1
|
Holt LJ, Delarue M. Macromolecular crowding: Sensing without a sensor. Curr Opin Cell Biol 2023; 85:102269. [PMID: 37897928 DOI: 10.1016/j.ceb.2023.102269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 09/28/2023] [Accepted: 10/01/2023] [Indexed: 10/30/2023]
Abstract
All living cells are crowded with macromolecules. Crowding can directly modulate biochemical reactions to various degrees depending on the sizes, shapes, and binding affinities of the reactants. Here, we explore the possibility that cells can sense and adapt to changes in crowding through the widespread modulation of biochemical reactions without the need for a dedicated sensor. Additionally, we explore phase separation as a general physicochemical response to changes in crowding, and a mechanism to both transduce information and physically restore crowding homeostasis.
Collapse
Affiliation(s)
- Liam J Holt
- New York University Grossman School of Medicine, Institute for Systems Genetics, New York, NY, USA
| | - Morgan Delarue
- LAAS-CNRS, Université de Toulouse, CNRS, Toulouse, France.
| |
Collapse
|
2
|
Marfai J, McGorty RJ, Robertson-Anderson RM. Cooperative Rheological State-Switching of Enzymatically-Driven Composites of Circular DNA And Dextran. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2305824. [PMID: 37500570 DOI: 10.1002/adma.202305824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/17/2023] [Indexed: 07/29/2023]
Abstract
Polymer topology, which plays a principal role in the rheology of polymeric fluids, and non-equilibrium materials, which exhibit time-varying rheological properties, are topics of intense investigation. Here, composites of circular DNA and dextran are pushed out-of-equilibrium via enzymatic digestion of DNA rings to linear fragments. These time-resolved rheology measurements reveal discrete state-switching, with composites undergoing abrupt transitions between dissipative and elastic-like states. The gating time and lifetime of the elastic-like states, and the magnitude and sharpness of the transitions, are surprisingly decorrelated from digestion rates and non-monotonically depend on the DNA fraction. These results are modeled using sigmoidal two-state functions to show that bulk state-switching can arise from continuous molecular-level activity due to the necessity for cooperative percolation of entanglements to support macroscopic stresses. This platform, coupling the tunability of topological composites with the power of enzymatic reactions, may be leveraged for diverse material applications from wound-healing to self-repairing infrastructure.
Collapse
Affiliation(s)
- Juexin Marfai
- Department of Physics and Biophysics, University of San Diego, San Diego, CA, 92110, USA
| | - Ryan J McGorty
- Department of Physics and Biophysics, University of San Diego, San Diego, CA, 92110, USA
| | | |
Collapse
|
3
|
Molines AT, Lemière J, Gazzola M, Steinmark IE, Edrington CH, Hsu CT, Real-Calderon P, Suhling K, Goshima G, Holt LJ, Thery M, Brouhard GJ, Chang F. Physical properties of the cytoplasm modulate the rates of microtubule polymerization and depolymerization. Dev Cell 2022; 57:466-479.e6. [PMID: 35231427 PMCID: PMC9319896 DOI: 10.1016/j.devcel.2022.02.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 11/01/2021] [Accepted: 01/31/2022] [Indexed: 11/20/2022]
Abstract
The cytoplasm is a crowded, visco-elastic environment whose physical properties change according to physiological or developmental states. How the physical properties of the cytoplasm impact cellular functions in vivo remains poorly understood. Here, we probe the effects of cytoplasmic concentration on microtubules by applying osmotic shifts to fission yeast, moss, and mammalian cells. We show that the rates of both microtubule polymerization and depolymerization scale linearly and inversely with cytoplasmic concentration; an increase in cytoplasmic concentration decreases the rates of microtubule polymerization and depolymerization proportionally, whereas a decrease in cytoplasmic concentration leads to the opposite. Numerous lines of evidence indicate that these effects are due to changes in cytoplasmic viscosity rather than cellular stress responses or macromolecular crowding per se. We reconstituted these effects on microtubules in vitro by tuning viscosity. Our findings indicate that, even in normal conditions, the viscosity of the cytoplasm modulates the reactions that underlie microtubule dynamic behaviors.
Collapse
Affiliation(s)
- Arthur T Molines
- Department of Cell and Tissue Biology, University of California, San Francisco, USA; Marine Biological Laboratory, Woods Hole, MA 02543, USA.
| | - Joël Lemière
- Department of Cell and Tissue Biology, University of California, San Francisco, USA
| | - Morgan Gazzola
- University of Grenoble-Alpes, CEA, CNRS, INRA, Interdisciplinary Research Institute of Grenoble, Laboratoire de Phyiologie Cellulaire & Vegétale, CytoMorpho Lab, 38054 Grenoble, France
| | | | | | - Chieh-Ting Hsu
- Department of Physics, McGill University, Montréal, Quebec, Canada
| | - Paula Real-Calderon
- Department of Cell and Tissue Biology, University of California, San Francisco, USA
| | - Klaus Suhling
- Department of Physics, King's College London, London, UK
| | - Gohta Goshima
- Sugashima Marine Biological Laboratory and Division of Biological Science, Graduate School of Science, Nagoya University, Toba City, Mie, Japan; Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | - Liam J Holt
- Institute for Systems Genetics, New York University Langone Health, New York, NY 10016, USA; Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | - Manuel Thery
- University of Grenoble-Alpes, CEA, CNRS, INRA, Interdisciplinary Research Institute of Grenoble, Laboratoire de Phyiologie Cellulaire & Vegétale, CytoMorpho Lab, 38054 Grenoble, France; Université de Paris, INSERM, CEA, Institut de Recherche Saint Louis, U 976, CytoMorpho Lab, 75010 Paris, France
| | - Gary J Brouhard
- Department of Biology, McGill University, Montréal, Quebec, Canada
| | - Fred Chang
- Department of Cell and Tissue Biology, University of California, San Francisco, USA; Marine Biological Laboratory, Woods Hole, MA 02543, USA.
| |
Collapse
|
4
|
Betterton MD. A new view of how cytoplasmic viscosity affects microtubule dynamics. Dev Cell 2022; 57:419-420. [PMID: 35231424 DOI: 10.1016/j.devcel.2022.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
How the physical nature of the cytoplasm shapes cellular processes has been increasingly studied in recent years. Work in this issue demonstrates that cytoplasmic viscosity affects the dynamic instability of microtubules. Surprisingly, both polymerization and depolymerization slow with increasing viscosity. This raises interesting questions for future work.
