Directed Molecular Evolution Of G Protein-coupled Receptors For Stable And Functional Expression In Escherichia Coli
Funder
National Health and Medical Research Council
Funding Amount
$383,479.00
Summary
Approximately half of all prescription drugs on the market act on G protein coupled receptors (GPCRs). The mechanisms underlying GPCR function are mainly unknown due to a lack of structural information. No solved structures exist for any of the estimated 800 human GPCRs, making it difficult to design new drugs. By applying advanced protein engineering techniques I aim to produce human GPCRs in bacteria to ultimately acquire structural information, which will enable novel drug development.
A Functional Proteomics Approach To The Study Of Inducible Gene Transcription In A Chromatin Context.
Funder
National Health and Medical Research Council
Funding Amount
$452,310.00
Summary
Cells of the immune system detect assaults on the body such as infection, inflammatory or allergy-causing agents. Using a complex set of signaling pathways, the cells translate this information into a change in the pattern of expressed genes in those cells. These changes in gene expression occur rapidly and are generally transient. The changes that occur in gene expression pattern leads to functional changes in the cell that in turn are critical for the downstream events of the immune response. ....Cells of the immune system detect assaults on the body such as infection, inflammatory or allergy-causing agents. Using a complex set of signaling pathways, the cells translate this information into a change in the pattern of expressed genes in those cells. These changes in gene expression occur rapidly and are generally transient. The changes that occur in gene expression pattern leads to functional changes in the cell that in turn are critical for the downstream events of the immune response. One set of genes that is rapidly and transiently switched on in response to immune stimuli in T cells (one important immune cell type) are those that encode proteins known as cytokines. These cytokines function to send messages between cells thus activating downstream events of the immune response. Thus understanding the mechanism of how these genes are switched on and off is critical in understanding an immune response and in developing potential novel therapeutics based on gene transcription. Genes exist in the nucleus of the cell in the context of a complex structure known as chromatin. The process of RNA transcription from these genes, therefore, takes place in the context of this complex structure. While there have been many studies defining the molecular mechanisms that control the expression of cytokine genes, little attention has been paid to the role of chromatin in the inducible and transient nature of this gene transcription. This proposal addresses the molecular mechanisms by which inducible cytokine gene transcription occurs in a chromatin context. We will use both in vitro and in vivo approaches to probe the structure of chromatin that overlies these genes and the mechanism by which this structure is altered to allow the genes to be expressed.Read moreRead less
Molecular Mechanisms Of Receptor Activation And Signalling
Funder
National Health and Medical Research Council
Funding Amount
$571,980.00
Summary
Fundamental to our ability to respond to both immediate and long-term environmental changes and stresses is the coordinated regulation of cellular functions by hormonal and neurotransmitter stimuli. The great majority of such stimuli are sensed by G-protein coupled receptors (GPCR), complex glycoprotein molecules on the surface of most cells that selectively bind and are activated by various hormones and neurotransmitters. Although GPCRs are a superfamily of proteins that now compromise several ....Fundamental to our ability to respond to both immediate and long-term environmental changes and stresses is the coordinated regulation of cellular functions by hormonal and neurotransmitter stimuli. The great majority of such stimuli are sensed by G-protein coupled receptors (GPCR), complex glycoprotein molecules on the surface of most cells that selectively bind and are activated by various hormones and neurotransmitters. Although GPCRs are a superfamily of proteins that now compromise several hundred distinct but structurally-related members, the molecular mechanisms involved in their activation and, thus, their regulation of vital cellular functions, remains unclear. Based on insights that we have gained from the development and characterisation of several alpha1-adrenergic receptor mutants, we have developed a model of receptor activation. In this application we are proposing to further test and to extend the hypotheses underlying this model. Importantly, the functions regulated by GPCR include vital responses, such as the maintenance of circulatory homeostasis by augmenting heart pump function and by constricting vascular smooth muscle to maintain blood pressure. In addition, disordered cellular regulation by GPCR has been implicated in a wide variety of diseases, including hypertension, congestive heart failure and cardiac hypertrophy. Thus, the studies detailed here to further understand the molecular mechanisms of receptor activation have broad implications for our knowledge of critical physiological control systems, and may lead to novel therapeutic approaches to treat a variety of diseases.Read moreRead less