Co-ordinated Action of ATM and DNA-PK in DNA damage recognition. The aim of this project is to investigate the mechanism of repair of double straind breaks in DNA sustained after radiation damage. Specifically we will focus on two proteins ATM (mutated in the genetic disorder ataxia-telangiectasia) and DNA-PK mutated in scid mice. There two proteins recognize double straind breaks in DNA and signal this damage to the DNA repair machinery of the cell and to cell cycle checkpoints. The emphasis ....Co-ordinated Action of ATM and DNA-PK in DNA damage recognition. The aim of this project is to investigate the mechanism of repair of double straind breaks in DNA sustained after radiation damage. Specifically we will focus on two proteins ATM (mutated in the genetic disorder ataxia-telangiectasia) and DNA-PK mutated in scid mice. There two proteins recognize double straind breaks in DNA and signal this damage to the DNA repair machinery of the cell and to cell cycle checkpoints. The emphasis here will be in the relationship between the two proteins in co-ordinating the repair of breaks in DNA. This information will be important in understanding mechanisms for maintaining the integrity of the genome.Read moreRead less
Role Of FHA Domains As Protein-protein Interaction Modules In Cell Signalling
Funder
National Health and Medical Research Council
Funding Amount
$191,973.00
Summary
The proper processing of information in cells involves the association of different proteins to signalling complexes. We will decipher the role the so-called FHA module plays in the formation of protein complexes. FHA modules are present in several proteins that are important for the repair of damaged DNA and the stability of chromosomes. Understanding the structure and function of this module will be relevant for various forms of cancer where DNA is damaged.
SPRY Domain-containing SOCS Box (SSB) Protein Interaction With Par-4: Structure And Biochemical Implications
Funder
National Health and Medical Research Council
Funding Amount
$529,565.00
Summary
The suppressor of cytokine signalling (SOCS) proteins, are intracellular molecules that negatively regulate hormone and growth factor action, and whose functional importance has been borne out in many physiological studies. The SOCS box is a small part of the SOCS proteins that is believed to facilitate degradation of SOCS target proteins. The SPRY domain-containing SOCS box protein-2 (SSB-2) is one of four proteins within the greater SOCS family (SSB-1 to -4), which have a SOCS box and a centra ....The suppressor of cytokine signalling (SOCS) proteins, are intracellular molecules that negatively regulate hormone and growth factor action, and whose functional importance has been borne out in many physiological studies. The SOCS box is a small part of the SOCS proteins that is believed to facilitate degradation of SOCS target proteins. The SPRY domain-containing SOCS box protein-2 (SSB-2) is one of four proteins within the greater SOCS family (SSB-1 to -4), which have a SOCS box and a central SPRY domain. The SPRY domain mediates interaction with other proteins within the cell. Over 300 proteins are known to contain a SPRY domain. We recently determined the first atomic structure of a SPRY domain as part of SSB-2, using nuclear magnetic resonance (NMR) spectroscopy. We further identified Par-4 (prostate apoptosis response-4) as a novel and direct protein binding partner for SSB-1, -2 and -4, but not SSB-3. Extensive mutational analysis subsequently identified a series of SSB-2 mutants that were unable to bind Par-4 but retained structural integrity. Cancer cells develop through a series of genetic events and escape programmed cell death or apoptosis, continuing to grow inappropriately. Par-4 was originally discovered as a gene up-regulated in prostate cancer cells undergoing apoptosis and primarily appears to sensitise cancer cells to apoptotic stimuli. This proposal aims to further investigate SSB-Par-4 binding. The 3D structure of the complex will be determined and biochemical consequences of this interaction characterised. If SSB proteins regulate Par-4 levels, then chemical disruption of SSB-Par-4 binding could potentially result in an increase in Par-4 protein levels, making cancer cells more susceptible to killing by cytotoxic drugs.Read moreRead less
FHA Domain-dependent Functions Of Cell Cycle Checkpoint Kinases
Funder
National Health and Medical Research Council
Funding Amount
$235,500.00
Summary
Human chromosomes as carriers of the genetic information are constantly subjected to DNA damage. This usually occurs spontaneously, simply as a result of oxidation of DNA residues as a byproduct of cellular energy consumption or as a result of errors during chromosome duplication in growing cells, and is compounded by chemical or physical agents, for example carcinogens, UV rays or X-rays. DNA damage can have severe consequences if not properly repaired, leading to genomic instability with loss ....Human chromosomes as carriers of the genetic information are constantly subjected to DNA damage. This usually occurs spontaneously, simply as a result of oxidation of DNA residues as a byproduct of cellular energy consumption or as a result of errors during chromosome duplication in growing cells, and is compounded by chemical or physical agents, for example carcinogens, UV rays or X-rays. DNA damage can have severe consequences if not properly repaired, leading to genomic instability with loss of vast tracts of DNA or inappropriate genome rearrangements, that may ultimately give rise to cancer. To prevent such dire consequences, all organisms from yeast to man contain molecular checkpoints that sense the presence of DNA damage and then activate a cellular response program that includes damage repair and prevention of cell division while damage persists. These molecular checkpoints are highly conserved throughout evolution which allows us to analyse the details involved in simple organisms such as yeast, to draw general conclusions on their function in more complex human cells. Along these lines, we are studying the function of two yeast proteins that are similar to the human Chk2 protein, a tumour suppressor that is mutated in a subset of families suffering from the Li-Fraumeni multi-cancer syndrome. We have identified new pathways by which these proteins contribute to the survival of cells after treatment with DNA damaging agents and will further charaterise these in the present proposal.Read moreRead less
