. We found that a deficiency in cytoplasmic dynein phenocopies the lack of myosin-7a, in that melanosomes undergo fewer of the slow myosin-7a-dependent movements and are absent from the RPE apical domain. These results indicate that microtubule-based motility is required for the delivery of melanosomes to the actin-rich apical domain and support a capture mechanism that involves both microtubule and actin motors.
Collapse
Affiliation(s)
- Mei Jiang
- Departments of Ophthalmology and Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Antonio E Paniagua
- Departments of Ophthalmology and Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Stefanie Volland
- Departments of Ophthalmology and Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Hongxing Wang
- Departments of Ophthalmology and Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Adarsh Balaji
- Departments of Ophthalmology and Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - David G Li
- Departments of Ophthalmology and Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Vanda S Lopes
- Departments of Ophthalmology and Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Barry L Burgess
- Departments of Ophthalmology and Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - David S Williams
- Departments of Ophthalmology and Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Brain Research Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| |
Collapse
|
39
|
Cell response to substrate rigidity is regulated by active and passive cytoskeletal stress. Proc Natl Acad Sci U S A 2020; 117:12817-12825. [PMID: 32444491 DOI: 10.1073/pnas.1917555117] [Citation(s) in RCA: 98] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Morphogenesis, tumor formation, and wound healing are regulated by tissue rigidity. Focal adhesion behavior is locally regulated by stiffness; however, how cells globally adapt, detect, and respond to rigidity remains unknown. Here, we studied the interplay between the rheological properties of the cytoskeleton and matrix rigidity. We seeded fibroblasts onto flexible microfabricated pillar arrays with varying stiffness and simultaneously measured the cytoskeleton organization, traction forces, and cell-rigidity responses at both the adhesion and cell scale. Cells adopted a rigidity-dependent phenotype whereby the actin cytoskeleton polarized on stiff substrates but not on soft. We further showed a crucial role of active and passive cross-linkers in rigidity-sensing responses. By reducing myosin II activity or knocking down α-actinin, we found that both promoted cell polarization on soft substrates, whereas α-actinin overexpression prevented polarization on stiff substrates. Atomic force microscopy indentation experiments showed that this polarization response correlated with cell stiffness, whereby cell stiffness decreased when active or passive cross-linking was reduced and softer cells polarized on softer matrices. Theoretical modeling of the actin network as an active gel suggests that adaptation to matrix rigidity is controlled by internal mechanical properties of the cytoskeleton and puts forward a universal scaling between nematic order of the actin cytoskeleton and the substrate-to-cell elastic modulus ratio. Altogether, our study demonstrates the implication of cell-scale mechanosensing through the internal stress within the actomyosin cytoskeleton and its coupling with local rigidity sensing at focal adhesions in the regulation of cell shape changes and polarity.
Collapse
|
40
|
Early Events in Actin Cytoskeleton Dynamics and E-Cadherin-Mediated Cell-Cell Adhesion during Epithelial-Mesenchymal Transition. Cells 2020; 9:cells9030578. [PMID: 32121325 PMCID: PMC7140442 DOI: 10.3390/cells9030578] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Accepted: 02/28/2020] [Indexed: 12/21/2022] Open
Abstract
Epithelial-mesenchymal transition (EMT) plays an important role in development and also in initiation of metastasis during cancer. Disruption of cell-cell contacts during EMT allowing cells to detach from and migrate away from their neighbors remains poorly understood. Using immunofluorescent staining and live-cell imaging, we analyzed early events during EMT induced by epidermal growth factor (EGF) in IAR-20 normal epithelial cells. Control cells demonstrated stable adherens junctions (AJs) and robust contact paralysis, whereas addition of EGF caused rapid dynamic changes at the cell-cell boundaries: fragmentation of the circumferential actin bundle, assembly of actin network in lamellipodia, and retrograde flow. Simultaneously, an actin-binding protein EPLIN was phosphorylated, which may have decreased the stability of the circumferential actin bundle. Addition of EGF caused gradual replacement of linear E-cadherin–based AJs with dynamic and unstable punctate AJs, which, unlike linear AJs, colocalized with the mechanosensitive protein zyxin, confirming generation of centripetal force at the sites of cell-cell contacts during EMT. Our data show that early EMT promotes heightened dynamics at the cell-cell boundaries—replacement of stable AJs and actin structures with dynamic ones—which results in overall weakening of cell-cell adhesion, thus priming the cells for front-rear polarization and eventual migration.
