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
Recycling Endosomes Governing Cell Polarity And Cytokine Secretion.
Funder
National Health and Medical Research Council
Funding Amount
$958,412.00
Summary
Cytokines are chemical messengers released by cells to mount inflammatory responses to fight infections. The timing and direction of cytokine release must be tightly regulated. We investigate the cellular compartments and molecules that control cytokine secretion using sophisticated live cell imaging. Uncontrolled cytokine release is the main cause of ongoing inflammation in arthritis and inflammatory bowel disease and our studies aim to identify cellular targets for new drug development.
This work will analyse how cells, the building blocks of tissues, are organized together to form functioning organs. It focuses on the adhesion molecules that allow cells to recognize one another, which cooperate with the internal skeleton of cells to link them together. We aim to understand how these cellular systems work normally and how they are targeted to disrupt tissue integrity in diseases like cancer and inflammation.
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
Cortactin: Molecular Regulation Of Cadherin Activity And Epithelial Morphogenesis.
Funder
National Health and Medical Research Council
Funding Amount
$239,250.00
Summary
Interactions between cells and their neighbouring cells control many important processes in the body. The adhesion molecule E-cadherin is a major protein that controls how cells interact with one another in many epithelial tissues (e.g. breast, lung, gut). These tissues are the source of many common diseases, particular cancer and inflammation. E-cadherin is essential for these tissues to form normally, and loss of E-cadherin function contributes to disease in these tissues (especially common ca ....Interactions between cells and their neighbouring cells control many important processes in the body. The adhesion molecule E-cadherin is a major protein that controls how cells interact with one another in many epithelial tissues (e.g. breast, lung, gut). These tissues are the source of many common diseases, particular cancer and inflammation. E-cadherin is essential for these tissues to form normally, and loss of E-cadherin function contributes to disease in these tissues (especially common cancers, such as breast and lung). Understanding how E-cadherin controls normal cell function in these tissues will therefore provide key insights into how disease arises. In this study we will investigate how a protein which binds to E-cadherin, cortactin, contributes to the biological effect of E-cadherin in supporting tissue architecture. Understanding the fundamental elements of how cortactin works with E-cadherin will provide invaluable information into how cells recognize one another in health, and fail to adequately recognize each other in common diseases.Read moreRead less
MicroRNAs are small molecules that modulate the expression of most genes and so affect nearly every biological process and pathology although, they were only discovered in humans less than 10 years ago. The bottleneck in discovering the functions of miRNAs is in identifying their molecular targets, the majority of which remain unknown. We aim to comprehensively identify direct target genes of epithelial-specific microRNAs and to confirm a number of them by gene target validation approaches.
Role Of The MiR-200 Target Quaking In Alternative Splicing During EMT And Cancer Progression
Funder
National Health and Medical Research Council
Funding Amount
$443,160.00
Summary
The spread of cancer to other organs involves cancer cells changing to a more aggressive state and is a major cause of cancer related death. MicroRNAs are a class of genes that control whether cancer cells become more aggressive by regulating other genes. In this project we will examine the function of a new microRNA target which controls the cancer cell aggression. The outcome will be a better understanding of how cancers spread and the identification of new therapeutic targets.