Investigation of subunits of the cytoplasmic dynein complex using novel mouse models.
Doctoral thesis, UCL (University College London).
Cytoplasmic dynein is a multisubunit complex responsible for the transport of cellular components from the cell periphery towards the nucleus. The role of the dynein complex in vesicle trafficking, organelle positioning and chromosome segregation during mitosis has been extensively studied but still little is known of specific roles of distinct subunits of the complex. Cytoplasmic dynein is a dimeric complex consisting of heavy chains, intermediate chains, light intermediate chains and three light chains. In order to investigate the roles of the cytoplasmic dynein subunits, two mouse lines with chemically generated single point mutations in the intermediate chain 1 and 2 genes (Dync1i1, Dync1i2) were subjected to a behavioural analysis. The mouse line carrying a mutation in the intermediate chain 2 showed working memory deficits which suggested impairment in hippocampal functions. In order to examine the effects of mutation at the cellular level primary mouse embryonic fibroblasts (MEFs) lines were derived from embryos carrying mutations in the intermediate chains and used as a model system. Cell functions, such as trafficking of epidermal growth factor (EGF) positive endosomes, Golgi assembly were examined. Furthermore, biochemical analyses were performed focused on the expression of dynein subunits and their assembly in the functional complex. Alternative splicing is known to produce multiple isoforms of the intermediate chains. The analysis of various splice variants of these genes in a panel of mouse tissues resulted in detecting new isoforms which were compared with bioinformatics data available for human and rat thus establishing the splicing pattern of the mouse intermediate chains. Legs at odd angles (Dync1h1Loa) is another mutant mouse line carrying a point mutation in the dynein heavy chain which results in neurological defects. Here the effects of the Loa mutation in the trafficking of membranous organelles were investigated by an infection of cultured MEFs with Salmonella enterica serovar Typhimurium. Furthermore, upon the induction of a cellular stress the wildtype and the Loa homozygous cells showed significant differences in stress granule assembly suggesting the impairment in the stress signaling.
|Title:||Investigation of subunits of the cytoplasmic dynein complex using novel mouse models|
|Open access status:||An open access version is available from UCL Discovery|
|Additional information:||Printed volume contains published journal articles which have been removed from the e-thesis.|
|UCL classification:||UCL > School of Life and Medical Sciences > Faculty of Brain Sciences > Institute of Neurology > Neurodegenerative Diseases|
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