--- _id: '7572' abstract: - lang: eng text: The polymerization–depolymerization dynamics of cytoskeletal proteins play essential roles in the self-organization of cytoskeletal structures, in eukaryotic as well as prokaryotic cells. While advances in fluorescence microscopy and in vitro reconstitution experiments have helped to study the dynamic properties of these complex systems, methods that allow to collect and analyze large quantitative datasets of the underlying polymer dynamics are still missing. Here, we present a novel image analysis workflow to study polymerization dynamics of active filaments in a nonbiased, highly automated manner. Using treadmilling filaments of the bacterial tubulin FtsZ as an example, we demonstrate that our method is able to specifically detect, track and analyze growth and shrinkage of polymers, even in dense networks of filaments. We believe that this automated method can facilitate the analysis of a large variety of dynamic cytoskeletal systems, using standard time-lapse movies obtained from experiments in vitro as well as in the living cell. Moreover, we provide scripts implementing this method as supplementary material. alternative_title: - Methods in Cell Biology article_processing_charge: No author: - first_name: Paulo R full_name: Dos Santos Caldas, Paulo R id: 38FCDB4C-F248-11E8-B48F-1D18A9856A87 last_name: Dos Santos Caldas orcid: 0000-0001-6730-4461 - first_name: Philipp full_name: Radler, Philipp id: 40136C2A-F248-11E8-B48F-1D18A9856A87 last_name: Radler orcid: '0000-0001-9198-2182 ' - first_name: Christoph M full_name: Sommer, Christoph M id: 4DF26D8C-F248-11E8-B48F-1D18A9856A87 last_name: Sommer orcid: 0000-0003-1216-9105 - first_name: Martin full_name: Loose, Martin id: 462D4284-F248-11E8-B48F-1D18A9856A87 last_name: Loose orcid: 0000-0001-7309-9724 citation: ama: 'Dos Santos Caldas PR, Radler P, Sommer CM, Loose M. Computational analysis of filament polymerization dynamics in cytoskeletal networks. In: Tran P, ed. Methods in Cell Biology. Vol 158. Elsevier; 2020:145-161. doi:10.1016/bs.mcb.2020.01.006' apa: Dos Santos Caldas, P. R., Radler, P., Sommer, C. M., & Loose, M. (2020). Computational analysis of filament polymerization dynamics in cytoskeletal networks. In P. Tran (Ed.), Methods in Cell Biology (Vol. 158, pp. 145–161). Elsevier. https://doi.org/10.1016/bs.mcb.2020.01.006 chicago: Dos Santos Caldas, Paulo R, Philipp Radler, Christoph M Sommer, and Martin Loose. “Computational Analysis of Filament Polymerization Dynamics in Cytoskeletal Networks.” In Methods in Cell Biology, edited by Phong Tran, 158:145–61. Elsevier, 2020. https://doi.org/10.1016/bs.mcb.2020.01.006. ieee: P. R. Dos Santos Caldas, P. Radler, C. M. Sommer, and M. Loose, “Computational analysis of filament polymerization dynamics in cytoskeletal networks,” in Methods in Cell Biology, vol. 158, P. Tran, Ed. Elsevier, 2020, pp. 145–161. ista: 'Dos Santos Caldas PR, Radler P, Sommer CM, Loose M. 2020.Computational analysis of filament polymerization dynamics in cytoskeletal networks. In: Methods in Cell Biology. Methods in Cell Biology, vol. 158, 145–161.' mla: Dos Santos Caldas, Paulo R., et al. “Computational Analysis of Filament Polymerization Dynamics in Cytoskeletal Networks.” Methods in Cell Biology, edited by Phong Tran, vol. 158, Elsevier, 2020, pp. 145–61, doi:10.1016/bs.mcb.2020.01.006. short: P.R. Dos Santos Caldas, P. Radler, C.M. Sommer, M. Loose, in:, P. Tran (Ed.), Methods in Cell Biology, Elsevier, 2020, pp. 145–161. date_created: 2020-03-08T23:00:47Z date_published: 2020-02-27T00:00:00Z date_updated: 2023-10-04T09:50:24Z day: '27' department: - _id: MaLo doi: 10.1016/bs.mcb.2020.01.006 ec_funded: 1 editor: - first_name: 'Phong ' full_name: 'Tran, Phong ' last_name: Tran external_id: isi: - '000611826500008' intvolume: ' 158' isi: 1 language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1101/839571 month: '02' oa: 1 oa_version: Preprint page: 145-161 project: - _id: 2595697A-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '679239' name: Self-Organization of the Bacterial Cell - _id: 260D98C8-B435-11E9-9278-68D0E5697425 name: Reconstitution of Bacterial Cell Division Using Purified Components publication: Methods in Cell Biology publication_identifier: issn: - 0091679X publication_status: published publisher: Elsevier quality_controlled: '1' related_material: record: - id: '8358' relation: part_of_dissertation status: public scopus_import: '1' status: public title: Computational analysis of filament polymerization dynamics in cytoskeletal networks type: book_chapter user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 volume: 158 year: '2020' ... --- _id: '153' abstract: - lang: eng text: Cells migrating in multicellular organisms steadily traverse complex three-dimensional (3D) environments. To decipher the underlying cell biology, current experimental setups either use simplified 2D, tissue-mimetic 3D (e.g., collagen matrices) or in vivo environments. While only in vivo experiments are truly physiological, they do not allow for precise manipulation of environmental parameters. 