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Ghahramani Almanghadim H, Ghorbian S, Khademi NS, Soleymani Sadrabadi M, Jarrahi E, Nourollahzadeh Z, Dastani M, Shirvaliloo M, Sheervalilou R, Sargazi S. New Insights into the Importance of Long Non-Coding RNAs in Lung Cancer: Future Clinical Approaches. DNA Cell Biol 2021; 40:1476-1494. [PMID: 34931869 DOI: 10.1089/dna.2021.0563] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
In mammals, a large part of the gene expression products come from the non-coding ribonucleotide sequences of the protein. These short and long sequences are within the range of tens to hundreds of nucleotides, encompassing more than 200 RNA molecules, and their function is known as the molecular structure of long non-coding RNA (lncRNA). LncRNA molecules are unique nucleotides that have a substantial role in epigenetic regulation, transcription, and post-transcriptional modifications in different ways. According to the results of recent studies, lncRNAs have been shown to assume various roles, including tumor suppression or oncogenic functions in common types of cancer such as lung and breast cancer. These non-coding RNAs (ncRNAs) play a pivotal role in activating transcription factors, managing the ribonucleoproteins, the framework for collecting co-proteins, intermittent processing regulations, chromatin status alterations, and maintaining the control within the cell. Cutting-edge technologies have been introduced to disclose several types of lncRNAs within the nucleus and the cytoplasm, which have accomplished important achievements that are applicable in medicine. Due to these efforts, various data centers have been created to facilitate and modify scientific information related to these molecules, including detection, classification, biological evolution, gene status, spatial structure, status, and location of these small molecules. In the present study, we attempt to present the impacts of these ncRNAs on lung cancer with an emphasis on their mechanisms and functions.
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Affiliation(s)
| | - Saeed Ghorbian
- Department of Molecular Genetics, Ahar Branch, Islamic Azad University, Ahar, Iran
| | - Nazanin Sadat Khademi
- Department of Genetics, Faculty of Biological Science, Shahid Beheshti University, Tehran, Iran
| | | | - Esmaeil Jarrahi
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Zahra Nourollahzadeh
- Department of Biological Science, Ahar Branch, Islamic Azad University, Ahar, Iran
| | - Masomeh Dastani
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Milad Shirvaliloo
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Saman Sargazi
- Cellular and Molecular Research Center, Research Institute of Cellular and Molecular Sciences in Infectious Diseases, Zahedan University of Medical Sciences, Zahedan, Iran
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2
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Lv D, Li J, Ye S. The Assembly Switch Mechanism of FtsZ Filament Revealed by All-Atom Molecular Dynamics Simulations and Coarse-Grained Models. Front Microbiol 2021; 12:639883. [PMID: 33859629 PMCID: PMC8042166 DOI: 10.3389/fmicb.2021.639883] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 03/05/2021] [Indexed: 01/14/2023] Open
Abstract
Bacterial cytoskeletal protein FtsZ binds and hydrolyzes GTP, and assembles into dynamic filaments that are essential for cell division. Here, we used a multi-scale computational strategy that combined all-atom molecular dynamics (MD) simulations and coarse-grained models to reveal the conformational dynamics of assembled FtsZ. We found that the top end of a filament is highly dynamic and can undergo T-to-R transitions in both GTP- and GDP-bound states. We observed several subcategories of nucleation related dimer species, which leading to a feasible nucleation pathway. In addition, we observed that FtsZ filament exhibits noticeable amounts of twisting, indicating a substantial helicity of the FtsZ filament. These results agree with the previously models and experimental data. Anisotropy network model (ANM) analysis revealed a polymerization enhanced assembly cooperativity, and indicated that the cooperative motions in FtsZ are encoded in the structure. Taken together, our study provides a molecular-level understanding of the diversity of the structural states of FtsZ and the relationships among polymerization, hydrolysis, and cooperative assembly, which should shed new light on the molecular basis of FtsZ’s cooperativity.
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Affiliation(s)
- Dashuai Lv
- Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Jingyuan Li
- Zhejiang Province Key Laboratory of Quantum Technology and Device, Department of Physics, Institute of Quantitative Biology, Hangzhou, China
| | - Sheng Ye
- Life Sciences Institute, Zhejiang University, Hangzhou, China.,Tianjin Key Laboratory of Function and Application of Biological Macromolecular Structures, School of Life Sciences, Tianjin University, Tianjin, China
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3
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Swain A, Anil Kumar AV. A stochastic model for dynamics of FtsZ filaments and the formation of Z -ring. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2020; 43:43. [PMID: 32617695 DOI: 10.1140/epje/i2020-11967-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 06/16/2020] [Indexed: 06/11/2023]
Abstract
Understanding the mechanisms responsible for the formation and growth of FtsZ polymers and their subsequent formation of the Z -ring is important for gaining insight into the cell division in prokaryotic cells. In this work, we present a minimal stochastic model that qualitatively reproduces in vitro observations of polymerization, formation of dynamic contractile ring that is stable for a long time and depolymerization shown by FtsZ polymer filaments. In this stochastic model, we explore different mechanisms for ring breaking and hydrolysis. In addition to hydrolysis, which is known to regulate the dynamics of other tubulin polymers like microtubules, we find that the presence of the ring allows for an additional mechanism for regulating the dynamics of FtsZ polymers. Ring breaking dynamics in the presence of hydrolysis naturally induce rescue and catastrophe events in this model irrespective of the mechanism of hydrolysis.
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Affiliation(s)
- Arabind Swain
- School of Physical Sciences, National Institute of Science Education and Research, 752050, Jatni, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, 400094, Mumbai, India
| | - A V Anil Kumar
- School of Physical Sciences, National Institute of Science Education and Research, 752050, Jatni, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, 400094, Mumbai, India
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4
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Cell Division Protein FtsZ Is Unfolded for N-Terminal Degradation by Antibiotic-Activated ClpP. mBio 2020; 11:mBio.01006-20. [PMID: 32605984 PMCID: PMC7327170 DOI: 10.1128/mbio.01006-20] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Acyldepsipeptide (ADEP) antibiotics effectively kill multidrug-resistant Gram-positive pathogens, including vancomycin-resistant enterococcus, penicillin-resistant Streptococcus pneumoniae (PRSP), and methicillin-resistant Staphylococcus aureus (MRSA). The antibacterial activity of ADEP depends on a new mechanism of action, i.e., the deregulation of bacterial protease ClpP that leads to bacterial self-digestion. Our data allow new insights into the mode of ADEP action by providing a molecular explanation for the distinct bacterial phenotypes observed at low versus high ADEP concentrations. In addition, we show that ClpP alone, in the absence of any unfoldase or energy-consuming system, and only activated by the small molecule antibiotic ADEP, leads to the unfolding of the cell division protein FtsZ. Antibiotic acyldepsipeptides (ADEPs) deregulate ClpP, the proteolytic core of the bacterial Clp protease, thereby inhibiting its native functions and concomitantly activating it for uncontrolled proteolysis of nonnative substrates. Importantly, although ADEP-activated ClpP is assumed to target multiple polypeptide and protein substrates in the bacterial cell, not all proteins seem equally susceptible. In Bacillus subtilis, the cell division protein FtsZ emerged to be particularly sensitive to degradation by ADEP-activated ClpP at low inhibitory ADEP concentrations. In fact, FtsZ is the only bacterial protein that has been confirmed to be degraded in vitro as well as within bacterial cells so far. However, the molecular reason for this preferred degradation remained elusive. Here, we report the unexpected finding that ADEP-activated ClpP alone, in the absence of any Clp-ATPase, leads to an unfolding and subsequent degradation of the N-terminal domain of FtsZ, which can be prevented by the stabilization of the FtsZ fold via nucleotide binding. At elevated antibiotic concentrations, importantly, the C terminus of FtsZ is notably targeted for degradation in addition to the N terminus. Our results show that different target structures are more or less accessible to ClpP, depending on the ADEP level present. Moreover, our data assign a Clp-ATPase-independent protein unfolding capability to the ClpP core of the bacterial Clp protease and suggest that the protein fold of FtsZ may be more flexible than previously anticipated.
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5
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Silber N, Matos de Opitz CL, Mayer C, Sass P. Cell division protein FtsZ: from structure and mechanism to antibiotic target. Future Microbiol 2020; 15:801-831. [DOI: 10.2217/fmb-2019-0348] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Antimicrobial resistance to virtually all clinically applied antibiotic classes severely limits the available options to treat bacterial infections. Hence, there is an urgent need to develop and evaluate new antibiotics and targets with resistance-breaking properties. Bacterial cell division has emerged as a new antibiotic target pathway to counteract multidrug-resistant pathogens. New approaches in antibiotic discovery and bacterial cell biology helped to identify compounds that either directly interact with the major cell division protein FtsZ, thereby perturbing the function and dynamics of the cell division machinery, or affect the structural integrity of FtsZ by inducing its degradation. The impressive antimicrobial activities and resistance-breaking properties of certain compounds validate the inhibition of bacterial cell division as a promising strategy for antibiotic intervention.
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Affiliation(s)
- Nadine Silber
- Department of Microbial Bioactive Compounds, Interfaculty Institute of Microbiology & Infection Medicine, University of Tübingen, Auf der Morgenstelle 28, Tübingen 72076, Germany
| | - Cruz L Matos de Opitz
- Department of Microbial Bioactive Compounds, Interfaculty Institute of Microbiology & Infection Medicine, University of Tübingen, Auf der Morgenstelle 28, Tübingen 72076, Germany
| | - Christian Mayer
- Department of Microbial Bioactive Compounds, Interfaculty Institute of Microbiology & Infection Medicine, University of Tübingen, Auf der Morgenstelle 28, Tübingen 72076, Germany
| | - Peter Sass
- Department of Microbial Bioactive Compounds, Interfaculty Institute of Microbiology & Infection Medicine, University of Tübingen, Auf der Morgenstelle 28, Tübingen 72076, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Tübingen 72076, Germany
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6
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Huecas S, Canosa-Valls AJ, Araújo-Bazán L, Ruiz FM, Laurents DV, Fernández-Tornero C, Andreu JM. Nucleotide-induced folding of cell division protein FtsZ from Staphylococcus aureus. FEBS J 2020; 287:4048-4067. [PMID: 31997533 DOI: 10.1111/febs.15235] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 12/12/2019] [Accepted: 01/09/2020] [Indexed: 11/29/2022]
Abstract
The essential bacterial division protein FtsZ uses GTP binding and hydrolysis to assemble into dynamic filaments that treadmill around the Z-ring, guiding septal wall synthesis and cell division. FtsZ is a structural homolog of tubulin and a target for discovering new antibiotics. Here, using FtsZ from the pathogen S. aureus (SaFtsZ), we reveal that, prior to assembly, FtsZ monomers require nucleotide binding for folding; this is possibly relevant to other mesophilic FtsZs. Apo-SaFtsZ is essentially unfolded, as assessed by nuclear magnetic resonance and circular dichroism. Binding of GTP (≥ 1 mm) dramatically shifts the equilibrium toward the active folded protein. Supportingly, SaFtsZ refolded with GDP crystallizes in a native structure. Apo-SaFtsZ also folds with 3.4 m glycerol, enabling high-affinity GTP binding (KD 20 nm determined by isothermal titration calorimetry) similar to thermophilic stable FtsZ. Other stabilizing agents that enhance nucleotide binding include ethylene glycol, trimethylamine N-oxide, and several bacterial osmolytes. High salt stabilizes SaFtsZ without bound nucleotide in an inactive twisted conformation. We identified a cavity behind the SaFtsZ-GDP nucleotide-binding pocket that harbors different small compounds, which is available for extended nucleotide-replacing inhibitors. Furthermore, we devised a competition assay to detect any inhibitors that overlap the nucleotide site of SaFtsZ, or Escherichia coli FtsZ, employing osmolyte-stabilized apo-FtsZs and the specific fluorescence anisotropy change in mant-GTP upon dissociation from the protein. This robust assay provides a basis to screening for high-affinity GTP-replacing ligands, which combined with structural studies and phenotypic profiling should facilitate development of a next generation of FtsZ-targeting antibacterial inhibitors.
