Phloem unloading of sucrose: cloning, functional characterisation and regulation of novel membrane transporters. Sucrose is the principal form in which plant biomass, produced in photosynthetic leaves, is transported to non-photosynthetic organs for growth and storage. Sucrose transport proteins play pivotal roles in facilitating sucrose transport around plants. Hence activities of sucrose transporters directly impact on plant growth rates and crop yields. Our aim is to isolate hitherto unkno ....Phloem unloading of sucrose: cloning, functional characterisation and regulation of novel membrane transporters. Sucrose is the principal form in which plant biomass, produced in photosynthetic leaves, is transported to non-photosynthetic organs for growth and storage. Sucrose transport proteins play pivotal roles in facilitating sucrose transport around plants. Hence activities of sucrose transporters directly impact on plant growth rates and crop yields. Our aim is to isolate hitherto unknown membrane proteins that move sucrose at high rates between cells and discover their transport properties. Expected outcomes are to better understand mechanisms and regulation of sucrose transport and hence provide novel opportunities to enhance crop yield. The project will foster a productive international collaboration.Read moreRead less
Multifunctional channels as key components of biotrophic interfaces in legumes. In legumes there are two types of membrane interfaces between different genomes that are critical for growth and yield (nitrogen fixation and seed loading), which require cell-signalling pathways to control nutrient exchange. The membranes of these interfaces contain specialised proteins that form multifunctional channels through which water, uncharged molecules and electrolytes move. These channels are likely to be ....Multifunctional channels as key components of biotrophic interfaces in legumes. In legumes there are two types of membrane interfaces between different genomes that are critical for growth and yield (nitrogen fixation and seed loading), which require cell-signalling pathways to control nutrient exchange. The membranes of these interfaces contain specialised proteins that form multifunctional channels through which water, uncharged molecules and electrolytes move. These channels are likely to be responsible for supporting the bulk of transported nutrients and in controlling their exchange. We aim to discover how these channels function in nitrogen fixation and seed loading with a view to developing new technologies that may enhance crop productivity.Read moreRead less
Disorder as a novel determinant of photosynthetic structure and function: an experimental study. Australia enjoys a world reputation in photosynthesis research, typified by hosting the 2001 International Photosynthesis Congress. It also has a claim to fame for theoretical work in non-equilibrium thermodynamics concerning production of disorder or entropy, yielding new insights into planetary climates. This experimental project investigates the novel relation between entropy/entropy production ....Disorder as a novel determinant of photosynthetic structure and function: an experimental study. Australia enjoys a world reputation in photosynthesis research, typified by hosting the 2001 International Photosynthesis Congress. It also has a claim to fame for theoretical work in non-equilibrium thermodynamics concerning production of disorder or entropy, yielding new insights into planetary climates. This experimental project investigates the novel relation between entropy/entropy production and the structure/function of the solar powerhouse of plants (chloroplasts), and addresses fundamental questions at the interface of biology and physics. The research explores chloroplasts as a manifestation of the all-pervading Second Law of Thermodynamics, advancing Australia's contribution to basic science and helping to train researchers.Read moreRead less
Oxidative stress-induced alterations of the host erythrocyte by the malaria parasite. The malaria parasite spends part of its lifecycle inside the red blood cells of its host. During this time, the parasite modifies many of the features of the red blood cell and subjects it to high levels of oxidative stress. We will use and develop a variety of fluorescence and microscopic techniques to understand the molecular basis of the alterations in the organization of membrane proteins in malaria parasit ....Oxidative stress-induced alterations of the host erythrocyte by the malaria parasite. The malaria parasite spends part of its lifecycle inside the red blood cells of its host. During this time, the parasite modifies many of the features of the red blood cell and subjects it to high levels of oxidative stress. We will use and develop a variety of fluorescence and microscopic techniques to understand the molecular basis of the alterations in the organization of membrane proteins in malaria parasite-infected red blood cells. We will examine the roles of oxidative stress and of parasite proteins in modulating the properties of the host cell membrane.Read moreRead less
Conductance states of a brain glutamine transporter. Brain transporters are the target for many neuroactive drugs that are used to treat anxiety, depression and other psychotic disorders. Transport processes are also targeted to deliver neurotransmitter precursors to the brain to treat disorders such as Parkinson's disease. In this project we will study a transport process crucial for the function of neurons that release glutamate and GABA (gamma-aminobutyric acid) as neurotransmitters. The stud ....Conductance states of a brain glutamine transporter. Brain transporters are the target for many neuroactive drugs that are used to treat anxiety, depression and other psychotic disorders. Transport processes are also targeted to deliver neurotransmitter precursors to the brain to treat disorders such as Parkinson's disease. In this project we will study a transport process crucial for the function of neurons that release glutamate and GABA (gamma-aminobutyric acid) as neurotransmitters. The study of this transport process will be important for understanding disorders like epilepsy and other disorders affecting neuronal excitability.Read moreRead less
