--- _id: '8341' abstract: - lang: eng text: "One of the most striking hallmarks of the eukaryotic cell is the presence of intracellular vesicles and organelles. Each of these membrane-enclosed compartments has a distinct composition of lipids and proteins, which is essential for accurate membrane traffic and homeostasis. Interestingly, their biochemical identities are achieved with the help\r\nof small GTPases of the Rab family, which cycle between GDP- and GTP-bound forms on the selected membrane surface. While this activity switch is well understood for an individual protein, how Rab GTPases collectively transition between states to generate decisive signal propagation in space and time is unclear. In my PhD thesis, I present\r\nin vitro reconstitution experiments with theoretical modeling to systematically study a minimal Rab5 activation network from bottom-up. We find that positive feedback based on known molecular interactions gives rise to bistable GTPase activity switching on system’s scale. Furthermore, we determine that collective transition near the critical\r\npoint is intrinsically stochastic and provide evidence that the inactive Rab5 abundance on the membrane can shape the network response. Finally, we demonstrate that collective switching can spread on the lipid bilayer as a traveling activation wave, representing a possible emergent activity pattern in endosomal maturation. Together, our\r\nfindings reveal new insights into the self-organization properties of signaling networks away from chemical equilibrium. Our work highlights the importance of systematic characterization of biochemical systems in well-defined physiological conditions. This way, we were able to answer long-standing open questions in the field and close the gap between regulatory processes on a molecular scale and emergent responses on system’s level." acknowledged_ssus: - _id: Bio - _id: LifeSc - _id: NanoFab acknowledgement: My thanks goes to the Loose lab members, BioImaging, Life Science and Nanofabrication Facilities and the wonderful international community at IST for sharing this experience with me. alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Urban full_name: Bezeljak, Urban id: 2A58201A-F248-11E8-B48F-1D18A9856A87 last_name: Bezeljak orcid: 0000-0003-1365-5631 citation: ama: Bezeljak U. In vitro reconstitution of a Rab activation switch. 2020. doi:10.15479/AT:ISTA:8341 apa: Bezeljak, U. (2020). In vitro reconstitution of a Rab activation switch. Institute of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:8341 chicago: Bezeljak, Urban. “In Vitro Reconstitution of a Rab Activation Switch.” Institute of Science and Technology Austria, 2020. https://doi.org/10.15479/AT:ISTA:8341. ieee: U. Bezeljak, “In vitro reconstitution of a Rab activation switch,” Institute of Science and Technology Austria, 2020. ista: Bezeljak U. 2020. In vitro reconstitution of a Rab activation switch. Institute of Science and Technology Austria. mla: Bezeljak, Urban. In Vitro Reconstitution of a Rab Activation Switch. Institute of Science and Technology Austria, 2020, doi:10.15479/AT:ISTA:8341. short: U. Bezeljak, In Vitro Reconstitution of a Rab Activation Switch, Institute of Science and Technology Austria, 2020. date_created: 2020-09-08T08:53:53Z date_published: 2020-09-08T00:00:00Z date_updated: 2023-09-07T13:17:06Z day: '08' ddc: - '570' degree_awarded: PhD department: - _id: MaLo doi: 10.15479/AT:ISTA:8341 file: - access_level: closed checksum: 70871b335a595252a66c6bbf0824fb02 content_type: application/x-zip-compressed creator: dernst date_created: 2020-09-08T09:00:29Z date_updated: 2021-09-16T12:49:12Z file_id: '8342' file_name: 2020_Urban_Bezeljak_Thesis_TeX.zip file_size: 65246782 relation: source_file - access_level: open_access checksum: 59a62275088b00b7241e6ff4136434c7 content_type: application/pdf creator: dernst date_created: 2020-09-08T09:00:27Z date_updated: 2021-09-16T12:49:12Z file_id: '8343' file_name: 2020_Urban_Bezeljak_Thesis.pdf file_size: 31259058 relation: main_file file_date_updated: 2021-09-16T12:49:12Z has_accepted_license: '1' language: - iso: eng month: '09' oa: 1 oa_version: Published Version page: '215' publication_identifier: issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '7580' relation: part_of_dissertation status: public status: public supervisor: - first_name: Martin full_name: Loose, Martin id: 462D4284-F248-11E8-B48F-1D18A9856A87 last_name: Loose orcid: 0000-0001-7309-9724 title: In vitro reconstitution of a Rab activation switch tmp: image: /images/cc_by_nc_sa.png legal_code_url: https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode name: Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) short: CC BY-NC-SA (4.0) type: dissertation user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1 year: '2020' ...