1
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Onuh G, Harries D, Manor O. Depletion-Induced Self-Assembly of Colloidal Particles on a Solid Substrate. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:8554-8561. [PMID: 38651184 PMCID: PMC11044580 DOI: 10.1021/acs.langmuir.4c00186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 03/25/2024] [Accepted: 03/25/2024] [Indexed: 04/25/2024]
Abstract
We investigate the depletion contributions to the self-assembly of microcolloids on solid substrates. The assembly is driven by the exclusion of nanoparticles and nonadsorbing polymers from the depletion zone between the microcolloids in the liquid and the underlying substrate. The model system consists of 1 μm polystyrene particles that we deposit on a flat glass slab in an electrolyte solution. Using polystyrene nanoparticles and poly(acrylic acid) polymers as depleting agents, we demonstrate in our experiments that nanoparticle concentrations of 0.5% (w/v) support well-ordered packing of microcolloids on glass, while the presence of polymers leads to irregular aggregate deposition structures. A mixture of nanoparticles and polymers enhances the formation of colloidal aggregate and particulate surface coverage compared to using the polymers alone as a depletion agent. Moreover, tuning the polymer ionization state from pH 4 to 9 modifies the polymer conformational state and radius of gyration, which in turn alters the microcolloid deposition from compact multilayers to flocculated structures. Our study provides entropic strategies for manipulating particulate assembly on substrates from dispersed to continuous coatings.
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Affiliation(s)
- Gideon Onuh
- The
Wolfson Department of Chemical Engineering, Technion-Israel Institute of Technology, Haifa 3200000, Israel
| | - Daniel Harries
- The
Fritz Haber Research Center, and the Harvey M. Kruger Center for Nanoscience
& Nanotechnology, Institute of Chemistry, The Hebrew University, Jerusalem 9190401, Israel
| | - Ofer Manor
- The
Wolfson Department of Chemical Engineering, Technion-Israel Institute of Technology, Haifa 3200000, Israel
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2
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Alfonso C, Sobrinos-Sanguino M, Luque-Ortega JR, Zorrilla S, Monterroso B, Nuero OM, Rivas G. Studying Macromolecular Interactions of Cellular Machines by the Combined Use of Analytical Ultracentrifugation, Light Scattering, and Fluorescence Spectroscopy Methods. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 3234:89-107. [PMID: 38507202 DOI: 10.1007/978-3-031-52193-5_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
Cellular machines formed by the interaction and assembly of macromolecules are essential in many processes of the living cell. These assemblies involve homo- and hetero-associations, including protein-protein, protein-DNA, protein-RNA, and protein-polysaccharide associations, most of which are reversible. This chapter describes the use of analytical ultracentrifugation, light scattering, and fluorescence-based methods, well-established biophysical techniques, to characterize interactions leading to the formation of macromolecular complexes and their modulation in response to specific or unspecific factors. We also illustrate, with several examples taken from studies on bacterial processes, the advantages of the combined use of subsets of these techniques as orthogonal analytical methods to analyze protein oligomerization and polymerization, interactions with ligands, hetero-associations involving membrane proteins, and protein-nucleic acid complexes.
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Affiliation(s)
- Carlos Alfonso
- Structural and Chemical Biology Department, Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas, Madrid, Spain.
| | - Marta Sobrinos-Sanguino
- Molecular Interactions Facility, Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Juan Román Luque-Ortega
- Molecular Interactions Facility, Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Silvia Zorrilla
- Structural and Chemical Biology Department, Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Begoña Monterroso
- Structural and Chemical Biology Department, Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Oscar M Nuero
- Molecular Interactions Facility, Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Germán Rivas
- Structural and Chemical Biology Department, Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas, Madrid, Spain
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3
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Suigo L, Monterroso B, Sobrinos-Sanguino M, Alfonso C, Straniero V, Rivas G, Zorrilla S, Valoti E, Margolin W. Benzodioxane-benzamides as promising inhibitors of Escherichia coli FtsZ. Int J Biol Macromol 2023; 253:126398. [PMID: 37634788 DOI: 10.1016/j.ijbiomac.2023.126398] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 08/02/2023] [Accepted: 08/16/2023] [Indexed: 08/29/2023]
Abstract
The conserved process of cell division in bacteria has been a long-standing target for antimicrobials, although there are few examples of potent broad-spectrum compounds that inhibit this process. Most currently available compounds acting on division are directed towards the FtsZ protein, a self-assembling GTPase that is a central element of the division machinery in most bacteria. Benzodioxane-benzamides are promising candidates, but poorly explored in Gram-negatives. We have tested a number of these compounds on E. coli FtsZ and found that many of them significantly stabilized the polymers against disassembly and reduced the GTPase activity. Reconstitution in crowded cell-like conditions showed that FtsZ bundles were also susceptible to these compounds, including some compounds that were inactive on protofilaments in dilute conditions. They efficiently killed E. coli cells defective in the AcrAB efflux pump. The activity of the compounds on cell growth and division generally showed a good correlation with their effect in vitro, and our experiments are consistent with FtsZ being the target in vivo. Our results uncover the detrimental effects of benzodioxane-benzamides on permeable E. coli cells via its central division protein, implying that lead compounds may be found within this class for the development of antibiotics against Gram-negative bacteria.