Molecular analysis of photosynthetically-linked, active CO2 uptake and CO2 signal transduction by cyanobacteria (blue-green algae). Cyanobacteria (blue-green algae) have evolved a very efficient means of capturing and concentrating CO2 for photosynthetic fixation into sugars, the basic building blocks for cell growth. This process is dependent on the operation of several unique, active uptake systems for CO2 and HCO3-, with their genetic expression regulated by CO2 supply. This proposal will cap ....Molecular analysis of photosynthetically-linked, active CO2 uptake and CO2 signal transduction by cyanobacteria (blue-green algae). Cyanobacteria (blue-green algae) have evolved a very efficient means of capturing and concentrating CO2 for photosynthetic fixation into sugars, the basic building blocks for cell growth. This process is dependent on the operation of several unique, active uptake systems for CO2 and HCO3-, with their genetic expression regulated by CO2 supply. This proposal will capitalize on our progress in describing the functional genetics of this process and aims to elucidate the mechanism of active CO2 uptake and the way that cells sense the ambient CO2 concentration. The information gained is likely to be useful for designing improved crops.Read moreRead less
Characterisation of PQ loop proteins in plants: are they voltage insensitive nonselective cation channels? Millions of hectares of Australian agricultural land are affected by salinity. This results in the loss of hundreds of millions of dollars in revenue each year. The identification of the pathway for the initial influx of Na+ into plants from the soil will be important in helping to develop crop plants that are salt tolerant. This will increase our understanding of the mechanisms of salinity ....Characterisation of PQ loop proteins in plants: are they voltage insensitive nonselective cation channels? Millions of hectares of Australian agricultural land are affected by salinity. This results in the loss of hundreds of millions of dollars in revenue each year. The identification of the pathway for the initial influx of Na+ into plants from the soil will be important in helping to develop crop plants that are salt tolerant. This will increase our understanding of the mechanisms of salinity tolerance, an area of great importance to Australian agriculture and environmental sustainability. The future applications of this work will increase agricultural productivity and enhance the quality of life for both Australians and the international community.Read moreRead less
Monolayer crystallization of membrane proteins. Membrane proteins comprise 25-40% of all proteins and conduct a myriad of finely tuned reactions in every cell. Despite their importance and diversity only ~40 membrane protein structures have been solved, due to the difficulty of producing high quality 2D and 3D crystals. We propose to develop and use the new monolayer crystallization technique, which employs a lipid monolayer as a crystallization template for 2D crystal production. A number of ....Monolayer crystallization of membrane proteins. Membrane proteins comprise 25-40% of all proteins and conduct a myriad of finely tuned reactions in every cell. Despite their importance and diversity only ~40 membrane protein structures have been solved, due to the difficulty of producing high quality 2D and 3D crystals. We propose to develop and use the new monolayer crystallization technique, which employs a lipid monolayer as a crystallization template for 2D crystal production. A number of important membrane proteins are available for these structural studies including ABC transporters, Caveolin-3 and the NS1 protein of Dengue virus, all of which are difficult to crystallize using conventional techniques.Read moreRead less
Membrane Attack Complex / Perforin like proteins in Defence, Attack and Developmental Biology. This proposal will result in a major advancement of knowledge, for example, in our understanding of the emerging links between immunity and development as well as the role and mechanism of function of the pore forming family of MACPF proteins in host defence, attack, embryo development and diseases such as cancer. These data will be crucial for developing approaches to control unwanted MACPF function, ....Membrane Attack Complex / Perforin like proteins in Defence, Attack and Developmental Biology. This proposal will result in a major advancement of knowledge, for example, in our understanding of the emerging links between immunity and development as well as the role and mechanism of function of the pore forming family of MACPF proteins in host defence, attack, embryo development and diseases such as cancer. These data will be crucial for developing approaches to control unwanted MACPF function, for example in disease such as diabetes or transplant rejection. Furthermore, a detailed understanding of how MACPF proteins assemble into rings and punch holes in membranes will facilitate the development of these proteins as technological tools.Read moreRead less
Delineating the role of the GxxxG motif in transmembrane protein metabolism. This study will define how a well defined motif involved in transmembrane interactions affects the metabolism of proteins. Since this motif is present in proteins involved in Alzheimer's disease it has potential benefits for community health and combating ageing.