{"related_material":{"record":[{"id":"1096","relation":"dissertation_contains","status":"public"},{"status":"public","relation":"part_of_dissertation","id":"7001"}]},"status":"public","title":"Mechanosensation of tight junctions depends on ZO-1 phase separation and flow","alternative_title":["ISTA Thesis"],"date_created":"2019-12-16T14:26:14Z","user_id":"c635000d-4b10-11ee-a964-aac5a93f6ac1","oa":1,"oa_version":"Published Version","publisher":"Institute of Science and Technology Austria","publication_status":"published","date_published":"2019-12-16T00:00:00Z","abstract":[{"lang":"eng","text":"Tissue morphogenesis in developmental or physiological processes is regulated by molecular\r\nand mechanical signals. While the molecular signaling cascades are increasingly well\r\ndescribed, the mechanical signals affecting tissue shape changes have only recently been\r\nstudied in greater detail. To gain more insight into the mechanochemical and biophysical\r\nbasis of an epithelial spreading process (epiboly) in early zebrafish development, we studied\r\ncell-cell junction formation and actomyosin network dynamics at the boundary between\r\nsurface layer epithelial cells (EVL) and the yolk syncytial layer (YSL). During zebrafish epiboly,\r\nthe cell mass sitting on top of the yolk cell spreads to engulf the yolk cell by the end of\r\ngastrulation. It has been previously shown that an actomyosin ring residing within the YSL\r\npulls on the EVL tissue through a cable-constriction and a flow-friction motor, thereby\r\ndragging the tissue vegetal wards. Pulling forces are likely transmitted from the YSL\r\nactomyosin ring to EVL cells; however, the nature and formation of the junctional structure\r\nmediating this process has not been well described so far. Therefore, our main aim was to\r\ndetermine the nature, dynamics and potential function of the EVL-YSL junction during this\r\nepithelial tissue spreading. Specifically, we show that the EVL-YSL junction is a\r\nmechanosensitive structure, predominantly made of tight junction (TJ) proteins. The process\r\nof TJ mechanosensation depends on the retrograde flow of non-junctional, phase-separated\r\nZonula Occludens-1 (ZO-1) protein clusters towards the EVL-YSL boundary. Interestingly, we\r\ncould demonstrate that ZO-1 is present in a non-junctional pool on the surface of the yolk\r\ncell, and ZO-1 undergoes a phase separation process that likely renders the protein\r\nresponsive to flows. These flows are directed towards the junction and mediate proper\r\ntension-dependent recruitment of ZO-1. Upon reaching the EVL-YSL junction ZO-1 gets\r\nincorporated into the junctional pool mediated through its direct actin-binding domain.\r\nWhen the non-junctional pool and/or ZO-1 direct actin binding is absent, TJs fail in their\r\nproper mechanosensitive responses resulting in slower tissue spreading. We could further\r\ndemonstrate that depletion of ZO proteins within the YSL results in diminished actomyosin\r\nring formation. This suggests that a mechanochemical feedback loop is at work during\r\nzebrafish epiboly: ZO proteins help in proper actomyosin ring formation and actomyosin\r\ncontractility and flows positively influence ZO-1 junctional recruitment. Finally, such a\r\nmesoscale polarization process mediated through the flow of phase-separated protein\r\nclusters might have implications for other processes such as immunological synapse\r\nformation, C. elegans zygote polarization and wound healing."}],"department":[{"_id":"CaHe"}],"degree_awarded":"PhD","day":"16","file":[{"file_id":"7194","file_size":19431292,"date_created":"2019-12-19T15:18:11Z","date_updated":"2020-07-14T12:47:52Z","content_type":"application/zip","file_name":"DocumentSourceFiles.zip","access_level":"closed","creator":"cschwayer","relation":"source_file","checksum":"585583c1c875c5d9525703a539668a7c"},{"checksum":"9b9b24351514948d27cec659e632e2cd","relation":"main_file","content_type":"application/pdf","creator":"cschwayer","access_level":"open_access","file_name":"Thesis_CS_final.pdf","date_updated":"2020-07-14T12:47:52Z","file_id":"7195","file_size":19226428,"date_created":"2019-12-19T15:19:21Z"}],"type":"dissertation","date_updated":"2023-09-07T12:56:42Z","supervisor":[{"full_name":"Heisenberg, Carl-Philipp J","id":"39427864-F248-11E8-B48F-1D18A9856A87","last_name":"Heisenberg","first_name":"Carl-Philipp J","orcid":"0000-0002-0912-4566"}],"article_processing_charge":"No","month":"12","file_date_updated":"2020-07-14T12:47:52Z","ddc":["570"],"acknowledged_ssus":[{"_id":"Bio"},{"_id":"LifeSc"},{"_id":"EM-Fac"},{"_id":"SSU"}],"year":"2019","citation":{"ieee":"C. Schwayer, “Mechanosensation of tight junctions depends on ZO-1 phase separation and flow,” Institute of Science and Technology Austria, 2019.","mla":"Schwayer, Cornelia. <i>Mechanosensation of Tight Junctions Depends on ZO-1 Phase Separation and Flow</i>. Institute of Science and Technology Austria, 2019, doi:<a href=\"https://doi.org/10.15479/AT:ISTA:7186\">10.15479/AT:ISTA:7186</a>.","short":"C. Schwayer, Mechanosensation of Tight Junctions Depends on ZO-1 Phase Separation and Flow, Institute of Science and Technology Austria, 2019.","ista":"Schwayer C. 2019. Mechanosensation of tight junctions depends on ZO-1 phase separation and flow. Institute of Science and Technology Austria.","apa":"Schwayer, C. (2019). <i>Mechanosensation of tight junctions depends on ZO-1 phase separation and flow</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/AT:ISTA:7186\">https://doi.org/10.15479/AT:ISTA:7186</a>","chicago":"Schwayer, Cornelia. “Mechanosensation of Tight Junctions Depends on ZO-1 Phase Separation and Flow.” Institute of Science and Technology Austria, 2019. <a href=\"https://doi.org/10.15479/AT:ISTA:7186\">https://doi.org/10.15479/AT:ISTA:7186</a>.","ama":"Schwayer C. Mechanosensation of tight junctions depends on ZO-1 phase separation and flow. 2019. doi:<a href=\"https://doi.org/10.15479/AT:ISTA:7186\">10.15479/AT:ISTA:7186</a>"},"language":[{"iso":"eng"}],"_id":"7186","doi":"10.15479/AT:ISTA:7186","page":"107","author":[{"full_name":"Schwayer, Cornelia","id":"3436488C-F248-11E8-B48F-1D18A9856A87","first_name":"Cornelia","last_name":"Schwayer","orcid":"0000-0001-5130-2226"}],"has_accepted_license":"1","publication_identifier":{"issn":["2663-337X"]}}