1
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Bagdadi N, Wu J, Delaroche J, Serre L, Delphin C, De Andrade M, Carcel M, Nawabi H, Pinson B, Vérin C, Couté Y, Gory-Fauré S, Andrieux A, Stoppin-Mellet V, Arnal I. Stable GDP-tubulin islands rescue dynamic microtubules. J Cell Biol 2024; 223:e202307074. [PMID: 38758215 PMCID: PMC11101955 DOI: 10.1083/jcb.202307074] [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: 07/18/2023] [Revised: 02/26/2024] [Accepted: 05/04/2024] [Indexed: 05/18/2024] Open
Abstract
Microtubules are dynamic polymers that interconvert between phases of growth and shrinkage, yet they provide structural stability to cells. Growth involves hydrolysis of GTP-tubulin to GDP-tubulin, which releases energy that is stored within the microtubule lattice and destabilizes it; a GTP cap at microtubule ends is thought to prevent GDP subunits from rapidly dissociating and causing catastrophe. Here, using in vitro reconstitution assays, we show that GDP-tubulin, usually considered inactive, can itself assemble into microtubules, preferentially at the minus end, and promote persistent growth. GDP-tubulin-assembled microtubules are highly stable, displaying no detectable spontaneous shrinkage. Strikingly, islands of GDP-tubulin within dynamic microtubules stop shrinkage events and promote rescues. Microtubules thus possess an intrinsic capacity for stability, independent of accessory proteins. This finding provides novel mechanisms to explain microtubule dynamics.
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Affiliation(s)
- Nassiba Bagdadi
- Université Grenoble Alpes, INSERM, U1216, CNRS, CEA, Grenoble Institut Neurosciences (GIN), Grenoble, France
| | - Juliette Wu
- Université Grenoble Alpes, INSERM, U1216, CNRS, CEA, Grenoble Institut Neurosciences (GIN), Grenoble, France
| | - Julie Delaroche
- Université Grenoble Alpes, INSERM, U1216, CNRS, CEA, Grenoble Institut Neurosciences (GIN), Grenoble, France
| | - Laurence Serre
- Université Grenoble Alpes, INSERM, U1216, CNRS, CEA, Grenoble Institut Neurosciences (GIN), Grenoble, France
| | - Christian Delphin
- Université Grenoble Alpes, INSERM, U1216, CNRS, CEA, Grenoble Institut Neurosciences (GIN), Grenoble, France
| | - Manon De Andrade
- Université Grenoble Alpes, INSERM, U1216, CNRS, CEA, Grenoble Institut Neurosciences (GIN), Grenoble, France
| | - Marion Carcel
- Université Grenoble Alpes, INSERM, U1216, CNRS, CEA, Grenoble Institut Neurosciences (GIN), Grenoble, France
| | - Homaira Nawabi
- Université Grenoble Alpes, INSERM, U1216, CNRS, CEA, Grenoble Institut Neurosciences (GIN), Grenoble, France
| | - Benoît Pinson
- Metabolic Analyses Service, TBMCore—Université de Bordeaux—CNRS UAR 3427—INSERM US005, Bordeaux, France
| | - Claire Vérin
- Université Grenoble Alpes, INSERM, CEA, UA13 BGE, CNRS, FR2048, Grenoble, France
| | - Yohann Couté
- Université Grenoble Alpes, INSERM, CEA, UA13 BGE, CNRS, FR2048, Grenoble, France
| | - Sylvie Gory-Fauré
- Université Grenoble Alpes, INSERM, U1216, CNRS, CEA, Grenoble Institut Neurosciences (GIN), Grenoble, France
| | - Annie Andrieux
- Université Grenoble Alpes, INSERM, U1216, CNRS, CEA, Grenoble Institut Neurosciences (GIN), Grenoble, France
| | - Virginie Stoppin-Mellet
- Université Grenoble Alpes, INSERM, U1216, CNRS, CEA, Grenoble Institut Neurosciences (GIN), Grenoble, France
| | - Isabelle Arnal
- Université Grenoble Alpes, INSERM, U1216, CNRS, CEA, Grenoble Institut Neurosciences (GIN), Grenoble, France
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2
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McCormick LA, Cleary JM, Hancock WO, Rice LM. Interface-acting nucleotide controls polymerization dynamics at microtubule plus- and minus-ends. eLife 2024; 12:RP89231. [PMID: 38180336 PMCID: PMC10945504 DOI: 10.7554/elife.89231] [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] [Indexed: 01/06/2024] Open
Abstract
GTP-tubulin is preferentially incorporated at growing microtubule ends, but the biochemical mechanism by which the bound nucleotide regulates the strength of tubulin:tubulin interactions is debated. The 'self-acting' (cis) model posits that the nucleotide (GTP or GDP) bound to a particular tubulin dictates how strongly that tubulin interacts, whereas the 'interface-acting' (trans) model posits that the nucleotide at the interface of two tubulin dimers is the determinant. We identified a testable difference between these mechanisms using mixed nucleotide simulations of microtubule elongation: with a self-acting nucleotide, plus- and minus-end growth rates decreased in the same proportion to the amount of GDP-tubulin, whereas with interface-acting nucleotide, plus-end growth rates decreased disproportionately. We then experimentally measured plus- and minus-end elongation rates in mixed nucleotides and observed a disproportionate effect of GDP-tubulin on plus-end growth rates. Simulations of microtubule growth were consistent with GDP-tubulin binding at and 'poisoning' plus-ends but not at minus-ends. Quantitative agreement between simulations and experiments required nucleotide exchange at terminal plus-end subunits to mitigate the poisoning effect of GDP-tubulin there. Our results indicate that the interfacial nucleotide determines tubulin:tubulin interaction strength, thereby settling a longstanding debate over the effect of nucleotide state on microtubule dynamics.
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Affiliation(s)
- Lauren A McCormick
- Department of Biophysics and Biochemistry, the University of Texas Southwestern Medical CenterDallasUnited States
| | - Joseph M Cleary
- Department of Biomedical Engineering, Pennsylvania State UniversityState CollegeUnited States
| | - William O Hancock
- Department of Biomedical Engineering, Pennsylvania State UniversityState CollegeUnited States
| | - Luke M Rice
- Department of Biophysics and Biochemistry, the University of Texas Southwestern Medical CenterDallasUnited States
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3
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McCormick LA, Cleary JM, Hancock WO, Rice LM. Interface-acting nucleotide controls polymerization dynamics at microtubule plus- and minus-ends. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.03.539131. [PMID: 37205370 PMCID: PMC10187237 DOI: 10.1101/2023.05.03.539131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
GTP-tubulin is preferentially incorporated at growing microtubule ends, but the biochemical mechanism by which the bound nucleotide regulates the strength of tubulin:tubulin interactions is debated. The 'self-acting' (cis) model posits that the nucleotide (GTP or GDP) bound to a particular tubulin dictates how strongly that tubulin interacts, whereas the 'interface-acting' (trans) model posits that the nucleotide at the interface of two tubulin dimers is the determinant. We identified a testable difference between these mechanisms using mixed nucleotide simulations of microtubule elongation: with self-acting nucleotide, plus- and minus-end growth rates decreased in the same proportion to the amount of GDP-tubulin, whereas with interface-acting nucleotide, plus-end growth rates decreased disproportionately. We then experimentally measured plus- and minus-end elongation rates in mixed nucleotides and observed a disproportionate effect of GDP-tubulin on plus-end growth rates. Simulations of microtubule growth were consistent with GDP-tubulin binding at and 'poisoning' plus-ends but not at minus-ends. Quantitative agreement between simulations and experiments required nucleotide exchange at terminal plus-end subunits to mitigate the poisoning effect of GDP-tubulin there. Our results indicate that the interfacial nucleotide determines tubulin:tubulin interaction strength, thereby settling a longstanding debate over the effect of nucleotide state on microtubule dynamics.
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Affiliation(s)
- Lauren A McCormick
- Department of Biophysics and Biochemistry, the University of Texas Southwestern Medical Center, Dallas, TX
| | - Joseph M Cleary
- Department of Biomedical Engineering, Pennsylvania State University, University Park, PA
| | - William O Hancock
- Department of Biomedical Engineering, Pennsylvania State University, University Park, PA
| | - Luke M Rice
- Department of Biophysics and Biochemistry, the University of Texas Southwestern Medical Center, Dallas, TX
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4
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Chu Y, Tian Z, Yang M, Li W. Conformation and energy investigation of microtubule longitudinal dynamic instability induced by natural products. Chem Biol Drug Des 2023; 102:444-456. [PMID: 36509697 DOI: 10.1111/cbdd.14189] [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: 05/11/2022] [Revised: 08/29/2022] [Accepted: 11/28/2022] [Indexed: 12/15/2022]
Abstract
The natural products plinabulin, docetaxel, and vinblastine are microtubule targeting agents (MTAs). They have been used alone or in combination in cancer treatment. However, the exact nature of their effects on microtubule (MT) polymerization dynamics is poorly understood. To elucidate the longitudinal conformational and energetic changes during MT dynamics, a total of 140 ns molecular dynamic simulations combined with binding free energy calculations were performed on seven tubulin models. The results indicated that the drugs disrupted MT polymerization by altering both MT conformation and binding free energy of the neighboring tubulin subunits. The combination of plinabulin and docetaxel destabilized MT polymerization due to bending MT and weakening the polarity of tubulin polymerization. The new combination of docetaxel and vinblastine synergistically enhanced MT depolymerization and bending, while plinabulin and vinblastine had no synergistic inhibitory effects. The results were verified by the tubulin assembly assay. Our study obtained a comprehensive understanding of the action mechanisms of three natural drugs and their combinations on MT dynamic, provided theoretical guidance for new MTA combinations, and would promote the optimal use of MTA and contribute to developing new MTAs as anticancer agents.
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Affiliation(s)
- Yanyan Chu
- School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
- Innovation Center for Marine Drug Screening and Evaluation, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Zhenhua Tian
- School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
| | - Mengke Yang
- School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
| | - Wenbao Li
- School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
- Innovation Center for Marine Drug Screening and Evaluation, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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5
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Wagstaff JM, Planelles-Herrero VJ, Sharov G, Alnami A, Kozielski F, Derivery E, Löwe J. Diverse cytomotive actins and tubulins share a polymerization switch mechanism conferring robust dynamics. SCIENCE ADVANCES 2023; 9:eadf3021. [PMID: 36989372 PMCID: PMC10058229 DOI: 10.1126/sciadv.adf3021] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 03/01/2023] [Indexed: 06/19/2023]
Abstract
Protein filaments are used in myriads of ways to organize other molecules within cells. Some filament-forming proteins couple the hydrolysis of nucleotides to their polymerization cycle, thus powering the movement of other molecules. These filaments are termed cytomotive. Only members of the actin and tubulin protein superfamilies are known to form cytomotive filaments. We examined the basis of cytomotivity via structural studies of the polymerization cycles of actin and tubulin homologs from across the tree of life. We analyzed published data and performed structural experiments designed to disentangle functional components of these complex filament systems. Our analysis demonstrates the existence of shared subunit polymerization switches among both cytomotive actins and tubulins, i.e., the conformation of subunits switches upon assembly into filaments. These cytomotive switches can explain filament robustness, by enabling the coupling of kinetic and structural polarities required for cytomotive behaviors and by ensuring that single cytomotive filaments do not fall apart.