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Affiliation(s)
- Sonia Huecas
- Centro de Investigaciones Biológicas Margarita Salas CSIC, Madrid, Spain
| | | | - Lidia Araújo-Bazán
- Centro de Investigaciones Biológicas Margarita Salas CSIC, Madrid, Spain
| | - Federico M Ruiz
- Centro de Investigaciones Biológicas Margarita Salas CSIC, Madrid, Spain
| | | | | | - José M Andreu
- Centro de Investigaciones Biológicas Margarita Salas CSIC, Madrid, Spain
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7
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Lazo EO, Jakoncic J, RoyChowdhury S, Awasthi D, Ojima I. Novel T9 loop conformation of filamenting temperature-sensitive mutant Z from Mycobacterium tuberculosis. ACTA CRYSTALLOGRAPHICA SECTION F-STRUCTURAL BIOLOGY COMMUNICATIONS 2019; 75:359-367. [PMID: 31045565 DOI: 10.1107/s2053230x19004618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 04/04/2019] [Indexed: 11/10/2022]
Abstract
As of 2017, tuberculosis had infected 1.7 billion people (23% of the population of the world) and caused ten million deaths. Mycobacterium tuberculosis (Mtb) is quickly evolving, and new strains are classified as multidrug resistant. Thus, the identification of novel druggable targets is essential to combat the proliferation of these drug-resistant strains. Filamenting temperature-sensitive mutant Z (FtsZ) is a key protein involved in cytokinesis, an important process for Mtb proliferation and viability. FtsZ is required for bacterial cell division because it polymerizes into a structure called the Z-ring, which recruits accessory division proteins to the septum. Here, the crystal structure of the MtbFtsZ protein has been determined to 3.46 Å resolution and is described as a dimer of trimers, with an inter-subunit interface between protomers AB and DE. In this work, a novel conformation of MtbFtsZ is revealed involving the T9 loop and the nucleotide-binding pocket of protomers BC and EF.
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Affiliation(s)
- E O Lazo
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York, USA
| | - J Jakoncic
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York, USA
| | - S RoyChowdhury
- Institute of Chemical Biology and Drug Discovery and Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA
| | - D Awasthi
- Institute of Chemical Biology and Drug Discovery and Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA
| | - I Ojima
- Institute of Chemical Biology and Drug Discovery and Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA
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8
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Ramirez-Diaz DA, García-Soriano DA, Raso A, Mücksch J, Feingold M, Rivas G, Schwille P. Treadmilling analysis reveals new insights into dynamic FtsZ ring architecture. PLoS Biol 2018; 16:e2004845. [PMID: 29775478 PMCID: PMC5979038 DOI: 10.1371/journal.pbio.2004845] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 05/31/2018] [Accepted: 04/27/2018] [Indexed: 12/05/2022] Open
Abstract
FtsZ, the primary protein of the bacterial Z ring guiding cell division, has been recently shown to engage in intriguing treadmilling dynamics along the circumference of the division plane. When coreconstituted in vitro with FtsA, one of its natural membrane anchors, on flat supported membranes, these proteins assemble into dynamic chiral vortices compatible with treadmilling of curved polar filaments. Replacing FtsA by a membrane-targeting sequence (mts) to FtsZ, we have discovered conditions for the formation of dynamic rings, showing that the phenomenon is intrinsic to FtsZ. Ring formation is only observed for a narrow range of protein concentrations at the bilayer, which is highly modulated by free Mg2+ and depends upon guanosine triphosphate (GTP) hydrolysis. Interestingly, the direction of rotation can be reversed by switching the mts from the C-terminus to the N-terminus of the protein, implying that the filament attachment must have a perpendicular component to both curvature and polarity. Remarkably, this chirality switch concurs with previously shown inward or outward membrane deformations by the respective FtsZ mutants. Our results lead us to suggest an intrinsic helicity of FtsZ filaments with more than one direction of curvature, supporting earlier hypotheses and experimental evidence. FtsZ is a tubulin homologue and the primary protein of the bacterial Z ring that guides cell division. In vivo, but also in reconstituted systems, FtsZ shows an intriguing treadmilling dynamic along circular tracks of approximately 1 micrometer in diameter. In cells, this treadmilling along the circumference of the division site is suggested to dynamically guide peptidoglycan—and thus new cell wall—synthesis. In vitro, when reconstituted along with its membrane adaptor FtsA on flat supported membranes, FtsZ self-organizes into similarly treadmilling vortices as observed in vivo but with a clear chirality. With the aim of thoroughly investigating these dynamics, revealing the origin of chirality, and potentially relating it to a membrane-transforming ability of FtsZ, we reconstituted different membrane-targeted mutants of FtsZ on flat membranes. In this minimized system, we found that dynamic ring formation is an intrinsic feature of FtsZ without the need of any other protein. However, self-organization into dynamic treadmilling only occurs within a specific protein, cation, and guanosine triphosphate (GTP) concentration range. Our work led us to propose that the observed chirality of FtsZ treadmilling may be explained by an inherent helical character of the filaments with more than one direction of curvature.
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Affiliation(s)
- Diego A. Ramirez-Diaz
- Department of Cellular and Molecular Biophysics, Max Planck Institute for Biochemistry, Martinsried, Germany
- Graduate School for Quantitative Biosciences (QBM), Ludwig-Maximillians-University, Munich, Germany
| | - Daniela A. García-Soriano
- Department of Cellular and Molecular Biophysics, Max Planck Institute for Biochemistry, Martinsried, Germany
- Graduate School for Quantitative Biosciences (QBM), Ludwig-Maximillians-University, Munich, Germany
| | - Ana Raso
- Department of Cellular and Molecular Biophysics, Max Planck Institute for Biochemistry, Martinsried, Germany
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Jonas Mücksch
- Department of Cellular and Molecular Biophysics, Max Planck Institute for Biochemistry, Martinsried, Germany
| | - Mario Feingold
- Department of Physics, Ben Gurion University, Beer Sheva, Israel
| | - Germán Rivas
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Petra Schwille
- Department of Cellular and Molecular Biophysics, Max Planck Institute for Biochemistry, Martinsried, Germany
- * E-mail:
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9
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Sung MW, Shaik R, TerBush AD, Osteryoung KW, Vitha S, Holzenburg A. The chloroplast division protein ARC6 acts to inhibit disassembly of GDP-bound FtsZ2. J Biol Chem 2018; 293:10692-10706. [PMID: 29769312 DOI: 10.1074/jbc.ra117.000999] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 04/14/2018] [Indexed: 01/12/2023] Open
Abstract
Chloroplasts host photosynthesis and fulfill other metabolic functions that are essential to plant life. They have to divide by binary fission to maintain their numbers throughout cycles of cell division. Chloroplast division is achieved by a complex ring-shaped division machinery located on both the inner (stromal) and the outer (cytosolic) side of the chloroplast envelope. The inner division ring (termed the Z ring) is formed by the assembly of tubulin-like FtsZ1 and FtsZ2 proteins. ARC6 is a key chloroplast division protein that interacts with the Z ring. ARC6 spans the inner envelope membrane, is known to stabilize or maintain the Z ring, and anchors the Z ring to the inner membrane through interaction with FtsZ2. The underlying mechanism of Z ring stabilization is not well-understood. Here, biochemical and structural characterization of ARC6 was conducted using light scattering, sedimentation, and light and transmission EM. The recombinant protein was purified as a dimer. The results indicated that a truncated form of ARC6 (tARC6), representing the stromal portion of ARC6, affects FtsZ2 assembly without forming higher-order structures and exerts its effect via FtsZ2 dynamics. tARC6 prevented GDP-induced FtsZ2 disassembly and caused a significant net increase in FtsZ2 assembly when GDP was present. Single particle analysis and 3D reconstruction were performed to elucidate the structural basis of ARC6 activity. Together, the data reveal that a dimeric form of tARC6 binds to FtsZ2 filaments and does not increase FtsZ polymerization rates but rather inhibits GDP-associated FtsZ2 disassembly.
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Affiliation(s)
- Min Woo Sung
- From the Department of Biology, Texas A&M University, College Station, Texas 77843
| | - Rahamthulla Shaik
- From the Department of Biology, Texas A&M University, College Station, Texas 77843
| | - Allan D TerBush
- the Biochemistry and Molecular Biology Graduate Program and.,Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | | | - Stanislav Vitha
- the Microscopy and Imaging Center, Texas A&M University, College Station, Texas 77843, and
| | - Andreas Holzenburg
- From the Department of Biology, Texas A&M University, College Station, Texas 77843.,the Microscopy and Imaging Center, Texas A&M University, College Station, Texas 77843, and.,the Department of Biomedical Sciences, School of Medicine, University of Texas Rio Grande Valley, Brownsville-Edinburg-Harlingen, Texas 78550
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10
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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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11
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Concha-Marambio L, Maldonado P, Lagos R, Monasterio O, Montecinos-Franjola F. Thermal adaptation of mesophilic and thermophilic FtsZ assembly by modulation of the critical concentration. PLoS One 2017; 12:e0185707. [PMID: 28982174 PMCID: PMC5628889 DOI: 10.1371/journal.pone.0185707] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Accepted: 09/18/2017] [Indexed: 01/16/2023] Open
Abstract
Cytokinesis is the last stage in the cell cycle. In prokaryotes, the protein FtsZ guides cell constriction by assembling into a contractile ring-shaped structure termed the Z-ring. Constriction of the Z-ring is driven by the GTPase activity of FtsZ that overcomes the energetic barrier between two protein conformations having different propensities to assemble into polymers. FtsZ is found in psychrophilic, mesophilic and thermophilic organisms thereby functioning at temperatures ranging from subzero to >100°C. To gain insight into the functional adaptations enabling assembly of FtsZ in distinct environmental conditions, we analyzed the energetics of FtsZ function from mesophilic Escherichia coli in comparison with FtsZ from thermophilic Methanocaldococcus jannaschii. Presumably, the assembly may be similarly modulated by temperature for both FtsZ orthologs. The temperature dependence of the first-order rates of nucleotide hydrolysis and of polymer disassembly, indicated an entropy-driven destabilization of the FtsZ-GTP intermediate. This destabilization was true for both mesophilic and thermophilic FtsZ, reflecting a conserved mechanism of disassembly. From the temperature dependence of the critical concentrations for polymerization, we detected a change of opposite sign in the heat capacity, that was partially explained by the specific changes in the solvent-accessible surface area between the free and polymerized states of FtsZ. At the physiological temperature, the assembly of both FtsZ orthologs was found to be driven by a small positive entropy. In contrast, the assembly occurred with a negative enthalpy for mesophilic FtsZ and with a positive enthalpy for thermophilic FtsZ. Notably, the assembly of both FtsZ orthologs is characterized by a critical concentration of similar value (1–2 μM) at the environmental temperatures of their host organisms. These findings suggest a simple but robust mechanism of adaptation of FtsZ, previously shown for eukaryotic tubulin, by adjustment of the critical concentration for polymerization.