Structural Studies Of The Jak And Abl Kinases: A Prerequisite For Drug Design
Funder
National Health and Medical Research Council
Funding Amount
$360,965.00
Summary
Protein tyrosine kinases (PTK) are a large, pivotal family of signalling molecules implicated in diseases such as cancer and immune related disorders. This fellowship aims to develop more potent kinase inhibitors of a number of PTKs using Cytopia’s drug discovery capability coupled with the X-ray crystallography expertise within Monash University. This innovative approach will permit a rational structure-based drug discovery platform to be established and will lead to the creation of a portfolio ....Protein tyrosine kinases (PTK) are a large, pivotal family of signalling molecules implicated in diseases such as cancer and immune related disorders. This fellowship aims to develop more potent kinase inhibitors of a number of PTKs using Cytopia’s drug discovery capability coupled with the X-ray crystallography expertise within Monash University. This innovative approach will permit a rational structure-based drug discovery platform to be established and will lead to the creation of a portfolio of phase I therapeutics, which will be of substantial benefit in the medical health area.Read moreRead less
The Structural Basis Of Cytokine Signalling Inhibition
Funder
National Health and Medical Research Council
Funding Amount
$239,473.00
Summary
Cell-cell communcation is vital for the correct functioning of the body. Cells need to be told the correct time to divide, to produce certain enzymes or chemicals, to migrate and also when to apoptose, or die. Cells receive these signals through the binding of small soluble proteins called cytokines. Cytokines bind to specialized receptors on the surface of the cell and initiate an intracellular signaling cascade that passes the correct message to the nucleus. It is important that cells react to ....Cell-cell communcation is vital for the correct functioning of the body. Cells need to be told the correct time to divide, to produce certain enzymes or chemicals, to migrate and also when to apoptose, or die. Cells receive these signals through the binding of small soluble proteins called cytokines. Cytokines bind to specialized receptors on the surface of the cell and initiate an intracellular signaling cascade that passes the correct message to the nucleus. It is important that cells react to these protein messengers however it is just as vital that they don't overreact. Many human diseases, especially inflammatory diseases such as rheumatoid arthritis and type II diabetes, are due to aberrant cytokine signaling. To ensure this doesn't occur, cells have evolved a mechanism to quickly switch off the signaling cascade after it has started. This mechanism involves an entire family of proteins, the Suppressors of Cytokine Signalling (SOCS) family. These proteins can act via two distinct mechanisms. The first is to directly block the JAK-STAT proteins, proteins that initiate the intracellular part of the signaling cascade. The second mechanism has been less well studied, it involves the SOCS proteins upregulating the degradation of signaling intermediates. The SOCS proteins can do this through the action of a 40 residue domain called the SOCS box. The SOCS box directs proteins bound to other domains of the SOCS proteins to be degraded by interacting with a complex called an E3 ubiquitin ligase. This project involves determining the three-dimensional atomic structure of the SOCS-E3 ligase interaction and investigating biophysical aspects of the interaction. This information will lead to a fuller understanding of the mechanism of signaling inhibition and will provide information crucial to the design of SOCS inhibitors. Such inhibitors would be therapeutically important in the treatment of a number of human diseases such as cancer, arthritis and type II diabetes.Read moreRead less
Recent evidence suggests that the Siah proteins are involved in sensing low oxygen levels in cells, and subsequently activating processes to help the cell survive under these conditions. Low oxygen conditions occur in cancer and sites of inflammation, suggesting that inhibiting Siah may improve patient outcomes in diseases such as cancer and arthritis. We aim to perform a high throughput screen for drugs that inhibit Siah protein function and to test these in cancer cells.
Structural Characterisation Of SNARE Protein Complexes Involved In Insulin-regulated Glucose Transport
Funder
National Health and Medical Research Council
Funding Amount
$320,803.00
Summary
Insulin-regulated glucose transportation is defective in type 2 diabetes, a disease that is a major health problem worldwide and in some cases can lead to death. The aim of this work is to investigate the molecular structure and function of proteins critical to the transportation and delivery of glucose to muscle and fat cells, which will lead to the validation of new therapeutic targets and the development of new treatments for diabetes.
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