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.
Engineered Histones As DNA Carriers With Application In Therapeutic Gene Delivery
Funder
National Health and Medical Research Council
Funding Amount
$417,750.00
Summary
We intend to apply our knowledge of protein transport to the nucleus to enhance the delivery of DNA to target cells. This relates to the use of gene therapy to treat genetic defects such as inborn errors of metabolism, where a disease-causing lack-of-function mutation can be overcome by engineering cells within the organism which express, in the necessary quantities and in response to the appropriate regulatory signals, the particular component which is lacking. A limiting factor in gene therapy ....We intend to apply our knowledge of protein transport to the nucleus to enhance the delivery of DNA to target cells. This relates to the use of gene therapy to treat genetic defects such as inborn errors of metabolism, where a disease-causing lack-of-function mutation can be overcome by engineering cells within the organism which express, in the necessary quantities and in response to the appropriate regulatory signals, the particular component which is lacking. A limiting factor in gene therapy approaches is the low efficiency of nuclear uptake of introduced DNA, where it has been estimated that < 1% of the DNA taken up is actually expressed. Our proposal seeks to develop approaches to enhance non-viral-mediated gene delivery, in particular by optimising this critical, limiting step of the delivery of exogenous DNA to the nucleus. We intend to apply knowledge from studies of nuclear targeting and chromatin assembly to improve gene transfer technologies. We will build on our work showing that specific signals for nuclear import - nuclear targeting signals (NTSs) - can be used to enhance nuclear gene delivery and expression. Since DNA in the normal cellular context is in the form of chromatin - a specific complex with proteins such as histones - we intend to use reconstituted chromatin as the transfecting DNA, whereby histones engineered to include NTSs and other modular sequence elements will be used. Chromatin should not only enable NTSs and other sequence modules to be linked to the DNA but also protect against nuclease-mediated degradation prior to nuclear entry, condense the DNA to enable more efficient cellular-nuclear entry, and ensure expression of the transfected reporter gene by presenting it to the cell in a physiological context. Our approaches should contribute to bringing gene therapy closer to reality in the clinic.Read moreRead less
Functional Characterisation Of N4WBP5 And N4WBP5A, Novel Nedd4-interacting Proteins
Funder
National Health and Medical Research Council
Funding Amount
$480,750.00
Summary
The proteins that make up a cell must be correctly localised in order to perform their normal function. Specialised cellular activities are carried out in distinct compartments within a cell and proteins must correctly localise in them and traffic between them. Intracellular protein trafficking is a highly regulated process involving many components. Recent findings have shown that intracellular trafficking is regulated in many cases by distinct protein modifications. One such modification is ta ....The proteins that make up a cell must be correctly localised in order to perform their normal function. Specialised cellular activities are carried out in distinct compartments within a cell and proteins must correctly localise in them and traffic between them. Intracellular protein trafficking is a highly regulated process involving many components. Recent findings have shown that intracellular trafficking is regulated in many cases by distinct protein modifications. One such modification is tagging of a small protein called ubiquitin to proteins that are being trafficked. A focus of research in our laboratory is the study of a protein, called Nedd4, which directly tags proteins with ubiquitin. We have recently identified two novel proteins that interact with Nedd4 and localise to distinct subcellular compartments that are sites for the correct sorting and delivery of proteins trafficking within the cell. The main aim of our proposal is to characterise how these proteins function. We propose that these proteins are involved in intracellular trafficking and that they may function by targeting Nedd4 to the cellular trafficking machinery. This may be required for Nedd4 to tag molecules with ubiquitin that are involved in intracellular trafficking. Our experiments will test the functional relationship between Nedd4 and the novel proteins and determine the particular trafficking pathways in which these proteins are involved. Defects in cellular processes regulated by Nedd4 and other similar proteins cause a number of human diseases including an inherited form of hypertension and a specific group of cancers. In addition, a large number of human diseases result directly from defects which disrupt intracellular trafficking pathways. The results of this study will provide further insight into this essential cellular process and may ultimately contribute to the development of therapies for diseases resulting from defects in intracellular trafficking.Read moreRead less
Inside our cells is a complex traffic system. The vehicles are vesicles that come in different shapes and sizes and travel to specific destinations in the cell to deliver cargo such as: surface growth factor receptors that are to have their signalling terminated, proteins and lipids destined for the cell wall for growth or development (like neurite outgrowth) and proteins and hormones destined for secretion (like neurotransmitter release). More than 100 human genetic disorders map to defects in ....Inside our cells is a complex traffic system. The vehicles are vesicles that come in different shapes and sizes and travel to specific destinations in the cell to deliver cargo such as: surface growth factor receptors that are to have their signalling terminated, proteins and lipids destined for the cell wall for growth or development (like neurite outgrowth) and proteins and hormones destined for secretion (like neurotransmitter release). More than 100 human genetic disorders map to defects in one of the components of this system. Proteins called small GTPases provide order for this traffic and allow specific cargo to reach specific destinations. They regulate cell functions by acting as switches, turning biochemical processes on and off inside the cell. Ral is a small GTPase enzyme found in brain and broadly distributed in other cells. We have discovered that Ral is part of a large signalling complex. When activated Ral stimulates effectors, either the exocyst or RalBP1. In turn, mild oxidative stress controls a Ral inhibitor protein called ERp57. The research proposed aims to establish the functional role for the Ral signalling complex in cells. We will determine with which vesicle trafficking events Ral is associated, which effector it utilises in that pathway, and how that effector directs the traffic. We will also map the steps that may lead to inactivation of Ral via ERp57 in cells, and propose that this is mediated by mild oxidative stress. Techniques of molecular biology, biochemistry, molecular biology, proteomics and microscopy will be used to establish these functions. The research will lead to increased knowledge of the significance of this protein to cellular and particularly neuronal cell function. This forms the basis for understanding normal cell function and for identification of further factors causing diseases of vesicle transport. In time, such research aids in the development of specific therapies for sufferers of such diseases.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