Collapse
|
41
|
Guoren Z, Zhaohui F, Wei Z, Mei W, Yuan W, Lin S, Xiaoyue X, Xiaomei Z, Bo S. TFAP2A Induced ITPKA Serves as an Oncogene and Interacts with DBN1 in Lung Adenocarcinoma. Int J Biol Sci 2020; 16:504-514. [PMID: 32015686 PMCID: PMC6990902 DOI: 10.7150/ijbs.40435] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 11/12/2019] [Indexed: 12/22/2022] Open
Abstract
The inositol polyphosphate kinase (IPK) family member ITPKA (inositol 1,4,5-trisphosphate 3-kinase) regulates the levels of many inositol polyphosphates which are important in cellular signaling. Several recent studies reported the aberrant expression of ITPKA in malignancy disease and usually made cancer more aggressive. However, the contribution of the inositol polyphosphate kinase ITPKA to lung cancer development remains unclear. Here we report that ITPKA is overexpressed in lung adenocarcinoma (LUAD) and positively correlated with advanced clinical parameters. ITPKA contributes to the malignant phenotypes in-vitro. Mechanistically, ITPKA executed its action through the inducting of epithelial-mesenchymal transition (EMT) and interacting with Drebrin 1 (which is related to cancer metastasis). Moreover, the hyper-expression of ITPKA in LUAD is transcriptionally activated by the transcription factor TFAP2A. In survival analysis by using tissue microarray (TMA), we indicate that ITPKA is hyper-expressed in LUAD tissues compared to adjacent normal tissues, and increased expression of ITPKA is associated with poor prognosis. Collectively, this study indicates that TFAP2A induced ITPKA hyperexpression promotes LUAD via interacting with Drebrin 1 and activating epithelial-mesenchymal transition (EMT). ITPKA might represent a potent candidate for the treatment and prognostic prediction of LUAD.
Collapse
Affiliation(s)
- Zhou Guoren
- Jiangsu Cancer Hospital, Jiangsu Institute Of Cancer Research, Nanjing Medical University Affiliated Cancer Hospital; 42 Baiziting, Nanjing, Jiangsu, 210009, China (Corresponding Address)
| | - Fan Zhaohui
- Jiangsu Cancer Hospital, Jiangsu Institute Of Cancer Research, Nanjing Medical University Affiliated Cancer Hospital; 42 Baiziting, Nanjing, Jiangsu, 210009, China (Corresponding Address)
| | - Zhu Wei
- School Of Medicine, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Wang Mei
- School Of Medicine, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Wu Yuan
- Jiangsu Cancer Hospital, Jiangsu Institute Of Cancer Research, Nanjing Medical University Affiliated Cancer Hospital; 42 Baiziting, Nanjing, Jiangsu, 210009, China (Corresponding Address)
| | - Shi Lin
- Jiangsu Cancer Hospital, Jiangsu Institute Of Cancer Research, Nanjing Medical University Affiliated Cancer Hospital; 42 Baiziting, Nanjing, Jiangsu, 210009, China (Corresponding Address)
| | - Xu Xiaoyue
- Jiangsu Cancer Hospital, Jiangsu Institute Of Cancer Research, Nanjing Medical University Affiliated Cancer Hospital; 42 Baiziting, Nanjing, Jiangsu, 210009, China (Corresponding Address)
| | - Zhang Xiaomei
- Jiangsu Cancer Hospital, Jiangsu Institute Of Cancer Research, Nanjing Medical University Affiliated Cancer Hospital; 42 Baiziting, Nanjing, Jiangsu, 210009, China (Corresponding Address)
| | - Shen Bo
- Jiangsu Cancer Hospital, Jiangsu Institute Of Cancer Research, Nanjing Medical University Affiliated Cancer Hospital; 42 Baiziting, Nanjing, Jiangsu, 210009, China (Corresponding Address)
| |
Collapse
|
42
|
