Polarized Trafficking Of E-cadherin In Epithelial Cells.
Funder
National Health and Medical Research Council
Funding Amount
$515,564.00
Summary
The cell adhesion protein E-cadherin is expressed in all epithelial tissues of the body where it has essential functions during development and in the adult in establishing and maintaining polarized cell monolayers. E-cadherin is also a vital tumour suppressor, its normal function guarantees that cells or even early tumours cannot metastasise; in contrast E-cadherin is always lost or malfunctions in malignant tumours. Earlier studies showed that E-cadherin is constantly moved, or trafficked, to ....The cell adhesion protein E-cadherin is expressed in all epithelial tissues of the body where it has essential functions during development and in the adult in establishing and maintaining polarized cell monolayers. E-cadherin is also a vital tumour suppressor, its normal function guarantees that cells or even early tumours cannot metastasise; in contrast E-cadherin is always lost or malfunctions in malignant tumours. Earlier studies showed that E-cadherin is constantly moved, or trafficked, to and from the surface of epithelial cells. This trafficking has dual roles, firstly in delivering newly-made E-cadherin to the surface where it functions and secondly, in regulating its adhesive function. Our research in this project is focussed on the molecules and intracellular compartments that control the delivery of E-cadherin to the cell surface. E-cadherin must be sorted in order to be delivered to the correct side of the cell. Having previously discovered the sorting signal in E-cadherin, we will now identify the cognate adaptor protein(s) that accomplish this sorting. New imaging techniques allow us to study protein trafficking inside live cells. Such studies have recently revealed that E-cadherin passes through a recycling endosome compartment on its way to the cell surface. This unexpected route, and the structure and role of the recycling endosome will now be studied in detail in live cells. Finally we will compare the sorting and trafficking of E-cadherin with the closely-related N-cadherin protein, to determine whether there are inherent differences in their trafficking that could explain their opposite roles in tumour cells, where N-cadherin is substituted for E-cadherin and allows metastatic behaviour. These studies will provide important information for understanding the adhesive and tumour suppressive roles of E-cadherin. In addition our findings will generate information fundamental to our understanding of cell polarity and protein sorting.Read moreRead less
PrtFII, A Streptococcus Pyogenes Fibronectin Binding Protein, And Invasive Diseases.
Funder
National Health and Medical Research Council
Funding Amount
$296,540.00
Summary
Our recent work revealed that, in the Aboriginal population, young age is a risk factor for severe invasive diseases caused by group A streptococcus. For group A streptococcus infection to occur, bacterial attachment is the first step. The bacterium attaches to host cells through interactions involving host fibronectin and the pathogen's fibronectin-binding proteins. We have found that streptococcal strains from severe disease cases are more likely to have the gene for PrtFII, a fibronectin bind ....Our recent work revealed that, in the Aboriginal population, young age is a risk factor for severe invasive diseases caused by group A streptococcus. For group A streptococcus infection to occur, bacterial attachment is the first step. The bacterium attaches to host cells through interactions involving host fibronectin and the pathogen's fibronectin-binding proteins. We have found that streptococcal strains from severe disease cases are more likely to have the gene for PrtFII, a fibronectin binding protein, than those from uncomplicated skin sores. In this application we propose to extend this observation and compare biochemical properties of PrtFII from strains belonging to the above two sets of collections. We hypothesise that PrtFII from invasive strains bind to fibronectin more tightly than the proteins from strains that cause uncomplicated infection. We also will test whether sera from invasive disease cases have lower titre of antibodies to the conserved region of PrtFII than sera from uncomplicated cases. A streptococcal vaccine by necessity has to be a multi-component vaccine to cover a wide spectrum of diseases and epidemiological differences. The study proposed here may provide a basis to argue whether or not to include PrtFII in such a multi-component vaccine.Read moreRead less
Centre Of Research Excellence On Sitting Time And Chronic Disease Prevention – Mechanisms, Measurement And Interventions
Funder
National Health and Medical Research Council
Funding Amount
$2,657,874.00
Summary
Australian research has identified serious health consequences arising from the 7 to 10 hours of daily sitting that most people do, especially in relation to ‘diseases of inactivity’ – type 2 diabetes, coronary heart disease and breast and colon cancer – that are an unwelcome burden on individuals, families and health systems. This new research examines the practical feasibility and the preventive-health benefits of changing children’s and adults’ sitting time in schools, workplaces and the home ....Australian research has identified serious health consequences arising from the 7 to 10 hours of daily sitting that most people do, especially in relation to ‘diseases of inactivity’ – type 2 diabetes, coronary heart disease and breast and colon cancer – that are an unwelcome burden on individuals, families and health systems. This new research examines the practical feasibility and the preventive-health benefits of changing children’s and adults’ sitting time in schools, workplaces and the home environment.Read moreRead less
Delayed Radial Glial Maturation Linked To NFI Deficiency As An Underlying Cause Of Cortical Defects In Humans And Mice
Funder
National Health and Medical Research Council
Funding Amount
$801,979.00
Summary
The timely generation of neurons and glia is important for brain development and consequently brain function throughout life. Nuclear factor I (NFI) genes are important for regulating the production of neurons and glia, and people with disrupted NFI genes have severe cognitive and motor deficits. Using human genetic data and mouse models, we will analyse how disrupting these genes affects brain development, and changes the overall structure and wiring of the cerebral cortex as well as behaviour.