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Affiliation(s)
- James Mark Wagstaff
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | | | - Grigory Sharov
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Aisha Alnami
- Department of Pharmaceutical and Biological Chemistry, School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Frank Kozielski
- Department of Pharmaceutical and Biological Chemistry, School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Emmanuel Derivery
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Jan Löwe
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
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6
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Hoff KJ, Neumann AJ, Moore JK. The molecular biology of tubulinopathies: Understanding the impact of variants on tubulin structure and microtubule regulation. Front Cell Neurosci 2022; 16:1023267. [PMID: 36406756 PMCID: PMC9666403 DOI: 10.3389/fncel.2022.1023267] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 09/30/2022] [Indexed: 11/24/2022] Open
Abstract
Heterozygous, missense mutations in both α- and β-tubulin genes have been linked to an array of neurodevelopment disorders, commonly referred to as "tubulinopathies." To date, tubulinopathy mutations have been identified in three β-tubulin isotypes and one α-tubulin isotype. These mutations occur throughout the different genetic domains and protein structures of these tubulin isotypes, and the field is working to address how this molecular-level diversity results in different cellular and tissue-level pathologies. Studies from many groups have focused on elucidating the consequences of individual mutations; however, the field lacks comprehensive models for the molecular etiology of different types of tubulinopathies, presenting a major gap in diagnosis and treatment. This review highlights recent advances in understanding tubulin structural dynamics, the roles microtubule-associated proteins (MAPs) play in microtubule regulation, and how these are inextricably linked. We emphasize the value of investigating interactions between tubulin structures, microtubules, and MAPs to understand and predict the impact of tubulinopathy mutations at the cell and tissue levels. Microtubule regulation is multifaceted and provides a complex set of controls for generating a functional cytoskeleton at the right place and right time during neurodevelopment. Understanding how tubulinopathy mutations disrupt distinct subsets of those controls, and how that ultimately disrupts neurodevelopment, will be important for establishing mechanistic themes among tubulinopathies that may lead to insights in other neurodevelopment disorders and normal neurodevelopment.
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Affiliation(s)
| | | | - Jeffrey K. Moore
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
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7
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Hoff KJ, Aiken JE, Gutierrez MA, Franco SJ, Moore JK. Tubulinopathy mutations in TUBA1A that disrupt neuronal morphogenesis and migration override XMAP215/Stu2 regulation of microtubule dynamics. eLife 2022; 11:76189. [PMID: 35511030 PMCID: PMC9236607 DOI: 10.7554/elife.76189] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 04/29/2022] [Indexed: 11/13/2022] Open
Abstract
Heterozygous, missense mutations in α- or β-tubulin genes are associated with a wide range of human brain malformations, known as tubulinopathies. We seek to understand whether a mutation’s impact at the molecular and cellular levels scale with the severity of brain malformation. Here, we focus on two mutations at the valine 409 residue of TUBA1A, V409I, and V409A, identified in patients with pachygyria or lissencephaly, respectively. We find that ectopic expression of TUBA1A-V409I/A mutants disrupt neuronal migration in mice and promote excessive neurite branching and a decrease in the number of neurite retraction events in primary rat neuronal cultures. These neuronal phenotypes are accompanied by increased microtubule acetylation and polymerization rates. To determine the molecular mechanisms, we modeled the V409I/A mutants in budding yeast and found that they promote intrinsically faster microtubule polymerization rates in cells and in reconstitution experiments with purified tubulin. In addition, V409I/A mutants decrease the recruitment of XMAP215/Stu2 to plus ends in budding yeast and ablate tubulin binding to TOG (tumor overexpressed gene) domains. In each assay tested, the TUBA1A-V409I mutant exhibits an intermediate phenotype between wild type and the more severe TUBA1A-V409A, reflecting the severity observed in brain malformations. Together, our data support a model in which the V409I/A mutations disrupt microtubule regulation typically conferred by XMAP215 proteins during neuronal morphogenesis and migration, and this impact on tubulin activity at the molecular level scales with the impact at the cellular and tissue levels. Proteins are molecules made up of long chains of building blocks called amino acids. When a mutation changes one of these amino acids, it can lead to the protein malfunctioning, which can have many effects at the cell and tissue level. Given that human proteins are made up of 20 different amino acids, each building block in a protein could mutate to any of the other 19 amino acids, and each mutations could have different effects. Tubulins are proteins that form microtubules, thin tubes that help give cells their shape and allow them to migrate. These proteins are added or removed to microtubules depending on the cell’s needs, meaning that microtubules can grow or shrink depending on the situation. Mutations in the tubulin proteins have been linked to malformations of varying severities involving the formation of ridges and folds on the surface of the brain, including lissencephaly, pachygyria or polymicrogyria. Hoff et al. wanted to establish links between tubulin mutations and the effects observed at both cell and tissue level in the brain. They focused on two mutations in the tubulin protein TUBA1A that affect the amino acid in position 409 in the protein, which is normally a valine. One of the mutations turns this valine into an amino acid called isoleucine. This mutation is associated with pachygyria, which leads to the brain developing few ridges that are broad and flat. The second mutation turns the valine into an alanine, and is linked to lissencephaly, a more severe condition in which the brain develops no ridges, appearing smooth. Hoff et al. found that both mutations interfere with the development of the brain by stopping neurons from migrating properly, which prevents them from forming the folds in the brain correctly. At the cellular level, the mutations lead to tubulins becoming harder to remove from microtubules, making microtubules more stable than usual. This results in longer microtubules that are harder for the cell to shorten or destroy as needed. Additionally, Hoff et al. showed that the mutant versions of TUBA1A have weaker interactions with a protein called XMAP215, which controls the addition of tubulin to microtubules. This causes the microtubules to grow uncontrollably. Hoff et al. also established that the magnitude of the effects of each mutation on microtubule growth scale with the severity of the disorder they cause. Specifically, cells in which TUBA1A is not mutated have microtubules that grow at a normal rate, and lead to typical brain development. Meanwhile, cells carrying the mutation that turns a valine into an alanine, which is linked to the more severe condition lissencephaly, have microtubules that grow very fast. Finally, cells in which the valine is mutated to an isoleucine – the mutation associated with the less severe malformation pachygyria – have microtubules that grow at an intermediate rate. These findings provide a link between mutations in tubulin proteins and larger effects on cell movement that lead to brain malformations. Additionally, they also link the severity of the malformation to the severity of the microtubule defect caused by each mutation. Further work could examine whether microtubule stabilization is also seen in other similar diseases, which, in the long term, could reveal ways to detect and treat these illnesses.
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Affiliation(s)
- Katelyn J Hoff
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, United States
| | - Jayne E Aiken
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, United States
| | - Mark A Gutierrez
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, United States
| | - Santos J Franco
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, United States
| | - Jeffrey K Moore
- University of Colorado School of Medicine, Aurora, United States
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8
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Wang J, Miller DD, Li W. Molecular interactions at the colchicine binding site in tubulin: An X-ray crystallography perspective. Drug Discov Today 2022; 27:759-776. [PMID: 34890803 PMCID: PMC8901563 DOI: 10.1016/j.drudis.2021.12.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 07/27/2021] [Accepted: 12/02/2021] [Indexed: 01/02/2023]
Abstract
Tubulin is an important cancer drug target. Compounds that bind at the colchicine site in tubulin have attracted significant interest as they are generally less affected by multidrug resistance than other potential drugs. Modeling is useful in understanding the interactions between tubulin and colchicine binding site inhibitors (CBSIs), but because the colchicine binding site contains two flexible loops whose conformations are highly ligand-dependent, modeling has its limitations. X-ray crystallography provides experimental pictures of tubulin-ligand interactions at this challenging colchicine site. Since 2004, when the first X-ray structure of tubulin in complex with N-deacetyl-N-(2-mercaptoacetyl)-colchicine (DAMA-colchicine) was published, many X-ray crystal structures have been reported for tubulin complexes involving the colchicine binding site. In this review, we summarize the crystal structures of tubulin in complexes with various CBSIs, aiming to facilitate the discovery of new generations of tubulin inhibitors.
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Affiliation(s)
| | | | - Wei Li
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
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9
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Rice LM, Moritz M, Agard DA. Microtubules form by progressively faster tubulin accretion, not by nucleation-elongation. J Cell Biol 2021; 220:211894. [PMID: 33734292 PMCID: PMC7980253 DOI: 10.1083/jcb.202012079] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 02/12/2021] [Accepted: 02/17/2021] [Indexed: 01/14/2023] Open
Abstract
Microtubules are dynamic polymers that play fundamental roles in all eukaryotes. Despite their importance, how new microtubules form is poorly understood. Textbooks have focused on variations of a nucleation–elongation mechanism in which monomers rapidly equilibrate with an unstable oligomer (nucleus) that limits the rate of polymer formation; once formed, the polymer then elongates efficiently from this nucleus by monomer addition. Such models faithfully describe actin assembly, but they fail to account for how more complex polymers like hollow microtubules assemble. Here, we articulate a new model for microtubule formation that has three key features: (1) microtubules initiate via rectangular, sheet-like structures that grow faster the larger they become; (2) the dominant pathway proceeds via accretion, the stepwise addition of longitudinal or lateral layers; and (3) a “straightening penalty” to account for the energetic cost of tubulin’s curved-to-straight conformational transition. This model can quantitatively fit experimental assembly data, providing new insights into biochemical determinants and assembly pathways for microtubule nucleation.
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Affiliation(s)
- Luke M Rice
- Departments of Biophysics and Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX
| | - Michelle Moritz
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco CA
| | - David A Agard
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco CA
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10
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Regulation of microtubule dynamics, mechanics and function through the growing tip. Nat Rev Mol Cell Biol 2021; 22:777-795. [PMID: 34408299 DOI: 10.1038/s41580-021-00399-x] [Citation(s) in RCA: 85] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/05/2021] [Indexed: 02/07/2023]
Abstract
Microtubule dynamics and their control are essential for the normal function and division of all eukaryotic cells. This plethora of functions is, in large part, supported by dynamic microtubule tips, which can bind to various intracellular targets, generate mechanical forces and couple with actin microfilaments. Here, we review progress in the understanding of microtubule assembly and dynamics, focusing on new information about the structure of microtubule tips. First, we discuss evidence for the widely accepted GTP cap model of microtubule dynamics. Next, we address microtubule dynamic instability in the context of structural information about assembly intermediates at microtubule tips. Three currently discussed models of microtubule assembly and dynamics are reviewed. These are considered in the context of established facts and recent data, which suggest that some long-held views must be re-evaluated. Finally, we review structural observations about the tips of microtubules in cells and describe their implications for understanding the mechanisms of microtubule regulation by associated proteins, by mechanical forces and by microtubule-targeting drugs, prominently including cancer chemotherapeutics.
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11
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Abstract
Members of the tubulin superfamily are GTPases; the activities of GTPases are necessary for life. The members of the tubulin superfamily are the constituents of the microtubules and the γ-tubulin meshwork. Mutations in members of the tubulin superfamily are involved in developmental brain disorders, and tubulin activities are the target for various chemotherapies. The intricate functions (game) of tubulins depend on the activities of the GTP-binding domain of α-, β-, and γ-tubulin. This review compares the GTP-binding domains of γ-tubulin, α-tubulin, and β-tubulin and, based on their similarities, recapitulates the known functions and the impact of the γ-tubulin GTP-binding domain in the regulation of the γ-tubulin meshwork and cellular homeostasis.
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Affiliation(s)
- Maria Alvarado Kristensson
- Molecular Pathology, Department of Translational Medicine, Lund University, Skåne University Hospital, 20502 Malmö, Sweden
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12
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Andreu JM. How Protein Filaments Treadmill. Biophys J 2020; 119:717-720. [PMID: 32730792 DOI: 10.1016/j.bpj.2020.06.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 06/11/2020] [Indexed: 10/23/2022] Open
Affiliation(s)
- José M Andreu
- Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, Spain.
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13
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Gudimchuk NB, Ulyanov EV, O'Toole E, Page CL, Vinogradov DS, Morgan G, Li G, Moore JK, Szczesna E, Roll-Mecak A, Ataullakhanov FI, Richard McIntosh J. Mechanisms of microtubule dynamics and force generation examined with computational modeling and electron cryotomography. Nat Commun 2020; 11:3765. [PMID: 32724196 PMCID: PMC7387542 DOI: 10.1038/s41467-020-17553-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 07/08/2020] [Indexed: 01/15/2023] Open
Abstract
Microtubules are dynamic tubulin polymers responsible for many cellular processes, including the capture and segregation of chromosomes during mitosis. In contrast to textbook models of tubulin self-assembly, we have recently demonstrated that microtubules elongate by addition of bent guanosine triphosphate tubulin to the tips of curving protofilaments. Here we explore this mechanism of microtubule growth using Brownian dynamics modeling and electron cryotomography. The previously described flaring shapes of growing microtubule tips are remarkably consistent under various assembly conditions, including different tubulin concentrations, the presence or absence of a polymerization catalyst or tubulin-binding drugs. Simulations indicate that development of substantial forces during microtubule growth and shortening requires a high activation energy barrier in lateral tubulin-tubulin interactions. Modeling offers a mechanism to explain kinetochore coupling to growing microtubule tips under assisting force, and it predicts a load-dependent acceleration of microtubule assembly, providing a role for the flared morphology of growing microtubule ends.
