1
|
Kuhn J, Banerjee P, Haye A, Robinson DN, Iglesias PA, Devreotes PN. Complementary Cytoskeletal Feedback Loops Control Signal Transduction Excitability and Cell Polarity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.13.580131. [PMID: 38405988 PMCID: PMC10888828 DOI: 10.1101/2024.02.13.580131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
To move through complex environments, cells must constantly integrate chemical and mechanical cues. Signaling networks, such as those comprising Ras and PI3K, transmit chemical cues to the cytoskeleton, but the cytoskeleton must also relay mechanical information back to those signaling systems. Using novel synthetic tools to acutely control specific elements of the cytoskeleton in Dictyostelium and neutrophils, we delineate feedback mechanisms that alter the signaling network and promote front- or back-states of the cell membrane and cortex. First, increasing branched actin assembly increases Ras/PI3K activation while reducing polymeric actin levels overall decreases activation. Second, reducing myosin II assembly immediately increases Ras/PI3K activation and sensitivity to chemotactic stimuli. Third, inhibiting branched actin alone increases cortical actin assembly and strongly blocks Ras/PI3K activation. This effect is mitigated by reducing filamentous actin levels and in cells lacking myosin II. Finally, increasing actin crosslinking with a controllable activator of cytoskeletal regulator RacE leads to a large decrease in Ras activation both globally and locally. Curiously, RacE activation can trigger cell spreading and protrusion with no detectable activation of branched actin nucleators. Taken together with legacy data that Ras/PI3K promotes branched actin assembly and myosin II disassembly, our results define front- and back-promoting positive feedback loops. We propose that these loops play a crucial role in establishing cell polarity and mediating signal integration by controlling the excitable state of the signal transduction networks in respective regions of the membrane and cortex. This interplay enables cells to navigate intricate topologies like tissues containing other cells, the extracellular matrix, and fluids.
Collapse
Affiliation(s)
- Jonathan Kuhn
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, MD
| | - Parijat Banerjee
- Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD
| | - Andrew Haye
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, MD
| | | | - Pablo A. Iglesias
- Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD
| | - Peter N. Devreotes
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, MD
| |
Collapse
|
2
|
Ecke M, Prassler J, Gerisch G. Expanding ring-shaped cleavage furrows in multinucleate cells. Mol Biol Cell 2023; 34:ar27. [PMID: 36652336 PMCID: PMC10092652 DOI: 10.1091/mbc.e22-10-0487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Multinucleate cells of Dictyostelium discoideum divide usually by unilateral cleavage furrows that ingress from the cell border. Along their path into the cell, they follow regions that are rich in myosin II and cortexillin and leave out the areas around the spindle poles that are populated with microtubule asters. In cells of a D. discoideum mutant that remain spread during mitosis we observed, as a rare event, cleavage by the expansion of a hole that is initiated in the middle of the cell area and has no connection with the cell's periphery. Here we show that these ring-shaped furrows develop in two phases, the first being reversible. During the first phase, the dorsal and ventral cell cortices come in close apposition and the cell membrane detaches locally from the substrate surface. The second phase comprises formation of the hole by membrane fusion and expansion of the opening toward the border of the cell, eventually cutting the multinucleate cell into pieces. We address the three-dimensional organization of ring-shaped furrows, their interaction with lateral furrows, and their association with filamentous myosin II and cortexillin. Thus, despite their geometrical divergence, similar molecular mechanisms might link the expanding hole to the standard contractile ring.
