Cellular asymmetry plays a critical role in the development of multicellular organisms. In this thesis, the development of the Drosophila central nervous system (CNS) has been studied as a model for asymmetric localisation and cell division. Multipotent neuroblast (NB) stem cells of the CNS divide asymmetrically to produce all of the neurons and glial cells of the adult fly. During mitosis, the NB localises several protein and mRNA molecules to distinct compartments of the cell. The cell then divides asymmetrically along its apico-basal axis, segregating the localised molecules differently between the two daughter cells. One daughter cell inherits a set of molecules allowing it to continue to divide. The other inherits molecules that switch off cell division and switch on differentiation. Currently, the mechanisms which underlie this protein localisation and segregation are not well understood. In this thesis, a combination of molecular biology, biochemical, biophysical and structural approaches have been used to investigate the roles played by four proteins (Rab6, Inscuteable, Miranda and Prospero) in asymmetric protein localisation and cell division. Fragments of the Inscuteable, Miranda and Prospero proteins that interact with each other, have been designed, expressed in E. coli and characterised using chromatography and biophysical techniques. Preliminary analysis of the interactions between these protein fragments has been carried out. The proteins have also been subjected to crystallisation trials, in the hope of yielding crystals for structure determination. These have yet to produce diffracting crystals. The crystal structure of the Rab6 protein has been solved to 1.4 A and is currently the highest resolution Rab6 structure available. It is also the only structure of a Drosophila Rab protein to date.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:582099 |
| Date | January 2011 |
| Creators | Walden, Miriam |
| Publisher | University of Leeds |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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