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Affiliation(s)
- Luis Concha-Marambio
- Laboratorio de Biologia Estructural y Molecular/Departamento de Biologia/Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Paula Maldonado
- Laboratorio de Biologia Estructural y Molecular/Departamento de Biologia/Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Rosalba Lagos
- Laboratorio de Biologia Estructural y Molecular/Departamento de Biologia/Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Octavio Monasterio
- Laboratorio de Biologia Estructural y Molecular/Departamento de Biologia/Facultad de Ciencias, Universidad de Chile, Santiago, Chile
- * E-mail: (OM); (FMF)
| | - Felipe Montecinos-Franjola
- Laboratorio de Biologia Estructural y Molecular/Departamento de Biologia/Facultad de Ciencias, Universidad de Chile, Santiago, Chile
- * E-mail: (OM); (FMF)
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12
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Minton AP. Explicit Incorporation of Hard and Soft Protein-Protein Interactions into Models for Crowding Effects in Protein Mixtures. 2. Effects of Varying Hard and Soft Interactions upon Prototypical Chemical Equilibria. J Phys Chem B 2017; 121:5515-5522. [PMID: 28505444 DOI: 10.1021/acs.jpcb.7b02378] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Previously derived approximate analytical relations for the activity coefficient of each solute in a mixture of up to three spherical solutes in a highly nonideal solution interacting via square well potentials of mean force (Hoppe, T.; Minton, A. P. J Phys Chem B. 2016, 120, 11866-11872) were used to explore the effect of heterogeneity in volume occupancy and intermolecular interactions upon prototypical schemes representing solubility, partitioning, conformational isomerization, and self-association in crowded solutions. Results generally indicate that all of the equilibria explored are exquisitely sensitive to variations in both volume occupancy and intermolecular interaction and have important implications for the design and execution of more detailed simulations of complex media.
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Affiliation(s)
- Allen P Minton
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, United States Department of Health and Human Welfare , Bethesda, Maryland United States
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13
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Chen Y, Porter K, Osawa M, Augustus AM, Milam SL, Joshi C, Osteryoung KW, Erickson HP. The Chloroplast Tubulin Homologs FtsZA and FtsZB from the Red Alga Galdieria sulphuraria Co-assemble into Dynamic Filaments. J Biol Chem 2017; 292:5207-5215. [PMID: 28174299 DOI: 10.1074/jbc.m116.767715] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 02/06/2017] [Indexed: 01/09/2023] Open
Abstract
FtsZ is a homolog of eukaryotic tubulin and is present in almost all bacteria and many archaea, where it is the major cytoskeletal protein in the Z ring, required for cell division. Unlike some other cell organelles of prokaryotic origin, chloroplasts have retained FtsZ as an essential component of the division machinery. However, chloroplast FtsZs have been challenging to study because they are difficult to express and purify. To this end, we have used a FATT tag expression system to produce as soluble proteins the two chloroplast FtsZs from Galdieria sulphuraria, a thermophilic red alga. GsFtsZA and GsFtsZB assembled individually in the presence of GTP, forming large bundles of protofilaments. GsFtsZA also assembled in the presence of GDP, the first member of the FtsZ/tubulin superfamily to do so. Mixtures of GsFtsZA and GsFtsZB assembled protofilament bundles and hydrolyzed GTP at a rate approximately equal to the sum of their individual rates, suggesting a random co-assembly. GsFtsZA assembly by itself in limiting GTP gave polymers that remained stable for a prolonged time. However, when GsFtsZB was added, the co-polymers disassembled with enhanced kinetics, suggesting that the GsFtsZB regulates and enhances disassembly dynamics. GsFtsZA-mts (where mts is a membrane-targeting amphipathic helix) formed Z ring-like helices when expressed in Escherichia coli Co-expression of GsFtsZB (without an mts) gave co-assembly of both into similar helices. In summary, we provide biochemical evidence that GsFtsZA assembles as the primary scaffold of the chloroplast Z ring and that GsFtsZB co-assembly enhances polymer disassembly and dynamics.
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Affiliation(s)
- Yaodong Chen
- From the College of Life Science, Northwest University, Xi'an, ShaanXi, China 710069.,the Department of Cell Biology, Duke University School of Medicine, Durham, North Carolina 27710-3709, and
| | - Katie Porter
- the Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824-1312
| | - Masaki Osawa
- the Department of Cell Biology, Duke University School of Medicine, Durham, North Carolina 27710-3709, and
| | - Anne Marie Augustus
- the Department of Cell Biology, Duke University School of Medicine, Durham, North Carolina 27710-3709, and
| | - Sara L Milam
- the Department of Cell Biology, Duke University School of Medicine, Durham, North Carolina 27710-3709, and
| | - Chandra Joshi
- the Department of Cell Biology, Duke University School of Medicine, Durham, North Carolina 27710-3709, and
| | - Katherine W Osteryoung
- the Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824-1312
| | - Harold P Erickson
- the Department of Cell Biology, Duke University School of Medicine, Durham, North Carolina 27710-3709, and
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14
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Abstract
In comparison with bacteria and eukaryotes, the large and diverse group of microorganisms known as archaea possess a great diversity of cytoskeletal proteins, including members of the tubulin superfamily. Many species contain FtsZ, CetZ and even possible tubulins; however, some major taxonomic groups do not contain any member of the tubulin superfamily. Studies using the model archaeon, Halferax volcanii have recently been instrumental in defining the fundamental roles of FtsZ and CetZ in archaeal cell division and cell shape regulation. Structural studies of archaeal tubulin superfamily proteins provide a definitive contribution to the cytoskeletal field, showing which protein-types must have developed prior to the divergence of archaea and eukaryotes. Several regions of the globular core domain - the "signature" motifs - combine in the 3D structure of the common molecular fold to form the GTP-binding site. They are the most conserved sequence elements and provide the primary basis for identification of new superfamily members through homology searches. The currently well-characterised proteins also all share a common mechanism of GTP-dependent polymerisation, in which GTP molecules are sandwiched between successive subunits that are arranged in a head-to-tail manner. However, some poorly-characterised archaeal protein families retain only some of the signature motifs and are unlikely to be capable of dynamic polymerisation, since the promotion of depolymerisation by hydrolysis to GDP depends on contributions from both subunits that sandwich the nucleotide in the polymer.
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Affiliation(s)
- Christopher H S Aylett
- Department of Biology, Institute for Molecular Biology and Biophysics, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland
| | - Iain G Duggin
- The iThree Institute, University of Technology Sydney, Sydney, NSW, 2007, Australia.
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15
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Abstract
FtsZ assembles in vitro into protofilaments (pfs) that are one subunit thick and ~50 subunits long. In vivo these pfs assemble further into the Z ring, which, along with accessory division proteins, constricts to divide the cell. We have reconstituted Z rings in liposomes in vitro, using pure FtsZ that was modified with a membrane targeting sequence to directly bind the membrane. This FtsZ-mts assembled Z rings and constricted the liposomes without any accessory proteins. We proposed that the force for constriction was generated by a conformational change from straight to curved pfs. Evidence supporting this mechanism came from switching the membrane tether to the opposite side of the pf. These switched-tether pfs assembled "inside-out" Z rings, and squeezed the liposomes from the outside, as expected for the bending model. We propose three steps for the full process of cytokinesis: (a) pf bending generates a constriction force on the inner membrane, but the rigid peptidoglycan wall initially prevents any invagination; (b) downstream proteins associate to the Z ring and remodel the peptidoglycan, permitting it to follow the constricting FtsZ to a diameter of ~250 nm; the final steps of closure of the septum and membrane fusion are achieved by excess membrane synthesis and membrane fluctuations.
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Affiliation(s)
- Harold P Erickson
- Department of Cell Biology, Duke University, Durham, NC, 27710, USA.
| | - Masaki Osawa
- Department of Cell Biology, Duke University, Durham, NC, 27710, USA
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16
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Mishra S, Jakkala K, Srinivasan R, Arumugam M, Ranjeri R, Gupta P, Rajeswari H, Ajitkumar P. NDK Interacts with FtsZ and Converts GDP to GTP to Trigger FtsZ Polymerisation--A Novel Role for NDK. PLoS One 2015; 10:e0143677. [PMID: 26630542 PMCID: PMC4668074 DOI: 10.1371/journal.pone.0143677] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Accepted: 11/09/2015] [Indexed: 11/19/2022] Open
Abstract
Introduction Nucleoside diphosphate kinase (NDK), conserved across bacteria to humans, synthesises NTP from NDP and ATP. The eukaryotic homologue, the NDPK, uses ATP to phosphorylate the tubulin-bound GDP to GTP for tubulin polymerisation. The bacterial cytokinetic protein FtsZ, which is the tubulin homologue, also uses GTP for polymerisation. Therefore, we examined whether NDK can interact with FtsZ to convert FtsZ-bound GDP and/or free GDP to GTP to trigger FtsZ polymerisation. Methods Recombinant and native NDK and FtsZ proteins of Mycobacterium smegmatis and Mycobacterium tuberculosis were used as the experimental samples. FtsZ polymersation was monitored using 90° light scattering and FtsZ polymer pelleting assays. The γ32P-GTP synthesised by NDK from GDP and γ32P-ATP was detected using thin layer chromatography and quantitated using phosphorimager. The FtsZ bound 32P-GTP was quantitated using phosphorimager, after UV-crosslinking, followed by SDS-PAGE. The NDK-FtsZ interaction was determined using Ni2+-NTA-pulldown assay and co-immunoprecipitation of the recombinant and native proteins in vitro and ex vivo, respectively. Results NDK triggered instantaneous polymerisation of GDP-precharged recombinant FtsZ in the presence of ATP, similar to the polymerisation of recombinant FtsZ (not GDP-precharged) upon the direct addition of GTP. Similarly, NDK triggered polymerisation of recombinant FtsZ (not GDP-precharged) in the presence of free GDP and ATP as well. Mutant NDK, partially deficient in GTP synthesis from ATP and GDP, triggered low level of polymerisation of MsFtsZ, but not of MtFtsZ. As characteristic of NDK’s NTP substrate non-specificity, it used CTP, TTP, and UTP also to convert GDP to GTP, to trigger FtsZ polymerisation. The NDK of one mycobacterial species could trigger the polymerisation of the FtsZ of another mycobacterial species. Both the recombinant and the native NDK and FtsZ showed interaction with each other in vitro and ex vivo, alluding to the possibility of direct phosphorylation of FtsZ-bound GDP by NDK. Conclusion Irrespective of the bacterial species, NDK interacts with FtsZ in vitro and ex vivo and, through the synthesis of GTP from FtsZ-bound GDP and/or free GDP, and ATP (CTP/TTP/UTP), triggers FtsZ polymerisation. The possible biological context of this novel activity of NDK is presented.
