1
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Sun S, Zhou J, Liu P. Liquid-liquid phase separation of microtubule-binding proteins in the regulation of spindle assembly. Cell Prolif 2024:e13649. [PMID: 38736355 DOI: 10.1111/cpr.13649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 03/19/2024] [Accepted: 04/15/2024] [Indexed: 05/14/2024] Open
Abstract
Cell division is a highly regulated process essential for the accurate segregation of chromosomes. Central to this process is the assembly of a bipolar mitotic spindle, a highly dynamic microtubule (MT)-based structure responsible for chromosome movement. The nucleation and dynamics of MTs are intricately regulated by MT-binding proteins. Over the recent years, various MT-binding proteins have been reported to undergo liquid-liquid phase separation, forming either single- or multi-component condensates on MTs. Herein, we provide a comprehensive summary of the phase separation characteristics of these proteins. We underscore their critical roles in MT nucleation, spindle assembly and kinetochore-MT attachment during the cell division process. Furthermore, we discuss the current challenges and various remaining unsolved problems, highlights the ongoing research efforts aimed at a deeper understanding of the role of the phase separation process during spindle assembly and orientation. Our review aims to contribute to the collective knowledge in this area and stimulate further investigations that will enhance our comprehension of the intricate mechanisms governing cell division.
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Affiliation(s)
- Shuang Sun
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Institute of Biomedical Sciences, College of Life Sciences, Shandong Normal University, Jinan, China
| | - Jun Zhou
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Institute of Biomedical Sciences, College of Life Sciences, Shandong Normal University, Jinan, China
- State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecosystem, College of Life Sciences, Nankai University, Tianjin, China
| | - Peiwei Liu
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Institute of Biomedical Sciences, College of Life Sciences, Shandong Normal University, Jinan, China
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2
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Sun X, Zhou Y, Wang Z, Peng M, Wei X, Xie Y, Wen C, Liu J, Ye M. Biomolecular Condensates Decipher Molecular Codes of Cell Fate: From Biophysical Fundamentals to Therapeutic Practices. Int J Mol Sci 2024; 25:4127. [PMID: 38612940 PMCID: PMC11012904 DOI: 10.3390/ijms25074127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 04/03/2024] [Accepted: 04/05/2024] [Indexed: 04/14/2024] Open
Abstract
Cell fate is precisely modulated by complex but well-tuned molecular signaling networks, whose spatial and temporal dysregulation commonly leads to hazardous diseases. Biomolecular condensates (BCs), as a newly emerging type of biophysical assemblies, decipher the molecular codes bridging molecular behaviors, signaling axes, and clinical prognosis. Particularly, physical traits of BCs play an important role; however, a panoramic view from this perspective toward clinical practices remains lacking. In this review, we describe the most typical five physical traits of BCs, and comprehensively summarize their roles in molecular signaling axes and corresponding major determinants. Moreover, establishing the recent observed contribution of condensate physics on clinical therapeutics, we illustrate next-generation medical strategies by targeting condensate physics. Finally, the challenges and opportunities for future medical development along with the rapid scientific and technological advances are highlighted.
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Affiliation(s)
- Xing Sun
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China; (X.S.); (Y.Z.); (Z.W.); (M.P.); (X.W.)
- Molecular Biology Research Center and Center for Medical Genetics, School of Life Sciences, Central South University, Changsha 410000, China; (Y.X.); (C.W.)
| | - Yangyang Zhou
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China; (X.S.); (Y.Z.); (Z.W.); (M.P.); (X.W.)
| | - Zhiyan Wang
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China; (X.S.); (Y.Z.); (Z.W.); (M.P.); (X.W.)
| | - Menglan Peng
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China; (X.S.); (Y.Z.); (Z.W.); (M.P.); (X.W.)
| | - Xianhua Wei
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China; (X.S.); (Y.Z.); (Z.W.); (M.P.); (X.W.)
| | - Yifang Xie
- Molecular Biology Research Center and Center for Medical Genetics, School of Life Sciences, Central South University, Changsha 410000, China; (Y.X.); (C.W.)
| | - Chengcai Wen
- Molecular Biology Research Center and Center for Medical Genetics, School of Life Sciences, Central South University, Changsha 410000, China; (Y.X.); (C.W.)
| | - Jing Liu
- Molecular Biology Research Center and Center for Medical Genetics, School of Life Sciences, Central South University, Changsha 410000, China; (Y.X.); (C.W.)
| | - Mao Ye
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China; (X.S.); (Y.Z.); (Z.W.); (M.P.); (X.W.)
