Tesis doctoral de Anna Shnyrova
Dynamic regulation of membrane shape by lipid-protein interactions is imperative for many intra and intercellular processes. While creation of the membrane curvature is a localized process, the shape transformation of the biological membrane involves long-range, multimolecular ordering. There are only two mechanisms of such ordering used by proteins: polymerization (or formation of rigid coats) and fluid-like segregation (or weak crystallization). The latter has been suggested theoretically for a long time, and has been routinely observed in lipid systems and recently modeled for polymers. However, it was not clear where and how proteins can indeed employ this mechanism. matrix proteins of many enveloped viruses have been suggested as the main responsible of the shape transformation of the cellular membrane into the viral vesicle. In the present work it was found that the matrix (m) protein of the newcastle disease virus (ndv) follows the fluid-like segregation mechanism to induce cellular budding. In order to investigate the molecular mechanism behind the matrix protein driven budding, the process was reconstituted with m protein purified from the ndv and different model lipid systems (such as planar lipid membranes, luv, guv or lipid monolayer). The budding activity of the m protein was characterized by different experimental approaches (electric admittance measurements, fluorescence microscopy, spectroscopic approaches, electron microscopy, surface pressure measurements, etc.). It was concluded that m protein from ndv does not need any other cellular or viral components to induce membrane budding and produce membrane vesicles with a size distribution similar to that of the ndv. Furthermore, the data confirmed the formation of «fluid-like» membrane domains that were induced by the protein self-assembly on the membrane surface prior to the membrane budding. the major conclusion of the present work is that the protein segregation into «fluid-like» domains on the lipid membrane surface may be a plausible mechanism of regulated shape transformation that have place in the cell.
Datos académicos de la tesis doctoral «Estudio de la interacción de la proteína matriz del virus de la enfermedad de newcastle con bicapas lipídicas: implicaciones en el mecanismo de la gemación vírica«
- Título de la tesis: Estudio de la interacción de la proteína matriz del virus de la enfermedad de newcastle con bicapas lipídicas: implicaciones en el mecanismo de la gemación vírica
- Autor: Anna Shnyrova
- Universidad: Salamanca
- Fecha de lectura de la tesis: 20/06/2008
Dirección y tribunal
- Director de la tesis
- Enrique Villar Ledesma
- Tribunal
- Presidente del tribunal: María angeles Serrano garcia
- paul Scott blank (vocal)
- alicia Alonso izquierdo (vocal)
- gorka Basañez asua (vocal)