Control of actin assembly by cell-cell adhesion: molecular effectors and higher order function. Functional cooperation between the actin cytoskeleton and cadherin cell-cell adhesion molecules plays critical roles during development and morphogenesis. This proposal builds on my lab's recent discovery that E-cadherin interacts with and regulates the Arp2/3 actin nucleator complex, a central determinant of actin assembly in cells. We will explore key implications of this finding, concentrating on d ....Control of actin assembly by cell-cell adhesion: molecular effectors and higher order function. Functional cooperation between the actin cytoskeleton and cadherin cell-cell adhesion molecules plays critical roles during development and morphogenesis. This proposal builds on my lab's recent discovery that E-cadherin interacts with and regulates the Arp2/3 actin nucleator complex, a central determinant of actin assembly in cells. We will explore key implications of this finding, concentrating on defining the molecular mechanisms that regulate Arp2/3 and actin assembly in cadherin-based adhesion. Our work combines molecular characterization of regulatory mechanisms and proteomic searches for new regulators, with tests of the higher-order function of this novel process in cell adhesion and recognition.Read moreRead less
Balancing cadherin-actin cooperation: the key regulatory role of Ena/VASP proteins. This project analyses a fundamental mechanism of how cells work together in tissues. Understanding the fundamental mechanisms of how cells work will provide important basic scientific information to enrich the scientific expertise in Australia and its part in the international community, generate insights relevant for understanding human disease and physical degeneration, and support the training of young scienti ....Balancing cadherin-actin cooperation: the key regulatory role of Ena/VASP proteins. This project analyses a fundamental mechanism of how cells work together in tissues. Understanding the fundamental mechanisms of how cells work will provide important basic scientific information to enrich the scientific expertise in Australia and its part in the international community, generate insights relevant for understanding human disease and physical degeneration, and support the training of young scientists in Australia.Read moreRead less
E-Cadherin Endocytosis In Morphogenesis: Recycling And Growth Factor Induced Uptake.
Funder
National Health and Medical Research Council
Funding Amount
$498,088.00
Summary
E-cadherin is a cell-cell adhesion protein expressed in all epithelia with essential roles in establishing cell polarity and in tissue patterning during development. In the adult, E-cadherin functions to maintain epithelial integrity. E-cadherin is also a vital tumour suppressor, protecting cells against metastatic transformation. Our earlier studies showed that E-cadherin is constantly moved, or trafficked, to and from the surface of epithelial cells. The endocytosis or internalisation of cell ....E-cadherin is a cell-cell adhesion protein expressed in all epithelia with essential roles in establishing cell polarity and in tissue patterning during development. In the adult, E-cadherin functions to maintain epithelial integrity. E-cadherin is also a vital tumour suppressor, protecting cells against metastatic transformation. Our earlier studies showed that E-cadherin is constantly moved, or trafficked, to and from the surface of epithelial cells. The endocytosis or internalisation of cell surface E-cadherin serves to regulate its role in adhesion. More recently, we and others have shown that E-cadherin is endocytosed in response to growth factors, in conjunction with the activated growth factor receptors themselves. E-cadherin can influence the trafficking and signaling of these receptor tyrosine kinases. This joint endocytosis is an elegant mechanism for the simultaneous downregulation of cell adhesion and activation of signaling for cell growth and motility. The growth and differentiation of epithelial cells during tissue patterning or morphogenesis relies critically on these endocytic pathways. Our research is aimed at defining the endosomes and cellular machinery involved in E-cadherin-receptor endocytosis, moreover we will pursue initial findings suggesting that there are different pathways and fates for E-cadherin endocytosed at the behest of different growth factors. We will study endocytosis during the processes of epithelial cyst formation and tubulation of cysts as an in vitro model for mammalian morphogenesis. These studies will provide important and novel information for understanding the roles of E-cadherin in adhesion and in growth factor signaling during epithelial morphogenesis. Ultimately these findings will be of relevance to epithelial development and the prevention of cancer.Read moreRead less
Linkage Infrastructure, Equipment And Facilities - Grant ID: LE110100028
Funder
Australian Research Council
Funding Amount
$720,000.00
Summary
Ultra-high resolution and advanced analytical scanning electron microscope facility. This scanning electron microscope facility will form an essential part of characterising a broad range of material types, from nanometre sized particles through to cells and their interactions.