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Affiliation(s)
- Saurabh Mishra
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Kishor Jakkala
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Ramanujam Srinivasan
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Muthu Arumugam
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Raghavendra Ranjeri
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Prabuddha Gupta
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Haryadi Rajeswari
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Parthasarathi Ajitkumar
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
- * E-mail:
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17
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Huecas S, Marcelo F, Perona A, Ruiz-Ávila LB, Morreale A, Cañada FJ, Jiménez-Barbero J, Andreu JM. Beyond a Fluorescent Probe: Inhibition of Cell Division Protein FtsZ by mant-GTP Elucidated by NMR and Biochemical Approaches. ACS Chem Biol 2015; 10:2382-92. [PMID: 26247422 DOI: 10.1021/acschembio.5b00444] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
FtsZ is the organizer of cell division in most bacteria and a target in the quest for new antibiotics. FtsZ is a tubulin-like GTPase, in which the active site is completed at the interface with the next subunit in an assembled FtsZ filament. Fluorescent mant-GTP has been extensively used for competitive binding studies of nucleotide analogs and synthetic GTP-replacing inhibitors possessing antibacterial activity. However, its mode of binding and whether the mant tag interferes with FtsZ assembly function were unknown. Mant-GTP exists in equilibrium as a mixture of C2'- and C3'-substituted isomers. We have unraveled the molecular recognition process of mant-GTP by FtsZ monomers. Both isomers bind in the anti glycosidic bond conformation: 2'-mant-GTP in two ribose puckering conformations and 3'-mant-GTP in the preferred C2' endo conformation. In each case, the mant tag strongly interacts with FtsZ at an extension of the GTP binding site, which is also supported by molecular dynamics simulations. Importantly, mant-GTP binding induces archaeal FtsZ polymerization into inactive curved filaments that cannot hydrolyze the nucleotide, rather than straight GTP-hydrolyzing assemblies, and also inhibits normal assembly of FtsZ from the Gram-negative bacterium Escherichia coli but is hydrolyzed by FtsZ from Gram-positive Bacillus subtilis. Thus, the specific interactions provided by the fluorescent mant tag indicate a new way to search for synthetic FtsZ inhibitors that selectively suppress the cell division of bacterial pathogens.
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Affiliation(s)
- Sonia Huecas
- Centro de Investigaciones
Biológicas, CIB-CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Filipa Marcelo
- Centro de Investigaciones
Biológicas, CIB-CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
- UCIBIO, REQUIMTE, Dept. de Química, Faculdade de Ciências
e Tecnologia, UNL, 2829-516 Caparica, Portugal
| | - Almudena Perona
- Unidad de Bioinformática,
Centro de Biología Molecular Severo Ochoa, CBMSO−CSIC, Cantoblanco, 28049 Madrid, Spain
| | - Laura B. Ruiz-Ávila
- Centro de Investigaciones
Biológicas, CIB-CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Antonio Morreale
- Unidad de Bioinformática,
Centro de Biología Molecular Severo Ochoa, CBMSO−CSIC, Cantoblanco, 28049 Madrid, Spain
| | - F. Javier Cañada
- Centro de Investigaciones
Biológicas, CIB-CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Jesús Jiménez-Barbero
- Centro de Investigaciones
Biológicas, CIB-CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - José M. Andreu
- Centro de Investigaciones
Biológicas, CIB-CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
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18
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Li X, Ma S. Advances in the discovery of novel antimicrobials targeting the assembly of bacterial cell division protein FtsZ. Eur J Med Chem 2015; 95:1-15. [DOI: 10.1016/j.ejmech.2015.03.026] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 03/10/2015] [Accepted: 03/12/2015] [Indexed: 01/23/2023]
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19
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Ojima I, Kumar K, Awasthi D, Vineberg JG. Drug discovery targeting cell division proteins, microtubules and FtsZ. Bioorg Med Chem 2014; 22:5060-77. [PMID: 24680057 PMCID: PMC4156572 DOI: 10.1016/j.bmc.2014.02.036] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 01/25/2014] [Accepted: 02/18/2014] [Indexed: 12/16/2022]
Abstract
Eukaryotic cell division or cytokinesis has been a major target for anticancer drug discovery. After the huge success of paclitaxel and docetaxel, microtubule-stabilizing agents (MSAs) appear to have gained a premier status in the discovery of next-generation anticancer agents. However, the drug resistance caused by MDR, point mutations, and overexpression of tubulin subtypes, etc., is a serious issue associated with these agents. Accordingly, the discovery and development of new-generation MSAs that can obviate various drug resistances has a significant meaning. In sharp contrast, prokaryotic cell division has been largely unexploited for the discovery and development of antibacterial drugs. However, recent studies on the mechanism of bacterial cytokinesis revealed that the most abundant and highly conserved cell division protein, FtsZ, would be an excellent new target for the drug discovery of next-generation antibacterial agents that can circumvent drug-resistances to the commonly used drugs for tuberculosis, MRSA and other infections. This review describes an account of our research on these two fronts in drug discovery, targeting eukaryotic as well as prokaryotic cell division.
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Affiliation(s)
- Iwao Ojima
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA; Institute of Chemical Biology & Drug Discovery, Stony Brook University, Stony Brook, NY 11794-3400, USA.
| | - Kunal Kumar
- Institute of Chemical Biology & Drug Discovery, Stony Brook University, Stony Brook, NY 11794-3400, USA
| | - Divya Awasthi
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA
| | - Jacob G Vineberg
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA
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20
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Montecinos-Franjola F, James NG, Concha-Marambio L, Brunet JE, Lagos R, Monasterio O, Jameson DM. Single tryptophan mutants of FtsZ: nucleotide binding/exchange and conformational transitions. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2014; 1844:1193-200. [PMID: 24704635 DOI: 10.1016/j.bbapap.2014.03.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 03/24/2014] [Accepted: 03/26/2014] [Indexed: 11/27/2022]
Abstract
Cell division protein FtsZ cooperatively self-assembles into straight filaments when bound to GTP. A set of conformational changes that are linked to FtsZ GTPase activity are involved in the transition from straight to curved filaments that eventually disassemble. In this work, we characterized the fluorescence of single Trp mutants as a reporter of the predicted conformational changes between the GDP- and GTP-states of Escherichia coli FtsZ. Steady-state fluorescence characterization showed the Trp senses different environments and displays low solvent accessibility. Time-resolved fluorescence data indicated that the main conformational changes in FtsZ occur at the interaction surface between the N and C domains, but also minor rearrangements were detected in the bulk of the N domain. Surprisingly, despite its location near the bottom protofilament interface at the C domain, the Trp 275 fluorescence lifetime did not report changes between the GDP and GTP states. The equilibrium unfolding of FtsZ features an intermediate that is stabilized by the nucleotide bound in the N-domain as well as by quaternary protein-protein interactions. In this context, we characterized the unfolding of the Trp mutants using time-resolved fluorescence and phasor plot analysis. A novel picture of the structural transition from the native state in the absence of denaturant, to the solvent-exposed unfolded state is presented. Taken together our results show that conformational changes between the GDP and GTP states of FtsZ, such as those observed in FtsZ unfolding, are restricted to the interaction surface between the N and C domains.
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Affiliation(s)
- Felipe Montecinos-Franjola
- Laboratorio de Biología Estructural y Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 7800024, Chile.
| | - Nicholas G James
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu 96813, HI, USA.
| | - Luis Concha-Marambio
- Laboratorio de Biología Estructural y Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 7800024, Chile.
| | - Juan E Brunet
- Instituto de Química, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Valparaíso 2373223, Chile.
| | - Rosalba Lagos
- Laboratorio de Biología Estructural y Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 7800024, Chile.
| | - Octavio Monasterio
- Laboratorio de Biología Estructural y Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 7800024, Chile.
| | - David M Jameson
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu 96813, HI, USA.
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21
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Marcelo F, Huecas S, Ruiz-Ávila LB, Cañada FJ, Perona A, Poveda A, Martín-Santamaría S, Morreale A, Jiménez-Barbero J, Andreu JM. Interactions of bacterial cell division protein FtsZ with C8-substituted guanine nucleotide inhibitors. A combined NMR, biochemical and molecular modeling perspective. J Am Chem Soc 2013; 135:16418-28. [PMID: 24079270 DOI: 10.1021/ja405515r] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
FtsZ is the key protein of bacterial cell-division and target for new antibiotics. Selective inhibition of FtsZ polymerization without impairing the assembly of the eukaryotic homologue tubulin was demonstrated with C8-substituted guanine nucleotides. By combining NMR techniques with biochemical and molecular modeling procedures, we have investigated the molecular recognition of C8-substituted-nucleotides by FtsZ from Methanococcus jannaschii (Mj-FtsZ) and Bacillus subtilis (Bs-FtsZ). STD epitope mapping and trNOESY bioactive conformation analysis of each nucleotide were employed to deduce differences in their recognition mode by each FtsZ species. GMP binds in the same anti conformation as GTP, whereas 8-pyrrolidino-GMP binds in the syn conformation. However, the anti conformation of 8-morpholino-GMP is selected by Bs-FtsZ, while Mj-FtsZ binds both anti- and syn-geometries. The inhibitory potencies of the C8-modified-nucleotides on the assembly of Bs-FtsZ, but not of Mj-FtsZ, correlate with their binding affinities. Thus, MorphGTP behaves as a nonhydrolyzable analog whose binding induces formation of Mj-FtsZ curved filaments, resembling polymers formed by the inactive forms of this protein. NMR data, combined with molecular modeling protocols, permit explanation of the mechanism of FtsZ assembly impairment by C8-substituted GTP analogs. The presence of the C8-substituent induces electrostatic remodeling and small structural displacements at the association interface between FtsZ monomers to form filaments, leading to complete assembly inhibition or to formation of abnormal FtsZ polymers. The inhibition of bacterial Bs-FtsZ assembly may be simply explained by steric clashes of the C8-GTP-analogs with the incoming FtsZ monomer. This information may facilitate the design of antibacterial FtsZ inhibitors replacing GTP.