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3
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Meier SM, Steinmetz MO, Barral Y. Microtubule specialization by +TIP networks: from mechanisms to functional implications. Trends Biochem Sci 2024; 49:318-332. [PMID: 38350804 DOI: 10.1016/j.tibs.2024.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 12/23/2023] [Accepted: 01/12/2024] [Indexed: 02/15/2024]
Abstract
To fulfill their actual cellular role, individual microtubules become functionally specialized through a broad range of mechanisms. The 'search and capture' model posits that microtubule dynamics and functions are specified by cellular targets that they capture (i.e., a posteriori), independently of the microtubule-organizing center (MTOC) they emerge from. However, work in budding yeast indicates that MTOCs may impart a functional identity to the microtubules they nucleate, a priori. Key effectors in this process are microtubule plus-end tracking proteins (+TIPs), which track microtubule tips to regulate their dynamics and facilitate their targeted interactions. In this review, we discuss potential mechanisms of a priori microtubule specialization, focusing on recent findings indicating that +TIP networks may undergo liquid biomolecular condensation in different cell types.
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Affiliation(s)
- Sandro M Meier
- Institute of Biochemistry, Department of Biology, and Bringing Materials to Life Initiative, ETH Zürich, Switzerland; Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institut, Villigen, Switzerland; Bringing Materials to Life Initiative, ETH Zürich, Switzerland
| | - Michel O Steinmetz
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institut, Villigen, Switzerland; University of Basel, Biozentrum, CH-4056 Basel, Switzerland.
| | - Yves Barral
- Institute of Biochemistry, Department of Biology, and Bringing Materials to Life Initiative, ETH Zürich, Switzerland; Bringing Materials to Life Initiative, ETH Zürich, Switzerland.
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4
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Higa T, Kijima ST, Sasaki T, Takatani S, Asano R, Kondo Y, Wakazaki M, Sato M, Toyooka K, Demura T, Fukuda H, Oda Y. Microtubule-associated phase separation of MIDD1 tunes cell wall spacing in xylem vessels in Arabidopsis thaliana. NATURE PLANTS 2024; 10:100-117. [PMID: 38172572 DOI: 10.1038/s41477-023-01593-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 11/14/2023] [Indexed: 01/05/2024]
Abstract
Properly patterned cell walls specify cellular functions in plants. Differentiating protoxylem and metaxylem vessel cells exhibit thick secondary cell walls in striped and pitted patterns, respectively. Cortical microtubules are arranged in distinct patterns to direct cell wall deposition. The scaffold protein MIDD1 promotes microtubule depletion by interacting with ROP GTPases and KINESIN-13A in metaxylem vessels. Here we show that the phase separation of MIDD1 fine-tunes cell wall spacing in protoxylem vessels in Arabidopsis thaliana. Compared with wild-type, midd1 mutants exhibited narrower gaps and smaller pits in the secondary cell walls of protoxylem and metaxylem vessel cells, respectively. Live imaging of ectopically induced protoxylem vessels revealed that MIDD1 forms condensations along the depolymerizing microtubules, which in turn caused massive catastrophe of microtubules. The MIDD1 condensates exhibited rapid turnover and were susceptible to 1,6-hexanediol. Loss of ROP abolished the condensation of MIDD1 and resulted in narrow cell wall gaps in protoxylem vessels. These results suggest that the microtubule-associated phase separation of MIDD1 facilitates microtubule arrangement to regulate the size of gaps in secondary cell walls. This study reveals a new biological role of phase separation in the fine-tuning of cell wall patterning.
