Regulation Of The Tumour Suppressors APC And BRCA1 By Nuclear Export
Funder
National Health and Medical Research Council
Funding Amount
$530,874.00
Summary
Cancer cells lack the ability to control their own growth, and thus continously divide in their local environment, leading to tumour formation. Tumour suppressor proteins, like APC and BRCA1, normally function as regulators to help cells respond to outside signals and to stop growing when necessary. The inactivation and altered cellular localisation of tumour suppressor proteins can contribute to cancer development. We have found that the APC and BRCA1 proteins, whose inactivation leads to devel ....Cancer cells lack the ability to control their own growth, and thus continously divide in their local environment, leading to tumour formation. Tumour suppressor proteins, like APC and BRCA1, normally function as regulators to help cells respond to outside signals and to stop growing when necessary. The inactivation and altered cellular localisation of tumour suppressor proteins can contribute to cancer development. We have found that the APC and BRCA1 proteins, whose inactivation leads to development of colon cancer and breast cancer, respectively, contain signals that dictate their movement within the cell. Our novel preliminary findings reveal that APC and BRCA1 are able to move in and out of the cell nucleus. We aim to define how this occurs, and examine how the regulation of their cellular location affects the normal function of these cancer-suppressing proteins. Finally, abnormalities in the nuclear passage of APC or BRCA1 might explain their altered cellular location in cancer cells.Read moreRead less
Regulation Of BRCA1 And APC Tumour Suppressor Functions By Nuclear Export
Funder
National Health and Medical Research Council
Funding Amount
$433,500.00
Summary
Cancer cells are unique, in that their ability to divide and grow is no longer controlled. Moreover, the DNA of cancer cells is less stable, and vital control genes often gain small mutations which culminate in a more aggressive or malignant cancer cell. Cancers from different tissues progress and respond in different ways to treatment, and the eventual development of tailored treatments or therapies will require a detailed understanding of how cancers from different tissues arise. Our laborator ....Cancer cells are unique, in that their ability to divide and grow is no longer controlled. Moreover, the DNA of cancer cells is less stable, and vital control genes often gain small mutations which culminate in a more aggressive or malignant cancer cell. Cancers from different tissues progress and respond in different ways to treatment, and the eventual development of tailored treatments or therapies will require a detailed understanding of how cancers from different tissues arise. Our laboratory studies two proteins, BRCA1 and APC, which are encoded by the genes most often associated with breast and colon cancer, respectively. We have made important discoveries linking the movement and location of these proteins inside the cell with their cancer-causing activity. In this project, we will continue to study how and why APC and BRCA1 move between different compartments inside cancer cells, and how this movement can sometimes signal cancer cells to die. Detailed understanding of these processes is essential for the eventual design of drug, peptide or gene therapies aimed at correcting defects in the expression or localisation of APC or BRCA1 in breast or colon cancer cells, and hopefully provide clues for that magic bullet that specifically targets and kills cancer cells.Read moreRead less
Regulation Of Hedgehog Signalling Through Intracellular Trafficking Events
Funder
National Health and Medical Research Council
Funding Amount
$220,500.00
Summary
The hedgehog signalling cascade plays a role in forming almost every organ of the body during development of an embryo. Perturbation of the function of key members of this pathway during embryonic development often results in death in utero or severe childhood abnormalities. In addition, disruption to this pathway also results in a range of cancers, most notably the extremely common skin cancer basal cell carcinoma. In this proposal we aim to investigate in detail the regulatory mechanisms which ....The hedgehog signalling cascade plays a role in forming almost every organ of the body during development of an embryo. Perturbation of the function of key members of this pathway during embryonic development often results in death in utero or severe childhood abnormalities. In addition, disruption to this pathway also results in a range of cancers, most notably the extremely common skin cancer basal cell carcinoma. In this proposal we aim to investigate in detail the regulatory mechanisms which operate to ensure that this complex pathway of interacting molecules functions correctly during embryonic development. By understanding how this regulation occurs we will gain valuable insight into how disruption of this pathway results in such a range of disease, as well as into how agents which modulate this pathway may potentially act in a therapeutic setting.Read moreRead less
Approaches to combat AIDS and its causative agent, the human immunodeficiency virus HIV-1, have thus far proved ineffective. The proposed research program intends to investigate the nuclear import of two HIV-1 proteins which have central roles in HIV infection. We will apply our expertise in the area of the regulation of nuclear import of viral proteins, and build on our observations with respect to these proteins to attempt to establish the mechanistic basis of their nuclear import, and how thi ....Approaches to combat AIDS and its causative agent, the human immunodeficiency virus HIV-1, have thus far proved ineffective. The proposed research program intends to investigate the nuclear import of two HIV-1 proteins which have central roles in HIV infection. We will apply our expertise in the area of the regulation of nuclear import of viral proteins, and build on our observations with respect to these proteins to attempt to establish the mechanistic basis of their nuclear import, and how this differs from the conventional nuclear import pathways used by normal cellular proteins. We already have evidence that nuclear import of HIV-Tat is regulated in novel fashion by cellular factors, and intend, through determining its mechanistic basis, to be able to form the basis of a strategy to block this import pathway specifically, and thereby inhibit HIV replication. This may form the basis in the future of a new pharmaceutical approach to combat HIV-AIDS.Read moreRead less
The Role Of Cholesterol In Patched/hedgehog Signalling During Mammalian Development.