Collapse
Affiliation(s)
- Mary Ecke
- Max Planck Institute of Biochemistry, D-82152 Martinsried, Germany
| | - Jana Prassler
- Max Planck Institute of Biochemistry, D-82152 Martinsried, Germany
| | - Günther Gerisch
- Max Planck Institute of Biochemistry, D-82152 Martinsried, Germany
| |
Collapse
|
3
|
Banerjee T, Biswas D, Pal DS, Miao Y, Iglesias PA, Devreotes PN. Spatiotemporal dynamics of membrane surface charge regulates cell polarity and migration. Nat Cell Biol 2022; 24:1499-1515. [PMID: 36202973 PMCID: PMC10029748 DOI: 10.1038/s41556-022-00997-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 08/18/2022] [Indexed: 12/12/2022]
Abstract
During cell migration and polarization, numerous signal transduction and cytoskeletal components self-organize to generate localized protrusions. Although biochemical and genetic analyses have delineated many specific interactions, how the activation and localization of so many different molecules are spatiotemporally orchestrated at the subcellular level has remained unclear. Here we show that the regulation of negative surface charge on the inner leaflet of the plasma membrane plays an integrative role in the molecular interactions. Surface charge, or zeta potential, is transiently lowered at new protrusions and within cortical waves of Ras/PI3K/TORC2/F-actin network activation. Rapid alterations of inner leaflet anionic phospholipids-such as PI(4,5)P2, PI(3,4)P2, phosphatidylserine and phosphatidic acid-collectively contribute to the surface charge changes. Abruptly reducing the surface charge by recruiting positively charged optogenetic actuators was sufficient to trigger the entire biochemical network, initiate de novo protrusions and abrogate pre-existing polarity. These effects were blocked by genetic or pharmacological inhibition of key signalling components such as AKT and PI3K/TORC2. Conversely, increasing the negative surface charge deactivated the network and locally suppressed chemoattractant-induced protrusions or subverted EGF-induced ERK activation. Computational simulations involving excitable biochemical networks demonstrated that slight changes in feedback loops, induced by recruitment of the charged actuators, could lead to outsized effects on system activation. We propose that key signalling network components act on, and are in turn acted upon, by surface charge, closing feedback loops, which bring about the global-scale molecular self-organization required for spontaneous protrusion formation, cell migration and polarity establishment.
Collapse
Affiliation(s)
- Tatsat Banerjee
- Department of Cell Biology and Center for Cell Dynamics, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
- Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Debojyoti Biswas
- Department of Electrical and Computer Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Dhiman Sankar Pal
- Department of Cell Biology and Center for Cell Dynamics, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Yuchuan Miao
- Department of Cell Biology and Center for Cell Dynamics, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
- Department of Biological Chemistry, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Pablo A Iglesias
- Department of Cell Biology and Center for Cell Dynamics, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
- Department of Electrical and Computer Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Peter N Devreotes
- Department of Cell Biology and Center for Cell Dynamics, School of Medicine, Johns Hopkins University, Baltimore, MD, USA.
- Department of Biological Chemistry, School of Medicine, Johns Hopkins University, Baltimore, MD, USA.
| |
Collapse
|
4
|
Ogasawara T, Watanabe J, Adachi R, Ono Y, Kamimura Y, Muramoto T. CRISPR/Cas9-based genome-wide screening of Dictyostelium. Sci Rep 2022; 12:11215. [PMID: 35780186 PMCID: PMC9250498 DOI: 10.1038/s41598-022-15500-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 06/24/2022] [Indexed: 02/06/2023] Open
Abstract
Genome-wide screening is powerful method used to identify genes and pathways associated with a phenotype of interest. The simple eukaryote Dictyostelium discoideum has a unique life cycle and is often used as a crucial research model for a wide range of biological processes and rare metabolites. To address the inadequacies of conventional genetic screening approaches, we developed a highly efficient CRISPR/Cas9-based genome-wide screening system for Dictyostelium. A genome-wide library of 27,405 gRNAs and a kinase library of 4,582 gRNAs were compiled and mutant pools were generated. The resulting mutants were screened for defects in cell growth and more than 10 candidate genes were identified. Six of these were validated and five recreated mutants presented with growth abnormalities. Finally, the genes implicated in developmental defects were screened to identify the unknown genes associated with a phenotype of interest. These findings demonstrate the potential of the CRISPR/Cas9 system as an efficient genome-wide screening method.
