Neuronal characterisation of syncoilin

Abstract

Syncoilin is a member of the intermediate filament protein family. It is highly expressed in skeletal and cardiac muscle, where it binds to the dystrophin associated protein complex, via a-dystrobrevin. Syncoilin is increased in the muscles ofpatients with muscular dystrophies. Previous data from this laboratory indicated that syncoilin is also expressed in neurons, but its function in the nervous system is unknown. The aim ofthis thesis was to determine the neuronal function of syncoilin, by the identification of its binding partners. This is an important question because cytoskeletal dynamics are critical in the development and regeneration of neurons, and moreover, mutations in other intermediate filament proteins can cause amyotrophic lateral sclerosis and Charcot-Marie-Tooth disease. In this thesis, a co-immunoprecipitation and mass spectrometry strategy was used to identify binding partners for syncoilin in neurons. Two novel binding partners were identified, namely a-tubulin and the chaperone CCT, and verified using other methods. Additionally, the interaction of syncoilin with the neuronal intermediate filament peripherin was confirmed and investigated further. Finally, three syncoilin gene variants identified in a dHPLC screen ofpatients with motor neuropathies were characterised in terms of their predicted effects on the structure and binding properties ofsyncoilin and their subcellular localisation in the NSC-34 motor neuron cell line. The identification ofnovel binding partners for syncoilin in neurons gives important insights into the architecture and dynamic organisation ofthe neuronal cytoskeleton, and may also contribute to the understanding of syncoilin in skeletal muscle. Furthermore, the identification of syncoilin variants in patients with motor neuropathies suggests that syncoilin may be involved in the pathogenesis of motor neuron disease.EThOS - Electronic Theses Online ServiceGBUnited Kingdo