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Affiliation(s)
- Takeshi Higa
- Department of Gene Function and Phenomics, National Institute of Genetics, Mishima, Japan
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Japan
| | - Saku T Kijima
- Department of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan
- Plant Gene Regulation Research Group, Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki, Japan
| | - Takema Sasaki
- Department of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Shogo Takatani
- Department of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Ryosuke Asano
- Department of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Yohei Kondo
- Quantitative Biology Research Group, Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Japan
- Division of Quantitative Biology, National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki, Japan
- Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Japan
| | - Mayumi Wakazaki
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
| | - Mayuko Sato
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
| | | | - Taku Demura
- Center for Digital Green-innovation, Nara Institute of Science and Technology, Ikoma, Japan
- Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
| | - Hiroo Fukuda
- Department of Bioscience and Biotechnology, Faculty of Bioenvironmental Sciences, Kyoto University of Advanced Science, Kameoka, Japan
- Akita Prefectural University, Akita, Japan
| | - Yoshihisa Oda
- Department of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan.
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5
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Volkov VA, Akhmanova A. Phase separation on microtubules: from droplet formation to cellular function? Trends Cell Biol 2024; 34:18-30. [PMID: 37453878 DOI: 10.1016/j.tcb.2023.06.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 06/18/2023] [Accepted: 06/19/2023] [Indexed: 07/18/2023]
Abstract
Microtubules are cytoskeletal polymers that play important roles in numerous cellular processes, ranging from the control of cell shape and polarity to cell division and intracellular transport. Many of these roles rely on proteins that bind to microtubule ends and shafts, carry intrinsically disordered regions, and form complex multivalent interaction networks. A flurry of recent studies demonstrated that these properties allow diverse microtubule-binding proteins to undergo liquid-liquid phase separation (LLPS) in vitro. It is proposed that LLPS could potentially affect multiple microtubule-related processes, such as microtubule nucleation, control of microtubule dynamics and organization, and microtubule-based transport. Here, we discuss the evidence in favor and against the occurrence of LLPS and its functional significance for microtubule-based processes in cells.
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Affiliation(s)
- Vladimir A Volkov
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, E1 4NS, UK.
| | - Anna Akhmanova
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, Utrecht 3584 CH, The Netherlands.
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6
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Lawrence EJ, Chatterjee S, Zanic M. More is different: Reconstituting complexity in microtubule regulation. J Biol Chem 2023; 299:105398. [PMID: 37898404 PMCID: PMC10694663 DOI: 10.1016/j.jbc.2023.105398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 10/13/2023] [Accepted: 10/18/2023] [Indexed: 10/30/2023] Open
Abstract
Microtubules are dynamic cytoskeletal filaments that undergo stochastic switching between phases of polymerization and depolymerization-a behavior known as dynamic instability. Many important cellular processes, including cell motility, chromosome segregation, and intracellular transport, require complex spatiotemporal regulation of microtubule dynamics. This coordinated regulation is achieved through the interactions of numerous microtubule-associated proteins (MAPs) with microtubule ends and lattices. Here, we review the recent advances in our understanding of microtubule regulation, focusing on results arising from biochemical in vitro reconstitution approaches using purified multiprotein ensembles. We discuss how the combinatory effects of MAPs affect both the dynamics of individual microtubule ends, as well as the stability and turnover of the microtubule lattice. In addition, we highlight new results demonstrating the roles of protein condensates in microtubule regulation. Our overall intent is to showcase how lessons learned from reconstitution approaches help unravel the regulatory mechanisms at play in complex cellular environments.
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Affiliation(s)
- Elizabeth J Lawrence
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - Saptarshi Chatterjee
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - Marija Zanic
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, USA; Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee, USA; Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA.