Collapse
Affiliation(s)
- Meredith D Betterton
- Department of Physics, University of Colorado, Boulder, CO, USA; Department of MCD Biology, University of Colorado, Boulder, CO, USA; Center for Computational Biology, Flatiron Institute, New York, NY, USA.
| |
Collapse
|
5
|
Reuther C, Santos-Otte P, Grover R, Heldt G, Woehlke G, Diez S. Multiplication of Motor-Driven Microtubules for Nanotechnological Applications. NANO LETTERS 2022; 22:926-934. [PMID: 35050639 DOI: 10.1021/acs.nanolett.1c03619] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Microtubules gliding on motor-functionalized surfaces have been explored for various nanotechnological applications. However, when moving over large distances (several millimeters) and long times (tens of minutes), microtubules are lost due to surface detachment. Here, we demonstrate the multiplication of kinesin-1-driven microtubules that comprises two concurrent processes: (i) severing of microtubules by the enzyme spastin and (ii) elongation of microtubules by self-assembly of tubulin dimers at the microtubule ends. We managed to balance the individual processes such that the average length of the microtubules stayed roughly constant over time while their number increased. Moreover, we show microtubule multiplication in physical networks with topographical channel structures. Our method is expected to broaden the toolbox for microtubule-based in vitro applications by counteracting the microtubule loss from substrate surfaces. Among others, this will enable upscaling of network-based biocomputation, where it is vital to increase the number of microtubules during operation.
Collapse
Affiliation(s)
- Cordula Reuther
- B CUBE - Center for Molecular Bioengineering, Technische Universität Dresden, 01062 Dresden, Germany
| | - Paula Santos-Otte
- B CUBE - Center for Molecular Bioengineering, Technische Universität Dresden, 01062 Dresden, Germany
| | - Rahul Grover
- B CUBE - Center for Molecular Bioengineering, Technische Universität Dresden, 01062 Dresden, Germany
| | - Georg Heldt
- Fraunhofer Institute for Electronic Nano Systems, 09126 Chemnitz, Germany
| | - Günther Woehlke
- Center for Functional Protein Assemblies, Technische Universität München, 85748 Garching, Germany
| | - Stefan Diez
- B CUBE - Center for Molecular Bioengineering, Technische Universität Dresden, 01062 Dresden, Germany
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
- Cluster of Excellence Physics of Life, Technische Universität Dresden, 01062 Dresden, Germany
| |
Collapse
|
6
|
Kuo YW, Howard J. In Vitro Reconstitution of Microtubule Dynamics and Severing Imaged by Label-Free Interference-Reflection Microscopy. Methods Mol Biol 2022; 2430:73-91. [PMID: 35476326 PMCID: PMC9131738 DOI: 10.1007/978-1-0716-1983-4_5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The dynamic architecture of the microtubule cytoskeleton is crucial for cell division, motility and morphogenesis. The dynamic properties of microtubules-growth, shrinkage, nucleation, and severing-are regulated by an arsenal of microtubule-associated proteins (MAPs). The activities of many of these MAPs have been reconstituted in vitro using microscope assays. As an alternative to fluorescence microscopy, interference-reflection microscopy (IRM) has been introduced as an easy-to-use, wide-field imaging technique that allows label-free visualization of microtubules with high contrast and speed. IRM circumvents several problems associated with fluorescence microscopy including the high concentrations of tubulin required for fluorescent labeling, the potential perturbation of function caused by the fluorophores, and the risks of photodamage. IRM can be implemented on a standard epifluorescence microscope at low cost and can be combined with fluorescence techniques like total-internal-reflection-fluorescence (TIRF) microscopy. Here we describe the experimental procedure to image microtubule dynamics and severing using IRM , providing practical tips and guidelines to resolve possible experimental hurdles.
Collapse
Affiliation(s)
- Yin-Wei Kuo
- Department of Chemistry, Yale University, New Haven, CT, USA
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Jonathon Howard
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA.
| |
Collapse
|
7
|
Peddireddy KR, Michieletto D, Aguirre G, Garamella J, Khanal P, Robertson-Anderson RM. DNA Conformation Dictates Strength and Flocculation in DNA-Microtubule Composites. ACS Macro Lett 2021; 10:1540-1548. [PMID: 35549144 PMCID: PMC9239750 DOI: 10.1021/acsmacrolett.1c00638] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Polymer topology has been shown to play a key role in tuning the dynamics of complex fluids and gels. At the same time, polymer composites, ubiquitous in everyday life, have been shown to exhibit emergent desirable mechanical properties not attainable in single-species systems. Yet, how topology impacts the dynamics and structure of polymer composites remains poorly understood. Here, we create composites of rigid rods (microtubules) polymerized within entangled solutions of flexible linear and ring polymers (DNA) of equal length. We couple optical tweezers microrheology with confocal microscopy and scaled particle theory to show that composites with linear DNA exhibit a strongly nonmonotonic dependence of elasticity and stiffness on microtubule concentration due to depletion-driven polymerization and flocculation of microtubules. In contrast, composites containing ring DNA show a much more modest monotonic increase in elastic strength with microtubule concentration, which we demonstrate arises from the decreased conformational size and increased miscibility of rings.