2D in vitro experiments do allow mechanical and chemical manipulations, but increasing evidence demonstrates substantial differences of migratory mechanisms in 2D and 3D. Here, we describe simple, robust, and versatile “pillar forests” to investigate cell migration in complex but fully controllable 3D environments. Pillar forests are polydimethylsiloxane-based setups, in which two closely adjacent surfaces are interconnected by arrays of micrometer-sized pillars. Changing the pillar shape, size, height and the inter-pillar distance precisely manipulates microenvironmental parameters (e.g., pore sizes, micro-geometry, micro-topology), while being easily combined with chemotactic cues, surface coatings, diverse cell types and advanced imaging techniques. Thus, pillar forests combine the advantages of 2D cell migration assays with the precise definition of 3D environmental parameters. article_processing_charge: No author: - first_name: Jörg full_name: Renkawitz, Jörg id: 3F0587C8-F248-11E8-B48F-1D18A9856A87 last_name: Renkawitz orcid: 0000-0003-2856-3369 - first_name: Anne full_name: Reversat, Anne id: 35B76592-F248-11E8-B48F-1D18A9856A87 last_name: Reversat orcid: 0000-0003-0666-8928 - first_name: Alexander F full_name: Leithner, Alexander F id: 3B1B77E4-F248-11E8-B48F-1D18A9856A87 last_name: Leithner orcid: 0000-0002-1073-744X - first_name: Jack full_name: Merrin, Jack id: 4515C308-F248-11E8-B48F-1D18A9856A87 last_name: Merrin orcid: 0000-0001-5145-4609 - first_name: Michael K full_name: Sixt, Michael K id: 41E9FBEA-F248-11E8-B48F-1D18A9856A87 last_name: Sixt orcid: 0000-0002-6620-9179 citation: ama: 'Renkawitz J, Reversat A, Leithner AF, Merrin J, Sixt MK. Micro-engineered “pillar forests” to study cell migration in complex but controlled 3D environments. In: Methods in Cell Biology. Vol 147. Academic Press; 2018:79-91. doi:10.1016/bs.mcb.2018.07.004' apa: Renkawitz, J., Reversat, A., Leithner, A. F., Merrin, J., & Sixt, M. K. (2018). Micro-engineered “pillar forests” to study cell migration in complex but controlled 3D environments. In Methods in Cell Biology (Vol. 147, pp. 79–91). Academic Press. https://doi.org/10.1016/bs.mcb.2018.07.004 chicago: Renkawitz, Jörg, Anne Reversat, Alexander F Leithner, Jack Merrin, and Michael K Sixt. “Micro-Engineered ‘Pillar Forests’ to Study Cell Migration in Complex but Controlled 3D Environments.” In Methods in Cell Biology, 147:79–91. Academic Press, 2018. https://doi.org/10.1016/bs.mcb.2018.07.004. ieee: J. Renkawitz, A. Reversat, A. F. Leithner, J. Merrin, and M. K. Sixt, “Micro-engineered ‘pillar forests’ to study cell migration in complex but controlled 3D environments,” in Methods in Cell Biology, vol. 147, Academic Press, 2018, pp. 79–91. ista: 'Renkawitz J, Reversat A, Leithner AF, Merrin J, Sixt MK. 2018.Micro-engineered “pillar forests” to study cell migration in complex but controlled 3D environments. In: Methods in Cell Biology. vol. 147, 79–91.' mla: Renkawitz, Jörg, et al. “Micro-Engineered ‘Pillar Forests’ to Study Cell Migration in Complex but Controlled 3D Environments.” Methods in Cell Biology, vol. 147, Academic Press, 2018, pp. 79–91, doi:10.1016/bs.mcb.2018.07.004. short: J. Renkawitz, A. Reversat, A.F. Leithner, J. Merrin, M.K. Sixt, in:, Methods in Cell Biology, Academic Press, 2018, pp. 79–91. date_created: 2018-12-11T11:44:54Z date_published: 2018-07-27T00:00:00Z date_updated: 2023-09-13T08:56:35Z day: '27' department: - _id: MiSi - _id: NanoFab doi: 10.1016/bs.mcb.2018.07.004 external_id: isi: - '000452412300006' pmid: - '30165964' intvolume: ' 147' isi: 1 language: - iso: eng month: '07' oa_version: None page: 79 - 91 pmid: 1 publication: Methods in Cell Biology publication_identifier: issn: - 0091679X publication_status: published publisher: Academic Press publist_id: '7768' quality_controlled: '1' scopus_import: '1' status: public title: Micro-engineered “pillar forests” to study cell migration in complex but controlled 3D environments type: book_chapter user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1 volume: 147 year: '2018' ... --- _id: '1213' abstract: - lang: eng text: Bacterial cytokinesis is commonly initiated by the Z-ring, a dynamic cytoskeletal structure