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Affiliation(s)
- Nikita B Gudimchuk
- Department of Physics, Lomonosov Moscow State University, Moscow, Russia.
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russia.
- Dmitry Rogachev National Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia.
| | - Evgeni V Ulyanov
- Department of Physics, Lomonosov Moscow State University, Moscow, Russia
| | - Eileen O'Toole
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO, USA
| | - Cynthia L Page
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO, USA
| | - Dmitrii S Vinogradov
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russia
| | - Garry Morgan
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO, USA
| | - Gabriella Li
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Jeffrey K Moore
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Ewa Szczesna
- Cell Biology and Biophysics Unit, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Antonina Roll-Mecak
- Cell Biology and Biophysics Unit, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Fazoil I Ataullakhanov
- Department of Physics, Lomonosov Moscow State University, Moscow, Russia
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russia
- Dmitry Rogachev National Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia
| | - J Richard McIntosh
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO, USA
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14
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Corbin LC, Erickson HP. A Unified Model for Treadmilling and Nucleation of Single-Stranded FtsZ Protofilaments. Biophys J 2020; 119:792-805. [PMID: 32763138 DOI: 10.1016/j.bpj.2020.05.041] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 05/19/2020] [Accepted: 05/27/2020] [Indexed: 10/25/2022] Open
Abstract
Bacterial cell division is tightly coupled to the dynamic behavior of FtsZ, a tubulin homolog. Recent experimental work in vitro and in vivo has attributed FtsZ's assembly dynamics to treadmilling, in which subunits add to the bottom and dissociate from the top of protofilaments. However, the molecular mechanisms producing treadmilling have yet to be characterized and quantified. We have developed a Monte Carlo model for FtsZ assembly that explains treadmilling, and also explains assembly nucleation by the same mechanisms. A key element of the model is a conformational change from R (relaxed), which is highly favored for monomers, to T (tense), which is favored for subunits in a protofilament. This model was created in MATLAB. Kinetic parameters were converted to probabilities of execution during a single, small time step. These were used to stochastically determine FtsZ dynamics. Our model is able to accurately describe the results of several in vitro and in vivo studies for a variety of FtsZ flavors. With standard conditions, the model FtsZ polymerized and produced protofilaments that treadmilled at 23 nm/s, hydrolyzed GTP at 3.6-3.7 GTP min-1 FtsZ-1, and had an average length of 30-40 subunits, all similar to experimental results. Adding a bottom capper resulted in shorter protofilaments and higher GTPase, similar to the effect of the known bottom capper protein MciZ. The model could match nucleation kinetics of several flavors of FtsZ using the same parameters as treadmilling and varying only the R to T transition of monomers.
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Affiliation(s)
- Lauren C Corbin
- Department of Biomedical Engineering, Duke University, Durham, North Carolina
| | - Harold P Erickson
- Department of Biomedical Engineering, Duke University, Durham, North Carolina; Department of Cell Biology, Duke University, Durham, North Carolina.
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15
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Oliva MA, Prota AE, Rodríguez-Salarichs J, Bennani YL, Jiménez-Barbero J, Bargsten K, Canales Á, Steinmetz MO, Díaz JF. Structural Basis of Noscapine Activation for Tubulin Binding. J Med Chem 2020; 63:8495-8501. [DOI: 10.1021/acs.jmedchem.0c00855] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- María A. Oliva
- Centro de Investigaciones Biológicas Margarita Salas-CSIC, Ramiro de Maeztu, 9, C.P. 28040 Madrid, Spain
| | - Andrea E. Prota
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - Javier Rodríguez-Salarichs
- Centro de Investigaciones Biológicas Margarita Salas-CSIC, Ramiro de Maeztu, 9, C.P. 28040 Madrid, Spain
| | - Youssef L. Bennani
- adMare Bio Innovations, Centre d’innovation NÉOMED, 7171 Frederick-Banting, Montréal, Quebec H4S 1Z9, Canada
| | - Jesús Jiménez-Barbero
- CIC bioGUNE, Basque Research Technology Alliance (BRTA), Bizkaia Technology Park, Building 801A, 48170 Derio, Spain
- Ikerbasque, Basque Foundation for Science, María Díaz de Haro 13, Bilbao 48009, Spain
- Department of Organic Chemistry II, Faculty of Science & Technology, University of the Basque Country, 48940 Leioa, Bizkaia, Spain
| | - Katja Bargsten
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - Ángeles Canales
- Departamento Química Orgánica I, Facultad Ciencias Químicas, Universidad Complutense de Madrid, Avd. Complutense s/n, C.P. 28040 Madrid, Spain
| | - Michel O. Steinmetz
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
- University of Basel, Biozentrum, Basel CH-4056, Switzerland
| | - J. Fernando Díaz
- Centro de Investigaciones Biológicas Margarita Salas-CSIC, Ramiro de Maeztu, 9, C.P. 28040 Madrid, Spain
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16
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Dynamic and asymmetric fluctuations in the microtubule wall captured by high-resolution cryoelectron microscopy. Proc Natl Acad Sci U S A 2020; 117:16976-16984. [PMID: 32636254 DOI: 10.1073/pnas.2001546117] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Microtubules are tubular polymers with essential roles in numerous cellular activities. Structures of microtubules have been captured at increasing resolution by cryo-EM. However, dynamic properties of the microtubule are key to its function, and this behavior has proved difficult to characterize at a structural level due to limitations in existing structure determination methods. We developed a high-resolution cryo-EM refinement method that divides an imaged microtubule into its constituent protofilaments, enabling deviations from helicity and other sources of heterogeneity to be quantified and corrected for at the single-subunit level. We demonstrate that this method improves the resolution of microtubule 3D reconstructions and substantially reduces anisotropic blurring artifacts, compared with methods that utilize helical symmetry averaging. Moreover, we identified an unexpected, discrete behavior of the m-loop, which mediates lateral interactions between neighboring protofilaments and acts as a flexible hinge between them. The hinge angle adopts preferred values corresponding to distinct conformations of the m-loop that are incompatible with helical symmetry. These hinge angles fluctuate in a stochastic manner, and perfectly cylindrical microtubule conformations are thus energetically and entropically penalized. The hinge angle can diverge further from helical symmetry at the microtubule seam, generating a subpopulation of highly distorted microtubules. However, the seam-distorted subpopulation disappears in the presence of Taxol, a microtubule stabilizing agent. These observations provide clues into the structural origins of microtubule flexibility and dynamics and highlight the role of structural polymorphism in defining microtubule behavior.
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17
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Tong D, Voth GA. Microtubule Simulations Provide Insight into the Molecular Mechanism Underlying Dynamic Instability. Biophys J 2020; 118:2938-2951. [PMID: 32413312 DOI: 10.1016/j.bpj.2020.04.028] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 04/20/2020] [Accepted: 04/24/2020] [Indexed: 12/14/2022] Open
Abstract
The dynamic instability of microtubules (MTs), which refers to their ability to switch between polymerization and depolymerization states, is crucial for their function. It has been proposed that the growing MT ends are protected by a "GTP cap" that consists of GTP-bound tubulin dimers. When the speed of GTP hydrolysis is faster than dimer recruitment, the loss of this GTP cap will lead the MT to undergo rapid disassembly. However, the underlying atomistic mechanistic details of the dynamic instability remains unclear. In this study, we have performed long-time atomistic molecular dynamics simulations (1 μs for each system) for MT patches as well as a short segment of a closed MT in both GTP- and GDP-bound states. Our results confirmed that MTs in the GDP state generally have weaker lateral interactions between neighboring protofilaments (PFs) and less cooperative outward bending conformational change, where the difference between bending angles of neighboring PFs tends to be larger compared with GTP ones. As a result, when the GDP state tubulin dimer is exposed at the growing MT end, these factors will be more likely to cause the MT to undergo rapid disassembly. We also compared simulation results between the special MT seam region and the remaining material and found that the lateral interactions between MT PFs at the seam region were comparatively much weaker. This finding is consistent with the experimental suggestion that the seam region tends to separate during the disassembly process of an MT.
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Affiliation(s)
- Dudu Tong
- Department of Chemistry, Chicago Center for Theoretical Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois
| | - Gregory A Voth
- Department of Chemistry, Chicago Center for Theoretical Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois.
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18
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Aratsu K, Takeya R, Pauw BR, Hollamby MJ, Kitamoto Y, Shimizu N, Takagi H, Haruki R, Adachi SI, Yagai S. Supramolecular copolymerization driven by integrative self-sorting of hydrogen-bonded rosettes. Nat Commun 2020; 11:1623. [PMID: 32238806 PMCID: PMC7113319 DOI: 10.1038/s41467-020-15422-6] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 03/09/2020] [Indexed: 11/12/2022] Open
Abstract
Molecular recognition to preorganize noncovalently polymerizable supramolecular complexes is a characteristic process of natural supramolecular polymers, and such recognition processes allow for dynamic self-alteration, yielding complex polymer systems with extraordinarily high efficiency in their targeted function. We herein show an example of such molecular recognition-controlled kinetic assembly/disassembly processes within artificial supramolecular polymer systems using six-membered hydrogen-bonded supramolecular complexes (rosettes). Electron-rich and poor monomers are prepared that kinetically coassemble through a temperature-controlled protocol into amorphous coaggregates comprising a diverse mixture of rosettes. Over days, the electrostatic interaction between two monomers induces an integrative self-sorting of rosettes. While the electron-rich monomer inherently forms toroidal homopolymers, the additional electrostatic interaction that can also guide rosette association allows helicoidal growth of supramolecular copolymers that are comprised of an alternating array of two monomers. Upon heating, the helicoidal copolymers undergo a catastrophic transition into amorphous coaggregates via entropy-driven randomization of the monomers in the rosette. Unlike natural supramolecular polymers, artificial counterparts do not have molecular recognition processes to preorganize the supramolecular complexes before final assembly. Here, the authors show supramolecular copolymerization driven by integrative self-sorting of two different monomers into discrete six-membered supramolecular complexes (rosettes).
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Affiliation(s)
- Keisuke Aratsu
- Division of Advanced Science and Engineering, Graduate School of Science and Engineering, Chiba University, 1-33 Yayoi-Cho, Inage-Ku, Chiba, 263-8522, Japan
| | - Rika Takeya
- Division of Advanced Science and Engineering, Graduate School of Science and Engineering, Chiba University, 1-33 Yayoi-Cho, Inage-Ku, Chiba, 263-8522, Japan
| | - Brian R Pauw
- BAM Federal Institute for Materials Research and Testing Unter den Eichen 87, 12205, Berlin, Germany.
| | - Martin J Hollamby
- School of Physical and Geographical Sciences, Keele University, Keele, Staffordshire, ST55BG, UK.
| | - Yuichi Kitamoto
- Institute for Global Prominent Research (IGPR), Chiba University, 1-33 Yayoi-Cho, Inage-Ku, Chiba, 263-8522, Japan
| | - Nobutaka Shimizu
- Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba, 305-0801, Japan
| | - Hideaki Takagi
- Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba, 305-0801, Japan
| | - Rie Haruki
- Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba, 305-0801, Japan
| | - Shin-Ichi Adachi
- Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba, 305-0801, Japan
| | - Shiki Yagai
- Institute for Global Prominent Research (IGPR), Chiba University, 1-33 Yayoi-Cho, Inage-Ku, Chiba, 263-8522, Japan. .,Graduate School of Engineering, Chiba University, 1-33 Yayoi-Cho, Inage-Ku, Chiba, 263-8522, Japan.