Collapse
Affiliation(s)
- Karthik R Peddireddy
- Department of Physics and Biophysics, University of San Diego, 5998 Alcala Park, San Diego, California 92110, United States
| | - Davide Michieletto
- School of Physics and Astronomy, University of Edinburgh, Peter Guthrie Tait Road, Edinburgh, EH9 3FD, United Kingdom
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Gina Aguirre
- Department of Physics and Biophysics, University of San Diego, 5998 Alcala Park, San Diego, California 92110, United States
| | - Jonathan Garamella
- Department of Physics and Biophysics, University of San Diego, 5998 Alcala Park, San Diego, California 92110, United States
| | - Pawan Khanal
- Department of Physics and Biophysics, University of San Diego, 5998 Alcala Park, San Diego, California 92110, United States
| | - Rae M Robertson-Anderson
- Department of Physics and Biophysics, University of San Diego, 5998 Alcala Park, San Diego, California 92110, United States
| |
Collapse
|
8
|
Evers TMJ, Holt LJ, Alberti S, Mashaghi A. Reciprocal regulation of cellular mechanics and metabolism. Nat Metab 2021; 3:456-468. [PMID: 33875882 PMCID: PMC8863344 DOI: 10.1038/s42255-021-00384-w] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 03/12/2021] [Indexed: 12/12/2022]
Abstract
Metabolism and mechanics are intrinsically intertwined. External forces, sensed through the cytoskeleton or distortion of the cell and organelles, induce metabolic changes in the cell. The resulting changes in metabolism, in turn, feed back to regulate every level of cell biology, including the mechanical properties of cells and tissues. Here we examine the links between metabolism and mechanics, highlighting signalling pathways involved in the regulation and response to cellular mechanosensing. We consider how forces and metabolism regulate one another through nanoscale molecular sensors, micrometre-scale cytoskeletal networks, organelles and dynamic biomolecular condensates. Understanding this cross-talk will create diagnostic and therapeutic opportunities for metabolic disorders such as cancer, cardiovascular pathologies and obesity.
Collapse
Affiliation(s)
- Tom M J Evers
- Medical Systems Biophysics and Bioengineering, Leiden Academic Centre for Drug Research, Faculty of Science, Leiden University, Leiden, the Netherlands
| | - Liam J Holt
- Institute for Systems Genetics, New York University Langone Health, New York, NY, USA
| | - Simon Alberti
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Alireza Mashaghi
- Medical Systems Biophysics and Bioengineering, Leiden Academic Centre for Drug Research, Faculty of Science, Leiden University, Leiden, the Netherlands.
| |
Collapse
|
9
|
Yamamoto S, Yabuki R, Kitagawa D. Biophysical and biochemical properties of Deup1 self-assemblies: a potential driver for deuterosome formation during multiciliogenesis. Biol Open 2021; 10:10/3/bio056432. [PMID: 33658185 PMCID: PMC7938805 DOI: 10.1242/bio.056432] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The deuterosome is a non-membranous organelle involved in large-scale centriole amplification during multiciliogenesis. Deuterosomes are specifically assembled during the process of multiciliogenesis. However, the molecular mechanisms underlying deuterosome formation are poorly understood. In this study, we investigated the molecular properties of deuterosome protein 1 (Deup1), an essential protein involved in deuterosome assembly. We found that Deup1 has the ability to self-assemble into macromolecular condensates both in vitro and in cells. The Deup1-containing structures formed in multiciliogenesis and the Deup1 condensates self-assembled in vitro showed low turnover of Deup1, suggesting that Deup1 forms highly stable structures. Our biochemical analyses revealed that an increase of the concentration of Deup1 and a crowded molecular environment both facilitate Deup1 self-assembly. The self-assembly of Deup1 relies on its N-terminal region, which contains multiple coiled coil domains. Using an optogenetic approach, we demonstrated that self-assembly and the C-terminal half of Deup1 were sufficient to spatially compartmentalize centrosomal protein 152 (Cep152) and polo like kinase 4 (Plk4), master components for centriole biogenesis, in the cytoplasm. Collectively, the present data suggest that Deup1 forms the structural core of the deuterosome through self-assembly into stable macromolecular condensates.This article has an associated First Person interview with the first author of the paper.
Collapse
Affiliation(s)
- Shohei Yamamoto
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Tokyo 113-0033, Japan
| | - Ryoichi Yabuki
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Tokyo 113-0033, Japan
| | - Daiju Kitagawa
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Tokyo 113-0033, Japan
| |
Collapse
|
10
|
VanDelinder V, Sickafoose I, Imam ZI, Ko R, Bachand GD. The effects of osmolytes on in vitro kinesin-microtubule motility assays. RSC Adv 2020; 10:42810-42815. [PMID: 35514903 PMCID: PMC9057942 DOI: 10.1039/d0ra08148e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 11/18/2020] [Indexed: 01/05/2023] Open
Abstract
The gliding motility of microtubule filaments has been used to study the biophysical properties of kinesin motors, as well as being used in a variety of nanotechnological applications. While microtubules are generally stabilized in vitro with paclitaxel (Taxol®), osmolytes such as polyethylene glycol (PEG) and trimethylamine N-oxide (TMAO) are also able to inhibit depolymerization over extended periods of time. High concentrations of TMAO have also been reported to reversibly inhibit kinesin motility of paclitaxel-stabilized microtubules. Here, we examined the effects of the osmolytes PEG, TMAO, and glycerol on stabilizing microtubules during gliding motility on kinesin-coated substrates. As previously observed, microtubule depolymerization was inhibited in a concentration dependent manner by the addition of the different osmolytes. Kinesin-driven motility also exhibited concentration dependent effects with the addition of the osmolytes, specifically reducing the velocity, increasing rates of pinning, and altering trajectories of the microtubules. These data suggest that there is a delicate balance between the ability of osmolytes to stabilize microtubules without inhibiting motility. Overall, these findings provide a more comprehensive understanding of how osmolytes affect the dynamics of microtubules and kinesin motors, and their interactions in crowded environments.