Collapse
Affiliation(s)
- Takanori Ogasawara
- Department of Biology, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba, 274-8510, Japan
| | - Jun Watanabe
- Department of Biology, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba, 274-8510, Japan
| | - Remi Adachi
- Department of Biology, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba, 274-8510, Japan
| | - Yusuke Ono
- Department of Biology, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba, 274-8510, Japan
| | - Yoichiro Kamimura
- Laboratory for Cell Signaling Dynamics, RIKEN, Center for Biosystems Dynamics Research (BDR), Suita, Osaka, 565-0874, Japan
| | - Tetsuya Muramoto
- Department of Biology, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba, 274-8510, Japan.
| |
Collapse
|
5
|
Mijanović L, Weber I. Adhesion of Dictyostelium Amoebae to Surfaces: A Brief History of Attachments. Front Cell Dev Biol 2022; 10:910736. [PMID: 35721508 PMCID: PMC9197732 DOI: 10.3389/fcell.2022.910736] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 05/13/2022] [Indexed: 12/23/2022] Open
Abstract
Dictyostelium amoebae adhere to extracellular material using similar mechanisms to metazoan cells. Notably, the cellular anchorage loci in Amoebozoa and Metazoa are both arranged in the form of discrete spots and incorporate a similar repertoire of intracellular proteins assembled into multicomponent complexes located on the inner side of the plasma membrane. Surprisingly, however, Dictyostelium lacks integrins, the canonical transmembrane heterodimeric receptors that dominantly mediate adhesion of cells to the extracellular matrix in multicellular animals. In this review article, we summarize the current knowledge about the cell-substratum adhesion in Dictyostelium, present an inventory of the involved proteins, and draw parallels with the situation in animal cells. The emerging picture indicates that, while retaining the basic molecular architecture common to their animal relatives, the adhesion complexes in free-living amoeboid cells have evolved to enable less specific interactions with diverse materials encountered in their natural habitat in the deciduous forest soil. Dissection of molecular mechanisms that underlay short lifetime of the cell-substratum attachments and high turnover rate of the adhesion complexes in Dictyostelium should provide insight into a similarly modified adhesion phenotype that accompanies the mesenchymal-amoeboid transition in tumor metastasis.
Collapse
Affiliation(s)
| | - Igor Weber
- Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| |
Collapse
|
6
|
Gerisch G, Prassler J, Ecke M. Patterning of the cell cortex and the localization of cleavage furrows in multi-nucleate cells. J Cell Sci 2022; 135:275044. [PMID: 35274133 PMCID: PMC9016623 DOI: 10.1242/jcs.259648] [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: 12/01/2021] [Accepted: 03/07/2022] [Indexed: 12/03/2022] Open
Abstract
In multi-nucleate cells of Dictyostelium, cytokinesis is performed by unilateral cleavage furrows that ingress the large cells from their border. We use a septase (sepA)-null mutant with delayed cytokinesis to show that in anaphase a pattern is generated in the cell cortex of cortexillin and myosin II. In multi-nucleate cells, these proteins decorate the entire cell cortex except circular zones around the centrosomes. Unilateral cleavage furrows are initiated at spaces free of microtubule asters and invade the cells along trails of cortexillin and myosin II accumulation. Where these areas widen, the cleavage furrow may branch or expand. When two furrows meet, they fuse, thus separating portions of the multi-nucleate cell from each other. Unilateral furrows are distinguished from the contractile ring of a normal furrow by their expansion rather than constriction. This is particularly evident for expanding ring-shaped furrows that are formed in the centre of a large multi-nucleate cell. Our data suggest that the myosin II-enriched area in multi-nucleate cells is a contractile sheet that pulls on the unilateral furrows and, in that way, expands them. Summary: Multi-nucleate Dictyostelium cells divide by unilateral cleavage furrows that progress and expand according to a pattern of cortexillin and myosin II that is determined by microtubule asters at the spindle poles.