that assembles at the site of division. Its primary component is FtsZ, a tubulin-like GTPase, that like its eukaryotic relative forms protein filaments in the presence of GTP. Since the discovery of the Z-ring 25 years ago, various models for the role of FtsZ have been suggested. However, important information about the architecture and dynamics of FtsZ filaments during cytokinesis is still missing. One reason for this lack of knowledge has been the small size of bacteria, which has made it difficult to resolve the orientation and dynamics of individual FtsZ filaments in the Z-ring. While superresolution microscopy experiments have helped to gain more information about the organization of the Z-ring in the dividing cell, they were not yet able to elucidate a mechanism of how FtsZ filaments reorganize during assembly and disassembly of the Z-ring. In this chapter, we explain how to use an in vitro reconstitution approach to investigate the self-organization of FtsZ filaments recruited to a biomimetic lipid bilayer by its membrane anchor FtsA. We show how to perform single-molecule experiments to study the behavior of individual FtsZ monomers during the constant reorganization of the FtsZ-FtsA filament network. We describe how to analyze the dynamics of single molecules and explain why this information can help to shed light onto possible mechanism of Z-ring constriction. We believe that similar experimental approaches will be useful to study the mechanism of membrane-based polymerization of other cytoskeletal systems, not only from prokaryotic but also eukaryotic origin. acknowledged_ssus: - _id: Bio acknowledgement: Natalia Baranova is supported by an EMBO Long-Term Fellowship (EMBO ALTF 1163-2015) and Martin Loose by an ERC Starting Grant (ERCStG-2015-SelfOrganiCell). alternative_title: - Methods in Cell Biology article_processing_charge: No author: - first_name: Natalia full_name: Baranova, Natalia id: 38661662-F248-11E8-B48F-1D18A9856A87 last_name: Baranova orcid: 0000-0002-3086-9124 - first_name: Martin full_name: Loose, Martin id: 462D4284-F248-11E8-B48F-1D18A9856A87 last_name: Loose orcid: 0000-0001-7309-9724 citation: ama: 'Baranova NS, Loose M. Single-molecule measurements to study polymerization dynamics of FtsZ-FtsA copolymers. In: Echard A, ed. Cytokinesis. Vol 137. Academic Press; 2017:355-370. doi:10.1016/bs.mcb.2016.03.036' apa: Baranova, N. S., & Loose, M. (2017). Single-molecule measurements to study polymerization dynamics of FtsZ-FtsA copolymers. In A. Echard (Ed.), Cytokinesis (Vol. 137, pp. 355–370). Academic Press. https://doi.org/10.1016/bs.mcb.2016.03.036 chicago: Baranova, Natalia S., and Martin Loose. “Single-Molecule Measurements to Study Polymerization Dynamics of FtsZ-FtsA Copolymers.” In Cytokinesis, edited by Arnaud Echard, 137:355–70. Academic Press, 2017. https://doi.org/10.1016/bs.mcb.2016.03.036. ieee: N. S. Baranova and M. Loose, “Single-molecule measurements to study polymerization dynamics of FtsZ-FtsA copolymers,” in Cytokinesis, vol. 137, A. Echard, Ed. Academic Press, 2017, pp. 355–370. ista: 'Baranova NS, Loose M. 2017.Single-molecule measurements to study polymerization dynamics of FtsZ-FtsA copolymers. In: Cytokinesis. Methods in Cell Biology, vol. 137, 355–370.' mla: Baranova, Natalia S., and Martin Loose. “Single-Molecule Measurements to Study Polymerization Dynamics of FtsZ-FtsA Copolymers.” Cytokinesis, edited by Arnaud Echard, vol. 137, Academic Press, 2017, pp. 355–70, doi:10.1016/bs.mcb.2016.03.036. short: N.S. Baranova, M. Loose, in:, A. Echard (Ed.), Cytokinesis, Academic Press, 2017, pp. 355–370. date_created: 2018-12-11T11:50:45Z date_published: 2017-12-01T00:00:00Z date_updated: 2023-09-20T11:16:30Z day: '01' department: - _id: MaLo doi: 10.1016/bs.mcb.2016.03.036 ec_funded: 1 editor: - first_name: 'Arnaud ' full_name: 'Echard, Arnaud ' last_name: Echard external_id: isi: - '000403542900022' intvolume: ' 137' isi: 1 language: - iso: eng month: '12' oa_version: None page: 355 - 370 project: - _id: 2596EAB6-B435-11E9-9278-68D0E5697425 grant_number: ALTF 2015-1163 name: Synthesis of bacterial cell wall - _id: 25681D80-B435-11E9-9278-68D0E5697425 call_identifier: FP7 grant_number: '291734' name: International IST Postdoc Fellowship Programme publication: Cytokinesis publication_identifier: issn: - 0091679X publication_status: published publisher: Academic Press publist_id: '6134' quality_controlled: '1' scopus_import: '1' status: public title: Single-molecule measurements to study polymerization dynamics of FtsZ-FtsA copolymers type: book_chapter user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1 volume: 137 year: '2017' ...