SCIENCE AT THE SHINE DOME canberra 2 - 4 may 2007
New Fellows Seminar
Wednesday, 2 May 2007
Professor Ian Dawes
Professor of Genetics, School of Biotechnology and Biomolecular Sciences,
University of New South Wales
Ian Dawes has a BSc from the University of New South Wales and a DPhil from the University of Oxford in the UK. He is interested in the regulation of gene expression during cell development and the response to stress or environmental changes. He has used biochemical and genetic approaches to study cellular responses to oxidative stress, nutritional changes, ageing, how cells respond to anti-tumour drugs, how cells regulate metabolic networks, and how control systems interact with each other. He is an editor of the journal FEMS Yeast Research and a member of the editorial boards of Yeast and the Journal of Microbiology. He is a Board Member of the Victor Chang Cardiac Research Institute and of the Australian Proteomic Analytical Facility, Chairman of the International Yeast Genetics and Molecular Biology Community and past President of the Lorne Genome Conference and the Society for Free Radical Research (Australasia).
Oxidative stress and cell ageing
Aerobic organisms encounter oxidative stress as a consequence of efficient energy generation. Cells possess numerous defence systems to detoxify the reactive oxygen species (ROS) that are formed as a by-product of respiration. An imbalance between ROS formation during normal metabolism or as a result of environmental stress, leads to the accumulation of free radicals that can react with many cellular constituents including DNA, protein and lipids. According to the free radical theory of ageing, accumulated damage caused by ROS contributes to ageing of organisms.
Our research has focussed on how cells respond to oxidative stress, and how this is related to cell ageing, using the bread yeast Saccharomyces cerevisiae as a model organism. We have shown that yeast cells have a range of different responses to ROS depending on the level of exposure. These include: adapting to become more resistant; delay of cell division; activating repair systems; and ageing leading to senescence and death. The application of recent genomic technologies has shown how cells turn on repair and defence processes in response to oxidative damage, and has provided detailed insight into the processes needed for cells to maintain their resistance. We have shown that aged cells have accumulated ROS and that they undergo a form of programmed cell death as part of the normal ageing process.