Collapse
Affiliation(s)
- Günther Gerisch
- Max Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany
| | - Jana Prassler
- Max Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany
| | - Mary Ecke
- Max Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany
| |
Collapse
|
7
|
Cellular inertia. Sci Rep 2021; 11:23799. [PMID: 34893617 PMCID: PMC8664931 DOI: 10.1038/s41598-021-02384-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Accepted: 11/09/2021] [Indexed: 11/18/2022] Open
Abstract
It has been experimentally reported that chemotactic cells exhibit cellular memory, that is, a tendency to maintain the migration direction despite changes in the chemoattractant gradient. In this study, we analyzed a phenomenological model assuming the presence of cellular inertia, as well as a response time in motility, resulting in the reproduction of the cellular memory observed in the previous experiments. According to the analysis, the cellular motion is described by the superposition of multiple oscillative functions induced by the multiplication of the oscillative polarity and motility. The cellular intertia generates cellular memory by regulating phase differences between those oscillative functions. By applying the theory to the experimental data, the cellular inertia was estimated at \documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$m=3-6$$\end{document}m=3-6 min. In addition, physiological parameters, such as response time in motility and intracellular processing speed, were also evaluated. The agreement between the experiemental data and theory suggests the possibility of the presence of the response time in motility, which has never been biologically verified and should be explored in the future.
Collapse
|
8
|
Kuhn J, Lin Y, Devreotes PN. Using Live-Cell Imaging and Synthetic Biology to Probe Directed Migration in Dictyostelium. Front Cell Dev Biol 2021; 9:740205. [PMID: 34676215 PMCID: PMC8523838 DOI: 10.3389/fcell.2021.740205] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 09/08/2021] [Indexed: 12/30/2022] Open
Abstract
For decades, the social amoeba Dictyostelium discoideum has been an invaluable tool for dissecting the biology of eukaryotic cells. Its short growth cycle and genetic tractability make it ideal for a variety of biochemical, cell biological, and biophysical assays. Dictyostelium have been widely used as a model of eukaryotic cell motility because the signaling and mechanical networks which they use to steer and produce forward motion are highly conserved. Because these migration networks consist of hundreds of interconnected proteins, perturbing individual molecules can have subtle effects or alter cell morphology and signaling in major unpredictable ways. Therefore, to fully understand this network, we must be able to quantitatively assess the consequences of abrupt modifications. This ability will allow us better control cell migration, which is critical for development and disease, in vivo. Here, we review recent advances in imaging, synthetic biology, and computational analysis which enable researchers to tune the activity of individual molecules in single living cells and precisely measure the effects on cellular motility and signaling. We also provide practical advice and resources to assist in applying these approaches in Dictyostelium.
Collapse
|
9
|
Crews DC, Wilson KL, Sohn J, Kabacoff CM, Poynton SL, Murphy LR, Bolz J, Wolfe A, White PT, Will C, Collins C, Gauda E, Robinson DN. Helping Scholars Overcome Socioeconomic Barriers to Medical and Biomedical Careers: Creating a Pipeline Initiative. TEACHING AND LEARNING IN MEDICINE 2020; 32:422-433. [PMID: 32096414 DOI: 10.1080/10401334.2020.1729161] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Problem: To achieve their potential in medical and biomedical careers, students (scholars) from under-resourced backgrounds must build sophisticated skills and develop confidence and professionalism. To flourish in an advanced educational system that may be unfamiliar, these scholars also need networks of mentors and role models. These challenges can affect scholars at multiple stages of their education. Intervention: To meet these challenges, we created a broad and innovative biomedical research-focused pipeline program: the Johns Hopkins Initiative for Careers in Science in Medicine (CSM Initiative). This initiative targets three levels: high school, undergraduate, and post-baccalaureate/pre-doctoral (graduate and medical). We provide training in essential academic, research, professional, and social skills to meet the unique challenges of our scholars from under-resourced backgrounds. Scholars also build relationships with mentors who provide career guidance and support. We present an overview of the training and assessment at each level of this initiative. Context: The initiative took place at an institution located in the greater Baltimore area and that is endowed with exceptional doctoral and postdoctoral trainees, staff, and faculty including clinicians, physician-scientists, and scientists who served as key role models and mentors. Our pipeline program draws from local high school students and a local and national pool of undergraduates and post-baccalaureates preparing for medical or graduate school. Impact: Our goals for the high school scholars are significant improvement in academic skills, increased confidence, and matriculation into higher education systems. Currently, at least 83% of high school scholars have matriculated into four-year college programs and 73% have chosen science, technology, engineering, math, and medicine (STEMM)-related majors. Among undergraduate participants, 42% have matriculated thus far into medical or biomedical graduate programs and this number is expected to rise as more scholars graduate from college and either enter graduate training or pursue STEMM careers. Another 25% have returned to our post-baccalaureate program. Among post-baccalaureate scholars, 71% have now matriculated into doctoral-level graduate biomedical programs (medical or graduate school) and the remaining 29% are pursuing careers in STEMM-related fields such as biomedical research with some still aiming at graduate-level education. Our long-term goal is to see a large majority of our scholars become successful professionals in medicine, biomedical research, allied healthcare, or other STEMM fields. Analysis of the early phases of the CSM initiative demonstrates such outcomes are attainable. Lessons Learned: This program provides experiences in which scholars develop and practice core competencies essential for developing their self-identity as scientists and professionals. The most important lesson learned is that mentorship teams must be highly dynamic, flexible, thoughtful, and personal in responding to the wide range of challenges and obstacles that scholars from under-resourced backgrounds must overcome to achieve career success.
