All cells have a characteristic shape (morphology), which is intrinsic to cellular function. A blood cell is designed to move in a liquid medium whereas a muscle cell is optimised for physical movement of attached bones. We are studying the mechanisms which control cell shape. We focus on the components of the cell skeleton (cytoskeleton) which are implicated in the regulation of shape. In particular, we study the actin based microfilament system. We have previously shown that two types of these ....All cells have a characteristic shape (morphology), which is intrinsic to cellular function. A blood cell is designed to move in a liquid medium whereas a muscle cell is optimised for physical movement of attached bones. We are studying the mechanisms which control cell shape. We focus on the components of the cell skeleton (cytoskeleton) which are implicated in the regulation of shape. In particular, we study the actin based microfilament system. We have previously shown that two types of these components of the cytoskeleton are able to control the structure of cells. In addition, we have found that variants of these two components (called isoforms) are used to build structures in different parts of cells. This has led us to think about the anatomy of cells and tissues in a new way. In some ways its like building a city. You create different kinds of buildings to suit their purpose. Each building uses a combination of building blocks which suit the structural demands of rooms and the overall building. In this study, we are proposing to dissect out genes, or parts of genes, which supply specific types of building blocks. To do this, we plan to change these genes in mice and then examine the impact on cell and tissue anatomy. This promises to contribute to the conversion of anatomical science and pathology from descriptive to experimental-mechanistic disciplines.Read moreRead less
Inhibition Of Retinoblastoma Protein Degradation By Interaction With The Serpin PAI-2 Via A Novel Consensus Motif
Funder
National Health and Medical Research Council
Funding Amount
$463,500.00
Summary
Plasminogen activator inhibitor-2 (PAI-2) has previously been shown to inhibit the activity of enzymes outside the cell that are involved in blood clotting and cell migration. We have discovered that this activity is probably not the major role of PAI-2. PAI-2 also has a function inside cells that protect and increases the activity of an important tumour suppressor protein called the retinoblastoma tumour suppressor protein (Rb). Rb is involved in many cellular functions such as, cell death, cel ....Plasminogen activator inhibitor-2 (PAI-2) has previously been shown to inhibit the activity of enzymes outside the cell that are involved in blood clotting and cell migration. We have discovered that this activity is probably not the major role of PAI-2. PAI-2 also has a function inside cells that protect and increases the activity of an important tumour suppressor protein called the retinoblastoma tumour suppressor protein (Rb). Rb is involved in many cellular functions such as, cell death, cell differentiation, cell growth, and most importantly prevention of cancer development. Rb is attacked and destroyed by several viruses which causes cells to become cancerous. This grant seeks to fully understand how PAI-2 protects and interacts with Rb. We have already found a new site on Rb to which PAI-2 binds. This site is also used by other proteins in the cell as well as disease causing virus proteins. Examples of these proteins are BRCA1, a protein involved in breast cancer development, and EBNA6, a protein from Epstein Barr virus that causes glandular fever and tumours. We have also found, and seek to explore further, how PAI-2 reverses the activities of the cervical cancer causing proteins of the human papilloma virus. Although at an early stage, these studies may lead to the development of new therapeutic drugs based on PAI-2 for the treatment of various types cancers or warts caused by HPV. Analysing the activity of PAI-2 inside cells will have implications for understanding much of the confusing scientific literature on PAI-2 and will provide a better comprehension of the role of PAI-2 in inflammation, cell differentiation, wound healing and cancer. For example it has long been known that the presence of PAI-2 in cancerous tumours is linked with a better prognosis, an activity that can now be understood in terms of the PAI-2 interaction with Rb. This new understanding may lead to the development of PAI-2 based prognostic assays for cancer.Read moreRead less