<> "The repository administrator has not yet configured an RDF license."^^ . <> . . "A Wnt-specific astacin proteinase restricts head organizer formation in Hydra"^^ . "The freshwater polyp Hydra is one of the best model organisms to analyze body axis patterning and organizer formation. Hydra possesses only one radial-symmetric body axis, which is established and maintained by autocatalytical Wnt/β-catenin signaling in the head organizer. Constant environmental influence, cell flow, as well as injury response can lead to an upregulation of Wnt/β-catenin signaling. A mechanism to restrict Wnt/β-catenin signaling is necessary to ensure the dominance of a single body axis and suppress the formation of ectopic axes and multiple head organizers. So far, only the transcription factor Sp5 (Vogg et al. 2019) has been described as a repressor of Wnt/β-catenin signaling in Hydra. Which factors restrict the activity of secreted Wnt ligands at the protein level has been elusive.\r\nIn this study, 11 novel Hydra astacin metalloproteases (HAS-1 to -11) are described, which were discovered by a secretome analysis for factors showing a proteolytic activity on HyWnt3. All Hydra astacins showed a transcriptional profile in endodermal gland cells and either exhibited a ring-like expression pattern under the head region or a graded expression pattern peaking at the tentacle base. \r\nHAS-7 was identified to be a promising candidate to restrict HyWnt3 at the protein level, as HAS-7 RNAi induced ectopic axis formation in Hydra. Importantly, HAS-7 was sufficient to revert double axis formation induced by HyWnt3 mRNA in Xenopus laevis embryos. An indirect regulation of HAS-7 by Wnt/β-catenin signaling was established by experimental promoter analysis and validated by mathematical modelling.\r\nIn summary, this work introduces HAS-7 as a negative regulator of HyWnt3 in the classical sense of the Gierer-Meinhardt activator-inhibitor model, and therefore plays an important role in Hydra axis formation and maintenance."^^ . "2021" . . . . . . . "Bérénice Dorothea"^^ . "Ziegler"^^ . "Bérénice Dorothea Ziegler"^^ . . . . . . "A Wnt-specific astacin proteinase restricts head organizer formation in Hydra (PDF)"^^ . . . "BereniceZieglerDissertation2021.pdf"^^ . . . "A Wnt-specific astacin proteinase restricts head organizer formation in Hydra (Other)"^^ . . . . . . "lightbox.jpg"^^ . . . "A Wnt-specific astacin proteinase restricts head organizer formation in Hydra (Other)"^^ . . . . . . "preview.jpg"^^ . . . "A Wnt-specific astacin proteinase restricts head organizer formation in Hydra (Other)"^^ . . . . . . "medium.jpg"^^ . . . "A Wnt-specific astacin proteinase restricts head organizer formation in Hydra (Other)"^^ . . . . . . "small.jpg"^^ . . . "A Wnt-specific astacin proteinase restricts head organizer formation in Hydra (Other)"^^ . . . . . . "indexcodes.txt"^^ . . "HTML Summary of #30006 \n\nA Wnt-specific astacin proteinase restricts head organizer formation in Hydra\n\n" . "text/html" . .