The 14-3-3 family of proteins are important signalling proteins involved in a number
of cellular processes. These include cell cycle regulation, apoptosis, signal
transduction and cell signalling. There is also considerable evidence in the literature
that 14-3-3 proteins play a vital role in the pathology of neurodegenerative diseases,
including Alzheimer’s, Parkinson’s, Huntington’s and Prion disease. The
neurodegenerative disease of focus in this research is Spinocerebellar Ataxia Type 1
(SCA1). SCA1 is a polyglutamine-repeat disease and the interaction of the disease
protein ataxin-1 with 14-3-3 proteins leads to the toxic accumulation and subsequent
protein aggregation which is characteristic of this disease. This study focused on
attempting to elucidate the structure of various domains of the disease protein and
also in identifying potential inhibitors of this deleterious interaction. Unfortunately,
structural studies were not successful due to a number of caveats encountered in the
expression and purification of the ataxin-1 protein domains. By utilising
computational methods and small molecule inhibitors, a number of potential lead
compounds which possess the ability to at least partly disrupt the interaction of 14-
3-3ζ have been identified. As 14-3-3 proteins play roles in other neurodegenerative
diseases, successful identification of potential drug lead treatments can have far
reaching benefits in a number of neurodegenerative diseases including SCA1.
Lipid rafts are also involved in neurodegenerative disease pathology. Lipid rafts are
cholesterol and sphingolipid rich domains which organise the plasma membrane
into discrete microdomains and act as signalling platforms and processing centres
which attach specific proteins and lipids. A number of disease proteins are
processed at these membrane regions, including those involved in Alzheimer’s,
Parkinson’s and Prion disease. This processing is a step which is critical in the
pathology of disease and abnormal processing leads to the formation of toxic
protein aggregates. Previous research in the lab identified the association of low
levels of the five main brain isoforms of 14-3-3 proteins with rafts. This study
expanded on this to positively identify the presence of the two phospho-forms of 14-3-3, α and δ. The mechanism by which 14-3-3 proteins associate with rafts was also
investigated, indicating that 14-3-3 associates with rafts via an unidentified raftbound
protein(s). In addition, the phosphorylation status and quaternary structure
of 14-3-3 in the presence of sphingolipids has been explored