Collapse
Affiliation(s)
- Virginia VanDelinder
- Center for Integrated Nanotechnologies, Sandia National Laboratories Albuquerque NM USA
| | - Ian Sickafoose
- Center for Integrated Nanotechnologies, Sandia National Laboratories Albuquerque NM USA
| | - Zachary I Imam
- Center for Integrated Nanotechnologies, Sandia National Laboratories Albuquerque NM USA
| | - Randy Ko
- Center for Integrated Nanotechnologies, Sandia National Laboratories Albuquerque NM USA
| | - George D Bachand
- Center for Integrated Nanotechnologies, Sandia National Laboratories Albuquerque NM USA
| |
Collapse
|
11
|
Geisterfer ZM, Zhu DY, Mitchison TJ, Oakey J, Gatlin JC. Microtubule Growth Rates Are Sensitive to Global and Local Changes in Microtubule Plus-End Density. Curr Biol 2020; 30:3016-3023.e3. [PMID: 32531285 DOI: 10.1016/j.cub.2020.05.056] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Revised: 04/14/2020] [Accepted: 05/18/2020] [Indexed: 01/02/2023]
Abstract
The microtubule cytoskeleton plays critically important roles in numerous cellular functions in eukaryotes, and it does so across a functionally diverse and morphologically disparate range of cell types [1]. In these roles, microtubule assemblies must adopt distinct morphologies and physical dimensions to perform specific functions [2-5]. As such, these macromolecular assemblies-as well as the dynamics of the individual microtubule polymers from which they are made-must scale and change in accordance with cell size, geometry, and function. Microtubules in cells typically assemble to a steady state in mass, leaving enough of their tubulin subunits soluble to allow rapid growth and turnover. This suggests some negative feedback that limits the extent of assembly, for example, decrease in growth rate, or increase in catastrophe rate, as the soluble subunit pool decreases. Although these ideas have informed the field for decades, they have not been observed experimentally. Here, we describe the application of an experimental approach that combines cell-free extracts with photo-patterned hydrogel micro-enclosures as a means to investigate microtubule dynamics in cytoplasmic volumes of defined size and shape. Our measurements reveal a negative correlation between microtubule plus-end density and microtubule growth rates and suggest that these rates are sensitive to the presence of nearby growing ends.
Collapse
Affiliation(s)
- Zachary M Geisterfer
- Department of Molecular Biology, University of Wyoming, 1000 E. University Avenue, Laramie, WY 82070, USA.
| | - Daniel Y Zhu
- Department of Molecular Biology, University of Wyoming, 1000 E. University Avenue, Laramie, WY 82070, USA
| | - Timothy J Mitchison
- Department of Systems Biology, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA; Marine Biological Laboratory, Cell Division and Organization Group, 7 MBL Street, Woods Hole, MA 02543, USA
| | - John Oakey
- Marine Biological Laboratory, Cell Division and Organization Group, 7 MBL Street, Woods Hole, MA 02543, USA; Department of Chemical Engineering, University of Wyoming, 1000 E. University Avenue, Laramie, WY 82070, USA
| | - Jesse C Gatlin
- Department of Molecular Biology, University of Wyoming, 1000 E. University Avenue, Laramie, WY 82070, USA; Marine Biological Laboratory, Cell Division and Organization Group, 7 MBL Street, Woods Hole, MA 02543, USA.
| |
Collapse
|
12
|
Investigation of the Electrical Properties of Microtubule Ensembles under Cell-Like Conditions. NANOMATERIALS 2020; 10:nano10020265. [PMID: 32033331 PMCID: PMC7075204 DOI: 10.3390/nano10020265] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 01/28/2020] [Accepted: 01/29/2020] [Indexed: 01/01/2023]
Abstract
Microtubules are hollow cylindrical polymers composed of the highly negatively-charged (~23e), high dipole moment (1750 D) protein α, β- tubulin. While the roles of microtubules in chromosomal segregation, macromolecular transport, and cell migration are relatively well-understood, studies on the electrical properties of microtubules have only recently gained strong interest. Here, we show that while microtubules at physiological concentrations increase solution capacitance, free tubulin has no appreciable effect. Further, we observed a decrease in electrical resistance of solution, with charge transport peaking between 20-60 Hz in the presence of microtubules, consistent with recent findings that microtubules exhibit electric oscillations at such low frequencies. We were able to quantify the capacitance and resistance of the microtubules (MT) network at physiological tubulin concentrations to be 1.27 × 10-5 F and 9.74 × 104 Ω. Our results show that in addition to macromolecular transport, microtubules also act as charge storage devices through counterionic condensation across a broad frequency spectrum. We conclude with a hypothesis of an electrically tunable cytoskeleton where the dielectric properties of tubulin are polymerisation-state dependent.
Collapse
|
13
|
Zhang Q, Bai Q, Zhu L, Hou T, Zhao J, Liang D. Macromolecular Crowding and Confinement Effect on the Growth of DNA Nanotubes in Dextran and Hyaluronic Acid Media. ACS APPLIED BIO MATERIALS 2019; 3:412-420. [DOI: 10.1021/acsabm.9b00892] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Qiufen Zhang
- Beijing National Laboratory for Molecular Sciences, Department of Polymer Science and Engineering and the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Qingwen Bai
- Beijing National Laboratory for Molecular Sciences, Department of Polymer Science and Engineering and the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Lin Zhu
- Beijing National Laboratory for Molecular Sciences, Department of Polymer Science and Engineering and the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Tianhao Hou
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Jiang Zhao
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Dehai Liang
- Beijing National Laboratory for Molecular Sciences, Department of Polymer Science and Engineering and the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| |
Collapse
|
14
|
Kalra AP, Kar P, Preto J, Rezania V, Dogariu A, Lewis JD, Tuszynski JA, Shankar K. Behavior of α, β tubulin in DMSO-containing electrolytes. NANOSCALE ADVANCES 2019; 1:3364-3371. [PMID: 36133560 PMCID: PMC9418024 DOI: 10.1039/c9na00035f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Accepted: 06/18/2019] [Indexed: 06/11/2023]
Abstract
α, β-tubulin is a cytoskeletal protein that forms cylindrical structures termed microtubules, which are crucial to the cell for a variety of roles. Microtubules are frequently modelled as one-dimensional bionanowires that act as ion transporters in the cell. In this work, we used dynamic light scattering (DLS) to measure the hydrodynamic diameter of tubulin in the presence of a polar aprotic co-solvent. We found that the hydrodynamic diameter increased with increasing DMSO volume fraction, almost doubling at 20% DMSO. To evaluate if this was due to an enlarged solvation shell, we performed reference interaction site model (RISM) simulations and found that the extent of solvation was unchanged. Using fluorescence microscopy, we then showed that tubulin was polymerization competent in the presence of colchicine, and thus inferred the presence of oligomers in the presence of DMSO, which points to its mechanism of action as a microtubule polymerization enhancing agent. Tubulin oligomers are known to form when microtubules depolymerize and are controversially implicated in microtubule polymerization. We show that DLS may be used to monitor early-state microtubule polymerization and is a viable alternative to fluorescence and electron microscopy-based methods. Our findings showing that DMSO causes tubulin oligomerization are thus of critical importance, both for creating bio-inspired nanotechnology and determining its biophysical roles in the cell.