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Affiliation(s)
- Lorenzo Suigo
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, Via Luigi Mangiagalli, 25, 20133 Milano, Italy
| | - Begoña Monterroso
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain
| | - Marta Sobrinos-Sanguino
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain
| | - Carlos Alfonso
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain
| | - Valentina Straniero
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, Via Luigi Mangiagalli, 25, 20133 Milano, Italy
| | - Germán Rivas
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain
| | - Silvia Zorrilla
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain.
| | - Ermanno Valoti
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, Via Luigi Mangiagalli, 25, 20133 Milano, Italy.
| | - William Margolin
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas, Houston 77030, TX, USA.
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4
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Minton AP. Simplified Equilibrium Model for Exploring the Combined Influences of Concentration, Aggregate Shape, Excluded Volume, and Surface Adsorption upon Aggregation Propensity and Distribution of Globular Macromolecules. J Phys Chem B 2023; 127:9303-9311. [PMID: 37871252 DOI: 10.1021/acs.jpcb.3c05594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
A mesoscopic model for the equilibrium self-association of a globular macromolecule that may form oligomers of various shapes and unlimited sizes is presented. Allowance is made within this model for the effects of variation in the free energy of subunit contact within an oligomer of specified size and different shapes, the free energy of adsorption of an oligomer of specified size and shape to a planar surface, and the free energy of nonspecific excluded volume interaction between an oligomer of specified size and shape and an inert species occupying a specified fraction of total volume. The model is analytically soluble and permits rapid calculation and analysis of the effects of variation in each of the three free energy parameters upon the concentration dependence of the weight-average stoichiometry of the oligomer, the fraction of total macromolecule that is adsorbed, and the fraction of differently shaped oligomers that are adsorbed and in free solution.
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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, U.S. Department of Health and Human Services, Bethesda Maryland 20892-0830, United States
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5
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Rivas G. Biophysical Reviews' "Meet the Editors Series"-a profile of Germán Rivas. Biophys Rev 2023; 15:151-156. [PMID: 37124917 PMCID: PMC10133429 DOI: 10.1007/s12551-023-01061-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/23/2023] [Indexed: 05/02/2023] Open
Abstract
German Rivas is an executive editor of the IUPAB Biophysical Reviews journal based in Spain. As the head of the Department of Structural and Chemical Biology at the Center for Biological Research (CIB) Margarita Salas (one of the largest research institutes devoted to life sciences of the Spanish National Research Council (CSIC)), he leads a research program aimed at understanding the structure function relationship of large macromolecular complexes (involved in bacterial cell division) when placed in physiologically complex and "crowded" media toward their reconstitution from the bottom up in cell-like compartments. In this "Meet the Editors'" piece, he briefly describes his research interests and history.
