Cells must regulate the flow of ions and water across their membranes in order to survive and function normally. The balance of ions and water is controlled by ion channels - proteins that control the permeability of the cell membrane. Of the ion channels, chloride channels are the most abundant in cells. They are central to the functioning of normal cells as well as playing a key role in many disease states. Our group was the first to identify and characterise a new class of chloride channel wh ....Cells must regulate the flow of ions and water across their membranes in order to survive and function normally. The balance of ions and water is controlled by ion channels - proteins that control the permeability of the cell membrane. Of the ion channels, chloride channels are the most abundant in cells. They are central to the functioning of normal cells as well as playing a key role in many disease states. Our group was the first to identify and characterise a new class of chloride channel which plays a key roles in the regulation of the immune system. These channels are unusual in that they can move between two states: a soluble state and a state that resides in the cell membrane. We have determined the first structures of this class of channel in both the soluble state and what is believed to be the membrane docking state. This has given us the first atomic picture of how this channel protein can alter its structure so as to carry out its function. In this project, we will determine: how the protein completes the transition into the membrane state; the structures of other key members of this class of channel protein; complexes between channel proteins and other cellular proteins; and the structure of the protein in the membrane state. We will also determine how several drugs control the activity of this channel. The results of our work will have specific implications for our channel and will serve as a paradigm other members of this new class of chloride channel. Understanding how this channel functions and how the current drugs control it will lead to the development of a new class of therapeutic agents that will control these channels by preventing the transition from the soluble to the membrane state.Read moreRead less
Regulation Of Pre-mRNA And MRNA Processing By The Neuron-specific Hu RNA-binding Proteins
Funder
National Health and Medical Research Council
Funding Amount
$477,750.00
Summary
The precise control of protein expression is absolutely critical in biology, and the key decisions about which genes are turned on or off at any one moment control the proper growth and maturation of an organism during development, and are responsible for the organism's homeostasis and proper response to environmental changes as an adult. Many gene expression programs are highly complex and controlled by regulating the activation of individual genes as they are copied from DNA to RNA. However, t ....The precise control of protein expression is absolutely critical in biology, and the key decisions about which genes are turned on or off at any one moment control the proper growth and maturation of an organism during development, and are responsible for the organism's homeostasis and proper response to environmental changes as an adult. Many gene expression programs are highly complex and controlled by regulating the activation of individual genes as they are copied from DNA to RNA. However, this activation is just the start of the process to produce an active protein. In higher organisms, these RNA copies almost always contain interruptions called introns, which must be excised from the RNA. Also, protein factors bound to specific RNAs can dictate whether the RNA is used to make protein or not, and these factors can also affect the localisation of the RNA to a specific sub-cellular destination, giving rise to highly localised protein expression. Evidence suggests that neurons are a cell type that rely heavily on mechanisms of RNA regulation. During development neurons become highly polarised, acquiring an axon which can elongate and find distant synaptic targets. While much is known about how axon growth cones respond to various guidance cues, the mechanisms by which the axon is able to translate this guidance cue information into structural changes which allow the growth cone to expand or collapse is largely unexplored. Recent evidence suggests that accurate growth cone guidance is absolutely dependent upon local protein synthesis. The functional corollary of this finding is that axon guidance requires RNA localisation and control of protein synthesis of RNAs in the growth cone. This phenomenon of spatial gene regulation within an individual cell is a central research interest for understanding how the brain functions.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
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
The functional organisation of the trans-Golgi network: From cultured cells to physiological systems. This research will result in a better understanding of the secretory pathway of all eukaryotic cells, a process of broad biological and biomedical significance. It will impact on cell biology in the broadest sense, from membrane biogenesis to lipid domain organization, as well as membrane transport, protein structure and protein targeting. Furthermore, this work will utilize and develop fronti ....The functional organisation of the trans-Golgi network: From cultured cells to physiological systems. This research will result in a better understanding of the secretory pathway of all eukaryotic cells, a process of broad biological and biomedical significance. It will impact on cell biology in the broadest sense, from membrane biogenesis to lipid domain organization, as well as membrane transport, protein structure and protein targeting. Furthermore, this work will utilize and develop frontier technologies of live cell imaging and RNA interference as a genetic tool to investigate functions of a protein family. By training post-graduate students and post-doctoral staff, it will contribute to the expertise of cell biology in Australia. International collaborations will enhance connections between Australia and overseas research.Read moreRead less
Molecular microscopy: protein and membrane dynamics in resting and activated T cells. The aim of this research, to understand the molecular organization and dynamics of the plasma membrane that underlie the signal transduction events, is at the very heart of understanding cell communication. T cell recognition and activation initiates an adaptive immune response to invading pathogens and structurally altered proteins that can be found in cancers. By providing functional insights into the molecul ....Molecular microscopy: protein and membrane dynamics in resting and activated T cells. The aim of this research, to understand the molecular organization and dynamics of the plasma membrane that underlie the signal transduction events, is at the very heart of understanding cell communication. T cell recognition and activation initiates an adaptive immune response to invading pathogens and structurally altered proteins that can be found in cancers. By providing functional insights into the molecular mechanism of T cell activation, we will not only provide fundamental knowledge of receptor signalling but also specific details of T cell receptort triggering that may lead to the development of new therapeutic strategies to control T cell activation.Read moreRead less
The structure and function of the trans-Golgi network: role of golgins and G proteins. This research will provide a better understanding of the secretory pathway of all eukaryotic cells, a process of broad biological and biomedical significance. It will also contribute to a better understanding of how a cell works, including how cell membranes are organization, how the transport processes of the cell are regulated and how proteins are targeted to their intracellular destination. Further, this ....The structure and function of the trans-Golgi network: role of golgins and G proteins. This research will provide a better understanding of the secretory pathway of all eukaryotic cells, a process of broad biological and biomedical significance. It will also contribute to a better understanding of how a cell works, including how cell membranes are organization, how the transport processes of the cell are regulated and how proteins are targeted to their intracellular destination. Further, this work will utilize the frontier technology of RNA interference as a genetic tool to investigate functions of genes. By training post-graduate students and post-doctoral staff, it will contribute to the expertise of cell biology in Australia. International collaborations will enhance connections with overseas researchers.Read moreRead less
The role of a novel family of Golgi proteins in maintaining the structure and function of the trans-Golgi network. The secretory pathway of eukaryotic cells is fundamental for proper cell growth. The Golgi apparatus is a key organelle of this pathway where newly made proteins are selectively packaged into membrane-bound transport vehicles and then shipped to their correct destination, such as the surface of the cell. This research aims to understand the mechanism by which these cargo-loaded tr ....The role of a novel family of Golgi proteins in maintaining the structure and function of the trans-Golgi network. The secretory pathway of eukaryotic cells is fundamental for proper cell growth. The Golgi apparatus is a key organelle of this pathway where newly made proteins are selectively packaged into membrane-bound transport vehicles and then shipped to their correct destination, such as the surface of the cell. This research aims to understand the mechanism by which these cargo-loaded transport vehicles are generated from the Golgi apparatus. This information is of fundamental importance in understanding how a cell survives and grows, and is necessary to allow a rational basis for the engineering of secreted recombinant molecules.Read moreRead less
A unified model of amino acid homeostasis. This project aims to develop a unified model of amino acid homeostasis in mammalian cells and apply it to brain cells. The model will be underpinned by a mathematical algorithm that allows predicting amino acid levels in the cytosol based on fundamental parameters such as transport and metabolism. This project should provide the significant benefit of enabling the prediction of essential functions such as cell growth and survival.