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7
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Romeiro Motta M, Biswas S, Schaedel L. Beyond uniformity: Exploring the heterogeneous and dynamic nature of the microtubule lattice. Eur J Cell Biol 2023; 102:151370. [PMID: 37922811 DOI: 10.1016/j.ejcb.2023.151370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 10/17/2023] [Accepted: 10/26/2023] [Indexed: 11/07/2023] Open
Abstract
A fair amount of research on microtubules since their discovery in 1963 has focused on their dynamic tips. In contrast, the microtubule lattice was long believed to be highly regular and static, and consequently received far less attention. Yet, as it turned out, the microtubule lattice is neither as regular, nor as static as previously believed: structural studies uncovered the remarkable wealth of different conformations the lattice can accommodate. In the last decade, the microtubule lattice was shown to be labile and to spontaneously undergo renovation, a phenomenon that is intimately linked to structural defects and was called "microtubule self-repair". Following this breakthrough discovery, further recent research provided a deeper understanding of the lattice self-repair mechanism, which we review here. Instrumental to these discoveries were in vitro microtubule reconstitution assays, in which microtubules are grown from the minimal components required for their dynamics. In this review, we propose a shift from the term "lattice self-repair" to "lattice dynamics", since this phenomenon is an inherent property of microtubules and can happen without microtubule damage. We focus on how in vitro microtubule reconstitution assays helped us learn (1) which types of structural variations microtubules display, (2) how these structural variations influence lattice dynamics and microtubule damage caused by mechanical stress, (3) how lattice dynamics impact tip dynamics, and (4) how microtubule-associated proteins (MAPs) can play a role in structuring the lattice. Finally, we discuss the unanswered questions about lattice dynamics and how technical advances will help us tackle these questions.
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Affiliation(s)
- Mariana Romeiro Motta
- Department of Physics, Center for Biophysics, Campus A2 4, Saarland University, 66123 Saarbrücken, Germany; Laboratoire Reproduction et Développement des Plantes, Université de Lyon, École normale supérieure de Lyon, Lyon 69364, France
| | - Subham Biswas
- Department of Physics, Center for Biophysics, Campus A2 4, Saarland University, 66123 Saarbrücken, Germany
| | - Laura Schaedel
- Department of Physics, Center for Biophysics, Campus A2 4, Saarland University, 66123 Saarbrücken, Germany.
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8
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Duan D, Lyu W, Chai P, Ma S, Wu K, Wu C, Xiong Y, Sestan N, Zhang K, Koleske AJ. Abl2 repairs microtubules and phase separates with tubulin to promote microtubule nucleation. Curr Biol 2023; 33:4582-4598.e10. [PMID: 37858340 PMCID: PMC10877310 DOI: 10.1016/j.cub.2023.09.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 07/07/2023] [Accepted: 09/06/2023] [Indexed: 10/21/2023]
Abstract
Abl family kinases are evolutionarily conserved regulators of cell migration and morphogenesis. Genetic experiments in Drosophila suggest that Abl family kinases interact functionally with microtubules to regulate axon guidance and neuronal morphogenesis. Vertebrate Abl2 binds to microtubules and promotes their plus-end elongation, both in vitro and in cells, but the molecular mechanisms by which Abl2 regulates microtubule (MT) dynamics are unclear. We report here that Abl2 regulates MT assembly via condensation and direct interactions with both the MT lattice and tubulin dimers. We find that Abl2 promotes MT nucleation, which is further facilitated by the ability of the Abl2 C-terminal half to undergo liquid-liquid phase separation (LLPS) and form co-condensates with tubulin. Abl2 binds to regions adjacent to MT damage, facilitates MT repair via fresh tubulin recruitment, and increases MT rescue frequency and lifetime. Cryo-EM analyses strongly support a model in which Abl2 engages tubulin C-terminal tails along an extended MT lattice conformation at damage sites to facilitate repair via fresh tubulin recruitment. Abl2Δ688-790, which closely mimics a naturally occurring splice isoform, retains binding to the MT lattice but does not bind tubulin, promote MT nucleation, or increase rescue frequency. In COS-7 cells, MT reassembly after nocodazole treatment is greatly slowed in Abl2 knockout COS-7 cells compared with wild-type cells, and these defects are rescued by re-expression of Abl2, but not Abl2Δ688-790. We propose that Abl2 locally concentrates tubulin to promote MT nucleation and recruits it to defects in the MT lattice to enable repair and rescue.
