Acting Division Head: Associate Professor Thomas Preiss
The aim of the Molecular Genetics Program is to understand the mechanisms of gene regulation. Genes are bits of DNA residing in the cellular nuclei of higher organisms and they serve as a blueprint for the assembly of proteins. Because the information in the genes is precious, cells keep the genes as chromosomes in the nucleus and make accurate but perishable copies called messenger RNAs, in a process termed transcription. These copies are 'sent out' of the nucleus to protein factories called ribosomes, which read the message and manufacture the specified protein molecule. This is called translation.
All cells in the body carry the same set of genes in their nuclei. Cells in different organs chose to read different subsets of genes to make a different collection of proteins, and so deal with the very different tasks they have to perform. The whole process of turning the genetic information into functional proteins is called gene expression and needs to be tightly controlled. This is evident from the fact that erroneous gene transcription or translation is a major factor in human diseases including those that afflict the heart.
Associate Professor Thomas Preiss's Laboratory
There are two groups within the Molecular Genetics Program. The first is headed by A/Prof Thomas Preiss. His major research interests are the cellular mechanisms that control protein translation. In work carried out at the VCCRI and the European Molecular Biology Laboratory (EMBL) in Germany, Associate Professor Preiss and colleagues discovered an unexpected coupling of translation to earlier steps in the cellular gene expression pathway. Associate Professor Preiss and colleagues continue to investigate this super-efficient way that cells use to steer gene expression in response to changed requirements.
In related work, they focus on the translational changes that occur in human cells under stress conditions and when cells begin to die from apoptosis. Apoptosis is an orderly process by which cells die; it is vital for our survival. On the other hand, aberrant regulation of apoptosis also contributes to many pathologies associated with cell loss and disorders characterised by a failure to eliminate harmful cells. There is mounting evidence for specialised mechanisms of translation-initiation that may be critical for maintaining a healthy balance between cell death and proliferation.
Advancing our knowledge in these areas would have wide-ranging implications for the treatment of many diseases, where uncontrolled gene expression and protein translation is a problem. A/Prof Preiss's Laboratory is utilising new technologies, such as microarrays, to investigate changes to gene regulation in cells. His work promises to improve our knowledge of regulatory pathways that will be of critical importance in the fight against multiple diseases.
Dr Catherine Suter's Laboratory
The second group within the Molecular Genetics Program is headed by Dr Catherine Suter. Dr Suter's laboratory focuses on epigenetics. Epigenetics can be defined as the study of heritable changes in gene expression that do not involve changes in the DNA sequence itself. Epigenetics provides the primary mode of gene regulation in eukaryotes but remains a complex system that is poorly understood. Dr Suter's group is dedicated to the investigation of the role that epigenetics plays in phenotypic variation and human disease.
Dr Suter's recent work has focused on epimutations, a type of epigenetic accident where a gene becomes silent when it should be active. In collaboration with doctors at St Vincent's Hospital the laboratory has identified individuals who show evidence of epigenetic inactivation of a disease gene, and have the disease that is known to occur when the same gene is inactivated by a genetic mutation. There is also evidence that an affected person may pass an epimutation on to his or her children. This discovery may explain how human disease can be caused by changes in gene expression that are not inherited in the same way as genes.
Dr Suter's group is also interested in the role of nutrition and in utero environment in epigenetic variation and inheritance. The group has recently found that vitamin supplementation in genetically identical mice can have a health effect that is mediated by epigenetic changes and persists for generations.
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