Nakos K, Radler MR, Spiliotis ET. Septin 2/6/7 complexes tune microtubule plus-end growth and EB1 binding in a concentration- and filament-dependent manner. Mol Biol Cell 2019; 30:2913-2928. [PMID: 31577529 PMCID: PMC6822581 DOI: 10.1091/mbc.e19-07-0362] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Septins (SEPTs) are filamentous guanosine-5′-triphosphate (GTP)-binding proteins, which affect microtubule (MT)-dependent functions including membrane trafficking and cell division, but their precise role in MT dynamics is poorly understood. Here, in vitro reconstitution of MT dynamics with SEPT2/6/7, the minimal subunits of septin heteromers, shows that SEPT2/6/7 has a biphasic concentration-dependent effect on MT growth. Lower concentrations of SEPT2/6/7 enhance MT plus-end growth and elongation, while higher and intermediate concentrations inhibit and pause plus-end growth, respectively. We show that SEPT2/6/7 has a modest preference for GTP- over guanosine diphosphate (GDP)-bound MT lattice and competes with end-binding protein 1 (EB1) for binding to guanosine 5′-O-[γ-thio]triphosphate (GTPγS)-stabilized MTs, which mimic the EB1-preferred GDP-Pi state of polymerized tubulin. Strikingly, SEPT2/6/7 triggers EB1 dissociation from plus-end tips in cis by binding to the MT lattice and in trans when MT plus ends collide with SEPT2/6/7 filaments. At these intersections, SEPT2/6/7 filaments were more potent barriers than actin filaments in pausing MT growth and dissociating EB1 in vitro and in live cells. These data demonstrate that SEPT2/6/7 complexes and filaments can directly impact MT plus-end growth and the tracking of plus end–binding proteins and thereby may facilitate the capture of MT plus ends at intracellular sites of septin enrichment.
Collapse
Affiliation(s)
| | - Megan R Radler
- Department of Biology, Drexel University, Philadelphia, PA 19104
| | | |
Collapse
|
43
|
Fung TS, Ji WK, Higgs HN, Chakrabarti R. Two distinct actin filament populations have effects on mitochondria, with differences in stimuli and assembly factors. J Cell Sci 2019; 132:jcs234435. [PMID: 31413070 PMCID: PMC6765187 DOI: 10.1242/jcs.234435] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 08/07/2019] [Indexed: 12/12/2022] Open
Abstract
Recent studies show that mitochondria and actin filaments work together in two contexts: (1) increased cytoplasmic calcium induces cytoplasmic actin polymerization that stimulates mitochondrial fission and (2) mitochondrial depolarization causes actin assembly around mitochondria, with roles in mitophagy. It is unclear whether these two processes utilize similar actin assembly mechanisms. Here, we show that these are distinct actin assembly mechanisms in the acute phase after treatment (<10 min). Calcium-induced actin assembly is INF2 dependent and Arp2/3 complex independent, whereas depolarization-induced actin assembly is Arp2/3 complex dependent and INF2 independent. The two types of actin polymerization are morphologically distinct, with calcium-induced filaments throughout the cytosol and depolarization-induced filaments as 'clouds' around depolarized mitochondria. We have previously shown that calcium-induced actin stimulates increases in both mitochondrial calcium and recruitment of the dynamin GTPase Drp1 (also known as DNM1L). In contrast, depolarization-induced actin is temporally associated with extensive mitochondrial dynamics that do not result in mitochondrial fission, but in circularization of the inner mitochondrial membrane (IMM). These dynamics are dependent on the protease OMA1 and independent of Drp1. Actin cloud inhibition causes increased IMM circularization, suggesting that actin clouds limit these dynamics.This article has an associated First Person interview with the first author of the paper.
