PhD projects for research students
Sudden unexpected cardiac death is responsible for about half of all heart disease deaths. It is an unexpected death caused by a change in heart rhythm. The underlying mechanisms are still not fully understood. We have recently identified several point mutations in the gene PPA2 in infants and young people that died from sudden cardiac arrest. PPA2 encodes a mitochondrial enzyme and the identified mutations lead to mitochondrial defects. However, the exact molecular mechanisms remain unclear. Much of our understanding of mitochondrial function and defects is based on studies in the budding yeast Saccharomyces cerevisiae. Since PPA2 is highly conserved from yeast to men, budding yeast is an ideal system for the analysis of the effects of PPA2 mutations found in patients. It will be tested whether these point mutations have an effect on the enzyme activity and protein stability of Ppa2. It has been suggested that Ppa2 functions as a homodimer. It will therefore be tested whether Ppa2 forms dimers and whether the identified mutations have an effect on protein dimerization. It will also be tested whether Ppa2 mutations affect mitochondrial function and morphology.
A wide range of methods will be employed. This will include cloning techniques, co-immunoprecipitation, SDS-PAGE, immunoblotting, enzyme activity assays, fluorescence microscopy and yeast techniques.
Kennedy H, et al. (2016). Sudden cardiac death due to deficiency of the mitochondrial inorganic pyrophosphatase PPA2. Am. J. Hum. Genet. 99:674-82
Guimier A, et al. (2016). Biallelic PPA2 mutations cause sudden unexpected cardiac arrest in infancy. Am. J. Hum. Genet. 99:666-73