Infectious pathogens invade cells by hijacking cellular pathways, termed endocytosis, that normally internalise material from outside the cell. We will identify the molecular details of these pathways and how they are modulated in response to infection with Salmonella, a leading cause of human gastroenteritis. Such studies are necessary in order to understand host-pathogen interactions so that treatments can be developed targeting the symptoms of infection
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
Mechanism Of Action Of Sec1p-like Proteins In Membrane Trafficking
Funder
National Health and Medical Research Council
Funding Amount
$234,936.00
Summary
One of the most important evolutionary changes that has occurred is the development of intracellular compartments. All eukaryotic cells possess numerous membrane-encased structures which provide the basis for intracellular specialisation. For example, in order to degrade unwanted components cells have developed degradative enzymes. It is vital for the cell that these enzymes are sequestered away from other cellular components to avoid destruction of valuable molecules. In addition, the cell has ....One of the most important evolutionary changes that has occurred is the development of intracellular compartments. All eukaryotic cells possess numerous membrane-encased structures which provide the basis for intracellular specialisation. For example, in order to degrade unwanted components cells have developed degradative enzymes. It is vital for the cell that these enzymes are sequestered away from other cellular components to avoid destruction of valuable molecules. In addition, the cell has developed a complex assembly line of modifications that are added to proteins in a specific order as they travel to their final destination within the cell. This necessitates the accurate passage of molecules between compartments, a process known as vesicle transport. To orchestrate the complex network of vesicular transport steps between all of the various intracellular compartments it is necessary to employ complex machinery to guide and check that these steps occur with high fidelity. The goal of our research proposal is to define the function of one of the molecules involved in this control process, the so-called Sec1p proteins. The strength of our proposal lies in the diversity of our approach. We intend to explore the molecular advantages of a relatively simple eukaryotic organism, a yeast cell, and apply the findings obtained from this cell to a more complex but highly related vesicular transport process; that of the insulin-regulated movement of a glucose transporter in mammalian fat and muscle cells. While we intend to apply our findings to the treatment of patients with diabetes, it is our ultimate goal to be able to learn more about this fundamental cell biological process so that we can apply our knowledge to understanding many different disease states.Read moreRead less