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Affiliation(s)
- Daisy Duan
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510, USA
| | - Wanqing Lyu
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510, USA
| | - Pengxin Chai
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510, USA
| | - Shaojie Ma
- Department of Neuroscience, Yale University, New Haven, CT 06510, USA
| | - Kuanlin Wu
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510, USA
| | - Chunxiang Wu
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510, USA
| | - Yong Xiong
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510, USA
| | - Nenad Sestan
- Department of Neuroscience, Yale University, New Haven, CT 06510, USA; Department of Genetics, Yale School of Medicine, New Haven, CT 06510, USA; Department of Psychiatry, Yale School of Medicine, New Haven, CT 06510, USA; Department of Comparative Medicine, Yale School of Medicine, New Haven, CT 06510, USA; Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale School of Medicine, New Haven, CT 06510, USA; Yale Child Study Center, Yale School of Medicine, New Haven, CT 06510, USA
| | - Kai Zhang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510, USA
| | - Anthony J Koleske
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510, USA; Department of Neuroscience, Yale University, New Haven, CT 06510, USA.
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9
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Miesch J, Wimbish RT, Velluz MC, Aumeier C. Phase separation of +TIP networks regulates microtubule dynamics. Proc Natl Acad Sci U S A 2023; 120:e2301457120. [PMID: 37603768 PMCID: PMC10469336 DOI: 10.1073/pnas.2301457120] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 06/12/2023] [Indexed: 08/23/2023] Open
Abstract
Regulation of microtubule dynamics is essential for diverse cellular functions, and proteins that bind to dynamic microtubule ends can regulate network dynamics. Here, we show that two conserved microtubule end-binding proteins, CLIP-170 and EB3, undergo phase separation and form dense liquid networks. When CLIP-170 and EB3 act together, the multivalency of the network increases, which synergistically increases the amount of protein in the dense phase. In vitro and in cells, these liquid networks can concentrate tubulin. In vitro, in the presence of microtubules, phase separation of EB3/CLIP-170 can enrich tubulin all along the microtubule. In this condition, microtubule growth speed increases up to twofold and the frequency of depolymerization events are strongly reduced compared to conditions in which there is no phase separation. Our data show that phase separation of EB3/CLIP-170 adds an additional layer of regulation to the control of microtubule growth dynamics.
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Affiliation(s)
- Julie Miesch
- Department of Biochemistry, University of Geneva, Geneva1211, Switzerland
| | - Robert T. Wimbish
- Department of Biochemistry, University of Geneva, Geneva1211, Switzerland
| | | | - Charlotte Aumeier
- Department of Biochemistry, University of Geneva, Geneva1211, Switzerland
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10
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Guo G, Wang X, Zhang Y, Li T. Sequence variations of phase-separating proteins and resources for studying biomolecular condensates. Acta Biochim Biophys Sin (Shanghai) 2023; 55:1119-1132. [PMID: 37464880 PMCID: PMC10423696 DOI: 10.3724/abbs.2023131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 06/06/2023] [Indexed: 07/20/2023] Open
Abstract
Phase separation (PS) is an important mechanism underlying the formation of biomolecular condensates. Physiological condensates are associated with numerous biological processes, such as transcription, immunity, signaling, and synaptic transmission. Changes in particular amino acids or segments can disturb the protein's phase behavior and interactions with other biomolecules in condensates. It is thus presumed that variations in the phase-separating-prone domains can significantly impact the properties and functions of condensates. The dysfunction of condensates contributes to a number of pathological processes. Pharmacological perturbation of these condensates is proposed as a promising way to restore physiological states. In this review, we characterize the variations observed in PS proteins that lead to aberrant biomolecular compartmentalization. We also showcase recent advancements in bioinformatics of membraneless organelles (MLOs), focusing on available databases useful for screening PS proteins and describing endogenous condensates, guiding researchers to seek the underlying pathogenic mechanisms of biomolecular condensates.
