The Role Of The Ras Signalling Molecule, C3G, In The Interaction Of Neural Precursor Cells And Their Environment
Funder
National Health and Medical Research Council
Funding Amount
$319,446.00
Summary
Developmental brain disorders affect 1-3% of the population. The mental retardation disease spectrum includes neuronal migration disorders and neural precursor proliferation disorders. We propose to study a molecular mechanism regulating neuronal migration, survival and proliferation. We have identified a protein, C3G, which is essential for three aspects of nervous system development: (A) C3G limits neural precursor cell proliferation. (B) C3G is essential for neuronal survival. (C) C3G is cruc ....Developmental brain disorders affect 1-3% of the population. The mental retardation disease spectrum includes neuronal migration disorders and neural precursor proliferation disorders. We propose to study a molecular mechanism regulating neuronal migration, survival and proliferation. We have identified a protein, C3G, which is essential for three aspects of nervous system development: (A) C3G limits neural precursor cell proliferation. (B) C3G is essential for neuronal survival. (C) C3G is crucial for neuronal migration. C3G acts in a cascade of proteins, known as the Ras signalling pathway, which transmits signals from the extracellular environment into the cell nucleus to elicit appropriate responses of the cell to cues from the outside. We will identify proteins that, together with C3G, affect the important processes of neural precursor proliferation, and neuron survival and migration. This project will fully characterise a key regulatory mechanism of cellular processes crucial to the development of normal intelligence.Read moreRead less
Truncating Presenilin Mutations And Their Effects On Gamma-secretase Activity, Tau And Beta-catenin
Funder
National Health and Medical Research Council
Funding Amount
$414,005.00
Summary
Alzheimer's disease (AD) and cancer are increasingly important both in terms of human suffering and the burden of care it imposes on society and the economy. Sporadic (non-inherited) AD is the most common form of dementia but is poorly understood. The PRESENILIN genes, PSEN1 and PSEN2, are the major sites for mutations causing inherited AD and are also implicated in cancer. Using the zebrafish embryo model we have discovered that, contrary to current thought, mutations that truncate presenilin p ....Alzheimer's disease (AD) and cancer are increasingly important both in terms of human suffering and the burden of care it imposes on society and the economy. Sporadic (non-inherited) AD is the most common form of dementia but is poorly understood. The PRESENILIN genes, PSEN1 and PSEN2, are the major sites for mutations causing inherited AD and are also implicated in cancer. Using the zebrafish embryo model we have discovered that, contrary to current thought, mutations that truncate presenilin proteins potently suppress normal presenilin activity. (They are so called, dominant negatives). This means that they are lethal for embryo development and explains why such mutations have never been found in inherited AD. Notably, this discovery could only be made using a subtle form of gene manipulation that is possible in zebrafish embryos. Our work has also established the first assay for the non-apoptotic (non-cell death) function of PSEN2 and has shown that PSEN2 activity is inhibited by truncated PSEN1. This is the first indication of possible interaction between PSEN1 and PSEN2 proteins at normal physiological expression levels. Loss of presenilin activity promotes cancer. Truncated presenilin proteins could be produced by errors in gene transcription (aberrant transcript splicing) common in cancerous cells. This suggests that truncated, dominant negative forms of presenilin produced through aberrant splicing (or mutation in precancerous cells) might be common in tumour formation. The proposed research will define the region of PSEN1 in which truncation leads to dominant negative activity. This will allow further examination of the role of presenilins in the cell signalling pathways involved in AD and cancer. We will also investigate the role that age-related truncation of presenilins in human cells can play in the formation of sporadic AD. This may reveal a common molecular link between the inherited and sporadic forms of this disease.Read moreRead less
Cell Type Specification In Developing CNS: Functional Analysis Of Sox14
Funder
National Health and Medical Research Council
Funding Amount
$468,055.00
Summary
The central nervous system (CNS) is the most complex organ in the body. The vast majority of nerve cells in the CNS are classified as 'interneurons'. These cells relay sensory information and motor commands within the CNS. Abnormal functioning of interneurons is likely to be the underlying cause of some, if not many, human nervous system diseases. However, very little is known of the precise anatomy and function of interneurons, which genes control their development, and how these functions are ....The central nervous system (CNS) is the most complex organ in the body. The vast majority of nerve cells in the CNS are classified as 'interneurons'. These cells relay sensory information and motor commands within the CNS. Abnormal functioning of interneurons is likely to be the underlying cause of some, if not many, human nervous system diseases. However, very little is known of the precise anatomy and function of interneurons, which genes control their development, and how these functions are maintained in the adult. This has been largely due to a lack of efficient and reliable methods to identify and study interneurons. We have previously discovered that a gene termed Sox14 is active in distinct interneuron groups in the embryonic brain and spinal cord. Sox14 is a member of the Sox gene family, many of which act as genetic switches to control cell and tissue development. We found that Sox14 has been extremely well conserved throughout evolution and is active in similar interneuron groups in a number of animal species. These studies led us to hypothesise that Sox14 controls a critical molecular step in the generation of certain interneurons that may be involved in reflexes, locomotion or motor coordination. In this project, we will investigate both the role of Sox14 in interneuron development and the functions of interneurons in which this gene is active. We will do so by combining modern molecular and genetic techniques with physiological approaches. This project will reveal critical molecular steps in CNS development and determine the functions of a specific group of interneurons. To this end, we will generate mouse strains in which a specific group of interneurons are genetically marked and can be manipulated during development. We envisage that these mice with 'modified brain circuits' will become unique resources for future investigations of selected interneuron types and their functions.Read moreRead less
How do interactions between axon guidance molecules bring about directed axon growth? This project deals with a fundamental, yet poorly understood biological problem at the cutting edge of international science - how axons navigate to their targets. A better understanding of this basic biological process will greatly assist the development of therapies to treat a wide range of clinical conditions in which axonal connections between neurons are disrupted by trauma or disease.