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Affiliation(s)
- Germán Rivas
- Systems Biochemistry Lab, Department of Structural and Chemical Biology, CIB Margarita Salas – CSIC, 28040 Madrid, Spain
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6
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Sharma AK, Poddar SM, Chakraborty J, Nayak BS, Kalathil S, Mitra N, Gayathri P, Srinivasan R. A mechanism of salt bridge-mediated resistance to FtsZ inhibitor PC190723 revealed by a cell-based screen. Mol Biol Cell 2023; 34:ar16. [PMID: 36652338 PMCID: PMC10011733 DOI: 10.1091/mbc.e22-12-0538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Bacterial cell division proteins, especially the tubulin homologue FtsZ, have emerged as strong targets for developing new antibiotics. Here, we have utilized the fission yeast heterologous expression system to develop a cell-based assay to screen for small molecules that directly and specifically target the bacterial cell division protein FtsZ. The strategy also allows for simultaneous assessment of the toxicity of the drugs to eukaryotic yeast cells. As a proof-of-concept of the utility of this assay, we demonstrate the effect of the inhibitors sanguinarine, berberine, and PC190723 on FtsZ. Though sanguinarine and berberine affect FtsZ polymerization, they exert a toxic effect on the cells. Further, using this assay system, we show that PC190723 affects Helicobacter pylori FtsZ function and gain new insights into the molecular determinants of resistance to PC190723. On the basis of sequence and structural analysis and site-specific mutations, we demonstrate that the presence of salt bridge interactions between the central H7 helix and β-strands S9 and S10 mediates resistance to PC190723 in FtsZ. The single-step in vivo cell-based assay using fission yeast enabled us to dissect the contribution of sequence-specific features of FtsZ and cell permeability effects associated with bacterial cell envelopes. Thus, our assay serves as a potent tool to rapidly identify novel compounds targeting polymeric bacterial cytoskeletal proteins like FtsZ to understand how they alter polymerization dynamics and address resistance determinants in targets.
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Affiliation(s)
- Ajay Kumar Sharma
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Centre for Interdisciplinary Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Homi Bhabha National Institutes, Anushakti Nagar, Mumbai 400094, India
| | - Sakshi Mahesh Poddar
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Centre for Interdisciplinary Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Homi Bhabha National Institutes, Anushakti Nagar, Mumbai 400094, India
| | - Joyeeta Chakraborty
- Biology, Indian Institute of Science Education and Research, Pune 411008, India
| | - Bhagyashri Soumya Nayak
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Centre for Interdisciplinary Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Homi Bhabha National Institutes, Anushakti Nagar, Mumbai 400094, India
| | - Srilakshmi Kalathil
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Centre for Interdisciplinary Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Homi Bhabha National Institutes, Anushakti Nagar, Mumbai 400094, India
| | - Nivedita Mitra
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Centre for Interdisciplinary Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Homi Bhabha National Institutes, Anushakti Nagar, Mumbai 400094, India
| | - Pananghat Gayathri
- Biology, Indian Institute of Science Education and Research, Pune 411008, India
| | - Ramanujam Srinivasan
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Centre for Interdisciplinary Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Homi Bhabha National Institutes, Anushakti Nagar, Mumbai 400094, India
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7
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Zorrilla S, Monterroso B, Robles-Ramos MÁ, Margolin W, Rivas G. FtsZ Interactions and Biomolecular Condensates as Potential Targets for New Antibiotics. Antibiotics (Basel) 2021; 10:antibiotics10030254. [PMID: 33806332 PMCID: PMC7999717 DOI: 10.3390/antibiotics10030254] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 02/25/2021] [Accepted: 02/26/2021] [Indexed: 12/18/2022] Open
Abstract
FtsZ is an essential and central protein for cell division in most bacteria. Because of its ability to organize into dynamic polymers at the cell membrane and recruit other protein partners to form a “divisome”, FtsZ is a leading target in the quest for new antibacterial compounds. Strategies to potentially arrest the essential and tightly regulated cell division process include perturbing FtsZ’s ability to interact with itself and other divisome proteins. Here, we discuss the available methodologies to screen for and characterize those interactions. In addition to assays that measure protein-ligand interactions in solution, we also discuss the use of minimal membrane systems and cell-like compartments to better approximate the native bacterial cell environment and hence provide a more accurate assessment of a candidate compound’s potential in vivo effect. We particularly focus on ways to measure and inhibit under-explored interactions between FtsZ and partner proteins. Finally, we discuss recent evidence that FtsZ forms biomolecular condensates in vitro, and the potential implications of these assemblies in bacterial resistance to antibiotic treatment.
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Affiliation(s)
- Silvia Zorrilla
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain; (M.-Á.R.-R.); (G.R.)
- Correspondence: (S.Z.); (B.M.); Tel.: +34-91-837-3112 (S.Z. & B.M.)
| | - Begoña Monterroso
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain; (M.-Á.R.-R.); (G.R.)
