Secretion is an essential step in memory and learning, control of metabolism and reproduction and the functioning of most organs. Secretory dysfunction also underlies many diseases including type 2 diabetes. We plan experiments to test for a new model of control of insulin secretion.
Do Synaptic-like Mechanisms Control Insulin Secretion?
Funder
National Health and Medical Research Council
Funding Amount
$593,235.00
Summary
An estimated 415 million people world-wide were diagnosed with diabetes in 2015. One of the causal factors in disease is the dysregulation of insulin secretion. We have developed new techniques to study insulin secretion that has led us to propose a new model for secretory control. This proposal sets out experiments to critically test this model. The outcomes could have wide-reaching impact on understanding and for future treatment and prevention of the diabetes.
Deciphering The Molecular Steps Leading To The Potentiation Of Neuronal Exocytosis By Arachidonic Acid
Funder
National Health and Medical Research Council
Funding Amount
$273,000.00
Summary
Release of hormones and neurotransmitters relies on a process called exocytosis which involves SNARE proteins: syntaxin1A and SNAP-25 on the target plasma membrane and VAMP on the vesicular membrane. Availability of the t-SNARE on the plasma membrane is believed to play a major role in controlling the amount of exocytosis. Syntaxin1A bound to Munc18 constitute an 'unproductive-reserve' pool of closed Syntaxin that cannot interact with SNAP-25. Intracellular messengers capable of releasing Syntax ....Release of hormones and neurotransmitters relies on a process called exocytosis which involves SNARE proteins: syntaxin1A and SNAP-25 on the target plasma membrane and VAMP on the vesicular membrane. Availability of the t-SNARE on the plasma membrane is believed to play a major role in controlling the amount of exocytosis. Syntaxin1A bound to Munc18 constitute an 'unproductive-reserve' pool of closed Syntaxin that cannot interact with SNAP-25. Intracellular messengers capable of releasing Syntaxin1A from Munc18 thereby making it available to interact with SNAP-25, are foreseen to play a major role in potentiating exocytosis - a process with ramification for memory and learning. We have identified arachidonic acid, a lipidic messenger which fullfil this role. For the first time we are in a position to manipulate at the molecular level different pools of SNARE proteins with direct implications for our understanding of the mechanism of secretion. Very few models are currently available to understand how learning and memory occur in the brain. Our research points to a new direction: the amount of 'active' and 'unproductive-reserve' pools of SNARE proteins present on the plasma membrane of neurosecretory cells are in dynamic equilibrium and arachidonic acid, a second messenger capable of trans-synaptic action, can modify this equilibrium resulting in an increase of the amount of 'active' SNARE thereby potentiating the amount of transmitter-hormone released by exocytosis. Importantly, this research lays the basis for a dynamic view of the secretory mechanism with important implications for treatment of diseases such as diabetes and neurodegenerative diseases. Our hope is that by understanding at the molecular level how secretory cells regulate the amount of their secretion, we will be in a position to modify these parameters in order to counteract illnesses of the nervous system.Read moreRead less
Preventing The Evolution Of Transmissible Nitroimidazole Resistance In Mycobacterium Tuberculosis
Funder
National Health and Medical Research Council
Funding Amount
$664,463.00
Summary
Tuberculosis kills more people than any other infectious disease. Unfortunately, the drugs available to us to treat TB are losing their efficacy due to the evolution of drug resistance. A new class of drugs, nitroimidazoles, has been developed, but there is a risk that the bacterium that causes TB will develop resistance to these compounds too. We will identify resistance mutations before they occur in the wild, to help identify them and find new compounds for which resistance cannot develop.
DsbA Foldases From Multidrug Resistant Pathogens As Targets For New Antimicrobials
Funder
National Health and Medical Research Council
Funding Amount
$743,401.00
Summary
Bacteria that cause common human infections, such as cystitis and diarrhoea, are now resistant to many antibiotics. If no action is taken, by 2050 antibiotic resistant infections will kill more people each year than cancer. This project aims to address this global public health crisis by characterising promising new bacterial targets and inhibitors designed to disarm multidrug resistant pathogens. Longer term this work could provide new infection therapies that are urgently needed.
Broad Spectrum Inhibition Of An Enzyme Antibiotic Target
Funder
National Health and Medical Research Council
Funding Amount
$321,534.00
Summary
There is a well-documented need to replenish the antibiotic pipeline with new products to combat the rise of drug resistant bacteria. In this project, the enzyme dihydrodipicolinate synthase (DHDPS) is targetted which is essential to bacterial viability. A number of independent but synergistic drug discovery approaches are investigated to develop and test DHDPS inhibitors in the pursuit of a novel class of antibiotics.
Dissecting The Pathogenic Triad Of Enteric Pathogens: Assembly, Structure And Function Of Autotransporter Proteases
Funder
National Health and Medical Research Council
Funding Amount
$639,428.00
Summary
SPATEs are proteases secreted by many enteric bacteria that contribute to their pathogenic potential by damaging host tissues and evading the host immune response. We aim to study the structural basis of their assembly and biological function. The information we gain will assist the development of new diagnostics and improved therapies for enteric infections.