Collapse
Affiliation(s)
- Aarat P Kalra
- Department of Physics, University of Alberta 11335 Saskatchewan Dr NW Edmonton Alberta T6G 2M9 Canada
| | - Piyush Kar
- Department of Electrical and Computer Engineering, University of Alberta 9107-116 St Edmonton Alberta T6G 2V4 Canada
| | - Jordane Preto
- Department of Physics, University of Alberta 11335 Saskatchewan Dr NW Edmonton Alberta T6G 2M9 Canada
| | - Vahid Rezania
- Department of Physical Sciences, MacEwan University Edmonton Alberta T5J 4S2 Canada
| | - Aristide Dogariu
- CREOL, The College of Optics and Photonics, University of Central Florida Orlando FL 32816 USA
| | - John D Lewis
- Department of Oncology, University of Alberta Edmonton Alberta T6G 1Z2 Canada
| | - Jack A Tuszynski
- Department of Physics, University of Alberta 11335 Saskatchewan Dr NW Edmonton Alberta T6G 2M9 Canada
- Department of Oncology, University of Alberta Edmonton Alberta T6G 1Z2 Canada
| | - Karthik Shankar
- Department of Electrical and Computer Engineering, University of Alberta 9107-116 St Edmonton Alberta T6G 2V4 Canada
| |
Collapse
|
15
|
MTrack: Automated Detection, Tracking, and Analysis of Dynamic Microtubules. Sci Rep 2019; 9:3794. [PMID: 30846705 PMCID: PMC6405942 DOI: 10.1038/s41598-018-37767-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 12/05/2018] [Indexed: 11/11/2022] Open
Abstract
Microtubules are polar, dynamic filaments fundamental to many cellular processes. In vitro reconstitution approaches with purified tubulin are essential to elucidate different aspects of microtubule behavior. To date, deriving data from fluorescence microscopy images by manually creating and analyzing kymographs is still commonplace. Here, we present MTrack, implemented as a plug-in for the open-source platform Fiji, which automatically identifies and tracks dynamic microtubules with sub-pixel resolution using advanced objection recognition. MTrack provides automatic data interpretation yielding relevant parameters of microtubule dynamic instability together with population statistics. The application of our software produces unbiased and comparable quantitative datasets in a fully automated fashion. This helps the experimentalist to achieve higher reproducibility at higher throughput on a user-friendly platform. We use simulated data and real data to benchmark our algorithm and show that it reliably detects, tracks, and analyzes dynamic microtubules and achieves sub-pixel precision even at low signal-to-noise ratios.
Collapse
|
16
|
van Haren J, Wittmann T. Microtubule Plus End Dynamics - Do We Know How Microtubules Grow?: Cells boost microtubule growth by promoting distinct structural transitions at growing microtubule ends. Bioessays 2019; 41:e1800194. [PMID: 30730055 PMCID: PMC7021488 DOI: 10.1002/bies.201800194] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 12/22/2018] [Indexed: 12/31/2022]
Abstract
Microtubules form a highly dynamic filament network in all eukaryotic cells. Individual microtubules grow by tubulin dimer subunit addition and frequently switch between phases of growth and shortening. These unique dynamics are powered by GTP hydrolysis and drive microtubule network remodeling, which is central to eukaryotic cell biology and morphogenesis. Yet, our knowledge of the molecular events at growing microtubule ends remains incomplete. Here, recent ultrastructural, biochemical and cell biological data are integrated to develop a realistic model of growing microtubule ends comprised of structurally distinct but biochemically overlapping zones. Proteins that recognize microtubule lattice conformations associated with specific tubulin guanosine nucleotide states may independently control major structural transitions at growing microtubule ends. A model is proposed in which tubulin dimer addition and subsequent closure of the MT wall are optimized in cells to achieve rapid physiological microtubule growth.
Collapse
Affiliation(s)
- Jeffrey van Haren
- Department of Cell and Tissue Biology, University of California San Francisco, 513 Parnassus Avenue, San Francisco, CA, 94143, USA
| | - Torsten Wittmann
- Department of Cell and Tissue Biology, University of California San Francisco, 513 Parnassus Avenue, San Francisco, CA, 94143, USA
| |
Collapse
|
17
|
Chaaban S, Jariwala S, Hsu CT, Redemann S, Kollman JM, Müller-Reichert T, Sept D, Bui KH, Brouhard GJ. The Structure and Dynamics of C. elegans Tubulin Reveals the Mechanistic Basis of Microtubule Growth. Dev Cell 2018; 47:191-204.e8. [PMID: 30245157 DOI: 10.1016/j.devcel.2018.08.023] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 07/06/2018] [Accepted: 08/23/2018] [Indexed: 01/04/2023]
Abstract
The dynamic instability of microtubules is a conserved and fundamental mechanism in eukaryotes. Yet microtubules from different species diverge in their growth rates, lattice structures, and responses to GTP hydrolysis. Therefore, we do not know what limits microtubule growth, what determines microtubule structure, or whether the mechanisms of dynamic instability are universal. Here, we studied microtubules from the nematode C. elegans, which have strikingly fast growth rates and non-canonical lattices in vivo. Using a reconstitution approach, we discovered that C. elegans microtubules combine intrinsically fast growth with very frequent catastrophes. We solved the structure of C. elegans microtubules to 4.8 Å and discovered sequence divergence in the lateral contact loops, one of which is ordered in C. elegans but unresolved in other species. We provide direct evidence that C. elegans tubulin has a higher free energy in solution and propose a model wherein the ordering of lateral contact loops activates tubulin for growth.