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19
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Estévez-Gallego J, Josa-Prado F, Ku S, Buey RM, Balaguer FA, Prota AE, Lucena-Agell D, Kamma-Lorger C, Yagi T, Iwamoto H, Duchesne L, Barasoain I, Steinmetz MO, Chrétien D, Kamimura S, Díaz JF, Oliva MA. Structural model for differential cap maturation at growing microtubule ends. eLife 2020; 9:50155. [PMID: 32151315 PMCID: PMC7064335 DOI: 10.7554/elife.50155] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 01/25/2020] [Indexed: 11/13/2022] Open
Abstract
Microtubules (MTs) are hollow cylinders made of tubulin, a GTPase responsible for essential functions during cell growth and division, and thus, key target for anti-tumor drugs. In MTs, GTP hydrolysis triggers structural changes in the lattice, which are responsible for interaction with regulatory factors. The stabilizing GTP-cap is a hallmark of MTs and the mechanism of the chemical-structural link between the GTP hydrolysis site and the MT lattice is a matter of debate. We have analyzed the structure of tubulin and MTs assembled in the presence of fluoride salts that mimic the GTP-bound and GDP•Pi transition states. Our results challenge current models because tubulin does not change axial length upon GTP hydrolysis. Moreover, analysis of the structure of MTs assembled in the presence of several nucleotide analogues and of taxol allows us to propose that previously described lattice expansion could be a post-hydrolysis stage involved in Pi release.
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Affiliation(s)
- Juan Estévez-Gallego
- Structural and Chemical Biology Department, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | - Fernando Josa-Prado
- Structural and Chemical Biology Department, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | - Siou Ku
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, Rennes, France
| | - Ruben M Buey
- Structural and Chemical Biology Department, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain.,Departamento de Microbiología y Genética, Universidad de Salamanca-Campus Miguel de Unamuno, Salamanca, Spain
| | - Francisco A Balaguer
- Structural and Chemical Biology Department, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | - Andrea E Prota
- Division of Biology and Chemistry, Laboratory of Biomolecular Research, Paul Scherrer Institut, Villigen, Switzerland
| | - Daniel Lucena-Agell
- Structural and Chemical Biology Department, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | | | - Toshiki Yagi
- Department of Life Sciences, Faculty of Life and Environmental Sciences, Prefectural University of Hiroshima, Hiroshima, Japan
| | - Hiroyuki Iwamoto
- Diffraction and Scattering Division, Japan Synchrotron Radiation Research Institute, Hyogo, Japan
| | - Laurence Duchesne
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, Rennes, France
| | - Isabel Barasoain
- Structural and Chemical Biology Department, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | - Michel O Steinmetz
- Division of Biology and Chemistry, Laboratory of Biomolecular Research, Paul Scherrer Institut, Villigen, Switzerland.,University of Basel, Biozentrum, Basel, Switzerland
| | - Denis Chrétien
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, Rennes, France
| | - Shinji Kamimura
- Department of Biological Sciences, Faculty of Science and Engineering, Chuo University, Tokyo, Japan
| | - J Fernando Díaz
- Structural and Chemical Biology Department, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | - Maria A Oliva
- Structural and Chemical Biology Department, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
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20
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Ye X, Kim T, Geyer EA, Rice LM. Insights into allosteric control of microtubule dynamics from a buried β-tubulin mutation that causes faster growth and slower shrinkage. Protein Sci 2020; 29:1429-1439. [PMID: 32077153 DOI: 10.1002/pro.3842] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 02/14/2020] [Accepted: 02/17/2020] [Indexed: 01/27/2023]
Abstract
αβ-tubulin subunits cycle through a series of different conformations in the polymer lattice during microtubule growing and shrinking. How these allosteric responses to different tubulin:tubulin contacts contribute to microtubule dynamics, and whether the contributions are evolutionarily conserved, remains poorly understood. Here, we sought to determine whether the microtubule-stabilizing effects (slower shrinking) of the β:T238A mutation we previously observed using yeast αβ-tubulin would generalize to mammalian microtubules. Using recombinant human microtubules as a model, we found that the mutation caused slow microtubule shrinking, indicating that this effect of the mutation is indeed conserved. However, unlike in yeast, β:T238A human microtubules grew faster than wild-type and the mutation did not appear to attenuate the conformational change associated with guanosine 5'-triphosphate (GTP) hydrolysis in the lattice. We conclude that the assembly-dependent conformational change in αβ-tubulin can contribute to determine the rates of microtubule growing as well as shrinking. Our results also suggest that an allosteric perturbation like the β:T238A mutation can alter the behavior of terminal subunits without accompanying changes in the conformation of fully surrounded subunits in the body of the microtubule.
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Affiliation(s)
- Xuecheng Ye
- UT Southwestern Medical Center, Departments of Biophysics and Biochemistry, Dallas, Texas, USA
| | - Tae Kim
- UT Southwestern Medical Center, Departments of Biophysics and Biochemistry, Dallas, Texas, USA
| | - Elisabeth A Geyer
- UT Southwestern Medical Center, Departments of Biophysics and Biochemistry, Dallas, Texas, USA
| | - Luke M Rice
- UT Southwestern Medical Center, Departments of Biophysics and Biochemistry, Dallas, Texas, USA
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21
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Microtubule lattice plasticity. Curr Opin Cell Biol 2018; 56:88-93. [PMID: 30415187 DOI: 10.1016/j.ceb.2018.10.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 10/21/2018] [Indexed: 01/06/2023]
Abstract
In classical microtubule dynamic instability, the dynamics of the built polymer depend only on the nucleotide state of its individual tubulin molecules. Recent work is overturning this view, pointing instead towards lattice plasticity, in which the fine-structure and mechanics of the microtubule lattice are emergent properties that depend not only on the nucleotide state of each tubulin, but also on the nucleotide states of its neighbours, on its and their isotypes, and on interacting proteins, drugs, local mechanical strain, post translational modifications, packing defects and solvent conditions. In lattice plasticity models, the microtubule is an allosteric molecular collective that integrates multiple mechanochemical inputs and responds adaptively by adjusting its conformation, stiffness and dynamics.
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22
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Vicente-Blázquez A, González M, Álvarez R, Del Mazo S, Medarde M, Peláez R. Antitubulin sulfonamides: The successful combination of an established drug class and a multifaceted target. Med Res Rev 2018; 39:775-830. [PMID: 30362234 DOI: 10.1002/med.21541] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 09/02/2018] [Accepted: 09/06/2018] [Indexed: 12/13/2022]
Abstract
Tubulin, the microtubules and their dynamic behavior are amongst the most successful antitumor, antifungal, antiparasitic, and herbicidal drug targets. Sulfonamides are exemplary drugs with applications in the clinic, in veterinary and in the agrochemical industry. This review summarizes the actual state and recent progress of both fields looking from the double point of view of the target and its drugs, with special focus onto the structural aspects. The article starts with a brief description of tubulin structure and its dynamic assembly and disassembly into microtubules and other polymers. Posttranslational modifications and the many cellular means of regulating and modulating tubulin's biology are briefly presented in the tubulin code. Next, the structurally characterized drug binding sites, their occupying drugs and the effects they induce are described, emphasizing on the structural requirements for high potency, selectivity, and low toxicity. The second part starts with a summary of the favorable and highly tunable combination of physical-chemical and biological properties that render sulfonamides a prototypical example of privileged scaffolds with representatives in many therapeutic areas. A complete description of tubulin-binding sulfonamides is provided, covering the different species and drug sites. Some of the antimitotic sulfonamides have met with very successful applications and others less so, thus illustrating the advances, limitations, and future perspectives of the field. All of them combine in a mechanism of action and a clinical outcome that conform efficient drugs.
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Affiliation(s)
- Alba Vicente-Blázquez
- Laboratorio de Química Orgánica y Farmacéutica, Departamento de Ciencias Farmacéuticas, Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain.,Facultad de Farmacia, Instituto de Investigación Biomédica de Salamanca (IBSAL), Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain.,Facultad de Farmacia, Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca (CIETUS), Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain.,Laboratory of Cell Death and Cancer Therapy, Department of Molecular Biomedicine, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Myriam González
- Laboratorio de Química Orgánica y Farmacéutica, Departamento de Ciencias Farmacéuticas, Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain.,Facultad de Farmacia, Instituto de Investigación Biomédica de Salamanca (IBSAL), Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain.,Facultad de Farmacia, Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca (CIETUS), Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain
| | - Raquel Álvarez
- Laboratorio de Química Orgánica y Farmacéutica, Departamento de Ciencias Farmacéuticas, Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain.,Facultad de Farmacia, Instituto de Investigación Biomédica de Salamanca (IBSAL), Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain.,Facultad de Farmacia, Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca (CIETUS), Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain
| | - Sara Del Mazo
- Laboratorio de Química Orgánica y Farmacéutica, Departamento de Ciencias Farmacéuticas, Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain.,Facultad de Farmacia, Instituto de Investigación Biomédica de Salamanca (IBSAL), Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain.,Facultad de Farmacia, Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca (CIETUS), Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain
| | - Manuel Medarde
- Laboratorio de Química Orgánica y Farmacéutica, Departamento de Ciencias Farmacéuticas, Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain.,Facultad de Farmacia, Instituto de Investigación Biomédica de Salamanca (IBSAL), Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain.,Facultad de Farmacia, Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca (CIETUS), Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain
| | - Rafael Peláez
- Laboratorio de Química Orgánica y Farmacéutica, Departamento de Ciencias Farmacéuticas, Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain.,Facultad de Farmacia, Instituto de Investigación Biomédica de Salamanca (IBSAL), Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain.,Facultad de Farmacia, Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca (CIETUS), Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain
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23
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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.
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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.
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24
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Abstract
Microtubules are dynamic polymers of αβ-tubulin that are essential for intracellular organization, organelle trafficking and chromosome segregation. Microtubule growth and shrinkage occur via addition and loss of αβ-tubulin subunits, which are biochemical processes. Dynamic microtubules can also engage in mechanical processes, such as exerting forces by pushing or pulling against a load. Recent advances at the intersection of biochemistry and mechanics have revealed the existence of multiple conformations of αβ-tubulin subunits and their central role in dictating the mechanisms of microtubule dynamics and force generation. It has become apparent that microtubule-associated proteins (MAPs) selectively target specific tubulin conformations to regulate microtubule dynamics, and mechanical forces can also influence microtubule dynamics by altering the balance of tubulin conformations. Importantly, the conformational states of tubulin dimers are likely to be coupled throughout the lattice: the conformation of one dimer can influence the conformation of its nearest neighbours, and this effect can propagate over longer distances. This coupling provides a long-range mechanism by which MAPs and forces can modulate microtubule growth and shrinkage. These findings provide evidence that the interplay between biochemistry and mechanics is essential for the cellular functions of microtubules.
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Affiliation(s)
- Gary J Brouhard
- Department of Biology, McGill University, Montréal, Quebec, Canada.
| | - Luke M Rice
- Department of Biophysics, University of Texas Southwestern, Dallas, TX, USA.
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25
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Manandhar A, Kang M, Chakraborty K, Loverde SM. Effect of Nucleotide State on the Protofilament Conformation of Tubulin Octamers. J Phys Chem B 2018; 122:6164-6178. [PMID: 29768004 DOI: 10.1021/acs.jpcb.8b02193] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
At the molecular level, the dynamic instability (random growth and shrinkage) of the microtubule (MT) is driven by the nucleotide state (GTP vs GDP) in the β subunit of the tubulin dimers at the MT cap. Here, we use large-scale molecular dynamics (MD) simulations and normal-mode analysis (NMA) to characterize the effect of a single GTP cap layer on tubulin octamers composed of two neighboring protofilaments (PFs). We utilize recently reported high-resolution structures of dynamic MTs to simulate a GDP octamer both with and without a single GTP cap layer. We perform multiple replicas of long-time atomistic MD simulations (3 replicas, 0.3 μs for each replica, 0.9 μs for each octamer system, and 1.8 μs total) of both octamers. We observe that a single GTP cap layer induces structural differences in neighboring PFs, finding that one PF possesses a gradual curvature, compared to the second PF which possesses a kinked conformation. This results in either curling or splaying between these PFs. We suggest that this is due to asymmetric strengths of longitudinal contacts between the two PFs. Furthermore, using NMA, we calculate mechanical properties of these octamer systems and find that octamer system with a single GTP cap layer possesses a lower flexural rigidity.
