Inherited disorders of the blood, such as sickle-cell anaemia and thalassaemia, result from mutations in the genes that produce haemoglobin. Current treatments can partially alleviate some of the debilitating symptoms of these diseases but these treatments have significant side effects, and despite the best efforts of clinicians, many patients succumb to their conditions at an early age. It has been observed that certain individuals exhibit a milder form of the disease, as a consequence of the r ....Inherited disorders of the blood, such as sickle-cell anaemia and thalassaemia, result from mutations in the genes that produce haemoglobin. Current treatments can partially alleviate some of the debilitating symptoms of these diseases but these treatments have significant side effects, and despite the best efforts of clinicians, many patients succumb to their conditions at an early age. It has been observed that certain individuals exhibit a milder form of the disease, as a consequence of the reactivation of their foetal haemoglobin genes, (a distinct set of genes that would have been active in utero but are normally silenced around the time of birth). It is widely accepted that if pharmaceutical means can be found for reactivating the foetal haemoglobin genes then many patients would benefit. The regulation of the foetal globin genes, like most human genes, is complicated and there are few obvious means of increasing their activity. Nevertheless, it is believed that by investigating the molecular mechanisms by which they are controlled it will be possible to devise therapeutic agents that mimic these mechanisms or to develop agents that prevent the shutdown of the foetal genes around birth. To this end we have been working on the molecules that regulate the activity of the haemoglobin genes. We have recently cloned a number of DNA-binding proteins, and their co-factors, that appear to be involved in silencing foetal globin gene expression. This grant proposal is concerned with learning how these new molecules operate to silence gene expression as a first step towards designing agents that will prevent the silencing.Read moreRead less
Probing UDP-glucuronosyltransferase Protein-protein Interactions: The Power Of Two.
Funder
National Health and Medical Research Council
Funding Amount
$482,710.00
Summary
Drugs and other chemicals (eg. dietary constituents, environmental pollutants, and chemicals that occur naturally in the body - such as steroid hormones) are broken down by specialised proteins called enzymes. This process is referred to as biotransformation, or 'metabolism'. Drug and chemical metabolism serves as a detoxification mechanism (since the products of metabolism generally lack biological activity) and as a means of eliminating these substances from the body. UDP-Glucuronosyltransfera ....Drugs and other chemicals (eg. dietary constituents, environmental pollutants, and chemicals that occur naturally in the body - such as steroid hormones) are broken down by specialised proteins called enzymes. This process is referred to as biotransformation, or 'metabolism'. Drug and chemical metabolism serves as a detoxification mechanism (since the products of metabolism generally lack biological activity) and as a means of eliminating these substances from the body. UDP-Glucuronosyltransferase (UGT) is one of the most important enzymes involved in drug and chemical metabolism. Consistent with its ability to metabolise such a large number of compounds, UGT is known to exist as a 'superfamily' of structurally related proteins. Despite the importance of UGT, little is known about the structural characteristics of these enzymes that are responsible for recognising and binding different classes of chemicals. Accumulating evidence from this and other laboratories indicates that the individual UGT proteins may combine with themselves (to form a homodimer) and with other UGT proteins (to form heterodimers). This project largely seeks to define the scope of UGT homo- and hetero- dimerisation, identify the structural elements of the proteins responsible for association and characterise the functional significance of dimerisation. The project will further explore associations between UGTs and other proteins, namely albumin. Characterisation of UGT dimerisation and associations with other proteins is fundamental to our understanding of how this enzyme functions and selects particular chemicals for metabolism. The work also has important implications for the devlopment and interpretation of in vitro (or 'test-tube') approaches for predicting how drugs are metabolised in humans. Such tests are widely employed in research and pharmaceutical company laboratories to predict how the body 'handles' new drugs prior to their administration to humans.Read moreRead less
The Molecular Mechanism Of Sphingosine Kinase Activation
Funder
National Health and Medical Research Council
Funding Amount
$442,500.00
Summary
Many cell processes like growth, death and differentiation are controlled by hormones and other molecules that interact with receptors on the outside of the cell. When this type of molecule binds to a receptor, it often triggers the production of signaling molecules inside the cell that initiate a change in the cells behaviour. The lipid molecule, sphingosine phosphate has been identified as such a signaling molecule that appears to be involved in the regulation of a diverse array of important m ....Many cell processes like growth, death and differentiation are controlled by hormones and other molecules that interact with receptors on the outside of the cell. When this type of molecule binds to a receptor, it often triggers the production of signaling molecules inside the cell that initiate a change in the cells behaviour. The lipid molecule, sphingosine phosphate has been identified as such a signaling molecule that appears to be involved in the regulation of a diverse array of important mammalian cellular processes. Recent studies have found that sphingosine phosphate is involved in the inflammation of cells, and if its production can be blocked, inflammation is not seen. Therefore, this provides a potential target for therapeutic intervention in the inflammation process. However, the manner by which cells regulate sphingosine phosphate levels is not well known. It is known that sphingosine phosphate is produced by the enzyme sphingosine kinase, and strong evidence suggests that changes in this enzyme's activity in the cell regulate sphingosine phosphate levels. However, how the cell changes the levels of sphingosine kinase activity is completely unknown. This study will investigate this problem with the view that understanding this process will allow the development of new drugs to block increases in sphingosine kinase activity, preventing increases in sphingosine phosphate levels, and it turn, preventing cellular inflammation.Read moreRead less