Collapse
Affiliation(s)
- Sami Chaaban
- Department of Biology, 1205 Avenue Docteur Penfield, Montréal, QC H3A 1B1, Canada
| | - Shashank Jariwala
- Department of Computational Medicine and Bioinformatics, 100 Washtenaw Avenue, Ann Arbor, MI 48109, USA
| | - Chieh-Ting Hsu
- Department of Biology, 1205 Avenue Docteur Penfield, Montréal, QC H3A 1B1, Canada
| | - Stefanie Redemann
- Experimental Center, Technische Universität Dresden, Faculty of Medicine, Fiedlerstraße 42, 01307 Dresden, Germany; Center for Membrane & Cell Physiology, University of Virginia and Department of Molecular Physiology & Biological Physics, 480 Ray C. Hung Drive, Charlottesville, VA 22903, USA
| | - Justin M Kollman
- Department of Biochemistry, 1959 NE Pacific Street, Seattle, WA 98195, USA
| | - Thomas Müller-Reichert
- Experimental Center, Technische Universität Dresden, Faculty of Medicine, Fiedlerstraße 42, 01307 Dresden, Germany
| | - David Sept
- Department of Biomedical Engineering, 2200 Bonisteel Boulevard, Ann Arbor, MI 48109, USA
| | - Khanh Huy Bui
- Department of Anatomy and Cell Biology, 3640 Rue University, Montréal, QC H3A 0C7, Canada
| | - Gary J Brouhard
- Department of Biology, 1205 Avenue Docteur Penfield, Montréal, QC H3A 1B1, Canada.
| |
Collapse
|
18
|
Lacroix B, Letort G, Pitayu L, Sallé J, Stefanutti M, Maton G, Ladouceur AM, Canman JC, Maddox PS, Maddox AS, Minc N, Nédélec F, Dumont J. Microtubule Dynamics Scale with Cell Size to Set Spindle Length and Assembly Timing. Dev Cell 2018; 45:496-511.e6. [PMID: 29787710 DOI: 10.1016/j.devcel.2018.04.022] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 03/22/2018] [Accepted: 04/24/2018] [Indexed: 12/22/2022]
Abstract
Successive cell divisions during embryonic cleavage create increasingly smaller cells, so intracellular structures must adapt accordingly. Mitotic spindle size correlates with cell size, but the mechanisms for this scaling remain unclear. Using live cell imaging, we analyzed spindle scaling during embryo cleavage in the nematode Caenorhabditis elegans and sea urchin Paracentrotus lividus. We reveal a common scaling mechanism, where the growth rate of spindle microtubules scales with cell volume, which explains spindle shortening. Spindle assembly timing is, however, constant throughout successive divisions. Analyses in silico suggest that controlling the microtubule growth rate is sufficient to scale spindle length and maintain a constant assembly timing. We tested our in silico predictions to demonstrate that modulating cell volume or microtubule growth rate in vivo induces a proportional spindle size change. Our results suggest that scalability of the microtubule growth rate when cell size varies adapts spindle length to cell volume.
Collapse
Affiliation(s)
- Benjamin Lacroix
- Institut Jacques Monod, CNRS, UMR 7592, University Paris Diderot, Sorbonne Paris Cité, 75205 Paris, France.
| | - Gaëlle Letort
- Institut Curie, Mines Paris Tech, Inserm, U900, PSL Research University, 75005 Paris, France
| | - Laras Pitayu
- Institut Jacques Monod, CNRS, UMR 7592, University Paris Diderot, Sorbonne Paris Cité, 75205 Paris, France
| | - Jérémy Sallé
- Institut Jacques Monod, CNRS, UMR 7592, University Paris Diderot, Sorbonne Paris Cité, 75205 Paris, France
| | - Marine Stefanutti
- Institut Jacques Monod, CNRS, UMR 7592, University Paris Diderot, Sorbonne Paris Cité, 75205 Paris, France
| | - Gilliane Maton
- Institut Jacques Monod, CNRS, UMR 7592, University Paris Diderot, Sorbonne Paris Cité, 75205 Paris, France
| | | | - Julie C Canman
- Columbia University Medical Center, Department of Pathology and Cell Biology, New York, NY 10032, USA
| | - Paul S Maddox
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Amy S Maddox
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Nicolas Minc
- Institut Jacques Monod, CNRS, UMR 7592, University Paris Diderot, Sorbonne Paris Cité, 75205 Paris, France
| | - François Nédélec
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.
| | - Julien Dumont
- Institut Jacques Monod, CNRS, UMR 7592, University Paris Diderot, Sorbonne Paris Cité, 75205 Paris, France.
| |
Collapse
|
19
|
Hernández-Vega A, Braun M, Scharrel L, Jahnel M, Wegmann S, Hyman BT, Alberti S, Diez S, Hyman AA. Local Nucleation of Microtubule Bundles through Tubulin Concentration into a Condensed Tau Phase. Cell Rep 2018; 20:2304-2312. [PMID: 28877466 PMCID: PMC5828996 DOI: 10.1016/j.celrep.2017.08.042] [Citation(s) in RCA: 228] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 07/23/2017] [Accepted: 08/10/2017] [Indexed: 11/16/2022] Open
Abstract
Non-centrosomal microtubule bundles play important roles in cellular organization and function. Although many diverse proteins are known that can bundle microtubules, biochemical mechanisms by which cells could locally control the nucleation and formation of microtubule bundles are understudied. Here, we demonstrate that the concentration of tubulin into a condensed, liquid-like compartment composed of the unstructured neuronal protein tau is sufficient to nucleate microtubule bundles. We show that, under conditions of macro-molecular crowding, tau forms liquid-like drops. Tubulin partitions into these drops, efficiently increasing tubulin concentration and driving the nucleation of microtubules. These growing microtubules form bundles, which deform the drops while remaining enclosed by diffusible tau molecules exhibiting a liquid-like behavior. Our data suggest that condensed compartments of microtubule bundling proteins could promote the local formation of microtubule bundles in neurons by acting as non-centrosomal microtubule nucleation centers and that liquid-like tau encapsulation could provide both stability and plasticity to long axonal microtubule bundles.