Collapse
Affiliation(s)
- Deidra C Crews
- Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Katherine L Wilson
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Jungsan Sohn
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Cathryn M Kabacoff
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Sarah L Poynton
- Department of Molecular and Comparative Pathobiology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Laura R Murphy
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Jessica Bolz
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Andrew Wolfe
- Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Paul T White
- Office of Admissions, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Catherine Will
- Office of Graduate Affairs, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Chiquita Collins
- Office of Diversity, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Estelle Gauda
- Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Douglas N Robinson
- Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| |
Collapse
|
10
|
Singh SP, Thomason PA, Lilla S, Schaks M, Tang Q, Goode BL, Machesky LM, Rottner K, Insall RH. Cell-substrate adhesion drives Scar/WAVE activation and phosphorylation by a Ste20-family kinase, which controls pseudopod lifetime. PLoS Biol 2020; 18:e3000774. [PMID: 32745097 PMCID: PMC7425996 DOI: 10.1371/journal.pbio.3000774] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 08/13/2020] [Accepted: 07/13/2020] [Indexed: 01/22/2023] Open
Abstract
The Scar/WAVE complex is the principal catalyst of pseudopod and lamellipod formation. Here we show that Scar/WAVE's proline-rich domain is polyphosphorylated after the complex is activated. Blocking Scar/WAVE activation stops phosphorylation in both Dictyostelium and mammalian cells, implying that phosphorylation modulates pseudopods after they have been formed, rather than controlling whether they are initiated. Unexpectedly, phosphorylation is not promoted by chemotactic signaling but is greatly stimulated by cell:substrate adhesion and diminished when cells deadhere. Phosphorylation-deficient or phosphomimetic Scar/WAVE mutants are both normally functional and rescue the phenotype of knockout cells, demonstrating that phosphorylation is dispensable for activation and actin regulation. However, pseudopods and patches of phosphorylation-deficient Scar/WAVE last substantially longer in mutants, altering the dynamics and size of pseudopods and lamellipods and thus changing migration speed. Scar/WAVE phosphorylation does not require ERK2 in Dictyostelium or mammalian cells. However, the MAPKKK homologue SepA contributes substantially-sepA mutants have less steady-state phosphorylation, which does not increase in response to adhesion. The mutants also behave similarly to cells expressing phosphorylation-deficient Scar, with longer-lived pseudopods and patches of Scar recruitment. We conclude that pseudopod engagement with substratum is more important than extracellular signals at regulating Scar/WAVE's activity and that phosphorylation acts as a pseudopod timer by promoting Scar/WAVE turnover.
