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
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
Group A streptococcus (GAS) is a bacteria that causes a wide range of disease in humans. GAS diseases are more common in Australias Indigenous population, and other health and economically disadvantaged groups than more affluent groups. In this study we will evaluate the effectiveness of novel vaccine candidates designed to prevent infection from all strains of GAS.
Linkage Infrastructure, Equipment And Facilities - Grant ID: LE120100170
Funder
Australian Research Council
Funding Amount
$580,000.00
Summary
Bioaffinity mass spectrometry infrastructure to identify small molecules binding to therapeutic targets. The development of anti-infective therapies is challenging because the underlying biology and biochemistry of pathogen virulence is not yet completely understood. This mass spectrometer facility will be used to identify small molecules suited for development into new therapies for malaria, tuberculosis and HIV.
Development of small molecule primary sulfonamides as new drugs for malaria. Malaria is a major global health threat, causing approximately 800,000 deaths annually. Lives can be saved if patients are treated. The use of current antimalarial drugs is limited by drug resistance, low activity and poor safety. This project investigates the effectiveness of a new class of molecule as a safe drug treatment option to kill malaria parasites.
Movement of mitochondria between cells. This project aims to characterise how mitochondria move between cells into grafted cells with dysfunctional mitochondrial function. How mitochondria reach the acceptor cell and how they move from the donor cell is not known. The project will use a 'bottom-up' approach, starting from a reconstituted system, via in vitro, co-culture stage to a relevant biological model, increasing complexity and biological relevance. It will document that the process of mito ....Movement of mitochondria between cells. This project aims to characterise how mitochondria move between cells into grafted cells with dysfunctional mitochondrial function. How mitochondria reach the acceptor cell and how they move from the donor cell is not known. The project will use a 'bottom-up' approach, starting from a reconstituted system, via in vitro, co-culture stage to a relevant biological model, increasing complexity and biological relevance. It will document that the process of mitochondrial intercellular movement is dependent on intercellular bridges and a specific mobility system. The project is of high relevance for cell biology.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