- Correspondence: (S.Z.); (B.M.); Tel.: +34-91-837-3112 (S.Z. & B.M.)
| | - Miguel-Ángel Robles-Ramos
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain; (M.-Á.R.-R.); (G.R.)
| | - William Margolin
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas, Houston, TX 77030, USA;
| | - Germán Rivas
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain; (M.-Á.R.-R.); (G.R.)
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8
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Zorrilla S, Mónico A, Duarte S, Rivas G, Pérez-Sala D, Pajares MA. Integrated approaches to unravel the impact of protein lipoxidation on macromolecular interactions. Free Radic Biol Med 2019; 144:203-217. [PMID: 30991143 DOI: 10.1016/j.freeradbiomed.2019.04.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 04/03/2019] [Accepted: 04/10/2019] [Indexed: 12/13/2022]
Abstract
Protein modification by lipid derived reactive species, or lipoxidation, is increased during oxidative stress, a common feature observed in many pathological conditions. Biochemical and functional consequences of lipoxidation include changes in the conformation and assembly of the target proteins, altered recognition of ligands and/or cofactors, changes in the interactions with DNA or in protein-protein interactions, modifications in membrane partitioning and binding and/or subcellular localization. These changes may impact, directly or indirectly, signaling pathways involved in the activation of cell defense mechanisms, but when these are overwhelmed they may lead to pathological outcomes. Mass spectrometry provides state of the art approaches for the identification and characterization of lipoxidized proteins/residues and the modifying species. Nevertheless, understanding the complexity of the functional effects of protein lipoxidation requires the use of additional methodologies. Herein, biochemical and biophysical methods used to detect and measure functional effects of protein lipoxidation at different levels of complexity, from in vitro and reconstituted cell-like systems to cells, are reviewed, focusing especially on macromolecular interactions. Knowledge generated through innovative and complementary technologies will contribute to comprehend the role of lipoxidation in pathophysiology and, ultimately, its potential as target for therapeutic intervention.
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Affiliation(s)
- Silvia Zorrilla
- Dept. of Structural and Chemical Biology, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, 28040, Madrid, Spain.
| | - Andreia Mónico
- Dept. of Structural and Chemical Biology, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Sofia Duarte
- Dept. of Structural and Chemical Biology, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Germán Rivas
- Dept. of Structural and Chemical Biology, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Dolores Pérez-Sala
- Dept. of Structural and Chemical Biology, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - María A Pajares
- Dept. of Structural and Chemical Biology, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, 28040, Madrid, Spain.
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9
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Sobrinos-Sanguino M, Vélez M, Richter RP, Rivas G. Reversible Membrane Tethering by ZipA Determines FtsZ Polymerization in Two and Three Dimensions. Biochemistry 2019; 58:4003-4015. [PMID: 31390865 DOI: 10.1021/acs.biochem.9b00378] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In most bacteria, the early step of septum formation implies the association of soluble FtsZ polymers with the cytoplasmic membrane. ZipA, together with FtsA, provides membrane tethering to FtsZ in Escherichia coli, forming a dynamic proto-ring that serves as an assembly scaffold for the remaining elements of the divisome. Despite their importance for bacterial cell division, multivalent interactions between proto-ring elements at membrane surfaces remain poorly characterized in quantitative terms. We measured the binding of FtsZ to ZipA incorporated in supported lipid bilayers at controlled densities by using a combination of biophysical surface-sensitive techniques (quartz crystal microbalance and spectroscopic ellipsometry) and analyzed how ZipA density and FtsZ concentration control the state of assembly of FtsZ. We found that ZipA attachment enables FtsZ-GMPCPP (where GMPCPP is a GTP analogue with a reduced level of hydrolysis) to assemble in several distinct ways: (i) two-dimensional polymerization at the membrane and (ii) three-dimensional polymerization from the membrane into the solution phase where this may be associated with the formation of higher-order complexes. In these processes, ZipA is required to enrich FtsZ at the surface but the FtsZ bulk concentration defines which morphology is being formed. Moreover, we report a strong effect of the nucleotide (GDP vs GMPCPP/GTP) on the kinetics of ZipA association/dissociation of FtsZ. These results provide insights into the mode of interaction of proto-ring elements in minimal membrane systems and contribute to the completion of our understanding of the initial events of bacterial division.