Collapse
Affiliation(s)
| | | | | | - Matthias Schaks
- Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany & Cell Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Qing Tang
- Brandeis University, Waltham, Massachusetts, United States of America
| | - Bruce L. Goode
- Brandeis University, Waltham, Massachusetts, United States of America
| | | | - Klemens Rottner
- Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany & Cell Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Robert H. Insall
- CRUK Beatson Institute, Glasgow, United Kingdom
- Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom
| |
Collapse
|
11
|
Bhattacharya S, Banerjee T, Miao Y, Zhan H, Devreotes PN, Iglesias PA. Traveling and standing waves mediate pattern formation in cellular protrusions. SCIENCE ADVANCES 2020; 6:eaay7682. [PMID: 32821814 PMCID: PMC7413732 DOI: 10.1126/sciadv.aay7682] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 06/26/2020] [Indexed: 05/04/2023]
Abstract
The mechanisms regulating protrusions during amoeboid migration exhibit excitability. Theoretical studies have suggested the possible coexistence of traveling and standing waves in excitable systems. Here, we demonstrate the direct transformation of a traveling into a standing wave and establish conditions for the stability of this conversion. This theory combines excitable wave stopping and the emergence of a family of standing waves at zero velocity, without altering diffusion parameters. Experimentally, we show the existence of this phenomenon on the cell cortex of some Dictyostelium and mammalian mutant strains. We further predict a template that encompasses a spectrum of protrusive phenotypes, including pseudopodia and filopodia, through transitions between traveling and standing waves, allowing the cell to switch between excitability and bistability. Overall, this suggests that a previously-unidentified method of pattern formation, in which traveling waves spread, stop, and turn into standing waves that rearrange to form stable patterns, governs cell motility.
Collapse
Affiliation(s)
- Sayak Bhattacharya
- Department of Electrical and Computer Engineering, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA
| | - Tatsat Banerjee
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA
- Department of Cell Biology and Center for Cell Dynamics, Johns Hopkins School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205, USA
| | - Yuchuan Miao
- Department of Cell Biology and Center for Cell Dynamics, Johns Hopkins School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205, USA
- Department of Biological Chemistry, Johns Hopkins School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205, USA
| | - Huiwang Zhan
- Department of Cell Biology and Center for Cell Dynamics, Johns Hopkins School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205, USA
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
| | - Peter N. Devreotes
- Department of Cell Biology and Center for Cell Dynamics, Johns Hopkins School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205, USA
| | - Pablo A. Iglesias
- Department of Electrical and Computer Engineering, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA
- Department of Cell Biology and Center for Cell Dynamics, Johns Hopkins School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205, USA
| |
Collapse
|
12
|
Seong H, Higgins SG, Penders J, Armstrong JPK, Crowder SW, Moore AC, Sero JE, Becce M, Stevens MM. Size-Tunable Nanoneedle Arrays for Influencing Stem Cell Morphology, Gene Expression, and Nuclear Membrane Curvature. ACS NANO 2020; 14:5371-5381. [PMID: 32330008 PMCID: PMC7254837 DOI: 10.1021/acsnano.9b08689] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 04/24/2020] [Indexed: 05/16/2023]
Abstract
High-aspect-ratio nanostructures have emerged as versatile platforms for intracellular sensing and biomolecule delivery. Here, we present a microfabrication approach in which a combination of reactive ion etching protocols were used to produce high-aspect-ratio, nondegradable silicon nanoneedle arrays with tip diameters that could be finely tuned between 20 and 700 nm. We used these arrays to guide the long-term culture of human mesenchymal stem cells (hMSCs). Notably, we used changes in the nanoneedle tip diameter to control the morphology, nuclear size, and F-actin alignment of interfaced hMSCs and to regulate the expression of nuclear lamina genes, Yes-associated protein (YAP) target genes, and focal adhesion genes. These topography-driven changes were attributed to signaling by Rho-family GTPase pathways, differences in the effective stiffness of the nanoneedle arrays, and the degree of nuclear membrane impingement, with the latter clearly visualized using focused ion beam scanning electron microscopy (FIB-SEM). Our approach to design high-aspect-ratio nanostructures will be broadly applicable to design biomaterials and biomedical devices used for long-term cell stimulation and monitoring.