Collapse
Affiliation(s)
| | - Marcus Braun
- B CUBE-Center for Molecular Bioengineering, Technische Universität Dresden, Dresden 01307, Germany; Institute of Biotechnology CAS, BIOCEV, Vestec 25250, Czech Republic
| | - Lara Scharrel
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden 01307, Germany; B CUBE-Center for Molecular Bioengineering, Technische Universität Dresden, Dresden 01307, Germany
| | - Marcus Jahnel
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden 01307, Germany; BIOTEC, Biotechnology Center of the Technische Universität Dresden, Dresden 01307, Germany
| | - Susanne Wegmann
- Department Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Bradley T Hyman
- Department Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Simon Alberti
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden 01307, Germany
| | - Stefan Diez
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden 01307, Germany; B CUBE-Center for Molecular Bioengineering, Technische Universität Dresden, Dresden 01307, Germany.
| | - Anthony A Hyman
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden 01307, Germany.
| |
Collapse
|
20
|
Bachand GD, Jain R, Ko R, Bouxsein NF, VanDelinder V. Inhibition of Microtubule Depolymerization by Osmolytes. Biomacromolecules 2018; 19:2401-2408. [PMID: 29689154 DOI: 10.1021/acs.biomac.7b01799] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Microtubule dynamics play a critical role in the normal physiology of eukaryotic cells as well as a number of cancers and neurodegenerative disorders. The polymerization/depolymerization of microtubules is regulated by a variety of stabilizing and destabilizing factors, including microtubule-associated proteins and therapeutic agents (e.g., paclitaxel, nocodazole). Here we describe the ability of the osmolytes polyethylene glycol (PEG) and trimethylamine- N-oxide (TMAO) to inhibit the depolymerization of individual microtubule filaments for extended periods of time (up to 30 days). We further show that PEG stabilizes microtubules against both temperature- and calcium-induced depolymerization. Our results collectively suggest that the observed inhibition may be related to combination of the kosmotropic behavior and excluded volume/osmotic pressure effects associated with PEG and TMAO. Taken together with prior studies, our data suggest that the physiochemical properties of the local environment can regulate microtubule depolymerization and may potentially play an important role in in vivo microtubule dynamics.
Collapse
Affiliation(s)
- George D Bachand
- Center for Integrated Nanotechnologies , Sandia National Laboratories , P.O. Box 5800, MS 1303, Albuquerque , New Mexico 87185 , United States
| | - Rishi Jain
- Center for Integrated Nanotechnologies , Sandia National Laboratories , P.O. Box 5800, MS 1303, Albuquerque , New Mexico 87185 , United States
| | - Randy Ko
- Center for Integrated Nanotechnologies , Sandia National Laboratories , P.O. Box 5800, MS 1303, Albuquerque , New Mexico 87185 , United States
| | - Nathan F Bouxsein
- Center for Integrated Nanotechnologies , Sandia National Laboratories , P.O. Box 5800, MS 1303, Albuquerque , New Mexico 87185 , United States
| | - Virginia VanDelinder
- Center for Integrated Nanotechnologies , Sandia National Laboratories , P.O. Box 5800, MS 1303, Albuquerque , New Mexico 87185 , United States
| |
Collapse
|
21
|
Rufer AC, Kusznir E, Burger D, Stihle M, Ruf A, Rudolph MG. Domain swap in the C-terminal ubiquitin-like domain of human doublecortin. ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY 2018; 74:450-462. [PMID: 29717716 DOI: 10.1107/s2059798318004813] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 03/23/2018] [Indexed: 11/10/2022]
Abstract
Doublecortin, a microtubule-associated protein that is only produced during neurogenesis, cooperatively binds to microtubules and stimulates microtubule polymerization and cross-linking by unknown mechanisms. A domain swap is observed in the crystal structure of the C-terminal domain of doublecortin. As determined by analytical ultracentrifugation, an open conformation is also present in solution. At higher concentrations, higher-order oligomers of the domain are formed. The domain swap and additional interfaces observed in the crystal lattice can explain the formation of doublecortin tetramers or multimers, in line with the analytical ultracentrifugation data. Taken together, the domain swap offers a mechanism for the observed cooperative binding of doublecortin to microtubules. Doublecortin-induced cross-linking of microtubules can be explained by the same mechanism. The effect of several mutations leading to lissencephaly and double-cortex syndrome can be traced to the domain swap and the proposed self-association of doublecortin.