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Affiliation(s)
- Anjela Manandhar
- Department of Chemistry, College of Staten Island , City University of New York , 2800 Victory Boulevard , Staten Island , New York 10314 , United States.,Ph.D. Program in Biochemistry , The Graduate Center of the City University of New York , 365 Fifth Avenue , New York , New York 10016 , United States
| | - Myungshim Kang
- Department of Chemistry, College of Staten Island , City University of New York , 2800 Victory Boulevard , Staten Island , New York 10314 , United States
| | - Kaushik Chakraborty
- Department of Chemistry, College of Staten Island , City University of New York , 2800 Victory Boulevard , Staten Island , New York 10314 , United States
| | - Sharon M Loverde
- Department of Chemistry, College of Staten Island , City University of New York , 2800 Victory Boulevard , Staten Island , New York 10314 , United States.,Ph.D. Program in Biochemistry , The Graduate Center of the City University of New York , 365 Fifth Avenue , New York , New York 10016 , United States
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26
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McIntosh JR, O'Toole E, Morgan G, Austin J, Ulyanov E, Ataullakhanov F, Gudimchuk N. Microtubules grow by the addition of bent guanosine triphosphate tubulin to the tips of curved protofilaments. J Cell Biol 2018; 217:2691-2708. [PMID: 29794031 PMCID: PMC6080942 DOI: 10.1083/jcb.201802138] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Revised: 04/17/2018] [Accepted: 05/07/2018] [Indexed: 11/22/2022] Open
Abstract
How microtubules (MTs) grow during the addition of guanosine triphosphate (GTP) tubulin is not clear. McIntosh et al. now show that MTs elongating either in vivo or in vitro end in bent protofilaments that curve out from the microtubule axis, suggesting that GTP-tubulin is bent in solution and must straighten to join the MT wall. We used electron tomography to examine microtubules (MTs) growing from pure tubulin in vitro as well as two classes of MTs growing in cells from six species. The tips of all these growing MTs display bent protofilaments (PFs) that curve away from the MT axis, in contrast with previously reported MTs growing in vitro whose tips are either blunt or sheetlike. Neither high pressure nor freezing is responsible for the PF curvatures we see. The curvatures of PFs on growing and shortening MTs are similar; all are most curved at their tips, suggesting that guanosine triphosphate–tubulin in solution is bent and must straighten to be incorporated into the MT wall. Variations in curvature suggest that PFs are flexible in their plane of bending but rigid to bending out of that plane. Modeling by Brownian dynamics suggests that PF straightening for MT growth can be achieved by thermal motions, providing a simple mechanism with which to understand tubulin polymerization.
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Affiliation(s)
- J Richard McIntosh
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO
| | - Eileen O'Toole
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO
| | - Garry Morgan
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO
| | - Jotham Austin
- Advanced Electron Microscopy Facility, University of Chicago, Chicago, IL
| | - Evgeniy Ulyanov
- Department of Physics, Lomonosov Moscow State University, Moscow, Russia
| | - Fazoil Ataullakhanov
- Department of Physics, Lomonosov Moscow State University, Moscow, Russia.,Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russia
| | - Nikita Gudimchuk
- Department of Physics, Lomonosov Moscow State University, Moscow, Russia.,Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russia
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27
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Igaev M, Grubmüller H. Microtubule assembly governed by tubulin allosteric gain in flexibility and lattice induced fit. eLife 2018; 7:34353. [PMID: 29652248 PMCID: PMC5945277 DOI: 10.7554/elife.34353] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 04/12/2018] [Indexed: 11/24/2022] Open
Abstract
Microtubules (MTs) are key components of the cytoskeleton and play a central role in cell division and development. MT assembly is known to be associated with a structural change in αβ-tubulin dimers from kinked to straight conformations. How GTP binding renders individual dimers polymerization-competent, however, is still unclear. Here, we have characterized the conformational dynamics and energetics of unassembled tubulin using atomistic molecular dynamics and free energy calculations. Contrary to existing allosteric and lattice models, we find that GTP-tubulin favors a broad range of almost isoenergetic curvatures, whereas GDP-tubulin has a much lower bending flexibility. Moreover, irrespective of the bound nucleotide and curvature, two conformational states exist differing in location of the anchor point connecting the monomers that affects tubulin bending, with one state being strongly favored in solution. Our findings suggest a new combined model in which MTs incorporate and stabilize flexible GTP-dimers with a specific anchor point state.
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Affiliation(s)
- Maxim Igaev
- Department of Theoretical and Computational Biophysics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Helmut Grubmüller
- Department of Theoretical and Computational Biophysics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
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28
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Huecas S, Ramírez-Aportela E, Vergoñós A, Núñez-Ramírez R, Llorca O, Díaz JF, Juan-Rodríguez D, Oliva MA, Castellen P, Andreu JM. Self-Organization of FtsZ Polymers in Solution Reveals Spacer Role of the Disordered C-Terminal Tail. Biophys J 2017; 113:1831-1844. [PMID: 29045877 DOI: 10.1016/j.bpj.2017.08.046] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 07/28/2017] [Accepted: 08/30/2017] [Indexed: 11/24/2022] Open
Abstract
FtsZ is a self-assembling GTPase that forms, below the inner membrane, the mid-cell Z-ring guiding bacterial division. FtsZ monomers polymerize head to tail forming tubulin-like dynamic protofilaments, whose organization in the Z-ring is an unresolved problem. Rather than forming a well-defined structure, FtsZ protofilaments laterally associate in vitro into polymorphic condensates typically imaged on surfaces. We describe here nanoscale self-organizing properties of FtsZ assemblies in solution that underlie Z-ring assembly, employing time-resolved x-ray scattering and cryo-electron microscopy. We find that FtsZ forms bundles made of loosely bound filaments of variable length and curvature. Individual FtsZ protofilaments further bend upon nucleotide hydrolysis, highlighted by the observation of some large circular structures with 2.5-5° curvature angles between subunits, followed by disassembly end-products consisting of highly curved oligomers and 16-subunit -220 Å diameter mini-rings, here observed by cryo-electron microscopy. Neighbor FtsZ filaments in bundles are laterally spaced 70 Å, leaving a gap in between. In contrast, close contact between filament core structures (∼50 Å spacing) is observed in straight polymers of FtsZ constructs lacking the C-terminal tail, which is known to provide a flexible tether essential for FtsZ functions in cell division. Changing the length of the intrinsically disordered C-tail linker modifies the interfilament spacing. We propose that the linker prevents dynamic FtsZ protofilaments in bundles from sticking to one another, holding them apart at a distance similar to the lateral spacing observed by electron cryotomography in several bacteria and liposomes. According to this model, weak interactions between curved polar FtsZ protofilaments through their the C-tails may facilitate the coherent treadmilling dynamics of membrane-associated FtsZ bundles in reconstituted systems, as well as the recently discovered movement of FtsZ clusters around bacterial Z-rings that is powered by GTP hydrolysis and guides correct septal cell wall synthesis and cell division.
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Affiliation(s)
- Sonia Huecas
- Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | | | | | | | - Oscar Llorca
- Centro de Investigaciones Biológicas, CSIC, Madrid, Spain; Spanish National Cancer Research Center, CNIO, Madrid, Spain
| | | | | | - María A Oliva
- Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | - Patricia Castellen
- Centro de Investigaciones Biológicas, CSIC, Madrid, Spain; Department of Chemistry, State University of Ponta Grossa, Paraná, Brazil
| | - José M Andreu
- Centro de Investigaciones Biológicas, CSIC, Madrid, Spain.
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29
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Abstract
FtsZ, a homolog of tubulin, is found in almost all bacteria and archaea where it has a primary role in cytokinesis. Evidence for structural homology between FtsZ and tubulin came from their crystal structures and identification of the GTP box. Tubulin and FtsZ constitute a distinct family of GTPases and show striking similarities in many of their polymerization properties. The differences between them, more so, the complexities of microtubule dynamic behavior in comparison to that of FtsZ, indicate that the evolution to tubulin is attributable to the incorporation of the complex functionalities in higher organisms. FtsZ and microtubules function as polymers in cell division but their roles differ in the division process. The structural and partial functional homology has made the study of their dynamic properties more interesting. In this review, we focus on the application of the information derived from studies on FtsZ dynamics to study microtubule dynamics and vice versa. The structural and functional aspects that led to the establishment of the homology between the two proteins are explained to emphasize the network of FtsZ and microtubule studies and how they are connected.
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Affiliation(s)
- Rachana Rao Battaje
- Department of Biosciences and BioengineeringIndian Institute of Technology Bombay, Mumbai, India
| | - Dulal Panda
- Department of Biosciences and BioengineeringIndian Institute of Technology Bombay, Mumbai, India
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30
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TubZ filament assembly dynamics requires the flexible C-terminal tail. Sci Rep 2017; 7:43342. [PMID: 28230082 PMCID: PMC5322520 DOI: 10.1038/srep43342] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 01/24/2017] [Indexed: 11/12/2022] Open
Abstract
Cytomotive filaments are essential for the spatial organization in cells, showing a dynamic behavior based on nucleotide hydrolysis. TubZ is a tubulin-like protein that functions in extrachromosomal DNA movement within bacteria. TubZ filaments grow in a helical fashion following treadmilling or dynamic instability, although the underlying mechanism is unclear. We have unraveled the molecular basis for filament assembly and dynamics combining electron and atomic force microscopy and biochemical analyses. Our findings suggest that GTP caps retain the filament helical structure and hydrolysis triggers filament stiffening upon disassembly. We show that the TubZ C-terminal tail is an unstructured domain that fulfills multiple functions contributing to the filament helical arrangement, the polymer remodeling into tubulin-like rings and the full disassembly process. This C-terminal tail displays the binding site for partner proteins and we report how it modulates the interaction of the regulator protein TubY.
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31
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Artola M, Ruíz-Avila LB, Ramírez-Aportela E, Martínez RF, Araujo-Bazán L, Vázquez-Villa H, Martín-Fontecha M, Oliva MA, Martín-Galiano AJ, Chacón P, López-Rodríguez ML, Andreu JM, Huecas S. The structural assembly switch of cell division protein FtsZ probed with fluorescent allosteric inhibitors. Chem Sci 2017; 8:1525-1534. [PMID: 28616148 PMCID: PMC5460597 DOI: 10.1039/c6sc03792e] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 10/19/2016] [Indexed: 11/21/2022] Open
Abstract
FtsZ is a widely conserved tubulin-like GTPase that directs bacterial cell division and a new target for antibiotic discovery. This protein assembly machine cooperatively polymerizes forming single-stranded filaments, by means of self-switching between inactive and actively associating monomer conformations. The structural switch mechanism was proposed to involve a movement of the C-terminal and N-terminal FtsZ domains, opening a cleft between them, allosterically coupled to the formation of a tight association interface between consecutive subunits along the filament. The effective antibacterial benzamide PC190723 binds into the open interdomain cleft and stabilizes FtsZ filaments, thus impairing correct formation of the FtsZ ring for cell division. We have designed fluorescent analogs of PC190723 to probe the FtsZ structural assembly switch. Among them, nitrobenzoxadiazole probes specifically bind to assembled FtsZ rather than to monomers. Probes with several spacer lengths between the fluorophore and benzamide moieties suggest a binding site extension along the interdomain cleft. These probes label FtsZ rings of live Bacillus subtilis and Staphylococcus aureus, without apparently modifying normal cell morphology and growth, but at high concentrations they induce impaired bacterial division phenotypes typical of benzamide antibacterials. During the FtsZ assembly-disassembly process, the fluorescence anisotropy of the probes changes upon binding and dissociating from FtsZ, thus reporting open and closed FtsZ interdomain clefts. Our results demonstrate the structural mechanism of the FtsZ assembly switch, and suggest that the probes bind into the open clefts in cellular FtsZ polymers preferably to unassembled FtsZ in the bacterial cytosol.
