Lipid raft association and subcellular localization of UNC5 Netrin-1 receptors = Associació als lípids raft i localització subcel·lular de la familia de receptors de la Netrina-1 UNC5
[eng] During brain development, UNC5 receptors play a key role in controlling axonal extension through their sensing of the guidance molecule Netrin-1. The correct positioning of receptors into specific cholesterol-enriched membrane raft microdomains is of crucial importance for the efficient transd...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2019 |
| País: | España |
| Institución: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/147976 |
| Acceso en línea: | https://hdl.handle.net/2445/147976 http://hdl.handle.net/10803/668287 |
| Access Level: | acceso abierto |
| Palabra clave: | Membranes cel·lulars Proteïnes Cell membranes Proteins Axons |
| Sumario: | [eng] During brain development, UNC5 receptors play a key role in controlling axonal extension through their sensing of the guidance molecule Netrin-1. The correct positioning of receptors into specific cholesterol-enriched membrane raft microdomains is of crucial importance for the efficient transduction of the recognized signal. Whether such microdomains are required for the appropriate axonal guidance mediated by UNC5 receptors remains unknown. Here, we extend the classical biochemical characterization of raft microdomains by performing confocal microscopy, live cell FRAP analysis and sptPALM of fluorescently-tagged UNC5 receptors and we reveal for the first time differences into their membrane mobility properties. Using a combination of pharmacological and genetical approaches in primary neuronal cultures and brain cerebellar explants we further demonstrate that disrupting raft microdomains inhibit the chemorepulsive response of growth cones and axons against Netrin-1. Together, our findings indicate that the distribution of all UNC5 receptors into cholesterol-enriched raft microdomains is heterogeneous and that their specific localization have functional consequences for the axonal chemorepulsion against Netrin-1. Alternative splicing is a key mechanism in which a variety of proteins is achieved from "cut and paste" mRNA. The plethora of proteins resulting from alternative splicing processes is crucial for the proper function of certain protein isoforms. In this thesis we have detected alternative splicing in the UNC5A receptor in the nervous system. The resulting product is a UNC5A isoform that lacks the first TSPI repeat, uncovered here, to be important for cell membrane targeting. We have further analyzed the implications of losing the first TSPI repeat. |
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