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Affiliation(s)
- Gaigai Guo
- Department of Biomedical InformaticsSchool of Basic Medical SciencesPeking University Health Science CenterBeijing100191China
| | - Xinxin Wang
- Department of Biomedical InformaticsSchool of Basic Medical SciencesPeking University Health Science CenterBeijing100191China
| | - Yi Zhang
- Department of Biomedical InformaticsSchool of Basic Medical SciencesPeking University Health Science CenterBeijing100191China
| | - Tingting Li
- Department of Biomedical InformaticsSchool of Basic Medical SciencesPeking University Health Science CenterBeijing100191China
- Key Laboratory for NeuroscienceMinistry of Education/National Health Commission of ChinaPeking UniversityBeijing100191China
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11
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Chen X, Portran D, Widmer LA, Stangier MM, Czub MP, Liakopoulos D, Stelling J, Steinmetz MO, Barral Y. The motor domain of the kinesin Kip2 promotes microtubule polymerization at microtubule tips. J Cell Biol 2023; 222:214052. [PMID: 37093124 PMCID: PMC10130750 DOI: 10.1083/jcb.202110126] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 01/01/2023] [Accepted: 03/22/2023] [Indexed: 04/25/2023] Open
Abstract
Kinesins are microtubule-dependent motor proteins, some of which moonlight as microtubule polymerases, such as the yeast protein Kip2. Here, we show that the CLIP-170 ortholog Bik1 stabilizes Kip2 at microtubule ends where the motor domain of Kip2 promotes microtubule polymerization. Live-cell imaging and mathematical estimation of Kip2 dynamics reveal that disrupting the Kip2-Bik1 interaction aborts Kip2 dwelling at microtubule ends and abrogates its microtubule polymerization activity. Structural modeling and biochemical experiments identify a patch of positively charged residues that enables the motor domain to bind free tubulin dimers alternatively to the microtubule shaft. Neutralizing this patch abolished the ability of Kip2 to promote microtubule growth both in vivo and in vitro without affecting its ability to walk along microtubules. Our studies suggest that Kip2 utilizes Bik1 as a cofactor to track microtubule tips, where its motor domain then recruits free tubulin and catalyzes microtubule assembly.
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Affiliation(s)
- Xiuzhen Chen
- Institute of Biochemistry, Eidgenössische Technische Hochschule Zürich , Zurich, Switzerland
| | - Didier Portran
- CRBM, Université de Montpellier , CNRS, Montpellier, France
| | - Lukas A Widmer
- Department of Biosystems Science and Engineering, Eidgenössische Technische Hochschule Zürich, and Swiss Institute of Bioinformatics, Basel, Switzerland
| | - Marcel M Stangier
- Department of Biology and Chemistry, Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland
| | - Mateusz P Czub
- Department of Biology and Chemistry, Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland
| | - Dimitris Liakopoulos
- CRBM, Université de Montpellier , CNRS, Montpellier, France
- Laboratory of Biology, University of Ioannina, Faculty of Medicine, Ioannina, Greece
| | - Jörg Stelling
- Department of Biosystems Science and Engineering, Eidgenössische Technische Hochschule Zürich, and Swiss Institute of Bioinformatics, Basel, Switzerland
| | - Michel O Steinmetz
- Department of Biology and Chemistry, Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland
- University of Basel, Biozentrum , Basel, Switzerland
| | - Yves Barral
- Institute of Biochemistry, Eidgenössische Technische Hochschule Zürich , Zurich, Switzerland
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12
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Guo C, Alfaro-Aco R, Zhang C, Russell RW, Petry S, Polenova T. Structural basis of protein condensation on microtubules underlying branching microtubule nucleation. Nat Commun 2023; 14:3682. [PMID: 37344496 PMCID: PMC10284871 DOI: 10.1038/s41467-023-39176-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 06/01/2023] [Indexed: 06/23/2023] Open
Abstract
Targeting protein for Xklp2 (TPX2) is a key factor that stimulates branching microtubule nucleation during cell division. Upon binding to microtubules (MTs), TPX2 forms condensates via liquid-liquid phase separation, which facilitates recruitment of microtubule nucleation factors and tubulin. We report the structure of the TPX2 C-terminal minimal active domain (TPX2α5-α7) on the microtubule lattice determined by magic-angle-spinning NMR. We demonstrate that TPX2α5-α7 forms a co-condensate with soluble tubulin on microtubules and binds to MTs between two adjacent protofilaments and at the intersection of four tubulin heterodimers. These interactions stabilize the microtubules and promote the recruitment of tubulin. Our results reveal that TPX2α5-α7 is disordered in solution and adopts a folded structure on MTs, indicating that TPX2α5-α7 undergoes structural changes from unfolded to folded states upon binding to microtubules. The aromatic residues form dense interactions in the core, which stabilize folding of TPX2α5-α7 on microtubules. This work informs on how the phase-separated TPX2α5-α7 behaves on microtubules and represents an atomic-level structural characterization of a protein that is involved in a condensate on cytoskeletal filaments.
