Identifying Target Molecules Regulated By Nuclear Retention In Cancer And Development
Funder
National Health and Medical Research Council
Funding Amount
$267,173.00
Summary
Human DNA contains approximately 30000 genes; only twice as many as worms and flies, ten times as many as bacteria, and fewer than rice. Humans, however have considerably more complexity than these lower organisms. What are the factors responsible for the additional complexity? In the simplest scenario, one gene is transcribed to produce one message (mRNA), which is the blueprint for producing one protein. We now know that there are numerous mechanisms that potentially allow many different prote ....Human DNA contains approximately 30000 genes; only twice as many as worms and flies, ten times as many as bacteria, and fewer than rice. Humans, however have considerably more complexity than these lower organisms. What are the factors responsible for the additional complexity? In the simplest scenario, one gene is transcribed to produce one message (mRNA), which is the blueprint for producing one protein. We now know that there are numerous mechanisms that potentially allow many different proteins to be made from one gene. Also, it is the decisions about which gene will be made ( expressed ) into protein where and when in development, that is critical for our complexity. The control of gene expression is thus fundamental to all cellular processes and many diseases such as cancer and metabolic disorders are associated with some aspect of aberrant gene expression. The production of mRNA from DNA occurs in the human cell nucleus. The nucleus is not simply a bag of DNA, in fact, many important nuclear factors are organised into sub-nuclear bodies . Recently we discovered a novel sub-nuclear body, the paraspeckle and have been identifying its components and their function. Paraspeckles are involved in a previously undiscovered mechanism of the control of gene expression. Here, certain mRNA molecules are trapped in the nucleus until a signal is received from elsewhere in the cell, which causes the mRNA to be released and protein to be made. This Rapid Release Nuclear Retention mechanism effectively allows the quick production of specific proteins to be made on demand. In this project we propose to use cutting edge molecular and cell biology techniques to identify the special mRNA molecules that are trapped in paraspeckles in cancer cells. This will increase our understanding about the molecular details of this process, ultimately leading to potential uses in gene therapy, and should result in the discovery of important targets for cancer treatment.Read moreRead less
An Alternate Function Of The MicroRNA Biogenesis Machinery
Funder
National Health and Medical Research Council
Funding Amount
$302,981.00
Summary
Controlling the activity of genes is crucial. Too much or too little can result in a cell not functioning properly. We have discovered a new way genes are controlled. We have found that an enzyme called Drosha can prevent too much activation of some genes by chopping up the products of these genes. This way of controlling genes appears to be especially important for developmental processes, such as occurs in the embryo. Our goal is to understand this mechanism precisely at the molecular level.
MRNA Surveillance In Human Disease: Molecular Determinants Of Nonsense-mediated MRNA Decay
Funder
National Health and Medical Research Council
Funding Amount
$474,517.00
Summary
Inherited diseases are a common cause of human disability, illness and suffering. It has been estimated that 5-10% of the population will be affected by disorders with a genetic component. Thus studies on mechanisms of inherited diseases, especially those relating to genetic mechanisms with relevance across a wide range of individual disorders and gene mutations, are of great significance in diagnosis, molecular pathology and the eventual development of therapeutics. While there are many types o ....Inherited diseases are a common cause of human disability, illness and suffering. It has been estimated that 5-10% of the population will be affected by disorders with a genetic component. Thus studies on mechanisms of inherited diseases, especially those relating to genetic mechanisms with relevance across a wide range of individual disorders and gene mutations, are of great significance in diagnosis, molecular pathology and the eventual development of therapeutics. While there are many types of mutations, one relatively common type is called a premature termination mutation. Premature termination mutations introduce an inappropriate genetic signal that tells the cells to stop the formation of proteins before they are complete. This would result in the production of a protein that is shorter than normal, and these short proteins could be quite abnormal and drastically affect the normal function of cells. To overcome this, cells have developed elegant strategies that involve the deployment of quality control, or surveillance, mechanisms to remove the mutant gene product before it can be converted into an abnormal protein. This process is called nonsense mediated decay. Nonsense mediated decay is a complex process and some of the key components have been identified by studies on a small number of genes. However, our studies have identified several previously unknown aspects of the process that suggest that the currently held view of how nonsense mediated decay works is only the beginning of the story and further important complexity exists. The proposed research will explore the basic mechanisms of the surveillance process and determine the signals that initiate nonsense mediated decay. Since premature termination mutations cause one-third of all inherited genetic disorders, our studies will provide new insights into the surveillance mechanisms and will have wide applicability to our understanding of the basis of inherited disease.Read moreRead less
The Role Of The HuB RNA-binding Protein In Post-transcriptional Gene Regulation In The Pre-gastrula Zebrafish Embryo
Funder
National Health and Medical Research Council
Funding Amount
$545,216.00
Summary
The precise control of protein expression is absolutely critical in biology. The key decisions about which genes are turned on or off at any one moment control the proper growth of an organism during development, and are responsible for the organism's homeostasis and proper response to environmental changes as an adult. The spatio-temporal control of genes is critcal during embryogenesis and we aim to understand how these processes underlie development in the vertebrate embryo.