Funder
National Health and Medical Research Council
Funding Amount
$198,660.00
Summary
Fluctuations in levels of cholesterol during development of the mammalian embryo have been shown to have catastrophic affects leading to gross deformities particularly in terms of brain and facial development. The requirement of the developing embryo for cholesterol has been linked to the patched-hedgehog signalling pathway which we have previously shown to be central to mammalian development as well as tumour formation. In particular, the patched protein which is responsible for regulating sign ....Fluctuations in levels of cholesterol during development of the mammalian embryo have been shown to have catastrophic affects leading to gross deformities particularly in terms of brain and facial development. The requirement of the developing embryo for cholesterol has been linked to the patched-hedgehog signalling pathway which we have previously shown to be central to mammalian development as well as tumour formation. In particular, the patched protein which is responsible for regulating signalling through this complex cascade of protein interactions has a domain similar to that which in other proteins has been shown to detect and respond to intracellular levels of cholesterol. The patched protein binds to hedgehog at the surface of the cell and mediates the transduction of the the hedgehog signal into the cell. By analogy to the role of sterol sensing domains in other proteins, we hypothesise that this domain in patched detects fluctuations in intracellular cholesterol levels which in turn alter trafficking of patched to the cell surface where it can participate in the hedgehog receptor complex. This hypothesis is supported by our preliminary data which suggests that patched is normally localised both at the cell surface and intracellularly. We are proposing a series of experiments to test our hypothesis, most of which deal with determing the localisation of patched in a cell culure system exposed to agents aimed at varying the intracellular levels of cholesterol. Subcellular localisation of patched will be analysed by immunofluorescence, electron microscopy and immunoblotting analysis. We will also test the ability of patched to aggregate at the cell surface with other molecules important in receiving and sending the hedgehog signal. The experiments in this proposal are likely to give the first clues as to the function of the sterol sensing domain in patched and its role in mediating the vital link between cholesterol and embryonic development.Read moreRead less
NUCLEAR AND TRANSGOLGI TARGETING AND MEMBRANE INDUCTION BY DENGUE NS5 RNA-DEPENDENT RNA POLYMERASE INTERDOMAIN REGION
Funder
National Health and Medical Research Council
Funding Amount
$450,750.00
Summary
Dengue virus is the causative agent of a mosquito-borne disease, Dengue fever, relevant to northern Queensland, where antibodies from a previous infection can complex with virus of a different serotype in a subsequent infection, and cause a severe, potentially fatal form of the disease (Dengue haemorrhagic fever-Dengue shock syndrome). The present proposal seeks to further understanding of the role of the dengue RNA-dependent RNA polymerase NS5, which is essential for viral RNA replication, with ....Dengue virus is the causative agent of a mosquito-borne disease, Dengue fever, relevant to northern Queensland, where antibodies from a previous infection can complex with virus of a different serotype in a subsequent infection, and cause a severe, potentially fatal form of the disease (Dengue haemorrhagic fever-Dengue shock syndrome). The present proposal seeks to further understanding of the role of the dengue RNA-dependent RNA polymerase NS5, which is essential for viral RNA replication, within the viral infectious cycle. We intend to examine the subcellular targeting properties of a short central region (the interdomain) of NS5, which appears to play multiple roles in targeting to both the perinuclear Golgi-membranes and to the nucleus, as well as in inducing intracellular membranes derived from the Golgi which are the site of viral replication. We will determine how NS5 localisation-membrane induction may differ in insect and primate cells, and attempt to isolate binding partners of NS5 from the nucleus and Golgi compartment of insect and primate cells using various different approaches. Our studies should assist in understanding NS5's critical role in the Dengue infectious cycle, and contribute towards devising new anti-viral strategies such as vaccination and-or therapies targeted at the NS5 interdomain.Read moreRead less