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Affiliation(s)
- Changmiao Guo
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, 19716, USA
| | - Raymundo Alfaro-Aco
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA
| | - Chunting Zhang
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, 19716, USA
| | - Ryan W Russell
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, 19716, USA
| | - Sabine Petry
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA.
| | - Tatyana Polenova
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, 19716, USA.
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13
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Al-Hiyasat A, Tuna Y, Kuo YW, Howard J. Herding of proteins by the ends of shrinking polymers. Phys Rev E 2023; 107:L042601. [PMID: 37198784 DOI: 10.1103/physreve.107.l042601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 02/17/2023] [Indexed: 05/19/2023]
Abstract
The control of biopolymer length is mediated by proteins that localize to polymer ends and regulate polymerization dynamics. Several mechanisms have been proposed to achieve end localization. Here, we propose a novel mechanism by which a protein that binds to a shrinking polymer and slows its shrinkage will be spontaneously enriched at the shrinking end through a "herding" effect. We formalize this process using both lattice-gas and continuum descriptions, and we present experimental evidence that the microtubule regulator spastin employs this mechanism. Our findings extend to more general problems involving diffusion within shrinking domains.
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Affiliation(s)
- Amer Al-Hiyasat
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511, USA
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Yazgan Tuna
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511, USA
| | - Yin-Wei Kuo
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511, USA
| | - Jonathon Howard
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511, USA
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14
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Song X, Yang F, Yang T, Wang Y, Ding M, Li L, Xu P, Liu S, Dai M, Chi C, Xiang S, Xu C, Li D, Wang Z, Li L, Hill DL, Fu C, Yuan K, Li P, Zang J, Hou Z, Jiang K, Shi Y, Liu X, Yao X. Phase separation of EB1 guides microtubule plus-end dynamics. Nat Cell Biol 2023; 25:79-91. [PMID: 36536176 DOI: 10.1038/s41556-022-01033-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 10/21/2022] [Indexed: 12/24/2022]
Abstract
In eukaryotes, end-binding (EB) proteins serve as a hub for orchestrating microtubule dynamics and are essential for cellular dynamics and organelle movements. EB proteins modulate structural transitions at growing microtubule ends by recognizing and promoting an intermediate state generated during GTP hydrolysis. However, the molecular mechanisms and physiochemical properties of the EB1 interaction network remain elusive. Here we show that EB1 formed molecular condensates through liquid-liquid phase separation (LLPS) to constitute the microtubule plus-end machinery. EB1 LLPS is driven by multivalent interactions among different segments, which are modulated by charged residues in the linker region. Phase-separated EB1 provided a compartment for enriching tubulin dimers and other plus-end tracking proteins. Real-time imaging of chromosome segregation in HeLa cells expressing LLPS-deficient EB1 mutants revealed the importance of EB1 LLPS dynamics in mitotic chromosome movements. These findings demonstrate that EB1 forms a distinct physical and biochemical membraneless-organelle via multivalent interactions that guide microtubule dynamics.