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Affiliation(s)
- Marta Sobrinos-Sanguino
- Centro de Investigaciones Biológicas , Consejo Superior de Investigaciones Científicas (CSIC) , 28040 Madrid , Spain.,School of Biomedical Sciences, Faculty of Biological Sciences, School of Physics and Astronomy, Faculty of Engineering and Physical Sciences, and Astbury Centre for Structural Molecular Biology , University of Leeds , Leeds LS2 9JT , United Kingdom
| | - Marisela Vélez
- Instituto de Catálisis y Petroleoquímica , CSIC , 28049 Madrid , Spain
| | - Ralf P Richter
- School of Biomedical Sciences, Faculty of Biological Sciences, School of Physics and Astronomy, Faculty of Engineering and Physical Sciences, and Astbury Centre for Structural Molecular Biology , University of Leeds , Leeds LS2 9JT , United Kingdom.,Biosurfaces Lab , CIC biomaGUNE , 20014 San Sebastian , Spain
| | - Germán Rivas
- Centro de Investigaciones Biológicas , Consejo Superior de Investigaciones Científicas (CSIC) , 28040 Madrid , Spain
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10
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Montecinos-Franjola F, Chaturvedi SK, Schuck P, Sackett DL. All tubulins are not alike: Heterodimer dissociation differs among different biological sources. J Biol Chem 2019; 294:10315-10324. [PMID: 31110044 DOI: 10.1074/jbc.ra119.007973] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 05/10/2019] [Indexed: 12/27/2022] Open
Abstract
Tubulin, the subunit of microtubules, is a noncovalent heterodimer composed of one α- and one β-tubulin monomer. Both tubulins are encoded by multiple genes or composed of different isotypes, which are differentially expressed in different tissues and in development. Tubulin αβ dimers are found throughout the eukaryotes and, although very similar, are known to differ among organisms. We seek to investigate tubulins from different tissues and different organisms for a basic physical characteristic: heterodimer stability and monomer exchange between heterodimers. We previously showed that mammalian brain tubulin heterodimers reversibly dissociate, following the mass action law. Dissociation yields native monomers that can exchange with added tubulin to form new heterodimers. Here, we compared the dissociation of tubulins from multiple sources, including mammalian (rat) brain, cultured human cells (HeLa cells), chicken brain, chicken erythrocytes, and the protozoan Leishmania We used fluorescence-detected analytical ultracentrifugation to measure tubulin dissociation over a >1000-fold range in concentration and found that tubulin heterodimers from different biological sources differ in Kd by as much as 150-fold under the same conditions. Furthermore, when fluorescent tracer tubulins from various sources were titrated with unlabeled tubulin from a single source (rat brain tubulin), heterologous dimerization occurred, exhibiting similar affinities, in some cases binding even more strongly than with autologous tubulin. These results provide additional insight into the regulation of heterodimer formation of tubulin from different biological sources, revealing that monomer exchange appears to contribute to the sorting of α- and β-tubulin monomers that associate following tubulin folding.
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Affiliation(s)
| | - Sumit K Chaturvedi
- Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics, NIBIB, National Institutes of Health, Bethesda, Maryland 20892
| | - Peter Schuck
- Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics, NIBIB, National Institutes of Health, Bethesda, Maryland 20892
| | - Dan L Sackett
- From the Division of Basic and Translational Biophysics, NICHD, and
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11
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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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12
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Rivas G, Minton AP. Toward an understanding of biochemical equilibria within living cells. Biophys Rev 2018; 10:241-253. [PMID: 29235084 PMCID: PMC5899707 DOI: 10.1007/s12551-017-0347-6] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 11/13/2017] [Indexed: 12/19/2022] Open
Abstract
Four types of environmental effects that can affect macromolecular reactions in a living cell are defined: nonspecific intermolecular interactions, side reactions, partitioning between microenvironments, and surface interactions. Methods for investigating these interactions and their influence on target reactions in vitro are reviewed. Methods employed to characterize conformational and association equilibria in vivo are reviewed and difficulties in their interpretation cataloged. It is concluded that, in order to be amenable to unambiguous interpretation, in vivo studies must be complemented by in vitro studies carried out in well-characterized and controllable media designed to contain key elements of selected intracellular microenvironments.