Collapse
Affiliation(s)
- Tak Shun Fung
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
| | - Wei-Ke Ji
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Henry N Higgs
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
| | - Rajarshi Chakrabarti
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
| |
Collapse
|
44
|
Robust and automated detection of subcellular morphological motifs in 3D microscopy images. Nat Methods 2019; 16:1037-1044. [PMID: 31501548 PMCID: PMC7238333 DOI: 10.1038/s41592-019-0539-z] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 07/23/2019] [Indexed: 12/21/2022]
Abstract
Rapid developments in live-cell 3D microscopy enable imaging of cell morphology and signaling with unprecedented detail. However, tools to systematically measure and visualize the intricate relationships between intracellular signaling, cytoskeletal organization, and downstream cell morphological outputs do not exist. Here we introduce u-shape3D, a computer graphics and machine-learning pipeline to probe molecular mechanisms underlying 3D cell morphogenesis and to test the intriguing possibility that morphogenesis itself affects intracellular signaling. We demonstrate a generic morphological motif detector that automatically finds lamellipodia, filopodia, blebs, and other motifs. Combining motif detection with molecular localization, we measure the differential association of PIP2 and KrasV12 with blebs. Both signals associate with bleb edges, as expected for membrane-localized proteins, but only PIP2 is enhanced on blebs. This indicates that sub-cellular signaling processes are differentially modulated by local morphological motifs. Overall, our computational workflow enables the objective, 3D analysis of the coupling of cell shape and signaling.
Collapse
|
45
|
Reshetniak S, Rizzoli SO. Interrogating Synaptic Architecture: Approaches for Labeling Organelles and Cytoskeleton Components. Front Synaptic Neurosci 2019; 11:23. [PMID: 31507402 PMCID: PMC6716447 DOI: 10.3389/fnsyn.2019.00023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 08/02/2019] [Indexed: 01/06/2023] Open
Abstract
Synaptic transmission has been studied for decades, as a fundamental step in brain function. The structure of the synapse, and its changes during activity, turned out to be key aspects not only in the transfer of information between neurons, but also in cognitive processes such as learning and memory. The overall synaptic morphology has traditionally been studied by electron microscopy, which enables the visualization of synaptic structure in great detail. The changes in the organization of easily identified structures, such as the presynaptic active zone, or the postsynaptic density, are optimally studied via electron microscopy. However, few reliable methods are available for labeling individual organelles or protein complexes in electron microscopy. For such targets one typically relies either on combination of electron and fluorescence microscopy, or on super-resolution fluorescence microscopy. This review focuses on approaches and techniques used to specifically reveal synaptic organelles and protein complexes, such as cytoskeletal assemblies. We place the strongest emphasis on methods detecting the targets of interest by affinity binding, and we discuss the advantages and limitations of each method.
Collapse
Affiliation(s)
- Sofiia Reshetniak
- Institute for Neuro- and Sensory Physiology, Center for Biostructural Imaging of Neurodegeneration (BIN), University Medical Center Göttingen, Göttingen, Germany
- International Max Planck Research School for Molecular Biology, Göttingen, Germany
| | - Silvio O. Rizzoli
- Institute for Neuro- and Sensory Physiology, Center for Biostructural Imaging of Neurodegeneration (BIN), University Medical Center Göttingen, Göttingen, Germany
| |
Collapse
|
46
|
Roesler MK, Lombino FL, Freitag S, Schweizer M, Hermans-Borgmeyer I, Schwarz JR, Kneussel M, Wagner W. Myosin XVI Regulates Actin Cytoskeleton Dynamics in Dendritic Spines of Purkinje Cells and Affects Presynaptic Organization. Front Cell Neurosci 2019; 13:330. [PMID: 31474830 PMCID: PMC6705222 DOI: 10.3389/fncel.2019.00330] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 07/04/2019] [Indexed: 11/29/2022] Open
Abstract
The actin cytoskeleton is crucial for function and morphology of neuronal synapses. Moreover, altered regulation of the neuronal actin cytoskeleton has been implicated in neuropsychiatric diseases such as autism spectrum disorder (ASD). Myosin XVI is a neuronally expressed unconventional myosin known to bind the WAVE regulatory complex (WRC), a regulator of filamentous actin (F-actin) polymerization. Notably, the gene encoding the myosin’s heavy chain (MYO16) shows genetic association with neuropsychiatric disorders including ASD. Here, we investigated whether myosin XVI plays a role for actin cytoskeleton regulation in the dendritic spines of cerebellar Purkinje cells (PCs), a neuronal cell type crucial for motor learning, social cognition and vocalization. We provide evidence that both myosin XVI and the WRC component WAVE1 localize to PC spines. Fluorescence recovery after photobleaching (FRAP) analysis of GFP-actin in cultured PCs shows that Myo16 knockout as well as PC-specific Myo16 knockdown, lead to faster F-actin turnover in the dendritic spines of PCs. We also detect accelerated F-actin turnover upon interference with the WRC, and upon inhibition of Arp2/3 that drives formation of branched F-actin downstream of the WRC. In contrast, inhibition of formins that are responsible for polymerization of linear actin filaments does not cause faster F-actin turnover. Together, our data establish myosin XVI as a regulator of the postsynaptic actin cytoskeleton and suggest that it is an upstream activator of the WRC-Arp2/3 pathway in PC spines. Furthermore, ultra-structural and electrophysiological analyses of Myo16 knockout cerebellum reveals the presence of reduced numbers of synaptic vesicles at presynaptic terminals in the absence of the myosin. Therefore, we here define myosin XVI as an F-actin regulator important for presynaptic organization in the cerebellum.