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Affiliation(s)
- Xiaoyu Song
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China.,Keck Center for Organoids Plasticity, Morehouse School of Medicine, Atlanta, GA, USA
| | - Fengrui Yang
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China.,Keck Center for Organoids Plasticity, Morehouse School of Medicine, Atlanta, GA, USA
| | - Tongtong Yang
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China
| | - Yong Wang
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
| | - Mingrui Ding
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China.,Keck Center for Organoids Plasticity, Morehouse School of Medicine, Atlanta, GA, USA
| | - Linge Li
- Anhui Key Laboratory for Chemical Biology & Hefei National Center for Cross-disciplinary Sciences, Hefei, China
| | - Panpan Xu
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China
| | - Shuaiyu Liu
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China.,Anhui Key Laboratory for Chemical Biology & Hefei National Center for Cross-disciplinary Sciences, Hefei, China
| | - Ming Dai
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China
| | - Changbiao Chi
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China
| | - Shengqi Xiang
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China
| | - Chao Xu
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China
| | - Dong Li
- Institute of Biophysics, Beijing, China
| | - Zhikai Wang
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China.,Keck Center for Organoids Plasticity, Morehouse School of Medicine, Atlanta, GA, USA
| | - Lin Li
- CAS Center of Excellence in Molecular Cell Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Donald L Hill
- Department of Pathology, University of Alabama, Birmingham, AL, USA
| | - Chuanhai Fu
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China
| | - Kai Yuan
- Hunan Key Laboratory of Molecular Precision Medicine, Central South University School of Life Sciences, Changsha, China
| | - Pilong Li
- School of Life Sciences, Tsinghua University, Beijing, China
| | - Jianye Zang
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China
| | - Zhonghuai Hou
- Anhui Key Laboratory for Chemical Biology & Hefei National Center for Cross-disciplinary Sciences, Hefei, China
| | - Kai Jiang
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
| | - Yunyu Shi
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China
| | - Xing Liu
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China. .,Keck Center for Organoids Plasticity, Morehouse School of Medicine, Atlanta, GA, USA.
| | - Xuebiao Yao
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Center for Cross-disciplinary Sciences, University of Science & Technology of China School of Life Sciences, Hefei, China.
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15
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+TIPs condense on microtubule plus-ends. Nat Cell Biol 2023; 25:12-14. [PMID: 36650376 DOI: 10.1038/s41556-022-01068-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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16
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Maan R, Reese L, Volkov VA, King MR, van der Sluis EO, Andrea N, Evers WH, Jakobi AJ, Dogterom M. Multivalent interactions facilitate motor-dependent protein accumulation at growing microtubule plus-ends. Nat Cell Biol 2023; 25:68-78. [PMID: 36536175 PMCID: PMC9859754 DOI: 10.1038/s41556-022-01037-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 10/25/2022] [Indexed: 12/24/2022]
Abstract
Growing microtubule ends organize end-tracking proteins into comets of mixed composition. Here using a reconstituted fission yeast system consisting of end-binding protein Mal3, kinesin Tea2 and cargo Tip1, we found that these proteins can be driven into liquid-phase droplets both in solution and at microtubule ends under crowding conditions. In the absence of crowding agents, cryo-electron tomography revealed that motor-dependent comets consist of disordered networks where multivalent interactions may facilitate non-stoichiometric accumulation of cargo Tip1. We found that two disordered protein regions in Mal3 are required for the formation of droplets and motor-dependent accumulation of Tip1, while autonomous Mal3 comet formation requires only one of them. Using theoretical modelling, we explore possible mechanisms by which motor activity and multivalent interactions may lead to the observed enrichment of Tip1 at microtubule ends. We conclude that microtubule ends may act as platforms where multivalent interactions condense microtubule-associated proteins into large multi-protein complexes.
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Affiliation(s)
- Renu Maan
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Louis Reese
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands.,Physiology Course 2017, Marine Biological Laboratory, Woods Hole, MA, USA
| | - Vladimir A Volkov
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands.,Physiology Course 2017, Marine Biological Laboratory, Woods Hole, MA, USA.,School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Matthew R King
- Physiology Course 2017, Marine Biological Laboratory, Woods Hole, MA, USA.,Department of Biomedical Engineering, Washington University in St. Louis, St Louis, MO, USA
| | - Eli O van der Sluis
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Nemo Andrea
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Wiel H Evers
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Arjen J Jakobi
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Marileen Dogterom
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands. .,Physiology Course 2017, Marine Biological Laboratory, Woods Hole, MA, USA.
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