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Affiliation(s)
- Germán Rivas
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Allen P. Minton
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892 USA
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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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14
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Minton AP. Recent applications of light scattering measurement in the biological and biopharmaceutical sciences. Anal Biochem 2016; 501:4-22. [PMID: 26896682 PMCID: PMC5804501 DOI: 10.1016/j.ab.2016.02.007] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 02/04/2016] [Accepted: 02/05/2016] [Indexed: 01/09/2023]
Affiliation(s)
- Allen P Minton
- Laboratory of Biochemistry and Genetics, National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, U.S. Department of Health and Human Services, Bethesda, MD, 20892, USA.
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15
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Characterization of the in vitro assembly of FtsZ in Arthrobacter strain A3 using light scattering. Int J Biol Macromol 2016; 91:294-8. [PMID: 27164494 DOI: 10.1016/j.ijbiomac.2016.04.090] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 04/27/2016] [Accepted: 04/28/2016] [Indexed: 12/16/2022]
Abstract
The self-assembly of FtsZ, the bacterial homolog of tubulin, plays an essential role in cell division. Light scattering technique is applied to real-time monitor the in vitro assembly of FtsZ in Arthrobacter strain A3, a newly isolated psychrotrophic bacterium. The critical concentration needed for the assembly is estimated as 6.7μM. The polymerization of FtsZ in Arthrobacter strain A3 requires both GTP and divalent metal ions, while salt is an unfavorable condition for the assembly. The FtsZ polymerizes under a wide range of pHs, with the fastest rate around pH 6.0. The FtsZ from Arthrobacter strain A3 resembles Mycobacterium tuberculosis FtsZ in terms of the dependence on divalent metal ions and the slow polymerization rate, while it is different from M. tuberculosis FtsZ considering the sensitivity to salt and pH. The comparison of FtsZ from different organisms will greatly advance our understanding of the biological role of the key cell division protein.
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16
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Salvarelli E, Krupka M, Rivas G, Mingorance J, Gómez-Puertas P, Alfonso C, Rico AI. The Cell Division Protein FtsZ from Streptococcus pneumoniae Exhibits a GTPase Activity Delay. J Biol Chem 2015; 290:25081-9. [PMID: 26330552 DOI: 10.1074/jbc.m115.650077] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Indexed: 11/06/2022] Open
Abstract
The cell division protein FtsZ assembles in vitro by a mechanism of cooperative association dependent on GTP, monovalent cations, and Mg(2+). We have analyzed the GTPase activity and assembly dynamics of Streptococcus pneumoniae FtsZ (SpnFtsZ). SpnFtsZ assembled in an apparently cooperative process, with a higher critical concentration than values reported for other FtsZ proteins. It sedimented in the presence of GTP as a high molecular mass polymer with a well defined size and tended to form double-stranded filaments in electron microscope preparations. GTPase activity depended on K(+) and Mg(2+) and was inhibited by Na(+). GTP hydrolysis exhibited a delay that included a lag phase followed by a GTP hydrolysis activation step, until reaction reached the GTPase rate. The lag phase was not found in polymer assembly, suggesting a transition from an initial non-GTP-hydrolyzing polymer that switches to a GTP-hydrolyzing polymer, supporting models that explain FtsZ polymer cooperativity.
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Affiliation(s)
- Estefanía Salvarelli
- From the Servicio de Microbiología, Hospital Universitario La Paz, IdiPAZ, 28046 Madrid, Spain, Biomol-Informatics S.L., Universidad Autónoma, 28049 Madrid, Spain,
| | | | - Germán Rivas
- the Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, 28040 Madrid, Spain
| | - Jesus Mingorance
- From the Servicio de Microbiología, Hospital Universitario La Paz, IdiPAZ, 28046 Madrid, Spain
| | - Paulino Gómez-Puertas
- Biomol-Informatics S.L., Universidad Autónoma, 28049 Madrid, Spain, the Molecular Modelling Group, Centro de Biología Molecular "Severo Ochoa," Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain, and
| | - Carlos Alfonso
- the Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, 28040 Madrid, Spain
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17
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Cabré EJ, Monterroso B, Alfonso C, Sánchez-Gorostiaga A, Reija B, Jiménez M, Vicente M, Zorrilla S, Rivas G. The Nucleoid Occlusion SlmA Protein Accelerates the Disassembly of the FtsZ Protein Polymers without Affecting Their GTPase Activity. PLoS One 2015; 10:e0126434. [PMID: 25950808 PMCID: PMC4423959 DOI: 10.1371/journal.pone.0126434] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 04/02/2015] [Indexed: 11/20/2022] Open
Abstract
Division site selection is achieved in bacteria by different mechanisms, one of them being nucleoid occlusion, which prevents Z-ring assembly nearby the chromosome. Nucleoid occlusion in E. coli is mediated by SlmA, a sequence specific DNA binding protein that antagonizes FtsZ assembly. Here we show that, when bound to its specific target DNA sequences (SBS), SlmA reduces the lifetime of the FtsZ protofilaments in solution and of the FtsZ bundles when located inside permeable giant vesicles. This effect appears to be essentially uncoupled from the GTPase activity of the FtsZ protofilaments, which is insensitive to the presence of SlmA·SBS. The interaction of SlmA·SBS with either FtsZ protofilaments containing GTP or FtsZ oligomers containing GDP results in the disassembly of FtsZ polymers. We propose that SlmA·SBS complexes control the polymerization state of FtsZ by accelerating the disassembly of the FtsZ polymers leading to their fragmentation into shorter species that are still able to hydrolyze GTP at the same rate. SlmA defines therefore a new class of inhibitors of the FtsZ ring different from the SOS response regulator SulA and from the moonlighting enzyme OpgH, inhibitors of the GTPase activity. SlmA also shows differences compared with MinC, the inhibitor of the division site selection Min system, which shortens FtsZ protofilaments by interacting with the GDP form of FtsZ.