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Affiliation(s)
- Filipa Marcelo
- Centro de Investigaciones Biológicas, CIB-CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
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22
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Li Y, Hsin J, Zhao L, Cheng Y, Shang W, Huang KC, Wang HW, Ye S. FtsZ protofilaments use a hinge-opening mechanism for constrictive force generation. Science 2013; 341:392-5. [PMID: 23888039 DOI: 10.1126/science.1239248] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The essential bacterial protein FtsZ is a guanosine triphosphatase that self-assembles into a structure at the division site termed the "Z ring". During cytokinesis, the Z ring exerts a constrictive force on the membrane by using the chemical energy of guanosine triphosphate hydrolysis. However, the structural basis of this constriction remains unresolved. Here, we present the crystal structure of a guanosine diphosphate-bound Mycobacterium tuberculosis FtsZ protofilament, which exhibits a curved conformational state. The structure reveals a longitudinal interface that is important for function. The protofilament curvature highlights a hydrolysis-dependent conformational switch at the T3 loop that leads to longitudinal bending between subunits, which could generate sufficient force to drive cytokinesis.
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Affiliation(s)
- Ying Li
- Life Sciences Institute, Zhejiang University, Hangzhou, 310058 Zhejiang, P.R. China
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23
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Hsin J, Fu R, Huang KC. Dimer dynamics and filament organization of the bacterial cell division protein FtsA. J Mol Biol 2013; 425:4415-26. [PMID: 23871894 DOI: 10.1016/j.jmb.2013.07.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2013] [Revised: 06/25/2013] [Accepted: 07/11/2013] [Indexed: 01/22/2023]
Abstract
FtsA is a bacterial actin homolog and one of the core proteins involved in cell division. While previous studies have demonstrated the capability of FtsA to polymerize, little is known about its polymerization state in vivo or if polymerization is necessary for FtsA function. Given that one function of FtsA is to tether FtsZ filaments to the membrane, in vivo polymerization of FtsA imposes geometric constraints and requires a specific polymer curvature direction. Here, we report a series of molecular dynamics simulations probing the structural dynamics of FtsA as a dimer and as a tetrameric single filament. We found that the FtsA polymer exhibits a preferred bending direction that would allow for its placement parallel with FtsZ polymers underneath the cytoplasmic membrane. We also identified key interfacial amino acids that mediate FtsA-FtsA interaction and propose that some amino acids play more critical roles than others. We performed in silico mutagenesis on FtsA and demonstrated that, while a moderate mutation at the polymerization interface does not significantly affect polymer properties such as bending direction and association strength, more drastic mutations change both features and could lead to non-functional FtsA.
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Affiliation(s)
- Jen Hsin
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
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24
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Jamous C, Basdevant N, Ha-Duong T. Influence of GTP/GDP and magnesium ion on the solvated structure of the protein FtsZ: a molecular dynamics study. J Biomol Struct Dyn 2013; 32:916-27. [PMID: 23782014 DOI: 10.1080/07391102.2013.799436] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
We present here a structural analysis of ten extensive all-atom molecular dynamics simulations of the monomeric protein FtsZ in various binding states. Since the polymerization and GTPase activities of FtsZ depend on the nature of a bound nucleotide as well as on the presence of a magnesium ion, we studied the structural differences between the average conformations of the following five systems: FtsZ-Apo, FtsZ-GTP, FtsZ-GDP, FtsZ-GTP-Mg, and FtsZ-GDP-Mg. The in silico solvated average structure of FtsZ-Apo significantly differs from the crystallographic structure 1W59 of FtsZ which was crystallized in a dimeric form without nucleotide and magnesium. The simulated Apo form of the protein also clearly differs from the FtsZ structures when it is bound to its ligand, the most important discrepancies being located in the loops surrounding the nucleotide binding pocket. The three average structures of FtsZ-GTP, FtsZ-GDP, and FtsZ-GTP-Mg are overall similar, except for the loop T7 located at the opposite side of the binding pocket and whose conformation in FtsZ-GDP notably differs from the one in FtsZ-GTP and FtsZ-GTP-Mg. The presence of a magnesium ion in the binding pocket has no impact on the FtsZ conformation when it is bound to GTP. In contrast, when the protein is bound to GDP, the divalent cation causes a translation of the nucleotide outwards the pocket, inducing a significant conformational change of the loop H6-H7 and the top of helix H7.
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Affiliation(s)
- Carla Jamous
- a LAMBE - UMR CNRS 8587, Université d'Evry-Val-d'Essonne, Rue du Père André Jarlan , 91025 , Evry Cedex , France
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Natarajan K, Senapati S. Probing the conformational flexibility of monomeric FtsZ in GTP-bound, GDP-bound, and nucleotide-free states. Biochemistry 2013; 52:3543-51. [PMID: 23617789 DOI: 10.1021/bi400170f] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The mechanism of nucleotide-regulated assembly and disassembly of the prokaryotic cell division protein FtsZ is not yet clearly understood. In this work, we attempt to characterize the functional motions in monomeric FtsZ through molecular dynamics simulations and essential dynamics (ED) analyses and correlate those motions to FtsZ assembly and disassembly. Results suggest that the nucleotide binding subdomain of FtsZ can switch between multitudes of curved conformations in all nucleotide states, but it prefers to be in an assembly competent less curved conformation in the GTP-bound state. Further, the GDP to GTP exchange invokes a subtle conformational change in the nucleotide binding pocket that tends to align the top portion of core helix H7 along the longitudinal axis of the protein. ED analyses suggest that the longitudinal movements of H7 and the adjacent H6-H7 region modulate the motions of C-domain elements coherently. These longitudinal movements of functionally relevant H7, H6-H7, T3, T7, and H10 regions are likely to facilitate the assembly of GTP-FtsZ into straight filament. On the other hand, the observed radial or random movements of FtsZ residues in the GDP state might not allow the monomers to assemble as efficiently as GTP-bound monomers and could produce curved filaments. Our results correlate very well with recent mutagenesis data that inferred FtsZ conformational flexibility and the involvement of the H6-H7 region in assembly.
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Affiliation(s)
- Kathiresan Natarajan
- Department of Biotechnology, Indian Institute of Technology Madras , Chennai 600036, India
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26
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Nucleotide-dependent conformations of FtsZ dimers and force generation observed through molecular dynamics simulations. Proc Natl Acad Sci U S A 2012; 109:9432-7. [PMID: 22647609 DOI: 10.1073/pnas.1120761109] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The bacterial cytoskeletal protein FtsZ is a GTPase that is thought to provide mechanical constriction force via an unidentified mechanism. Purified FtsZ polymerizes into filaments with varying structures in vitro: while GTP-bound FtsZ assembles into straight or gently curved filaments, GDP-bound FtsZ forms highly curved filaments, prompting the hypothesis that a difference in the inherent curvature of FtsZ filaments provides mechanical force. However, no nucleotide-dependent structural transition of FtsZ monomers has been observed to support this force generation model. Here, we present a series of all-atom molecular dynamics simulations probing the effects of nucleotide binding on the structure of an FtsZ dimer. We found that the FtsZ-dimer structure is dependent on nucleotide-binding state. While a GTP-bound FtsZ dimer retained a firm monomer-monomer contact, a GDP-bound FtsZ dimer lost some of the monomer-monomer association, leading to a "hinge-opening" event that resulted in a more bent dimer, while leaving each monomer structure largely unaffected. We constructed models of FtsZ filaments and found that a GDP-FtsZ filament is much more curved than a GTP-FtsZ filament, with the degree of curvature matching prior experimental data. FtsZ dynamics were used to estimate the amount of force an FtsZ filament could exert when hydrolysis occurs (20-30 pN per monomer). This magnitude of force is sufficient to direct inward cell-wall growth during division, and to produce the observed degree of membrane pinching in liposomes. Taken together, our data provide molecular-scale insight on the origin of FtsZ-based constriction force, and the mechanism underlying prokaryotic cell division.
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Schaffner-Barbero C, Martín-Fontecha M, Chacón P, Andreu JM. Targeting the assembly of bacterial cell division protein FtsZ with small molecules. ACS Chem Biol 2012; 7:269-77. [PMID: 22047077 DOI: 10.1021/cb2003626] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
FtsZ is the key protein of bacterial cell division and an emergent target for new antibiotics. It is a filament-forming GTPase and a structural homologue of eukaryotic tubulin. A number of FtsZ-interacting compounds have been reported, some of which have powerful antibacterial activity. Here we review recent advances and new approaches in modulating FtsZ assembly with small molecules. This includes analyzing their chemical features, binding sites, mechanisms of action, the methods employed, and computational insights, aimed at a better understanding of their molecular recognition by FtsZ and at rational antibiotic design.
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Affiliation(s)
- Claudia Schaffner-Barbero
- Tubulins and
FtsZ, Centro de
Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Mar Martín-Fontecha
- Medicinal Chemistry, Dept. Química
Orgánica I, Facultad de Ciencias Químicas, UCM, Avda. Complutense s/n, 28040 Madrid, Spain
| | - Pablo Chacón
- Structural Bioinformatics, Instituto
de Química Física Rocasolano, CSIC, Serrano 119, 28006 Madrid, Spain
| | - José M. Andreu
- Tubulins and
FtsZ, Centro de
Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
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28
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Abstract
The emergence of multidrug-resistant Mycobacterium tuberculosis strains has made many of the currently available anti-tuberculosis (TB) drugs ineffective. Accordingly, there is a pressing need to identify new drug targets. Filamentous temperature-sensitive protein Z (FtsZ), a bacterial tubulin homologue, is an essential cell-division protein that polymerizes in a GTP-dependent manner, forming a highly dynamic cytokinetic ring, designated as the Z ring, at the septum site. Other cell-division proteins are recruited to the Z ring and, upon resolution of the septum, two daughter cells are produced. Since inactivation of FtsZ or alteration of FtsZ assembly results in the inhibition of Z-ring and septum formation, FtsZ is a very promising target for novel antimicrobial drug development. This review describes the function and dynamic behaviors of FtsZ and the recent development of FtsZ inhibitors as potential anti-TB agents.
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Awasthi D, Kumar K, Ojima I. Therapeutic potential of FtsZ inhibition: a patent perspective. Expert Opin Ther Pat 2011; 21:657-79. [PMID: 21413908 DOI: 10.1517/13543776.2011.568483] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Filamentous temperature sensitive mutant Z (FtsZ), an essential protein for bacterial cell division, has emerged as an attractive therapeutic target for the development of efficacious antibacterial agents active against drug-sensitive and drug-resistant bacterial strains. Recently, FtsZ has garnered special attention in the antibacterial research field, which is evident by the amount of research papers and patents disclosed in the public domain. Because of the significance of FtsZ as a highly promising target for the development of novel antibacterial agents, it is timely to review the patents on this subject so far published to date. AREAS COVERED This review article covers the patent literature on FtsZ-targeting potential antibacterial agents up to November 2010, including their pharmacological findings. EXPERT OPINION Since FtsZ is well preserved in various bacteria, the FtsZ-targeting agents would act as novel broad-spectrum antibacterial drugs in addition to their use against particular bacteria, especially drug-resistant strains. Based on the increasing interest and advancement in this field of research, it looks almost certain that a good number of clinical candidates targeting FtsZ will emerge in the near future.