Collapse
Affiliation(s)
- Mona Katrin Roesler
- Department of Molecular Neurogenetics, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Franco Luis Lombino
- Department of Molecular Neurogenetics, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sandra Freitag
- Department of Molecular Neurogenetics, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Michaela Schweizer
- Electron Microscopy Unit, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Irm Hermans-Borgmeyer
- Transgenic Animal Unit, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jürgen R Schwarz
- Department of Molecular Neurogenetics, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Matthias Kneussel
- Department of Molecular Neurogenetics, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Wolfgang Wagner
- Department of Molecular Neurogenetics, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| |
Collapse
|
47
|
Wagner W, Lippmann K, Heisler FF, Gromova KV, Lombino FL, Roesler MK, Pechmann Y, Hornig S, Schweizer M, Polo S, Schwarz JR, Eilers J, Kneussel M. Myosin VI Drives Clathrin-Mediated AMPA Receptor Endocytosis to Facilitate Cerebellar Long-Term Depression. Cell Rep 2019; 28:11-20.e9. [DOI: 10.1016/j.celrep.2019.06.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 05/01/2019] [Accepted: 05/31/2019] [Indexed: 11/30/2022] Open
|
48
|
Bolger-Munro M, Choi K, Scurll JM, Abraham L, Chappell RS, Sheen D, Dang-Lawson M, Wu X, Priatel JJ, Coombs D, Hammer JA, Gold MR. Arp2/3 complex-driven spatial patterning of the BCR enhances immune synapse formation, BCR signaling and B cell activation. eLife 2019; 8:e44574. [PMID: 31157616 PMCID: PMC6591008 DOI: 10.7554/elife.44574] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 06/01/2019] [Indexed: 12/17/2022] Open
Abstract
When B cells encounter antigens on the surface of an antigen-presenting cell (APC), B cell receptors (BCRs) are gathered into microclusters that recruit signaling enzymes. These microclusters then move centripetally and coalesce into the central supramolecular activation cluster of an immune synapse. The mechanisms controlling BCR organization during immune synapse formation, and how this impacts BCR signaling, are not fully understood. We show that this coalescence of BCR microclusters depends on the actin-related protein 2/3 (Arp2/3) complex, which nucleates branched actin networks. Moreover, in murine B cells, this dynamic spatial reorganization of BCR microclusters amplifies proximal BCR signaling reactions and enhances the ability of membrane-associated antigens to induce transcriptional responses and proliferation. Our finding that Arp2/3 complex activity is important for B cell responses to spatially restricted membrane-bound antigens, but not for soluble antigens, highlights a critical role for Arp2/3 complex-dependent actin remodeling in B cell responses to APC-bound antigens.