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Affiliation(s)
- Marta Artola
- Dept. Química Orgánica I , Facultad de Ciencias Químicas , UCM , 28040 Madrid , Spain
| | - Laura B Ruíz-Avila
- Centro de Investigaciones Biológicas , CSIC , Ramiro de Maeztu 9 , 28040 Madrid , Spain . ;
| | - Erney Ramírez-Aportela
- Centro de Investigaciones Biológicas , CSIC , Ramiro de Maeztu 9 , 28040 Madrid , Spain . ;
- Instituto de Química-Física Rocasolano , CSIC , Serrano 119 , 20006 Madrid , Spain
| | - R Fernando Martínez
- Dept. Química Orgánica I , Facultad de Ciencias Químicas , UCM , 28040 Madrid , Spain
| | - Lidia Araujo-Bazán
- Centro de Investigaciones Biológicas , CSIC , Ramiro de Maeztu 9 , 28040 Madrid , Spain . ;
| | - Henar Vázquez-Villa
- Dept. Química Orgánica I , Facultad de Ciencias Químicas , UCM , 28040 Madrid , Spain
| | - Mar Martín-Fontecha
- Dept. Química Orgánica I , Facultad de Ciencias Químicas , UCM , 28040 Madrid , Spain
| | - María A Oliva
- Centro de Investigaciones Biológicas , CSIC , Ramiro de Maeztu 9 , 28040 Madrid , Spain . ;
| | | | - Pablo Chacón
- Instituto de Química-Física Rocasolano , CSIC , Serrano 119 , 20006 Madrid , Spain
| | | | - José M Andreu
- Centro de Investigaciones Biológicas , CSIC , Ramiro de Maeztu 9 , 28040 Madrid , Spain . ;
| | - Sonia Huecas
- Centro de Investigaciones Biológicas , CSIC , Ramiro de Maeztu 9 , 28040 Madrid , Spain . ;
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32
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Zakharov P, Gudimchuk N, Voevodin V, Tikhonravov A, Ataullakhanov FI, Grishchuk EL. Molecular and Mechanical Causes of Microtubule Catastrophe and Aging. Biophys J 2016; 109:2574-2591. [PMID: 26682815 DOI: 10.1016/j.bpj.2015.10.048] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 09/11/2015] [Accepted: 10/05/2015] [Indexed: 10/22/2022] Open
Abstract
Tubulin polymers, microtubules, can switch abruptly from the assembly to shortening. These infrequent transitions, termed "catastrophes", affect numerous cellular processes but the underlying mechanisms are elusive. We approached this complex stochastic system using advanced coarse-grained molecular dynamics modeling of tubulin-tubulin interactions. Unlike in previous simplified models of dynamic microtubules, the catastrophes in this model arise owing to fluctuations in the composition and conformation of a growing microtubule tip, most notably in the number of protofilament curls. In our model, dynamic evolution of the stochastic microtubule tip configurations over a long timescale, known as the system's "aging", gives rise to the nonexponential distribution of microtubule lifetimes, consistent with experiment. We show that aging takes place in the absence of visible changes in the microtubule wall or tip, as this complex molecular-mechanical system evolves slowly and asymptotically toward the steady-state level of the catastrophe-promoting configurations. This new, to our knowledge, theoretical basis will assist detailed mechanistic investigations of the mechanisms of action of different microtubule-binding proteins and drugs, thereby enabling accurate control over the microtubule dynamics to treat various pathologies.
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Affiliation(s)
- Pavel Zakharov
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Nikita Gudimchuk
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russia; Moscow State University, Moscow, Russia; Federal Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia
| | | | | | - Fazoil I Ataullakhanov
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russia; Moscow State University, Moscow, Russia; Federal Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia
| | - Ekaterina L Grishchuk
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
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33
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Guesdon A, Bazile F, Buey RM, Mohan R, Monier S, García RR, Angevin M, Heichette C, Wieneke R, Tampé R, Duchesne L, Akhmanova A, Steinmetz MO, Chrétien D. EB1 interacts with outwardly curved and straight regions of the microtubule lattice. Nat Cell Biol 2016; 18:1102-8. [PMID: 27617931 DOI: 10.1038/ncb3412] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 08/18/2016] [Indexed: 12/16/2022]
Abstract
EB1 is a microtubule plus-end tracking protein that recognizes GTP-tubulin dimers in microtubules and thus represents a unique probe to investigate the architecture of the GTP cap of growing microtubule ends. Here, we conjugated EB1 to gold nanoparticles (EB1-gold) and imaged by cryo-electron tomography its interaction with dynamic microtubules assembled in vitro from purified tubulin. EB1-gold forms comets at the ends of microtubules assembled in the presence of GTP, and interacts with the outer surface of curved and straight tubulin sheets as well as closed regions of the microtubule lattice. Microtubules assembled in the presence of GTP, different GTP analogues or cell extracts display similarly curved sheets at their growing ends, which gradually straighten as their protofilament number increases until they close into a tube. Together, our data provide unique structural information on the interaction of EB1 with growing microtubule ends. They further offer insights into the conformational changes that tubulin dimers undergo during microtubule assembly and the architecture of the GTP-cap region.
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Affiliation(s)
- Audrey Guesdon
- Institute of Genetics and Development of Rennes, UMR6290 CNRS, University of Rennes 1, Campus Universitaire de Beaulieu, 35042 Rennes Cédex, France
| | - Franck Bazile
- Institute of Genetics and Development of Rennes, UMR6290 CNRS, University of Rennes 1, Campus Universitaire de Beaulieu, 35042 Rennes Cédex, France
| | - Rubén M Buey
- Laboratory of Biomolecular Research, Department of Biology and Chemistry, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.,Metabolic Engineering Group, Department of Microbiology and Genetics, University of Salamanca, Campus Miguel de Unamuno s/n, 37007 Salamanca, Spain
| | - Renu Mohan
- Cell Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Solange Monier
- Institute of Genetics and Development of Rennes, UMR6290 CNRS, University of Rennes 1, Campus Universitaire de Beaulieu, 35042 Rennes Cédex, France
| | - Ruddi Rodríguez García
- Cell Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Morgane Angevin
- Institute of Genetics and Development of Rennes, UMR6290 CNRS, University of Rennes 1, Campus Universitaire de Beaulieu, 35042 Rennes Cédex, France
| | - Claire Heichette
- Institute of Genetics and Development of Rennes, UMR6290 CNRS, University of Rennes 1, Campus Universitaire de Beaulieu, 35042 Rennes Cédex, France
| | - Ralph Wieneke
- Institute of Biochemistry, Biocenter, and Cluster of Excellence-Macromolecular Complexes, Goethe-University Frankfurt, Max-von-Laue Strasse 9, 60438 Frankfurt am Main, Germany
| | - Robert Tampé
- Institute of Biochemistry, Biocenter, and Cluster of Excellence-Macromolecular Complexes, Goethe-University Frankfurt, Max-von-Laue Strasse 9, 60438 Frankfurt am Main, Germany
| | - Laurence Duchesne
- Institute of Genetics and Development of Rennes, UMR6290 CNRS, University of Rennes 1, Campus Universitaire de Beaulieu, 35042 Rennes Cédex, France
| | - Anna Akhmanova
- Cell Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Michel O Steinmetz
- Laboratory of Biomolecular Research, Department of Biology and Chemistry, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - Denis Chrétien
- Institute of Genetics and Development of Rennes, UMR6290 CNRS, University of Rennes 1, Campus Universitaire de Beaulieu, 35042 Rennes Cédex, France.,Microscopy Rennes Imaging Centre, and Biosit, UMS3480 CNRS, University of Rennes 1, Campus Santé de Villejean, 35043 Rennes Cédex, France
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34
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Piedra FA, Kim T, Garza ES, Geyer EA, Burns A, Ye X, Rice LM. GDP-to-GTP exchange on the microtubule end can contribute to the frequency of catastrophe. Mol Biol Cell 2016; 27:3515-3525. [PMID: 27146111 PMCID: PMC5221584 DOI: 10.1091/mbc.e16-03-0199] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 04/26/2016] [Indexed: 11/11/2022] Open
Abstract
Microtubules are dynamic polymers of αβ-tubulin that have essential roles in chromosome segregation and organization of the cytoplasm. Catastrophe-the switch from growing to shrinking-occurs when a microtubule loses its stabilizing GTP cap. Recent evidence indicates that the nucleotide on the microtubule end controls how tightly an incoming subunit will be bound (trans-acting GTP), but most current models do not incorporate this information. We implemented trans-acting GTP into a computational model for microtubule dynamics. In simulations, growing microtubules often exposed terminal GDP-bound subunits without undergoing catastrophe. Transient GDP exposure on the growing plus end slowed elongation by reducing the number of favorable binding sites on the microtubule end. Slower elongation led to erosion of the GTP cap and an increase in the frequency of catastrophe. Allowing GDP-to-GTP exchange on terminal subunits in simulations mitigated these effects. Using mutant αβ-tubulin or modified GTP, we showed experimentally that a more readily exchangeable nucleotide led to less frequent catastrophe. Current models for microtubule dynamics do not account for GDP-to-GTP exchange on the growing microtubule end, so our findings provide a new way of thinking about the molecular events that initiate catastrophe.
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Affiliation(s)
- Felipe-Andrés Piedra
- Departments of Biophysics and Biochemistry, UT Southwestern Medical Center, Dallas, TX 75390
| | - Tae Kim
- Departments of Biophysics and Biochemistry, UT Southwestern Medical Center, Dallas, TX 75390
| | - Emily S Garza
- Departments of Biophysics and Biochemistry, UT Southwestern Medical Center, Dallas, TX 75390
| | - Elisabeth A Geyer
- Departments of Biophysics and Biochemistry, UT Southwestern Medical Center, Dallas, TX 75390
| | - Alexander Burns
- Departments of Biophysics and Biochemistry, UT Southwestern Medical Center, Dallas, TX 75390
| | - Xuecheng Ye
- Departments of Biophysics and Biochemistry, UT Southwestern Medical Center, Dallas, TX 75390
| | - Luke M Rice
- Departments of Biophysics and Biochemistry, UT Southwestern Medical Center, Dallas, TX 75390
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35
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Natarajan K, Mohan J, Senapati S. Relating nucleotide-dependent conformational changes in free tubulin dimers to tubulin assembly. Biopolymers 2016; 99:282-91. [PMID: 23426572 DOI: 10.1002/bip.22153] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Accepted: 08/29/2012] [Indexed: 11/07/2022]
Abstract
The complex dynamic behavior of microtubules (MTs) is believed to be primarily due to the αβ-tubulin dimer architecture and its intrinsic GTPase activity. Hence, a detailed knowledge of the conformational variations of isolated α-GTP-β-GTP- and α-GTP-β-GDP-tubulin dimers in solution and their implications to interdimer interactions and stability is directly relevant to understand the MT dynamics. An attempt has been made here by combining molecular dynamics (MD) simulations and protein-protein docking studies that unravels key structural features of tubulin dimer in different nucleotide states and correlates their association to tubulin assembly. Results from simulations suggest that tubulin dimers and oligomers attain curved conformations in both GTP and GDP states. Results also indicate that the tubulin C-terminal domain and the nucleotide state are closely linked. Protein-protein docking in combination with MD simulations suggest that the GTP-tubulin dimers engage in relatively stronger interdimer interactions even though the interdimer interfaces are bent in both GTP and GDP tubulin complexes, providing valuable insights on in vitro finding that GTP-tubulin is a better assembly candidate than GDP-tubulin during the MT nucleation and elongation processes.