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Affiliation(s)
- Elisa J. Cabré
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Begoña Monterroso
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Carlos Alfonso
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Alicia Sánchez-Gorostiaga
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Belén Reija
- Instituto de Química-Física Rocasolano, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Mercedes Jiménez
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Miguel Vicente
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Silvia Zorrilla
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
- Instituto de Química-Física Rocasolano, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
- * E-mail: (GR); (SZ)
| | - Germán Rivas
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
- * E-mail: (GR); (SZ)
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18
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Zhao H, Schuck P. Combining biophysical methods for the analysis of protein complex stoichiometry and affinity in SEDPHAT. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2015; 71:3-14. [PMID: 25615855 PMCID: PMC4304681 DOI: 10.1107/s1399004714010372] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 05/07/2014] [Indexed: 12/29/2022]
Abstract
Reversible macromolecular interactions are ubiquitous in signal transduction pathways, often forming dynamic multi-protein complexes with three or more components. Multivalent binding and cooperativity in these complexes are often key motifs of their biological mechanisms. Traditional solution biophysical techniques for characterizing the binding and cooperativity are very limited in the number of states that can be resolved. A global multi-method analysis (GMMA) approach has recently been introduced that can leverage the strengths and the different observables of different techniques to improve the accuracy of the resulting binding parameters and to facilitate the study of multi-component systems and multi-site interactions. Here, GMMA is described in the software SEDPHAT for the analysis of data from isothermal titration calorimetry, surface plasmon resonance or other biosensing, analytical ultracentrifugation, fluorescence anisotropy and various other spectroscopic and thermodynamic techniques. The basic principles of these techniques are reviewed and recent advances in view of their particular strengths in the context of GMMA are described. Furthermore, a new feature in SEDPHAT is introduced for the simulation of multi-method data. In combination with specific statistical tools for GMMA in SEDPHAT, simulations can be a valuable step in the experimental design.