Collapse
Affiliation(s)
- Madison Bolger-Munro
- Department of Microbiology and ImmunologyUniversity of British ColumbiaVancouverCanada
- Life Sciences Institute, I3 Research GroupUniversity of British ColumbiaVancouverCanada
| | - Kate Choi
- Department of Microbiology and ImmunologyUniversity of British ColumbiaVancouverCanada
- Life Sciences Institute, I3 Research GroupUniversity of British ColumbiaVancouverCanada
| | - Joshua M Scurll
- Department of Mathematics, Institute of Applied MathematicsUniversity of British ColumbiaVancouverCanada
| | - Libin Abraham
- Department of Microbiology and ImmunologyUniversity of British ColumbiaVancouverCanada
- Life Sciences Institute, I3 Research GroupUniversity of British ColumbiaVancouverCanada
- Department of Mathematics, Institute of Applied MathematicsUniversity of British ColumbiaVancouverCanada
| | - Rhys S Chappell
- Department of Mathematics, Institute of Applied MathematicsUniversity of British ColumbiaVancouverCanada
| | - Duke Sheen
- Department of Microbiology and ImmunologyUniversity of British ColumbiaVancouverCanada
- Life Sciences Institute, I3 Research GroupUniversity of British ColumbiaVancouverCanada
| | - May Dang-Lawson
- Department of Microbiology and ImmunologyUniversity of British ColumbiaVancouverCanada
- Life Sciences Institute, I3 Research GroupUniversity of British ColumbiaVancouverCanada
| | - Xufeng Wu
- Cell Biology and Physiology CenterNational Heart, Lung and Blood Institute, National Institutes of HealthBethesdaUnited States
| | - John J Priatel
- Department of Pathology and Laboratory MedicineUniversity of British ColumbiaVancouverCanada
- BC Children’s Hospital Research InstituteVancouverCanada
| | - Daniel Coombs
- Department of Mathematics, Institute of Applied MathematicsUniversity of British ColumbiaVancouverCanada
| | - John A Hammer
- Cell Biology and Physiology CenterNational Heart, Lung and Blood Institute, National Institutes of HealthBethesdaUnited States
| | - Michael R Gold
- Department of Microbiology and ImmunologyUniversity of British ColumbiaVancouverCanada
- Life Sciences Institute, I3 Research GroupUniversity of British ColumbiaVancouverCanada
| |
Collapse
|
49
|
Ultrastructure and dynamics of the actin-myosin II cytoskeleton during mitochondrial fission. Nat Cell Biol 2019; 21:603-613. [PMID: 30988424 PMCID: PMC6499663 DOI: 10.1038/s41556-019-0313-6] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 03/14/2019] [Indexed: 02/05/2023]
Abstract
Mitochondrial fission involves the preconstriction of an organelle followed by scission by dynamin-related protein Drp1. Preconstriction is facilitated by actin and non-muscle myosin II through a mechanism that remains unclear, largely due to the unknown cytoskeletal ultrastructure at mitochondrial constrictions. Here, using platinum replica electron microscopy, we show that mitochondria in cells are embedded in an interstitial cytoskeletal network that contains abundant unbranched actin filaments. Both spontaneous and induced mitochondrial constrictions typically associate with a criss-cross array of long actin filaments that comprise part of this interstitial network. Non-muscle myosin II is found adjacent to mitochondria but is not specifically enriched at the constriction sites. During ionomycin-induced mitochondrial fission, F-actin clouds colocalize with mitochondrial constriction sites, whereas dynamic myosin II clouds are present in the vicinity of constrictions. We propose that myosin II promotes mitochondrial constriction by inducing stochastic deformations of the interstitial actin network, which applies pressure on the mitochondrial surface and thus initiates curvature-sensing mechanisms that complete mitochondrial constriction.
Collapse
|
50
|
Abstract
Macropinocytosis is an actin-driven form of clathrin-independent endocytosis that generates an enlarged structure, the macropinosome. Although many studies focus on signaling molecules and phosphoinositides involved in initiating macropinocytosis, the commitment to forming a macropinosome and the handling of that membrane have not been studied in detail. Here we show in HT1080 cells, a human fibrosarcoma cell line, a requirement for microtubules, dynein, the JIP3 microtubule motor scaffold protein, and Arf6, a JIP3 interacting protein, for the formation and inward movement of the macropinosome. While actin and myosin II also play critical roles in the formation of ruffling membrane, microtubules provide an important tract for initiation, sealing, and transport of the macropinosome through the actin- and myosin-rich lamellar region.
Collapse
Affiliation(s)
- Chad D Williamson
- Cell and Developmental Biology Center, National Heart, Lung and Blood Institute, and.,Cell Biology and Neurobiology Branch, Eunice Kennedy Shriver Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
| | - Julie G Donaldson
- Cell and Developmental Biology Center, National Heart, Lung and Blood Institute, and
| |
Collapse
|