Assembly of mitochondrial respiratory chain complexes and defects associated with disease [ 2007 - 2009 ]

Research Grant

Researchers: Prof Michael Ryan (Principal investigator) ,  Dr Matthew Mckenzie ,  Prof David Thorburn

Brief description A group of protein assemblies termed respiratory complexes are found in the inner membrane of mitochondria in our cells and are responsible for producing most of our energy. These complexes consist of many different protein subunits and are built by the help of numerous known and unknown assembly factors. For example, assembly of Complex I of the respiratory chain requires 39 different proteins that are made outside mitochondria and are then transported inside to be somehow joined together with the 7 other subunits that are made by mitochondria. This is clearly a complicated procedure and we have little information on how its assembly is achieved. We do know however that mistakes in the assembly of these complexes (particularly Complex I) do happen. In Australia, about 50 children born each year have inherited disorders of mitochondrial energy generation. The most severe disorders cause infant death, while others present later causing a range of degenerative diseases, particularly affecting brain, muscle and heart. Defects in the respiratory chain have also been implicated in Parkinson's disease, Alzheimer's disease, type-2 diabetes and in cell death. In order to understand how respiratory complex defects cause disease, we need to understand more about how these complexes are built. The aim of this proposal is to investigate how Complex I is assembled, how it interacts with other respiratory complexes, and to identify and characterise proteins that aid in its assembly. We will also analyse assembly defects in cells from patients with suspected respiratory complex deficiencies. This work will aid in our understanding of not only how protein complexes are built, but how defects in their assembly can cause disease. This will be informative to families of affected individuals and may aid in future diagnosis and prevention of diseases where defects in mitochondria are implicated.

Funding Amount $AUD 464,610.05

Funding Scheme NHMRC Project Grants

Notes Standard Project Grant