Collapse
Affiliation(s)
- Hyejeong Seong
- Department
of Materials, Department of Bioengineering, and Institute of Biomedical Engineering, Imperial College London, Prince Consort Road, SW7 2AZ, London, U.K.
| | - Stuart G. Higgins
- Department
of Materials, Department of Bioengineering, and Institute of Biomedical Engineering, Imperial College London, Prince Consort Road, SW7 2AZ, London, U.K.
| | - Jelle Penders
- Department
of Materials, Department of Bioengineering, and Institute of Biomedical Engineering, Imperial College London, Prince Consort Road, SW7 2AZ, London, U.K.
| | - James P. K. Armstrong
- Department
of Materials, Department of Bioengineering, and Institute of Biomedical Engineering, Imperial College London, Prince Consort Road, SW7 2AZ, London, U.K.
| | - Spencer W. Crowder
- Department
of Materials, Department of Bioengineering, and Institute of Biomedical Engineering, Imperial College London, Prince Consort Road, SW7 2AZ, London, U.K.
| | - Axel C. Moore
- Department
of Materials, Department of Bioengineering, and Institute of Biomedical Engineering, Imperial College London, Prince Consort Road, SW7 2AZ, London, U.K.
| | - Julia E. Sero
- Department
of Materials, Department of Bioengineering, and Institute of Biomedical Engineering, Imperial College London, Prince Consort Road, SW7 2AZ, London, U.K.
| | - Michele Becce
- Department
of Materials, Department of Bioengineering, and Institute of Biomedical Engineering, Imperial College London, Prince Consort Road, SW7 2AZ, London, U.K.
| | - Molly M. Stevens
- Department
of Materials, Department of Bioengineering, and Institute of Biomedical Engineering, Imperial College London, Prince Consort Road, SW7 2AZ, London, U.K.
| |
Collapse
|
13
|
Statin-induced GGPP depletion blocks macropinocytosis and starves cells with oncogenic defects. Proc Natl Acad Sci U S A 2020; 117:4158-4168. [PMID: 32051246 DOI: 10.1073/pnas.1917938117] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Cancer cells display novel characteristics which can be exploited for therapeutic advantage. Isolated studies have shown that 1) the mevalonate pathway and 2) increased macropinocytosis are important in tumorigenesis, but a connection between these two observations has not been envisioned. A library screen for compounds that selectively killed Dictyostelium pten - cells identified pitavastatin. Pitavastatin also killed human breast epithelial MCF10A cells lacking PTEN or expressing K-RasG12V, as well as mouse tumor organoids. The selective killing of cells with oncogenic defects was traced to GGPP (geranylgeranyl diphosphate) depletion. Disruption of GGPP synthase in Dictyostelium revealed that GGPP is needed for pseudopod extension and macropinocytosis. Fluid-phase uptake through macropinocytosis is lower in PTEN-deleted cells and, as reported previously, higher in cells expressing activated Ras. Nevertheless, uptake was more sensitive to pitavastatin in cells with either of these oncogenic mutations than in wild-type cells. Loading the residual macropinosomes after pitavastatin with high concentrations of protein mitigated the cell death, indicating that defective macropinocytosis leads to amino acid starvation. Our studies suggest that the dependence of cancer cells on the mevalonate pathway is due to the role of GGPP in macropinocytosis and the reliance of these cells on macropinocytosis for nutrient uptake. Thus, inhibition of the networks mediating these processes is likely to be effective in cancer intervention.
Collapse
|
14
|
Kamprad N, Witt H, Schröder M, Kreis CT, Bäumchen O, Janshoff A, Tarantola M. Adhesion strategies of Dictyostelium discoideum- a force spectroscopy study. NANOSCALE 2018; 10:22504-22519. [PMID: 30480299 DOI: 10.1039/c8nr07107a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Biological adhesion is essential for all motile cells and generally limits locomotion to suitably functionalized substrates displaying a compatible surface chemistry. However, organisms that face vastly varying environmental challenges require a different strategy. The model organism Dictyostelium discoideum (D.d.), a slime mould dwelling in the soil, faces the challenge of overcoming variable chemistry by employing the fundamental forces of colloid science. To understand the origin of D.d. adhesion, we realized and modified a variety of conditions for the amoeba comprising the absence and presence of the specific adhesion protein Substrate Adhesion A (sadA), glycolytic degradation, ionic strength, surface hydrophobicity and strength of van der Waals interactions by generating tailored model substrates. By employing AFM-based single cell force spectroscopy we could show that experimental force curves upon retraction exhibit two regimes. The first part up to the critical adhesion force can be described in terms of a continuum model, while the second regime of the curve beyond the critical adhesion force is governed by stochastic unbinding of individual binding partners and bond clusters. We found that D.d. relies on adhesive interactions based on EDL-DLVO (Electrical Double Layer-Derjaguin-Landau-Verwey-Overbeek) forces and contributions from the glycocalix and specialized adhesion molecules like sadA. This versatile mechanism allows the cells to adhere to a large variety of natural surfaces under various conditions.