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Affiliation(s)
- Divya Awasthi
- State University of New York at Stony Brook, Department of Chemistry, Stony Brook, NY 11794-3400, USA
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30
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FtsZ in bacterial cytokinesis: cytoskeleton and force generator all in one. Microbiol Mol Biol Rev 2011; 74:504-28. [PMID: 21119015 DOI: 10.1128/mmbr.00021-10] [Citation(s) in RCA: 460] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
FtsZ, a bacterial homolog of tubulin, is well established as forming the cytoskeletal framework for the cytokinetic ring. Recent work has shown that purified FtsZ, in the absence of any other division proteins, can assemble Z rings when incorporated inside tubular liposomes. Moreover, these artificial Z rings can generate a constriction force, demonstrating that FtsZ is its own force generator. Here we review light microscope observations of how Z rings assemble in bacteria. Assembly begins with long-pitch helices that condense into the Z ring. Once formed, the Z ring can transition to short-pitch helices that are suggestive of its structure. FtsZ assembles in vitro into short protofilaments that are ∼30 subunits long. We present models for how these protofilaments might be further assembled into the Z ring. We discuss recent experiments on assembly dynamics of FtsZ in vitro, with particular attention to how two regulatory proteins, SulA and MinC, inhibit assembly. Recent efforts to develop antibacterial drugs that target FtsZ are reviewed. Finally, we discuss evidence of how FtsZ generates a constriction force: by protofilament bending into a curved conformation.
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31
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Schaffner-Barbero C, Gil-Redondo R, Ruiz-Avila LB, Huecas S, Läppchen T, den Blaauwen T, Diaz JF, Morreale A, Andreu JM. Insights into nucleotide recognition by cell division protein FtsZ from a mant-GTP competition assay and molecular dynamics. Biochemistry 2010; 49:10458-72. [PMID: 21058659 DOI: 10.1021/bi101577p] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Essential cell division protein FtsZ forms the bacterial cytokinetic ring and is a target for new antibiotics. FtsZ monomers bind GTP and assemble into filaments. Hydrolysis to GDP at the association interface between monomers leads to filament disassembly. We have developed a homogeneous competition assay, employing the fluorescence anisotropy change of mant-GTP upon binding to nucleotide-free FtsZ, which detects compounds binding to the nucleotide site in FtsZ monomers and measures their affinities within the millimolar to 10 nM range. We have employed this method to determine the apparent contributions of the guanine, ribose, and the α-, β-, and γ-phosphates to the free energy change of nucleotide binding. Similar relative contributions have also been estimated through molecular dynamics and binding free energy calculations, employing the crystal structures of FtsZ-nucleotide complexes. We find an energetically dominant contribution of the β-phosphate, comparable to the whole guanosine moiety. GTP and GDP bind with similar observed affinity to FtsZ monomers. Loss of the regulatory γ-phosphate results in a predicted accommodation of GDP which has not been observed in the crystal structures. The binding affinities of a series of C8-substituted GTP analogues, known to inhibit FtsZ but not eukaryotic tubulin assembly, correlate with their inhibitory capacity on FtsZ polymerization. Our methods permit testing of FtsZ inhibitors targeting its nucleotide site, as well as compounds from virtual screening of large synthetic libraries. Our results give insight into the FtsZ-nucleotide interactions, which could be useful in the rational design of new inhibitors, especially GTP phosphate mimetics.
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Mingorance J, Rivas G, Vélez M, Gómez-Puertas P, Vicente M. Strong FtsZ is with the force: mechanisms to constrict bacteria. Trends Microbiol 2010; 18:348-56. [PMID: 20598544 DOI: 10.1016/j.tim.2010.06.001] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Revised: 05/10/2010] [Accepted: 06/01/2010] [Indexed: 10/19/2022]
Abstract
FtsZ, the best-known prokaryotic division protein, assembles at midcell with other proteins forming a ring during septation. Widely conserved in bacteria, FtsZ represents the ancestor of tubulin. In the presence of GTP it forms polymers able to associate into multi-stranded flexible structures. FtsZ research is aimed at determining the role of the Z-ring in division, describing the polymerization and potential force-generating mechanisms and evaluating the roles of nucleotide exchange and hydrolysis. Systems to reconstruct the FtsZ ring in vitro have been described and some of its mechanical properties have been reproduced using in silico modeling. We discuss current research in FtsZ, some of the controversies, and finally propose further research needed to complete a model of FtsZ action that reconciles its in vitro properties with its role in division.
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Affiliation(s)
- Jesús Mingorance
- Unidad de Investigación y Servicio de Microbiología, Hospital Universitario La Paz (IdiPAZ), Paseo de La Castellana, 261, 28046 Madrid, Spain.
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Martín-Galiano AJ, Buey RM, Cabezas M, Andreu JM. Mapping flexibility and the assembly switch of cell division protein FtsZ by computational and mutational approaches. J Biol Chem 2010; 285:22554-65. [PMID: 20472561 DOI: 10.1074/jbc.m110.117127] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The molecular switch for nucleotide-regulated assembly and disassembly of the main prokaryotic cell division protein FtsZ is unknown despite the numerous crystal structures that are available. We have characterized the functional motions in FtsZ with a computational consensus of essential dynamics, structural comparisons, sequence conservation, and networks of co-evolving residues. Employing this information, we have constructed 17 mutants, which alter the FtsZ functional cycle at different stages, to modify FtsZ flexibility. The mutant phenotypes ranged from benign to total inactivation and included increased GTPase, reduced assembly, and stabilized assembly. Six mutations clustering at the long cleft between the C-terminal beta-sheet and core helix H7 deviated FtsZ assembly into curved filaments with inhibited GTPase, which still polymerize cooperatively. These mutations may perturb the predicted closure of the C-terminal domain onto H7 required for switching between curved and straight association modes and for GTPase activation. By mapping the FtsZ assembly switch, this work also gives insight into FtsZ druggability because the curved mutations delineate the putative binding site of the promising antibacterial FtsZ inhibitor PC190723.
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Affiliation(s)
- Antonio J Martín-Galiano
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu, 9, 28040 Madrid, Spain.
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Olson BJSC, Wang Q, Osteryoung KW. GTP-dependent heteropolymer formation and bundling of chloroplast FtsZ1 and FtsZ2. J Biol Chem 2010; 285:20634-43. [PMID: 20421292 DOI: 10.1074/jbc.m110.122614] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Bacteria and chloroplasts require the ring-forming cytoskeletal protein FtsZ for division. Although bacteria accomplish division with a single FtsZ, plant chloroplasts require two FtsZ types for division, FtsZ1 and FtsZ2. These proteins colocalize to a mid-plastid Z ring, but their biochemical relationship is poorly understood. We investigated the in vitro behavior of recombinant FtsZ1 and FtsZ2 separately and together. Both proteins bind and hydrolyze GTP, although GTPase activities are low compared with the activity of Escherichia coli FtsZ. Each protein undergoes GTP-dependent assembly into thin protofilaments in the presence of calcium as a stabilizing agent, similar to bacterial FtsZ. In contrast, when mixed without calcium, FtsZ1 and FtsZ2 exhibit slightly elevated GTPase activity and coassembly into extensively bundled protofilaments. Coassembly is enhanced by FtsZ1, suggesting that it promotes lateral interactions between protofilaments. Experiments with GTPase-deficient mutants reveal that FtsZ1 and FtsZ2 form heteropolymers. Maximum coassembly occurs in reactions containing equimolar FtsZ1 and FtsZ2, but significant coassembly occurs at other stoichiometries. The FtsZ1:FtsZ2 ratio in coassembled structures mirrors their input ratio, suggesting plasticity in protofilament and/or bundle composition. This behavior contrasts with that of alpha- and beta-tubulin and the bacterial tubulin-like proteins BtubA and BtubB, which coassemble in a strict 1:1 stoichiometry. Our findings raise the possibility that plasticity in FtsZ filament composition and heteropolymerization-induced bundling could have been a driving force for the coevolution of FtsZ1 and FtsZ2 in the green lineage, perhaps arising from an enhanced capacity for the regulation of Z ring composition and activity in vivo.
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Affiliation(s)
- Bradley J S C Olson
- Biochemistry and Molecular Biology Graduate Program, Michigan State University, East Lansing, MI 48824, USA
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35
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Promoting assembly and bundling of FtsZ as a strategy to inhibit bacterial cell division: a new approach for developing novel antibacterial drugs. Biochem J 2009; 423:61-9. [DOI: 10.1042/bj20090817] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
FtsZ plays an essential role in bacterial cell division. We have used the assembly of FtsZ as a screen to find antibacterial agents with a novel mechanism of action. The effects of 81 compounds of 29 different structural scaffolds on FtsZ assembly in vitro were examined using a sedimentation assay. Out of these 81 compounds, OTBA (3-{5-[4-oxo-2-thioxo-3-(3-trifluoromethyl-phenyl)-thiazolidin-5-ylidenemethyl]-furan-2-yl}-benzoic acid) was found to promote FtsZ assembly in vitro. OTBA increased the assembly of FtsZ, caused bundling of FtsZ protofilaments, prevented dilution-induced disassembly of FtsZ protofilaments and decreased the GTPase activity in vitro. It bound to FtsZ with an apparent dissociation constant of 15±1.5 μM. Furthermore, OTBA inhibited the proliferation of Bacillus subtilis 168 cells with an MIC (minimum inhibitory concentration) of 2 μM, whereas it exerted minimal effects on mammalian cell proliferation, indicating that it might have a potential use as an antibacterial drug. In the effective proliferation inhibitory concentration range, OTBA induced filamentation in bacteria and also perturbed the formation of the cytokinetic Z-rings in bacteria. However, the agent neither perturbed the membrane structures nor affected the nucleoid segregation in B. subtilis cells. The results suggested that the OTBA inhibited bacterial cytokinesis by perturbing the formation and functioning of the Z-ring via altering FtsZ assembly dynamics. The antibacterial mechanism of action of OTBA is similar to that of the widely used anticancer drug paclitaxel, which inhibits cancer cell proliferation by promoting the assembly of tubulin, a eukaryotic homologue of FtsZ.