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Affiliation(s)
- Huaying Zhao
- Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
| | - Peter Schuck
- Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
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19
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Jiménez M, Martos A, Cabré EJ, Raso A, Rivas G. Giant vesicles: a powerful tool to reconstruct bacterial division assemblies in cell-like compartments. Environ Microbiol 2013; 15:3158-68. [DOI: 10.1111/1462-2920.12214] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 07/10/2013] [Accepted: 07/11/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Mercedes Jiménez
- Centro de Investigaciones Biológicas; CSIC; c/Ramiro de Maeztu 9 28040 Madrid Spain
| | - Ariadna Martos
- Max Planck Institute of Biochemistry; Am Klopferspitz 18 D-82152 Martinsried Germany
| | - Elisa J. Cabré
- Centro de Investigaciones Biológicas; CSIC; c/Ramiro de Maeztu 9 28040 Madrid Spain
| | - Ana Raso
- Centro de Investigaciones Biológicas; CSIC; c/Ramiro de Maeztu 9 28040 Madrid Spain
- Max Planck Institute of Biochemistry; Am Klopferspitz 18 D-82152 Martinsried Germany
| | - Germán Rivas
- Centro de Investigaciones Biológicas; CSIC; c/Ramiro de Maeztu 9 28040 Madrid Spain
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20
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Ahijado-Guzmán R, Alfonso C, Reija B, Salvarelli E, Mingorance J, Zorrilla S, Monterroso B, Rivas G. Control by potassium of the size distribution of Escherichia coli FtsZ polymers is independent of GTPase activity. J Biol Chem 2013; 288:27358-27365. [PMID: 23940054 DOI: 10.1074/jbc.m113.482943] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The influence of potassium content (at neutral pH and millimolar Mg(2+)) on the size distribution of FtsZ polymers formed in the presence of constantly replenished GTP under steady-state conditions was studied by a combination of biophysical methods. The size of the GTP-FtsZ polymers decreased with lower potassium concentration, in contrast with the increase in the mass of the GDP-FtsZ oligomers, whereas no effect was observed on FtsZ GTPase activity and critical concentration of polymerization. Remarkably, the concerted formation of a narrow size distribution of GTP-FtsZ polymers previously observed at high salt concentration was maintained in all KCl concentrations tested. Polymers induced with guanosine 5'-(α,β-methylene)triphosphate, a slowly hydrolyzable analog of GTP, became larger and polydisperse as the potassium concentration was decreased. Our results suggest that the potassium dependence of the GTP-FtsZ polymer size may be related to changes in the subunit turnover rate that are independent of the GTP hydrolysis rate. The formation of a narrow size distribution of FtsZ polymers under very different solution conditions indicates that it is an inherent feature of FtsZ, not observed in other filament-forming proteins, with potential implications in the structural organization of the functional Z-ring.
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Affiliation(s)
- Rubén Ahijado-Guzmán
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid
| | - Carlos Alfonso
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid
| | - Belén Reija
- Instituto de Química-Física Rocasolano, CSIC, 28006 Madrid
| | - Estefanía Salvarelli
- Servicio de Microbiología, Hospital Universitario La Paz, IdiPAZ, 28046 Madrid; Biomol Informatics SL, Cantoblanco, 28049 Madrid, Spain
| | - Jesús Mingorance
- Servicio de Microbiología, Hospital Universitario La Paz, IdiPAZ, 28046 Madrid
| | | | - Begoña Monterroso
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid.
| | - Germán Rivas
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid.
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Hernández-Rocamora VM, García-Montañés C, Reija B, Monterroso B, Margolin W, Alfonso C, Zorrilla S, Rivas G. MinC protein shortens FtsZ protofilaments by preferentially interacting with GDP-bound subunits. J Biol Chem 2013; 288:24625-35. [PMID: 23853099 DOI: 10.1074/jbc.m113.483222] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The interaction of MinC with FtsZ and its effects on FtsZ polymerization were studied under close to physiological conditions by a combination of biophysical methods. The Min system is a widely conserved mechanism in bacteria that ensures the correct placement of the division machinery at midcell. MinC is the component of this system that effectively interacts with FtsZ and inhibits the formation of the Z-ring. Here we report that MinC produces a concentration-dependent reduction in the size of GTP-induced FtsZ protofilaments (FtsZ-GTP) as demonstrated by analytical ultracentrifugation, dynamic light scattering, fluorescence correlation spectroscopy, and electron microscopy. Our experiments show that, despite being shorter, FtsZ protofilaments maintain their narrow distribution in size in the presence of MinC. The protein had the same effect regardless of its addition prior to or after FtsZ polymerization. Fluorescence anisotropy measurements indicated that MinC bound to FtsZ-GDP with a moderate affinity (apparent KD ∼10 μM at 100 mm KCl and pH 7.5) very close to the MinC concentration corresponding to the midpoint of the inhibition of FtsZ assembly. Only marginal binding of MinC to FtsZ-GTP protofilaments was observed by analytical ultracentrifugation and fluorescence correlation spectroscopy. Remarkably, MinC effects on FtsZ-GTP protofilaments and binding affinity to FtsZ-GDP were strongly dependent on ionic strength, being severely reduced at 500 mM KCl compared with 100 mM KCl. Our results support a mechanism in which MinC interacts with FtsZ-GDP, resulting in smaller protofilaments of defined size and having the same effect on both preassembled and growing FtsZ protofilaments.
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Affiliation(s)
- Víctor M Hernández-Rocamora
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain
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