Translocase Of The Outer Mitochondrial Membrane: X-ray Structure Determination Of Core Components
Funder
National Health and Medical Research Council
Funding Amount
$336,118.00
Summary
This research will address the issue of protein transport into mitochondria, cellular organelles bounded by a complex double-membrane system that are primarily responsible for servicing the energy requirements of actively respiring cells. The outer membrane, or envelope, surrounding each mitrochondrion, is separated from a second (or inner) membrane by an inter-membrane space. The translocase of the outer mitochondrial membrane (TOM) cooperates with the translocase of the inner mitochondrial mem ....This research will address the issue of protein transport into mitochondria, cellular organelles bounded by a complex double-membrane system that are primarily responsible for servicing the energy requirements of actively respiring cells. The outer membrane, or envelope, surrounding each mitrochondrion, is separated from a second (or inner) membrane by an inter-membrane space. The translocase of the outer mitochondrial membrane (TOM) cooperates with the translocase of the inner mitochondrial membrane (TIM) to mediate the passage of unfolded preproteins into the mitochondria. Proteins are usually bulky in their active folded state, so preproteins transit the membrane as extended polypeptide chains, as the channel through which they pass is relatively narrow. Ancillary praoteins aid in recognition and targeting of preproteins, and help to maintain them in an unfolded state prior to their translocation through the pore, and later ensure that they are able to fold into the correct conformation once they have arrived in the mitochondria. Our research will entail determination of the three-dimensional atomic-level structures of selected constituents of the TOM machinery, allowing us to visualise freeze-frame snapshots of some aspects of protein translocation in molecular details. In combination with recent biochemical data, this information will provide an architectural framework which we can use to help in our interpretation of complicated structure-function relationships between components of TOM and other proteins with which they integrate their activities during translocation events. Ultimately such fundamental research will lead to the development of strategies for dealing with disorders linked to mitochondrial defects in humans, including, amongst others, Parkinson's and Alzheimer's diseases.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 Capsid Protein Nucleolar Localisation In Chikungunya Virus: Implications For Vaccine Development
Funder
National Health and Medical Research Council
Funding Amount
$520,520.00
Summary
Chikungunya virus (CHIKV) is a globally widespread mosquito-borne alphavirus capable of causing considerable human morbidity and mortality. With no CHIKV vaccine or antiviral available this proposal aims to develop a live attenuated CHIKV vaccine, rationally designed by investigating the host cell nucleolar trafficking of CHIKV capsid protein. This vaccine has the potential to provide cross-protection against additional arthritogenic alphaviruses endemic to Australia such as Ross River virus.
Regulation Of Nuclear Import Of Viral Oncoproteins And Transcription Factors By Protein-protein Interactions
Funder
National Health and Medical Research Council
Funding Amount
$650,383.00
Summary
The present application examines the controls that exerted over proteins that localize in the nucleus of eukaryotic cells. This relates relates integrally to cellular processes such as growth, development and oncogenesis. This research area is not represented elsewhere in Australia, and the particular experimental strategies to approach the problem, revolving around the use of special quantitative microscopic techniques are novel internationally. One part of the application seeks to examine tran ....The present application examines the controls that exerted over proteins that localize in the nucleus of eukaryotic cells. This relates relates integrally to cellular processes such as growth, development and oncogenesis. This research area is not represented elsewhere in Australia, and the particular experimental strategies to approach the problem, revolving around the use of special quantitative microscopic techniques are novel internationally. One part of the application seeks to examine transport within the cell of complexes of interacting proteins, rather than single proteins, under as close as possible to physiologically relevant conditions. This will be truly unique, and of great importance to our comprehension of eukaryotic cell function. This application examines particular types of negative control over protein nuclear localization. Since many proteins show such regulation, and in particular important proteins controlling cell growth and division, the results are fundamentally important to our understanding of how cells function in general. Further, this understanding may be applied in disease situations, such as viral-mediated oncogenesis. In the work we propose to do, viral proteins with functions relating to cancer will be examined in detail, as well as a cellular protein which is recognised by them - the tumor suppressor Rb. We intend to examine several viral oncoproteins which target Rb; one is a protein (E7) from the Human Papilloma Virus which has been frequently associated with cervical carcinomas and other cancers. Accordingly, the results may have direct application to viral-induced cancer, and our work may lead to understanding of the regulation of protein transport to the nucleus. This may thus afford a new approach at the pharmacological level to combat transformation.Read moreRead less
Characterising The Beta-catenin Nuclear Targeting Pathway In Cancer
Funder
National Health and Medical Research Council
Funding Amount
$485,081.00
Summary
Bowel cancer is caused by inherited gene mutations that cause build-up of beta-catenin protein in the cell nucleus. Bowel cancer is the second largest cause of cancer deaths in Australia. We aim to study the mechanisms controlling beta-catenin accumulation in the nucleus. We will characterise new signalling pathways that control movement and activity of beta-catenin in the nucleus. This will yield insights into the role of beta-catenin in cancer and possible targets for therapy.
Subcellular Trafficking Of P Proteins Of Human Pathogenic Viruses: Roles In Viral Pathogenicity And Targeting For Therapeutics
Funder
National Health and Medical Research Council
Funding Amount
$578,352.00
Summary
In order to infect humans, pathogenic viruses such as rabies, Nipah, Hendra and Australian bat lyssavirus must be able to evade the immune response. To do this, viruses produce "interferon antagonists" that interfere with specific immune processes by mechanisms that are not fully understood. Our study will characterise the mechanisms used by rabies and other viruses to block immunity, and identify strategies to disable viral immune evasion, rendering these lethal viruses susceptible to destructi ....In order to infect humans, pathogenic viruses such as rabies, Nipah, Hendra and Australian bat lyssavirus must be able to evade the immune response. To do this, viruses produce "interferon antagonists" that interfere with specific immune processes by mechanisms that are not fully understood. Our study will characterise the mechanisms used by rabies and other viruses to block immunity, and identify strategies to disable viral immune evasion, rendering these lethal viruses susceptible to destruction by the human immune system.Read moreRead less