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36
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Surovtsev IV, Morgan JJ, Lindahl PA. Kinetic modeling of the assembly, dynamic steady state, and contraction of the FtsZ ring in prokaryotic cytokinesis. PLoS Comput Biol 2008; 4:e1000102. [PMID: 18604268 PMCID: PMC2432035 DOI: 10.1371/journal.pcbi.1000102] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2008] [Accepted: 05/21/2008] [Indexed: 11/19/2022] Open
Abstract
Cytokinesis in prokaryotes involves the assembly of a polymeric ring composed of FtsZ protein monomeric units. The Z ring forms at the division plane and is attached to the membrane. After assembly, it maintains a stable yet dynamic steady state. Once induced, the ring contracts and the membrane constricts. In this work, we present a computational deterministic biochemical model exhibiting this behavior. The model is based on biochemical features of FtsZ known from in vitro studies, and it quantitatively reproduces relevant in vitro data. An essential part of the model is a consideration of interfacial reactions involving the cytosol volume, where monomeric FtsZ is dispersed, and the membrane surface in the cell's mid-zone where the ring is assembled. This approach allows the same chemical model to simulate either in vitro or in vivo conditions by adjusting only two geometrical parameters. The model includes minimal reactions, components, and assumptions, yet is able to reproduce sought-after in vivo behavior, including the rapid assembly of the ring via FtsZ-polymerization, the formation of a dynamic steady state in which GTP hydrolysis leads to the exchange of monomeric subunits between cytoplasm and the ring, and finally the induced contraction of the ring. The model gives a quantitative estimate for coupling between the rate of GTP hydrolysis and of FtsZ subunit turnover between the assembled ring and the cytoplasmic pool as observed. Membrane constriction is chemically driven by the strong tendency of GTP-bound FtsZ to self-assembly. The model suggests a possible mechanism of membrane contraction without a motor protein. The portion of the free energy of GTP hydrolysis released in cyclization is indirectly used in this energetically unfavorable process. The model provides a limit to the mechanistic complexity required to mimic ring behavior, and it highlights the importance of parallel in vitro and in vivo modeling.
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Affiliation(s)
- Ivan V. Surovtsev
- Departments of Chemistry and Biochemistry and Biophysics, Texas A&M University, College Station, Texas, United States of America
| | - Jeffrey J. Morgan
- Department of Mathematics, University of Houston, Houston, Texas, United States of America
| | - Paul A. Lindahl
- Departments of Chemistry and Biochemistry and Biophysics, Texas A&M University, College Station, Texas, United States of America
- * E-mail:
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37
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Abstract
In the cytoskeleton, unfavorable nucleation steps allow cells to regulate where, when, and how many polymers assemble. Nucleated polymerization is traditionally explained by a model in which multistranded polymers assemble cooperatively, whereas linear, single-stranded polymers do not. Recent data on the assembly of FtsZ, the bacterial homolog of tubulin, do not fit either category. FtsZ can polymerize into single-stranded protofilaments that are stable in the absence of lateral interactions, but that assemble cooperatively. We developed a model for cooperative polymerization that does not require polymers to be multistranded. Instead, a conformational change allows subunits in oligomers to associate with high affinity, whereas a lower-affinity conformation is favored in monomers. We derive equations for calculating polymer concentrations, subunit conformations, and the apparent affinity of subunits for polymer ends. Certain combinations of equilibrium constants produce the sharp critical concentrations characteristic of cooperative polymerization. In these cases, the low-affinity conformation predominates in monomers, whereas virtually all polymers are composed of high-affinity subunits. Our model predicts that the three routes to forming HH dimers all involve unstable intermediates, limiting nucleation. The mathematical framework developed here can represent allosteric assembly systems with a variety of biochemical interpretations, some of which can show cooperativity, and others of which cannot.
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Energetics and geometry of FtsZ polymers: nucleated self-assembly of single protofilaments. Biophys J 2007; 94:1796-806. [PMID: 18024502 DOI: 10.1529/biophysj.107.115493] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Essential cell division protein FtsZ is an assembling GTPase which directs the cytokinetic ring formation in dividing bacterial cells. FtsZ shares the structural fold of eukaryotic tubulin and assembles forming tubulin-like protofilaments, but does not form microtubules. Two puzzling problems in FtsZ assembly are the nature of protofilament association and a possible mechanism for nucleated self-assembly of single-stranded protofilaments above a critical FtsZ concentration. We assembled two-dimensional arrays of FtsZ on carbon supports, studied linear polymers of FtsZ with cryo-electron microscopy of vitrified unsupported solutions, and formulated possible polymerization models. Nucleated self-assembly of FtsZ from Escherichia coli with GTP and magnesium produces flexible filaments 4-6 nm-wide, only compatible with a single protofilament. This agrees with previous scanning transmission electron microscopy results and is supported by recent cryo-electron tomography studies of two bacterial cells. Observations of double-stranded FtsZ filaments in negative stain may come from protofilament accretion on the carbon support. Preferential protofilament cyclization does not apply to FtsZ assembly. The apparently cooperative polymerization of a single protofilament with identical intermonomer contacts is explained by the switching of one inactive monomer into the active structure preceding association of the next, creating a dimer nucleus. FtsZ behaves as a cooperative linear assembly machine.
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Huecas S, Schaffner-Barbero C, García W, Yébenes H, Palacios JM, Díaz JF, Menéndez M, Andreu JM. The interactions of cell division protein FtsZ with guanine nucleotides. J Biol Chem 2007; 282:37515-28. [PMID: 17977836 DOI: 10.1074/jbc.m706399200] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Prokaryotic cell division protein FtsZ, an assembling GTPase, directs the formation of the septosome between daughter cells. FtsZ is an attractive target for the development of new antibiotics. Assembly dynamics of FtsZ is regulated by the binding, hydrolysis, and exchange of GTP. We have determined the energetics of nucleotide binding to model apoFtsZ from Methanococcus jannaschii and studied the kinetics of 2'/3'-O-(N-methylanthraniloyl) (mant)-nucleotide binding and dissociation from FtsZ polymers, employing calorimetric, fluorescence, and stopped-flow methods. FtsZ binds GTP and GDP with K(b) values ranging from 20 to 300 microm(-1) under various conditions. GTP.Mg(2+) and GDP.Mg(2+) bind with slightly reduced affinity. Bound GTP and the coordinated Mg(2+) ion play a minor structural role in FtsZ monomers, but Mg(2+)-assisted GTP hydrolysis triggers polymer disassembly. Mant-GTP binds and dissociates quickly from FtsZ monomers, with approximately 10-fold lower affinity than GTP. Mant-GTP displacement measured by fluorescence anisotropy provides a method to test the binding of any competing molecules to the FtsZ nucleotide site. Mant-GTP is very slowly hydrolyzed and remains exchangeable in FtsZ polymers, but it becomes kinetically stabilized, with a 30-fold slower k(+) and approximately 500-fold slower k(-) than in monomers. The mant-GTP dissociation rate from FtsZ polymers is comparable with the GTP hydrolysis turnover and with the reported subunit turnover in Escherichia coli FtsZ polymers. Although FtsZ polymers can exchange nucleotide, unlike its eukaryotic structural homologue tubulin, GDP dissociation may be slow enough for polymer disassembly to take place first, resulting in FtsZ polymers cycling with GTP hydrolysis similarly to microtubules.
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Affiliation(s)
- Sonia Huecas
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu, 9, 28040, Madrid, Spain.
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40
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Díaz-Espinoza R, Garcés AP, Arbildua JJ, Montecinos F, Brunet JE, Lagos R, Monasterio O. Domain folding and flexibility of Escherichia coli FtsZ determined by tryptophan site-directed mutagenesis. Protein Sci 2007; 16:1543-56. [PMID: 17656575 PMCID: PMC2203363 DOI: 10.1110/ps.072807607] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
FtsZ has two domains, the amino GTPase domain with a Rossmann fold, and the carboxyl domain that resembles the chorismate mutase fold. Bioinformatics analyses suggest that the interdomain interaction is stronger than the interaction of the protofilament longitudinal interfaces. Crystal B factor analysis of FtsZ and detected conformational changes suggest a connection between these domains. The unfolding/folding characteristics of each domain of FtsZ were tested by introducing tryptophans into the flexible region of the amino (F135W) and the carboxyl (F275W and I294W) domains. As a control, the mutation F40W was introduced in a more rigid part of the amino domain. These mutants showed a native-like structure with denaturation and renaturation curves similar to wild type. However, the I294W mutant showed a strong loss of functionality, both in vivo and in vitro when compared to the other mutants. The functionality was recovered with the double mutant I294W/F275A, which showed full in vivo complementation with a slight increment of in vitro GTPase activity with respect to the single mutant. The formation of a stabilizing aromatic interaction involving a stacking between the tryptophan introduced at position 294 and phenylalanine 275 could account for these results. Folding/unfolding of these mutants induced by guanidinium chloride was compatible with a mechanism in which both domains within the protein show the same stability during FtsZ denaturation and renaturation, probably because of strong interface interactions.
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Affiliation(s)
- Rodrigo Díaz-Espinoza
- Laboratorio de Biología Estructural y Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile
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Oliva MA, Trambaiolo D, Löwe J. Structural insights into the conformational variability of FtsZ. J Mol Biol 2007; 373:1229-42. [PMID: 17900614 DOI: 10.1016/j.jmb.2007.08.056] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2007] [Revised: 08/22/2007] [Accepted: 08/23/2007] [Indexed: 11/16/2022]
Abstract
FtsZ is a prokaryotic homologue of the eukaryotic cytoskeletal protein tubulin and plays a central role in prokaryotic cell division. Both FtsZ and tubulin are known to pass through cycles of polymerization and depolymerization, but the structural mechanisms underlying this cycle remain to be determined. Comparison of tubulin structures obtained in different states has led to a model in which the tubulin monomer undergoes a conformational switch between a "straight" form found in the walls of microtubules and a "curved" form associated with depolymerization, and it was proposed recently that this model may apply also to FtsZ. Here, we present new structures of FtsZ from47 Aquifex aeolicus,47 Bacillus subtilis, Methanococcus jannaschii and Pseudomonas aeruginosa that provide strong constraints on any proposed role for a conformational switch in the FtsZ monomer. By comparing the full range of FtsZ structures determined in different crystal forms and nucleotide states, and in the presence or in the absence of regulatory proteins, we find no evidence of a conformational change involving domain movement. Our new structural data make it clear that the previously proposed straight and curved conformations of FtsZ were related to inter-species differences in domain orientation rather than two interconvertible conformations. We propose a new model in which lateral interactions help determine the curvature of protofilaments.
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Affiliation(s)
- María A Oliva
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK
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42
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Abstract
Bacterial cells contain a variety of structural filamentous proteins necessary for the spatial regulation of cell shape, cell division, and chromosome segregation, analogous to the eukaryotic cytoskeletal proteins. The molecular mechanisms by which these proteins function are beginning to be revealed, and these proteins show numerous three-dimensional structural features and biochemical properties similar to those of eukaryotic actin and tubulin, revealing their evolutionary relationship. Recent technological advances have illuminated links between cell division and chromosome segregation, suggesting a higher complexity and organization of the bacterial cell than was previously thought.
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Affiliation(s)
- Katharine A Michie
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 2QH, UK.
