Elucidating the pathway of centrosome formation

<p>Centrosomes are cellular organelles present in most animal cells, and are formed of two main components: the centrioles and the pericentriolar material (PCM). Centrosomes perform a variety of functions: they are the main microtubule organising centre in the cell, and are important localisat...

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Main Author: Costa Vicente, C
Other Authors: Raff, JW
Format: Thesis
Language:English
Published: 2013
Subjects:
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author Costa Vicente, C
author2 Raff, JW
author_facet Raff, JW
Costa Vicente, C
author_sort Costa Vicente, C
collection OXFORD
description <p>Centrosomes are cellular organelles present in most animal cells, and are formed of two main components: the centrioles and the pericentriolar material (PCM). Centrosomes perform a variety of functions: they are the main microtubule organising centre in the cell, and are important localisation hubs for kinases involved in regulating the cell cycle. Hundreds of proteins are thought to localise to centrosomes, but work in the last decade has narrowed down this list to a handful of proteins that are thought to be essential for centrosome structure and function in <em>Drosophila</em>. Asl, Ana2, DSas-4, DSas-6 and Sak have been identified as essential components for centriole duplication, while Cnn and DSpd-2 are thought to be important in establishing the PCM. However, the relative position of these 7 components in the pathway of centrosome assembly in <em>Drosophila</em> embryos remains elusive, as a genetics analysis of this process is hampered by the absence of centrioles in most mutant embryos for these proteins.</p><p>In this thesis I elucidate the pathway of centrosome assembly in <em>Drosophila</em> by using SAPs (DSas-6/Ana2 particles that form in <em>Drosophila</em> unfertilised eggs upon moderate expression of DSas-6 and Ana2) as proxy models of centrosomes. I show SAPs are very similar to centrosomes in composition and dynamics but unlike centrosomes are able to form even in the absence of some of the essential centriolar components. SAP analysis in the absence of each of the main centrosome components reveals that: Sak is not required for the recruitment of downstream components; DSas-4 is necessary for Ana2 and DSas-6 to interact; Asl is the most upstream component of the PCM recruitment pathway, followed by DSpd-2; it is likely that there is an additional PCM recruitment pathway. I then take advantage of some of these results to examine how centrosome formation is potentiated after egg activation. My work allows me to propose an improved description of the pathway of centrosome formation in <em>Drosophila</em>.</p>
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spelling oxford-uuid:a7c109ae-7e99-4121-a7f7-d070a01c2f422024-02-27T16:40:56ZElucidating the pathway of centrosome formationThesishttp://purl.org/coar/resource_type/c_db06uuid:a7c109ae-7e99-4121-a7f7-d070a01c2f42BiologyCell Biology (see also Plant sciences)Genetics (life sciences)Development (zoology)EnglishOxford University Research Archive - Valet2013Costa Vicente, CRaff, JW<p>Centrosomes are cellular organelles present in most animal cells, and are formed of two main components: the centrioles and the pericentriolar material (PCM). Centrosomes perform a variety of functions: they are the main microtubule organising centre in the cell, and are important localisation hubs for kinases involved in regulating the cell cycle. Hundreds of proteins are thought to localise to centrosomes, but work in the last decade has narrowed down this list to a handful of proteins that are thought to be essential for centrosome structure and function in <em>Drosophila</em>. Asl, Ana2, DSas-4, DSas-6 and Sak have been identified as essential components for centriole duplication, while Cnn and DSpd-2 are thought to be important in establishing the PCM. However, the relative position of these 7 components in the pathway of centrosome assembly in <em>Drosophila</em> embryos remains elusive, as a genetics analysis of this process is hampered by the absence of centrioles in most mutant embryos for these proteins.</p><p>In this thesis I elucidate the pathway of centrosome assembly in <em>Drosophila</em> by using SAPs (DSas-6/Ana2 particles that form in <em>Drosophila</em> unfertilised eggs upon moderate expression of DSas-6 and Ana2) as proxy models of centrosomes. I show SAPs are very similar to centrosomes in composition and dynamics but unlike centrosomes are able to form even in the absence of some of the essential centriolar components. SAP analysis in the absence of each of the main centrosome components reveals that: Sak is not required for the recruitment of downstream components; DSas-4 is necessary for Ana2 and DSas-6 to interact; Asl is the most upstream component of the PCM recruitment pathway, followed by DSpd-2; it is likely that there is an additional PCM recruitment pathway. I then take advantage of some of these results to examine how centrosome formation is potentiated after egg activation. My work allows me to propose an improved description of the pathway of centrosome formation in <em>Drosophila</em>.</p>
spellingShingle Biology
Cell Biology (see also Plant sciences)
Genetics (life sciences)
Development (zoology)
Costa Vicente, C
Elucidating the pathway of centrosome formation
title Elucidating the pathway of centrosome formation
title_full Elucidating the pathway of centrosome formation
title_fullStr Elucidating the pathway of centrosome formation
title_full_unstemmed Elucidating the pathway of centrosome formation
title_short Elucidating the pathway of centrosome formation
title_sort elucidating the pathway of centrosome formation
topic Biology
Cell Biology (see also Plant sciences)
Genetics (life sciences)
Development (zoology)
work_keys_str_mv AT costavicentec elucidatingthepathwayofcentrosomeformation