Designer RNA-binding Proteins For Research And Therapeutic Purposes
Funder
National Health and Medical Research Council
Funding Amount
$557,480.00
Summary
It has become clear recently that ribonucleic acids play many roles in the switching on and off of genes in humans and other organisms. These molecules play roles in a number of diseases, including HIV-AIDS, hepatitis, and a large number of inherited disorders. We propose to build a library of protein molecules that can bind specifically to a wide range of RNA targets and modulate their function. These molecules have the capacity to act as therapeutics for a wide range of diseases.
ALS4 Mice Show TDP-43 Protein Mislocalization In Motor Neurons Characteristic Of Sporadic ALS Patients; Suggesting This Model Is Likely To Reveal Important Patho-mechanistic Disease Insights
Funder
National Health and Medical Research Council
Funding Amount
$108,466.00
Summary
SETX gene mutations cause an inherited motor neurone disease (MND) known as ALS4. Our current understanding of MND was revolutionized by the discovery that a protein known as TDP-43 is the main component of protein accumulations found in dying human motor neurones. We have generated a unique mouse model of ALS disease that will be useful for research purposes, but may also prove effective for drug testing.
Regulation Of Pre-mRNA And MRNA Processing By The Neuron-specific Hu RNA-binding Proteins
Funder
National Health and Medical Research Council
Funding Amount
$477,750.00
Summary
The precise control of protein expression is absolutely critical in biology, and the key decisions about which genes are turned on or off at any one moment control the proper growth and maturation of an organism during development, and are responsible for the organism's homeostasis and proper response to environmental changes as an adult. Many gene expression programs are highly complex and controlled by regulating the activation of individual genes as they are copied from DNA to RNA. However, t ....The precise control of protein expression is absolutely critical in biology, and the key decisions about which genes are turned on or off at any one moment control the proper growth and maturation of an organism during development, and are responsible for the organism's homeostasis and proper response to environmental changes as an adult. Many gene expression programs are highly complex and controlled by regulating the activation of individual genes as they are copied from DNA to RNA. However, this activation is just the start of the process to produce an active protein. In higher organisms, these RNA copies almost always contain interruptions called introns, which must be excised from the RNA. Also, protein factors bound to specific RNAs can dictate whether the RNA is used to make protein or not, and these factors can also affect the localisation of the RNA to a specific sub-cellular destination, giving rise to highly localised protein expression. Evidence suggests that neurons are a cell type that rely heavily on mechanisms of RNA regulation. During development neurons become highly polarised, acquiring an axon which can elongate and find distant synaptic targets. While much is known about how axon growth cones respond to various guidance cues, the mechanisms by which the axon is able to translate this guidance cue information into structural changes which allow the growth cone to expand or collapse is largely unexplored. Recent evidence suggests that accurate growth cone guidance is absolutely dependent upon local protein synthesis. The functional corollary of this finding is that axon guidance requires RNA localisation and control of protein synthesis of RNAs in the growth cone. This phenomenon of spatial gene regulation within an individual cell is a central research interest for understanding how the brain functions.Read moreRead less
Heterogeneous Nuclear Ribonucleoprotein Role In Alternative RNA Splicing And Human Disease
Funder
National Health and Medical Research Council
Funding Amount
$254,250.00
Summary
Control of the use of DNA, gene expression, is vital to all living organisms, especially in development and disease. The information in the genes of DNA is transferred to an intermediate molecule, mRNA, in a process called transcription. The genetic information in the mRNA is subsequently used, in the process called translation, to make the protein encoded by the original gene. The switching on and off of DNA appears to be most frequently controlled at the transcription step but recently it has ....Control of the use of DNA, gene expression, is vital to all living organisms, especially in development and disease. The information in the genes of DNA is transferred to an intermediate molecule, mRNA, in a process called transcription. The genetic information in the mRNA is subsequently used, in the process called translation, to make the protein encoded by the original gene. The switching on and off of DNA appears to be most frequently controlled at the transcription step but recently it has become apparent that there are many post-transcriptional events that govern how efficiently the genetic information is ultimately converted to protein molecules. An important step is the cutting out of parts (introns) of the RNA molecule that is copied from DNA, and splicing of the retained sections (exons). During this process the RNA may also lose one or more of its exons. As a result of this variable retention of exons a single gene may produce many isoforms of the protein it encodes. By this mechanism the roughly 30,000 genes in the human genome can give rise to potentially hundreds of thousands of proteins. RNA splicing connects to cancer in two ways. First, changes in the concentrations of the proteins that control splicing may change the isoforms, resulting in changes that lead to uncontrolled cell proliferation. Secondly, DNA mutations that affect the splicing process can also vary the ratios of the isoforms produced from a gene: if this occurs in a protein that is involved in the growth of cells this too may lead to cancer. In this project we will study the molecular mechanism of this alternative splicing, and particularly a group of proteins that generally favour the excision of some exons, with a focus on cancer cells. Recent publications have highlighted the potential for the therapeutic use of drugs that target the splicing apparatus: it is anticipated that studies of alternative splicing will underpin development of new therapeutic agents.Read moreRead less