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Affiliation(s)
- Kathiresan Natarajan
- Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600036, India
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36
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Abstract
Microtubule dynamics are fundamental for many aspects of cell physiology, but their mechanistic underpinnings remain unclear despite 40 years of intense research. In recent years, the continued union of reconstitution biochemistry, structural biology, and modeling has yielded important discoveries that deepen our understanding of microtubule dynamics. These studies, which we review here, underscore the importance of GTP hydrolysis-induced changes in tubulin structure as microtubules assemble, and highlight the fact that each aspect of microtubule behavior is the output of complex, multi-step processes. Although this body of work moves us closer to appreciating the key features of microtubule biochemistry that drive dynamic instability, the divide between our understanding of microtubules in isolation versus within the cellular milieu remains vast. Bridging this gap will serve as fertile grounds of cytoskeleton-focused research for many years to come.
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Affiliation(s)
- Ryoma Ohi
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Marija Zanic
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA; Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee, USA
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37
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Kamimura S, Fujita Y, Wada Y, Yagi T, Iwamoto H. X-ray fiber diffraction analysis shows dynamic changes in axial tubulin repeats in native microtubules depending on paclitaxel content, temperature and GTP-hydrolysis. Cytoskeleton (Hoboken) 2016; 73:131-44. [PMID: 26873786 DOI: 10.1002/cm.21283] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 02/08/2016] [Accepted: 02/08/2016] [Indexed: 11/11/2022]
Abstract
Microtubules are key components of the cytoskeleton in eukaryotic cells. The dynamics between assembled microtubules and free tubulin dimers in the cytoplasm is closely related to the active shape changes of microtubule networks. One of the most fundamental questions is the association of microtubule dynamics with the molecular conformation of tubulin within microtubules. To address this issue, we applied a new technique for the rapid shear-flow alignment of biological filaments, enabling us to acquire the structural periodicity data of microtubules by X-ray fiber diffraction under various physiological conditions. We classified microtubules into three main groups on the basis of distinct axial tubulin periodicities and mean microtubule diameters that varied depending on GTP hydrolysis and the content of paclitaxel, a microtubule stabilizer. Paclitaxel induced rapid changes in tubulin axial repeats in a cooperative manner. This is the first demonstration of dynamic changes of axial tubulin repeats within native microtubules without fixation. We also found extraordinary features of negative thermal expansion of axial tubulin repeats in both paclitaxel-stabilized and GMPCPP-containing microtubules. Our results suggest that even in assembled microtubules, both GTP- and GDP-tubulin dimers can undergo dynamic conversion between at least two different states: short and long configurations.
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Affiliation(s)
- Shinji Kamimura
- Department of Biological Sciences, Faculty of Science and Engineering, Chuo University, Kasuga, Bunkyo, Tokyo, Japan
| | - Yosuke Fujita
- Department of Biological Sciences, Faculty of Science and Engineering, Chuo University, Kasuga, Bunkyo, Tokyo, Japan
| | - Yuuko Wada
- Department of Biological Sciences, Faculty of Science and Engineering, Chuo University, Kasuga, Bunkyo, Tokyo, Japan
| | - Toshiki Yagi
- Department of Life Sciences, Faculty of Life and Environmental Sciences, Prefectural University of Hiroshima, Shobara, Hiroshima, Japan
| | - Hiroyuki Iwamoto
- Life and Environmental Division, SPring-8, Japan Synchrotron Radiation Research Institute (JASRI), Sayo, Hyogo, Japan
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38
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Krieg E, Bastings MMC, Besenius P, Rybtchinski B. Supramolecular Polymers in Aqueous Media. Chem Rev 2016; 116:2414-77. [DOI: 10.1021/acs.chemrev.5b00369] [Citation(s) in RCA: 527] [Impact Index Per Article: 65.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
| | | | - Pol Besenius
- Institute
of Organic Chemistry, Johannes Gutenberg-Universität Mainz, Mainz 55128, Germany
| | - Boris Rybtchinski
- Department
of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel
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Geyer EA, Burns A, Lalonde BA, Ye X, Piedra FA, Huffaker TC, Rice LM. A mutation uncouples the tubulin conformational and GTPase cycles, revealing allosteric control of microtubule dynamics. eLife 2015; 4:e10113. [PMID: 26439009 PMCID: PMC4728127 DOI: 10.7554/elife.10113] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 10/06/2015] [Indexed: 11/18/2022] Open
Abstract
Microtubule dynamic instability depends on the GTPase activity of the polymerizing αβ-tubulin subunits, which cycle through at least three distinct conformations as they move into and out of microtubules. How this conformational cycle contributes to microtubule growing, shrinking, and switching remains unknown. Here, we report that a buried mutation in αβ-tubulin yields microtubules with dramatically reduced shrinking rate and catastrophe frequency. The mutation causes these effects by suppressing a conformational change that normally occurs in response to GTP hydrolysis in the lattice, without detectably changing the conformation of unpolymerized αβ-tubulin. Thus, the mutation weakens the coupling between the conformational and GTPase cycles of αβ-tubulin. By showing that the mutation predominantly affects post-GTPase conformational and dynamic properties of microtubules, our data reveal that the strength of the allosteric response to GDP in the lattice dictates the frequency of catastrophe and the severity of rapid shrinking. DOI:http://dx.doi.org/10.7554/eLife.10113.001 Protein filaments called microtubules help move cargo around inside cells. Chromosomes, which contain the cell’s genetic blueprints, are the microtubule’s most precious cargo. Before a cell divides, microtubules grow from the ends of the dividing cell towards the middle, where they attach to the chromosomes that are lined up along the centerline. Then the microtubules shrink and drag the chromosomes back to the opposite ends of the cell. This allows each of the new cells to get one copy of each chromosome. When the microtubules are growing, a molecule called guanosine triphosphate (or GTP) is attached to the proteins at the end of the filament. This acts like a cap and protects the microtubule from shrinking. Later a chemical reaction converts GTP into GDP (short for guanosine diphosphate). Without the protective GTP cap, the microtubule quickly shrinks. At the same time, the proteins that make up the microtubule also change shape. In the microtubule, the proteins adopt a straight shape when GTP is attached. The proteins favor a different shape in the microtubule when GDP is attached. However, it is unclear if or how these shape changes contribute to how a microtubule grows or shrinks. Geyer et al. now show how this shape shifting can influence microtubule shrinking, by first identifying a mutation in yeast microtubule proteins that cause the proteins to remain straight even when GDP is attached. Next, powerful microscopes were used to make time-lapse videos of the mutated microtubules. This allowed Geyer et al. to observe how the mutated microtubules behaved and compare this to the behavior of normal microtubules. The experiments revealed that the mutated microtubules were less likely to begin shrinking than typical microtubules. The mutated microtubules also shrunk more slowly. These findings indicate that the shape changes control the speed of shrinking and frequency of entering the shrinking phase. These new details about the control of microtubule growth and shrinkage may help scientists studying how cell division happens in both healthy and cancerous cells. DOI:http://dx.doi.org/10.7554/eLife.10113.002
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Affiliation(s)
- Elisabeth A Geyer
- Departments of Biophysics and Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States
| | - Alexander Burns
- Departments of Biophysics and Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States
| | - Beth A Lalonde
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
| | - Xuecheng Ye
- Departments of Biophysics and Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States
| | - Felipe-Andres Piedra
- Departments of Biophysics and Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States
| | - Tim C Huffaker
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
| | - Luke M Rice
- Departments of Biophysics and Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States
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40
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Ramírez-Aportela E, López-Blanco JR, Andreu JM, Chacón P. Understanding nucleotide-regulated FtsZ filament dynamics and the monomer assembly switch with large-scale atomistic simulations. Biophys J 2015; 107:2164-76. [PMID: 25418101 DOI: 10.1016/j.bpj.2014.09.033] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 09/23/2014] [Accepted: 09/30/2014] [Indexed: 01/08/2023] Open
Abstract
Bacterial cytoskeletal protein FtsZ assembles in a head-to-tail manner, forming dynamic filaments that are essential for cell division. Here, we study their dynamics using unbiased atomistic molecular simulations from representative filament crystal structures. In agreement with experimental data, we find different filament curvatures that are supported by a nucleotide-regulated hinge motion between consecutive FtsZ monomers. Whereas GTP-FtsZ filaments bend and twist in a preferred orientation, thereby burying the nucleotide, the differently curved GDP-FtsZ filaments exhibit a heterogeneous distribution of open and closed interfaces between monomers. We identify a coordinated Mg(2+) ion as the key structural element in closing the nucleotide site and stabilizing GTP filaments, whereas the loss of the contacts with loop T7 from the next monomer in GDP filaments leads to open interfaces that are more prone to depolymerization. We monitored the FtsZ monomer assembly switch, which involves opening/closing of the cleft between the C-terminal domain and the H7 helix, and observed the relaxation of isolated and filament minus-end monomers into the closed-cleft inactive conformation. This result validates the proposed switch between the low-affinity monomeric closed-cleft conformation and the active open-cleft FtsZ conformation within filaments. Finally, we observed how the antibiotic PC190723 suppresses the disassembly switch and allosterically induces closure of the intermonomer interfaces, thus stabilizing the filament. Our studies provide detailed structural and dynamic insights into modulation of both the intrinsic curvature of the FtsZ filaments and the molecular switch coupled to the high-affinity end-wise association of FtsZ monomers.
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Affiliation(s)
- Erney Ramírez-Aportela
- Department of Biological Physical Chemistry, Instituto de Química-Física Rocasolano, CSIC, Madrid, Spain; Department of Chemical and Physical Biology, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | - José Ramón López-Blanco
- Department of Biological Physical Chemistry, Instituto de Química-Física Rocasolano, CSIC, Madrid, Spain
| | - José Manuel Andreu
- Department of Chemical and Physical Biology, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | - Pablo Chacón
- Department of Biological Physical Chemistry, Instituto de Química-Física Rocasolano, CSIC, Madrid, Spain.
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41
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Abstract
Microtubules are dynamic polymers of αβ-tubulin that form diverse cellular structures, such as the mitotic spindle for cell division, the backbone of neurons, and axonemes. To control the architecture of microtubule networks, microtubule-associated proteins (MAPs) and motor proteins regulate microtubule growth, shrinkage, and the transitions between these states. Recent evidence shows that many MAPs exert their effects by selectively binding to distinct conformations of polymerized or unpolymerized αβ-tubulin. The ability of αβ-tubulin to adopt distinct conformations contributes to the intrinsic polymerization dynamics of microtubules. αβ-Tubulin conformation is a fundamental property that MAPs monitor and control to build proper microtubule networks.
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Affiliation(s)
- Gary J Brouhard
- Department of Biology, McGill University, Montréal, Quebec, Canada H3A1B1
| | - Luke M Rice
- Department of Biophysics and Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390 Department of Biophysics and Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390
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Negi AS, Gautam Y, Alam S, Chanda D, Luqman S, Sarkar J, Khan F, Konwar R. Natural antitubulin agents: importance of 3,4,5-trimethoxyphenyl fragment. Bioorg Med Chem 2014; 23:373-89. [PMID: 25564377 DOI: 10.1016/j.bmc.2014.12.027] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 12/11/2014] [Accepted: 12/12/2014] [Indexed: 01/29/2023]
Abstract
Microtubules are polar cytoskeletal filaments assembled from head-to-tail and comprised of lateral associations of α/β-tubulin heterodimers that play key role in various cellular processes. Because of their vital role in mitosis and various other cellular processes, microtubules have been attractive targets for several disease conditions and especially for cancer. Antitubulin is the most successful class of antimitotic agents in cancer chemotherapeutics. The target recognition of antimitotic agents as a ligand is not much explored so far. However, 3,4,5-trimethoxyphenyl fragment has been much highlighted and discussed in such type of interactions. In this review, some of the most important naturally occurring antimitotic agents and their interactions with microtubules are discussed with a special emphasis on the role of 3,4,5-trimethoxyphenyl unit. At last, some emerging naturally occurring antimitotic agents have also been tabulated.