Collapse
Affiliation(s)
- Arne C Rufer
- pRED, Therapeutic Modalities, F. Hoffmann-La Roche, 4070 Basel, Switzerland
| | - Eric Kusznir
- pRED, Therapeutic Modalities, F. Hoffmann-La Roche, 4070 Basel, Switzerland
| | - Dominique Burger
- pRED, Therapeutic Modalities, F. Hoffmann-La Roche, 4070 Basel, Switzerland
| | - Martine Stihle
- pRED, Therapeutic Modalities, F. Hoffmann-La Roche, 4070 Basel, Switzerland
| | - Armin Ruf
- pRED, Therapeutic Modalities, F. Hoffmann-La Roche, 4070 Basel, Switzerland
| | - Markus G Rudolph
- pRED, Therapeutic Modalities, F. Hoffmann-La Roche, 4070 Basel, Switzerland
| |
Collapse
|
22
|
Gao M, Held C, Patra S, Arns L, Sadowski G, Winter R. Crowders and Cosolvents-Major Contributors to the Cellular Milieu and Efficient Means to Counteract Environmental Stresses. Chemphyschem 2017; 18:2951-2972. [DOI: 10.1002/cphc.201700762] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Revised: 08/15/2017] [Indexed: 01/27/2023]
Affiliation(s)
- Mimi Gao
- TU Dortmund University; Faculty of Chemistry and Chemical Biology; Physical Chemistry I-Biophysical Chemistry; Otto Hahn Str. 4a 44227 Dortmund Germany
| | - Christoph Held
- TU Dortmund University; Department of Biochemical and Chemical Engineering; Emil-Figge-Str. 70 44227 Dortmund Germany
| | - Satyajit Patra
- TU Dortmund University; Faculty of Chemistry and Chemical Biology; Physical Chemistry I-Biophysical Chemistry; Otto Hahn Str. 4a 44227 Dortmund Germany
| | - Loana Arns
- TU Dortmund University; Faculty of Chemistry and Chemical Biology; Physical Chemistry I-Biophysical Chemistry; Otto Hahn Str. 4a 44227 Dortmund Germany
| | - Gabriele Sadowski
- TU Dortmund University; Department of Biochemical and Chemical Engineering; Emil-Figge-Str. 70 44227 Dortmund Germany
| | - Roland Winter
- TU Dortmund University; Faculty of Chemistry and Chemical Biology; Physical Chemistry I-Biophysical Chemistry; Otto Hahn Str. 4a 44227 Dortmund Germany
| |
Collapse
|
23
|
Castle BT, McCubbin S, Prahl LS, Bernens JN, Sept D, Odde DJ. Mechanisms of kinetic stabilization by the drugs paclitaxel and vinblastine. Mol Biol Cell 2017; 28:1238-1257. [PMID: 28298489 PMCID: PMC5415019 DOI: 10.1091/mbc.e16-08-0567] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 02/21/2017] [Accepted: 02/28/2017] [Indexed: 12/20/2022] Open
Abstract
Chemotherapeutic agents that target microtubule dynamics promote a universal phenotype of kinetic stabilization. Integrated computational modeling and fluorescence microscopy identify the fundamental kinetic and thermodynamic mechanisms that result in kinetic stabilization, specifically by the drugs paclitaxel and vinblastine. Microtubule-targeting agents (MTAs), widely used as biological probes and chemotherapeutic drugs, bind directly to tubulin subunits and “kinetically stabilize” microtubules, suppressing the characteristic self-assembly process of dynamic instability. However, the molecular-level mechanisms of kinetic stabilization are unclear, and the fundamental thermodynamic and kinetic requirements for dynamic instability and its elimination by MTAs have yet to be defined. Here we integrate a computational model for microtubule assembly with nanometer-scale fluorescence microscopy measurements to identify the kinetic and thermodynamic basis of kinetic stabilization by the MTAs paclitaxel, an assembly promoter, and vinblastine, a disassembly promoter. We identify two distinct modes of kinetic stabilization in live cells, one that truly suppresses on-off kinetics, characteristic of vinblastine, and the other a “pseudo” kinetic stabilization, characteristic of paclitaxel, that nearly eliminates the energy difference between the GTP- and GDP-tubulin thermodynamic states. By either mechanism, the main effect of both MTAs is to effectively stabilize the microtubule against disassembly in the absence of a robust GTP cap.
Collapse
Affiliation(s)
- Brian T Castle
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455
| | - Seth McCubbin
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109
| | - Louis S Prahl
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455
| | - Jordan N Bernens
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455
| | - David Sept
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109
| | - David J Odde
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455
| |
Collapse
|
24
|
Microtubule-associated proteins control the kinetics of microtubule nucleation. Nat Cell Biol 2015; 17:907-16. [PMID: 26098575 DOI: 10.1038/ncb3188] [Citation(s) in RCA: 141] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 05/14/2015] [Indexed: 02/07/2023]
Abstract
Microtubules are born and reborn continuously, even during quiescence. These polymers are nucleated from templates, namely γ-tubulin ring complexes (γ-TuRCs) and severed microtubule ends. Using single-molecule biophysics, we show that nucleation from γ-TuRCs, axonemes and seed microtubules requires tubulin concentrations that lie well above the critical concentration. We measured considerable time lags between the arrival of tubulin and the onset of steady-state elongation. Microtubule-associated proteins (MAPs) alter these time lags. Catastrophe factors (MCAK and EB1) inhibited nucleation, whereas a polymerase (XMAP215) and an anti-catastrophe factor (TPX2) promoted nucleation. We observed similar phenomena in cells. We conclude that GTP hydrolysis inhibits microtubule nucleation by destabilizing the nascent plus ends required for persistent elongation. Our results explain how MAPs establish the spatial and temporal profile of microtubule nucleation.
Collapse
|
25
|
Zhu L, Pan W, Lu X, Li D, Zhao J, Liang D. The growth of filaments under macromolecular confinement using scaling theory. Chem Commun (Camb) 2015; 51:15928-31. [DOI: 10.1039/c5cc06748k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Macromolecular confinement regulates the growth rate, structure, and length of the filaments, which can be quantitatively described using scaling theory.
Collapse
Affiliation(s)
- Lin Zhu
- Beijing National Laboratory for Molecular Sciences and the Key Laboratory of Polymer Chemistry and Physics of Ministry of Education
- College of Chemistry and Molecular Engineering
- Peking University
- Beijing 100871
- P. R. China
| | - Wei Pan
- Beijing National Laboratory for Molecular Sciences and the Key Laboratory of Polymer Chemistry and Physics of Ministry of Education
- College of Chemistry and Molecular Engineering
- Peking University
- Beijing 100871
- P. R. China
| | - Xi Lu
- Beijing National Laboratory for Molecular Sciences
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- P.R. China
| | - Desheng Li
- Beijing National Laboratory for Molecular Sciences
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- P.R. China
| | - Jiang Zhao
- Beijing National Laboratory for Molecular Sciences
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- P.R. China
| | - Dehai Liang
- Beijing National Laboratory for Molecular Sciences and the Key Laboratory of Polymer Chemistry and Physics of Ministry of Education
- College of Chemistry and Molecular Engineering
- Peking University
- Beijing 100871
- P. R. China
| |
Collapse
|