Collapse
Affiliation(s)
- Nadine Kamprad
- Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, 37077 Göttingen, Germany.
| | | | | | | | | | | | | |
Collapse
|
15
|
Insight from the maximal activation of the signal transduction excitable network in Dictyostelium discoideum. Proc Natl Acad Sci U S A 2018; 115:E3722-E3730. [PMID: 29602807 PMCID: PMC5910810 DOI: 10.1073/pnas.1710480115] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Cell migration requires the coordination of an excitable signal transduction network involving Ras and PI3K pathways with cytoskeletal activity. We show that expressing activated Ras GTPase-family proteins in cells lacking PTEN or other mutations which increase cellular protrusiveness transforms cells into a persistently activated state. Leading- and trailing-edge markers were found exclusively at the cell perimeter and the cytosol, respectively, of the dramatically flattened cells. In addition, the lifetimes of dynamic actin puncta were increased where they overlapped with actin waves, suggesting a mechanism for the coupling between these two networks. All of these phenotypes could be reversed by inhibiting signal transduction. Strikingly, maintaining cells in this state of constant activation led to a form of cell death by catastrophic fragmentation. These findings provide insight into the feedback loops that control excitability of the signal transduction network, which drives migration.
Collapse
|
16
|
Devreotes PN, Bhattacharya S, Edwards M, Iglesias PA, Lampert T, Miao Y. Excitable Signal Transduction Networks in Directed Cell Migration. Annu Rev Cell Dev Biol 2017; 33:103-125. [PMID: 28793794 DOI: 10.1146/annurev-cellbio-100616-060739] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Although directed migration of eukaryotic cells may have evolved to escape nutrient depletion, it has been adopted for an extensive range of physiological events during development and in the adult organism. The subversion of these movements results in disease, such as cancer. Mechanisms of propulsion and sensing are extremely diverse, but most eukaryotic cells move by extending actin-filled protrusions termed macropinosomes, pseudopodia, or lamellipodia or by extension of blebs. In addition to motility, directed migration involves polarity and directional sensing. The hundreds of gene products involved in these processes are organized into networks of parallel and interconnected pathways. Many of these components are activated or inhibited coordinately with stimulation and on each spontaneously extended protrusion. Moreover, these networks display hallmarks of excitability, including all-or-nothing responsiveness and wave propagation. Cellular protrusions result from signal transduction waves that propagate outwardly from an origin and drive cytoskeletal activity. The range of the propagating waves and hence the size of the protrusions can be altered by lowering or raising the threshold for network activation, with larger and wider protrusions favoring gliding or oscillatory behavior over amoeboid migration. Here, we evaluate the variety of models of excitable networks controlling directed migration and outline critical tests. We also discuss the utility of this emerging view in producing cell migration and in integrating the various extrinsic cues that direct migration.
Collapse
Affiliation(s)
- Peter N Devreotes
- Department of Cell Biology, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205;
| | - Sayak Bhattacharya
- Department of Electrical and Computer Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, Maryland 21218
| | - Marc Edwards
- Department of Cell Biology, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205;
| | - Pablo A Iglesias
- Department of Cell Biology, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205; .,Department of Electrical and Computer Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, Maryland 21218
| | - Thomas Lampert
- Department of Cell Biology, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205;
| | - Yuchuan Miao
- Department of Cell Biology, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205;
| |
Collapse
|