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
Insulin resistance (the inability of ordinarily insulin-sensitive tissues such as muscle and adipose tissue to respond to insulin) contributes to a number of diseases including diabetes and obesity. A key metabolic step in these tissues is the uptake of glucose from the blood stream. This step is accelerated by insulin thus allowing efficient clearance of glucose from the bloodstream after a meal. Our laboratory has played a major role in showing that insulin regulates glucose uptake into muscle ....Insulin resistance (the inability of ordinarily insulin-sensitive tissues such as muscle and adipose tissue to respond to insulin) contributes to a number of diseases including diabetes and obesity. A key metabolic step in these tissues is the uptake of glucose from the blood stream. This step is accelerated by insulin thus allowing efficient clearance of glucose from the bloodstream after a meal. Our laboratory has played a major role in showing that insulin regulates glucose uptake into muscle and adipose tissue by stimulating the movement of a glucose transport protein from inside the cell to the cell surface (see http:--www.imb.uq.edu.au-groups-james-glut4 for an animated description of this process). The purpose of this proposal is to dissect the molecular mechanisms by which this glucose transporter can be held inside the cell in the absence of insulin and then allowed to be released from this site moving to the surface in the presence of insulin. Our studies over the past 5 years have brought us much closer to understanding this process in detail. The identification of the molecules responsible for this regulatory step will not only aid our understanding of this process but it will also provide a valuable target for development of therapeutic agents that can be used to combat insulin resistance.Read moreRead less
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
The Regulation Of PI 3-kinase Second Messenger Molecules, PtdIns(3,4)P2 And PtdIns 3-P.
Funder
National Health and Medical Research Council
Funding Amount
$406,980.00
Summary
Cells respond to the external environment, hormones, and growth factors by generating messages inside the cell that send a signal to the nucleus that stimulates cell growth. One such signalling network is that produced by membrane lipids known as phosphoinositides. Enzymes that produce these signals are known as kinases. There has been considerable interest in the PI 3-kinase as the signals generated by this enzyme are increased in many human cancers. Inherited cancer syndromes have been describ ....Cells respond to the external environment, hormones, and growth factors by generating messages inside the cell that send a signal to the nucleus that stimulates cell growth. One such signalling network is that produced by membrane lipids known as phosphoinositides. Enzymes that produce these signals are known as kinases. There has been considerable interest in the PI 3-kinase as the signals generated by this enzyme are increased in many human cancers. Inherited cancer syndromes have been described that have lost the ability to switch off PI 3-kinase signals. The current project aims to investigate a recently identified enzyme called the 4-phosphatase that has the ability to terminate PI 3-kinase signals. Recent studies have shown this enzyme regulates cell growth. In addition key experiments have shown the enzyme is important as it may regulate certain strains of bacterial infection. This research proposal aims to investigate how the enzyme works to regulate these growth promoting signals. This may help us develop novel therapeutic strategies to control cell growth.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
Prof Parton is a cell biologist studying how the plasma membrane functions in health and in disease. These studies have provided new insights into potential vehicles that can be used to introduce therapeutic agents into cells.