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43
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Beuria TK, Shah JH, Santra MK, Kumar V, Panda D. Effects of pH and ionic strength on the assembly and bundling of FtsZ protofilaments: A possible role of electrostatic interactions in the bundling of protofilaments. Int J Biol Macromol 2006; 40:30-9. [PMID: 16815544 DOI: 10.1016/j.ijbiomac.2006.05.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2006] [Revised: 05/13/2006] [Accepted: 05/13/2006] [Indexed: 10/24/2022]
Abstract
Assembly, bundling and stability of FtsZ protofilaments are important for the formation and functioning of the cytokinetic Z-ring during bacterial division. We found that the bundling of FtsZ protofilaments decreased strongly with increasing pH from 6.0 to 7.9, while the assembly of FtsZ monomers did not decrease considerably. In addition, the disassembly of FtsZ protofilaments was strongly suppressed at pH 6.0 as compared to the elevated pHs. The far-UV circular dichroism spectra of the native FtsZ and the tryptophan emission spectra of mutated FtsZ (Y371W) did not change by increasing pH from 6 to 7.9 indicating that the structure of FtsZ was not altered significantly. Further, the inhibition of bundling of FtsZ protofilaments predominantly, and the inhibition of assembly to a lesser extent by salt indicated that electrostatic interactions are important for the assembly and bundling of FtsZ protofilaments. These observations are supported by the results of computational docking of Escherichia coli dimer structure. The results suggest that the basic intracellular pH (7.4-7.8) of E. coli may play a role in regulating the assembly dynamics of FtsZ in the Z-ring by reducing protofilament stability and bundling in bacterial cytoplasm.
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Affiliation(s)
- Tushar K Beuria
- School of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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44
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Tadros M, González JM, Rivas G, Vicente M, Mingorance J. Activation of the Escherichia coli cell division protein FtsZ by a low-affinity interaction with monovalent cations. FEBS Lett 2006; 580:4941-6. [PMID: 16930599 DOI: 10.1016/j.febslet.2006.07.083] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2006] [Revised: 07/26/2006] [Accepted: 07/31/2006] [Indexed: 11/22/2022]
Abstract
We have investigated the activation of FtsZ by monovalent cations. FtsZ polymerization was dependent on the concentrations of protein and monovalent salts, and was accompanied by the uptake of a single ion per monomer added. The affinity and the specificity for the cation were low. Potassium, ammonium, rubidium or sodium activated FtsZ to different extents. Electron microscopy showed that polymers formed with either rubidium, or potassium, were very similar, as were their nucleotide turnover rates. The GTPase activity was lower with rubidium than with potassium, indicating that nucleotide exchange is independent of nucleotide hydrolysis. Control of polymerization by binding of a low affinity cation might govern the dynamic behavior of the FtsZ polymers.
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Affiliation(s)
- Michael Tadros
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain
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45
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Buey RM, Díaz JF, Andreu JM. The nucleotide switch of tubulin and microtubule assembly: a polymerization-driven structural change. Biochemistry 2006; 45:5933-8. [PMID: 16681364 DOI: 10.1021/bi060334m] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
GTP-binding proteins from the tubulin family, including alphabeta-tubulin, gamma-tubulin, bacterial tubulin, and FtsZ, are key components of the cytoskeleton and play central roles in chromosome segregation and cell division. The nucleotide switch of alphabeta-tubulin is triggered by GTP hydrolysis and regulates microtubule assembly dynamics. The structural mechanism of the switch and how it modulates assembly are beginning to be understood. A conserved structural change between the active and inactive states, different from other GTPases, may be extracted from recent tubulin and FtsZ structures. From these and the biochemical properties of tubulin, the new concept emerges that, contrary to what was thought, unassembled tubulin-GTP is in the inactive, curved conformation as in tubulin-GDP rings, and it is driven into the straight microtubule conformation by the assembly contacts; binding of the GTP gamma-phosphate only lowers the free energy difference between the curved and straight forms.
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Affiliation(s)
- Rubén M Buey
- Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
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46
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Nogales E, Wang HW. Structural mechanisms underlying nucleotide-dependent self-assembly of tubulin and its relatives. Curr Opin Struct Biol 2006; 16:221-9. [PMID: 16549346 DOI: 10.1016/j.sbi.2006.03.005] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2006] [Revised: 02/07/2006] [Accepted: 03/10/2006] [Indexed: 10/24/2022]
Abstract
The alphabeta-tubulin dimer assembles into microtubules, essential polymers in all eukaryotic cells. Microtubules are highly dynamic, a property that derives from tubulin's GTPase activity. Both the bacterial homolog, FtsZ, and the recently discovered bacterial tubulins from Prosthecobacter self-assemble in a nucleotide-dependent manner into protofilaments similar to those that form the microtubule wall. A number of structural studies of alphabeta-tubulin, gamma-tubulin (the isoform involved in microtubule nucleation), FtsZ and bacterial tubulin, in a variety of nucleotide and polymerization states, have been reported in the past few years. These studies have revealed the similarities and differences between these structures and their possible functional implications. In particular, a two-state mechanism has been proposed for the recycling of alphabeta-tubulin during the microtubule disassembly-assembly cycle; this mechanism may be unique to eukaryotic dimeric tubulin and the microtubule structure.
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Affiliation(s)
- Eva Nogales
- Howard Hughes Medical Institute, Molecular and Cell Biology Department, University of California Berkeley and Lawrence Berkeley National Laboratory, 355 LSA, University of California Berkeley, Berkeley, CA 94720-3200, USA.
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47
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Hillebrand S, Garcia W, Delmar Cantú M, de Araújo APU, Tanaka M, Tanaka T, Garratt RC, Carrilho E. In vitro monitoring of GTPase activity and enzyme kinetics studies using capillary electrophoresis. Anal Bioanal Chem 2005; 383:92-7. [PMID: 16041603 DOI: 10.1007/s00216-005-3375-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2005] [Revised: 05/21/2005] [Accepted: 06/01/2005] [Indexed: 11/25/2022]
Abstract
A capillary electrophoresis (CE)-based method for the in vitro detection and monitoring of nucleotide-triphosphatase activity is described. This robust and reproducible method was used to investigate GTPase activity of a recombinant protein construct containing the catalytic domain of Human SEPT4/Bradeion beta (GST-rDGTPase). This example application demonstrates that the CE technique can replace classical radioactive methods for GTPase activity assays and may be used as a routine analytical tool. Enzyme kinetics of GST-rDGTPase was studied and yielded the following kinetic parameters: v(max) = 1.7 microM min(-1) +/- 0.1, Km = 1.0 mM +/- 0.3, and apKcat = 9 x 10(-3) s(-1). In addition the effect of co-factors such as Mg2+ and Mn2+ on the catalytic activity was investigated. The described analytical method was also shown to be useful to analyze diphosphated and triphosphated forms of other nucleotides.
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Affiliation(s)
- Sandro Hillebrand
- Centro de Biotecnologia Molecular e Estrutural, Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP, Brazil
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48
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Han Y, Wang X, Jiang J, Xu Y, Xu Z, Chong K. Biochemical character of the purified OsRAA1, a novel rice protein with GTP-binding activity, and its expression pattern in Oryza sativa. JOURNAL OF PLANT PHYSIOLOGY 2005; 162:1057-63. [PMID: 16173467 DOI: 10.1016/j.jplph.2004.12.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
OsRAA1, as previously reported, is a novel conserved protein in plants and plays an important role in rice root development. Overexpression of OsRAA1 results in reduced growth of primary roots and an increased number of adventitious roots. The biochemical functions and expression patterns of OsRAA1, however, remain poorly understood. To obtain purified OsRAA1 for biochemical analysis, the coding region was amplified by RT-PCR and expressed as a fusion protein with glutathione S-transferase in Escherichia coli. The antibodies to OsRAA1 were prepared by a synthetic 15-residue peptide (YYEDPSLFQFHKRGS) cross-linked with bovine serum albumin. Results of isotope labeling experiments suggested that OsRAA1 had binding activities with [alpha-32P]-GTP. The immunoprecipitation data showed that OsRAA1 had tissue-specific expression in roots and spikes rather than young shoots and leaves, which was consistent with its transcriptional expression. Our results indicate that OsRAA1 GTP-binding activity may contribute to the regulation mechanism of root development mediated by OsRAA1.
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Affiliation(s)
- Ye Han
- Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, China
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49
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Ozawa K, Harashina T, Yatsunami R, Nakamura S. Gene cloning, expression and partial characterization of cell division protein FtsZ1 from extremely halophilic archaeon Haloarcula japonica strain TR-1. Extremophiles 2005; 9:281-8. [PMID: 15844012 DOI: 10.1007/s00792-005-0443-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2004] [Accepted: 02/25/2005] [Indexed: 11/28/2022]
Abstract
The gene encoding a cell division protein FtsZ1 was cloned from an extremely halophilic archaeon, Haloarcula japonica strain TR-1. Nucleotide sequencing analysis of the ftsZ1 gene revealed that the structural gene consisted of an open reading frame of 1,158 nucleotides encoding 386 amino acids. Transcription of the ftsZ1 gene in Ha. japonica was confirmed by RT-PCR. A modified ftsZ1 gene was inserted into the shuttle vector pWL102 and used to transform Ha. japonica. The recombinant FtsZ1 was produced as a fusion with hexahistidine-tag in Ha. japonica host cells and purified. Purified recombinant FtsZ1 exhibited GTP-dependent polymerization activity and GTP-hydrolyzing activity in the presence of high concentrations of KCl.
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Affiliation(s)
- Kazumichi Ozawa
- Department of Bioengineering, Tokyo Institute of Technology, Yokohama, Japan
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50
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Mingorance J, Tadros M, Vicente M, González JM, Rivas G, Vélez M. Visualization of single Escherichia coli FtsZ filament dynamics with atomic force microscopy. J Biol Chem 2005; 280:20909-14. [PMID: 15793307 DOI: 10.1074/jbc.m503059200] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
FtsZ, the prokaryotic homologue of tubulin, is an essential cell division protein. In the cell, it localizes at the center, forming a ring that constricts during division. In vitro, it binds and hydrolyzes GTP and polymerizes in a GTP-dependent manner. We have used atomic force microscopy to study the structure and dynamics of FtsZ polymer assembly on a mica surface under buffer solution. The polymers were highly dynamic and flexible, and they continuously rearranged over the surface. End-to-end joining of filaments and depolymerization from internal zones were observed, suggesting that fragmentation and reannealing may contribute significantly to the dynamics of FtsZ assembly. The shape evolution of the restructured polymers manifested a strong inherent tendency to curve. Polymers formed in the presence of non-hydrolyzable nucleotide analogues or in the presence of GDP and AlF(3) were structurally similar but showed a slower dynamic behavior. These results provide experimental evidence supporting the model of single-strand polymerization plus cyclization recently proposed to explain the hydrodynamic behavior of the polymers in solution.
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Affiliation(s)
- Jesús Mingorance
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas and Instituto Nicolás Cabrera, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid 28049, Spain
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