Characterisation of subcellular compartments that contain signalling complexes of protein kinase C epsilon
Final Report Abstract
The aim of this project was to elucidate the signalling cascade downstream of hepatocyte growth factor (HGF). HGF is a hormone secreted by a subset of cells within the body. Secreted HGF then binds to its receptor c-Met which is located on the surface of cells. When HGF binds to c-Met this triggers a signalling cascade within the cell which in the end results in various biological outcomes, e.g. cell division or cell motility. While these signalling cascades are normally well regulated in the body, under certain conditions, signalling occurs in an unregulated manner and this can ultimately lead to disease, e.g. cancer. HGF for example, has been strongly implicated in the process of cancer metastasis. To better understand the development of cancer it is therefore important to understand in detail the HGF/c-Met signalling cascade. The aim of this project was to identify signalling molecules which play a role in this cascade. It is well established that c-Met once bound to HGF gets qickly taken up into the cell, a process called internalisation, and the signalling cascade then is triggered from within the cells. It was known from earlier studies that PKCepsilon is regulating the signalling downstream of internalised c-Met and we wanted to identify other proteins involved in this process. To do so we wanted to isolate proteins found in complex with PKCepsilon inside the cells. However, we were not able to isolate such structures and therefore used a different methodology to get insights into the HGF signalling cascade. Using the siRNA approach, we were able to specifically deplete cells of 1400 different proteins. We then tested, if this depletion had an effect on HGF-signalling. indeed we could identify a number of proteins that seem to be important for the HGF-induced biological response. Further work is needed to understand in detail how these players affect the HGF signalling cascade.