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Affiliation(s)
- Arvind S Negi
- CSIR-Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), Kukrail Picnic Spot Road, PO CIMAP, Lucknow 226015, India.
| | - Yashveer Gautam
- CSIR-Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), Kukrail Picnic Spot Road, PO CIMAP, Lucknow 226015, India
| | - Sarfaraz Alam
- CSIR-Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), Kukrail Picnic Spot Road, PO CIMAP, Lucknow 226015, India
| | - Debabrata Chanda
- CSIR-Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), Kukrail Picnic Spot Road, PO CIMAP, Lucknow 226015, India
| | - Suaib Luqman
- CSIR-Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), Kukrail Picnic Spot Road, PO CIMAP, Lucknow 226015, India
| | - Jayanta Sarkar
- CSIR-Central Drug Research Institute (CSIR-CDRI), B.S. 10/1, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Feroz Khan
- CSIR-Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), Kukrail Picnic Spot Road, PO CIMAP, Lucknow 226015, India
| | - Rituraj Konwar
- CSIR-Central Drug Research Institute (CSIR-CDRI), B.S. 10/1, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
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43
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Ayaz P, Munyoki S, Geyer EA, Piedra FA, Vu ES, Bromberg R, Otwinowski Z, Grishin NV, Brautigam CA, Rice LM. A tethered delivery mechanism explains the catalytic action of a microtubule polymerase. eLife 2014; 3:e03069. [PMID: 25097237 PMCID: PMC4145800 DOI: 10.7554/elife.03069] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Stu2p/XMAP215 proteins are essential microtubule polymerases that use multiple αβ-tubulin-interacting TOG domains to bind microtubule plus ends and catalyze fast microtubule growth. We report here the structure of the TOG2 domain from Stu2p bound to yeast αβ-tubulin. Like TOG1, TOG2 binds selectively to a fully 'curved' conformation of αβ-tubulin, incompatible with a microtubule lattice. We also show that TOG1-TOG2 binds non-cooperatively to two αβ-tubulins. Preferential interactions between TOGs and fully curved αβ-tubulin that cannot exist elsewhere in the microtubule explain how these polymerases localize to the extreme microtubule end. We propose that these polymerases promote elongation because their linked TOG domains concentrate unpolymerized αβ-tubulin near curved subunits already bound at the microtubule end. This tethering model can explain catalyst-like behavior and also predicts that the polymerase action changes the configuration of the microtubule end.
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Affiliation(s)
- Pelin Ayaz
- Department of Biophysics, UT Southwestern Medical Center, Dallas, United States Department of Biochemistry, UT Southwestern Medical Center, Dallas, United States
| | - Sarah Munyoki
- Department of Biophysics, UT Southwestern Medical Center, Dallas, United States Department of Biochemistry, UT Southwestern Medical Center, Dallas, United States
| | - Elisabeth A Geyer
- Department of Biophysics, UT Southwestern Medical Center, Dallas, United States Department of Biochemistry, UT Southwestern Medical Center, Dallas, United States
| | - Felipe-Andrés Piedra
- Department of Biophysics, UT Southwestern Medical Center, Dallas, United States Department of Biochemistry, UT Southwestern Medical Center, Dallas, United States
| | - Emily S Vu
- Department of Biophysics, UT Southwestern Medical Center, Dallas, United States Department of Biochemistry, UT Southwestern Medical Center, Dallas, United States
| | - Raquel Bromberg
- Department of Biophysics, UT Southwestern Medical Center, Dallas, United States Department of Biochemistry, UT Southwestern Medical Center, Dallas, United States
| | - Zbyszek Otwinowski
- Department of Biophysics, UT Southwestern Medical Center, Dallas, United States Department of Biochemistry, UT Southwestern Medical Center, Dallas, United States
| | - Nick V Grishin
- Department of Biophysics, UT Southwestern Medical Center, Dallas, United States Department of Biochemistry, UT Southwestern Medical Center, Dallas, United States Howard Hughes Medical Institute, UT Southwestern Medical Center, Dallas, United States
| | - Chad A Brautigam
- Department of Biophysics, UT Southwestern Medical Center, Dallas, United States
| | - Luke M Rice
- Department of Biophysics, UT Southwestern Medical Center, Dallas, United States Department of Biochemistry, UT Southwestern Medical Center, Dallas, United States
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44
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Abstract
We introduce a model for microtubule (MT) mechanics containing lateral bonds between dimers in neighboring protofilaments, bending rigidity of dimers, and repulsive interactions between protofilaments modeling steric constraints to investigate the influence of mechanical forces on hydrolysis and catastrophes. We use the allosteric dimer model, where tubulin dimers are characterized by an equilibrium bending angle, which changes from 0° to 22° by hydrolysis of a dimer. This also affects the lateral interaction and bending energies and, thus, the mechanical equilibrium state of the MT. As hydrolysis gives rise to conformational changes in dimers, mechanical forces also influence the hydrolysis rates by mechanical energy changes modulating the hydrolysis rate. The interaction via the MT mechanics then gives rise to correlation effects in the hydrolysis dynamics, which have not been taken into account before. Assuming a dominant influence of mechanical energies on hydrolysis rates, we investigate the most probable hydrolysis pathways both for vectorial and random hydrolysis. Investigating the stability with respect to lateral bond rupture, we identify initiation configurations for catastrophes along the hydrolysis pathways and values for a lateral bond rupture force. If we allow for rupturing of lateral bonds between dimers in neighboring protofilaments above this threshold force, our model exhibits avalanche-like catastrophe events.
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Affiliation(s)
- N Müller
- Department of Physics, TU Dortmund University, D-44221 Dortmund, Germany
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45
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Matsui T, Han X, Yu J, Yao M, Tanaka I. Structural change in FtsZ Induced by intermolecular interactions between bound GTP and the T7 loop. J Biol Chem 2013; 289:3501-9. [PMID: 24347164 DOI: 10.1074/jbc.m113.514901] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
FtsZ is a prokaryotic homolog of tubulin and is a key molecule in bacterial cell division. FtsZ with bound GTP polymerizes into tubulin-like protofilaments. Upon polymerization, the T7 loop of one subunit is inserted into the nucleotide-binding pocket of the second subunit, which results in GTP hydrolysis. Thus, the T7 loop is important for both polymerization and hydrolysis in the tubulin/FtsZ family. Although x-ray crystallography revealed both straight and curved conformations of tubulin, only a curved structure was known for FtsZ. Recently, however, FtsZ from Staphylococcus aureus has been shown to have a very different conformation from the canonical FtsZ structure. The present study was performed to investigate the structure of FtsZ from Staphylococcus aureus by mutagenesis experiments; the effects of amino acid changes in the T7 loop on the structure as well as on GTPase activity were studied. These analyses indicated that FtsZ changes its conformation suitable for polymerization and GTP hydrolysis by movement between N- and C-subdomains via intermolecular interactions between bound nucleotide and residues in the T7 loop.
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Affiliation(s)
- Takashi Matsui
- From the Faculty of Advanced Life Science, Hokkaido University, Sapporo 060-0810, Japan and
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46
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Quiniou E, Guichard P, Perahia D, Marco S, Mouawad L. An atomistic view of microtubule stabilization by GTP. Structure 2013; 21:833-43. [PMID: 23623730 DOI: 10.1016/j.str.2013.03.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 02/08/2013] [Accepted: 03/08/2013] [Indexed: 11/27/2022]
Abstract
A microtubule is a dynamic system formed of αβ-tubulins. The presence of nonhydrolyzable guanosine-5'-triphosphate (GTP)/guanosine diphosphate (GDP) on the β-tubulins provokes microtubule polymerization/depolymerization. Despite the large number of experimental studies of this dynamical process, its mechanism is still unclear. To provide insights into this mechanism we studied the first depolymerization steps of GDP/GTP-bound microtubules by normal-mode analysis with the all-atom model. We also constructed a depolymerizing microtubule and compared it to cryo-electron microscopy tomograms (cyro-ET). The results show that during depolymerization, the protofilaments not only curve but twist to weaken their lateral interactions. These interactions are stabilized by GTP, but not evenly. Not all of the interface residues are of equal importance: five of them, belonging to the H2-S3 loop, play a special role; acting as a lock whose key is the γ-phosphate of GTP. Sequence alignments of several tubulins confirm the importance of these residues.
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Affiliation(s)
- Eric Quiniou
- Institut Curie, Centre de Recherche, U759, Bât. 112, Centre Universitaire, 91405 Orsay Cedex, France
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47
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Grafmüller A, Noya EG, Voth GA. Nucleotide-dependent lateral and longitudinal interactions in microtubules. J Mol Biol 2013; 425:2232-46. [PMID: 23541590 DOI: 10.1016/j.jmb.2013.03.029] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 03/11/2013] [Accepted: 03/16/2013] [Indexed: 01/31/2023]
Abstract
Microtubule (MT) stability is related to the hydrolysis of the guanosine triphosphate nucleotide (NT) bound to β-tubulin. However, the molecular mechanism by which the NT state influences the stability of the contacts in the MT lattice remains elusive. Here, we present large-scale atomistic simulations of different tubulin aggregates, including individual dimers, short protofilaments, a small lattice patch, and a piece of the MT lattice with two infinite protofilaments in both NT states. Together with a coarse-grained (CG) analysis of the fluctuations, these simulations highlight several regions of the protein where local changes are induced by the NT state or by the lateral and longitudinal contacts in the aggregates. Additionally, the CG analysis provides an indication of how the structural changes affect the bonds between the proteins. The results suggest a consistent picture of a possible molecular mechanism by which the NT state induces changes in the H1-S2 loop and more stable longitudinal bonds, both of which locate the H1-S2 and M-loop in more favorable positions to form lateral contacts.
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Affiliation(s)
- Andrea Grafmüller
- Theory and Biosystems, Max Planck Institute for Colloids and Interfaces, 14424 Potsdam, Germany.
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48
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Field J, Díaz J, Miller J. The Binding Sites of Microtubule-Stabilizing Agents. ACTA ACUST UNITED AC 2013; 20:301-15. [DOI: 10.1016/j.chembiol.2013.01.014] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 01/14/2013] [Accepted: 01/17/2013] [Indexed: 11/25/2022]
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49
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Prota AE, Magiera MM, Kuijpers M, Bargsten K, Frey D, Wieser M, Jaussi R, Hoogenraad CC, Kammerer RA, Janke C, Steinmetz MO. Structural basis of tubulin tyrosination by tubulin tyrosine ligase. ACTA ACUST UNITED AC 2013; 200:259-70. [PMID: 23358242 PMCID: PMC3563685 DOI: 10.1083/jcb.201211017] [Citation(s) in RCA: 174] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Structural analysis of a complex of tubulin and tubulin tyrosine ligase (TTL) reveals insights into TTL’s enzymatic mechanism, how it discriminates between α- and β-tubulin, and its possible evolutionary origin. Tubulin tyrosine ligase (TTL) catalyzes the post-translational retyrosination of detyrosinated α-tubulin. Despite the indispensable role of TTL in cell and organism development, its molecular mechanism of action is poorly understood. By solving crystal structures of TTL in complex with tubulin, we here demonstrate that TTL binds to the α and β subunits of tubulin and recognizes the curved conformation of the dimer. Biochemical and cellular assays revealed that specific tubulin dimer recognition controls the activity of the enzyme, and as a consequence, neuronal development. The TTL–tubulin structure further illustrates how the enzyme binds the functionally crucial C-terminal tail sequence of α-tubulin and how this interaction catalyzes the tyrosination reaction. It also reveals how TTL discriminates between α- and β-tubulin, and between different post-translationally modified forms of α-tubulin. Together, our data suggest that TTL has specifically evolved to recognize and modify tubulin, thus highlighting a fundamental role of the evolutionary conserved tubulin tyrosination cycle in regulating the microtubule cytoskeleton.
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Affiliation(s)
- Andrea E Prota
- Biomolecular Research, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
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50
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Ludueña RF. A Hypothesis on the Origin and Evolution of Tubulin. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 302:41-185. [DOI: 10.1016/b978-0-12-407699-0.00002-9] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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