Shaping the vertebrate brain: defining the cellular and genetic drivers . This project aims to uncover specific cellular and genetic mechanisms that control growth and shape of the brain. How brain shape and size changes during evolution of vertebrates is enigmatic but important to know for better understanding of behaviour and function of intact and diseased brain. The project aims to assemble team of national and international experts to build international capacity and unique genetics model t ....Shaping the vertebrate brain: defining the cellular and genetic drivers . This project aims to uncover specific cellular and genetic mechanisms that control growth and shape of the brain. How brain shape and size changes during evolution of vertebrates is enigmatic but important to know for better understanding of behaviour and function of intact and diseased brain. The project aims to assemble team of national and international experts to build international capacity and unique genetics model to generate new knowledge of the cellular and genetic components that drive evolution of different brain parts and shapes the vertebrate brain. In doing so the project aims to provide research training, excellence and knowledge that in future may benefit health and the society. Read moreRead less
Identifying Mitochondrial Genome Variants Associated With Familial Migraine Susceptibility
Funder
National Health and Medical Research Council
Funding Amount
$443,273.00
Summary
New therapeutic targets for migraine are desperately needed. Although studies have identified some migraine genes there remains considerable underlying genetic variation to be characterised. This study aims to identify functional variants in the mitochondrial genome that contribute to migraine susceptibility, utilising the isolated Norfolk Island population. Outcomes will determine the significance of the variants identified, potentially leading to new diagnostics.
Identifying Novel Gene Mutations For Molecular Diagnosis Of Familial Hemiplegic Migraine
Funder
National Health and Medical Research Council
Funding Amount
$623,460.00
Summary
This proposal aims to identify novel FHM genes by undertaking an NGS screen of the whole exome of 209 FHM patient samples. We will test the pathological relevance of detected novel mutations by functional analysis in human cell models and using patient-specific stem cell techniques. Using whole genome NGS technology to identify novel mutations will assist in the design and development of a comprehensive NGS approach to diagnose and differentiate this severe neurological disorder.
Investigation Into The Roles Of A Novel Vertebrate Gene, S52, In CNS Development And Pathogenesis
Funder
National Health and Medical Research Council
Funding Amount
$272,389.00
Summary
Developmentally regulated genes when mutated or deleted can cause a variety of diseases including neurological diseases in humans. It is therefore important to understand the fundamental molecular genetics of development. We have discovered a novel human gene, termed S52, and its equivalent gene in the mouse. The predicted protein derived from these genes would indicate that S52 protein may interact with other proteins, possibly nerve growth factors, in the body to regulate normal development an ....Developmentally regulated genes when mutated or deleted can cause a variety of diseases including neurological diseases in humans. It is therefore important to understand the fundamental molecular genetics of development. We have discovered a novel human gene, termed S52, and its equivalent gene in the mouse. The predicted protein derived from these genes would indicate that S52 protein may interact with other proteins, possibly nerve growth factors, in the body to regulate normal development and possibly facilitate the survival of nerve cells in embryos. Strikingly, the worm C. elegans, an evoluationary very distant animal, also has a very similar gene to human. The fact that the protein has been so conserved throughout evolution supports the idea that S52 function is important in development. S52 mRNA is expressed in the developing brain, particularly in a special group of cells called the floor plate. Floor plate is a tissue that has ability to organize the patterning and differentiation of cells within the developing brain. S52 is also expressed in motor neurons in early stages of development and later in a subset of dorsal spinal cord neurons. We have mapped S52 to the short arm of human chromosome 2 (2p15-22). This region of chromosome 2 is linked to several human genetic diseases with neurological defects. Based on our preliminary data, we think S52 is not only important for normal brain development but may be mutated in a human neurological disease called Spastic Paraplegia Type 4 (SPG4) which is characterized by a degeneration of nerve cells in the spinal cord. The aim of this project is to further our understanding of the function of this gene and investigate its role in disease. This knowledge will contribute to an overall increase in our understanding of the molecular basis of brain development and neurological disease in humans.Read moreRead less
Nemaline myopathy is a neuromuscular condition characterised by muscle weakness, low muscle tone and the finding of nemaline bodies or rods on muscle biopsy. This study encompasses a natural history study of nemaline myopathy, genetic diagnosis and gene discovery using new methods of genetic testing, characterisation of a new disease gene for this condition, and reviewing patient experience with tyrosine, a medication commonly used in patients with nemaline myopathy.
Truncating presenilin mutations and their effects on gamma-secretase activity, tau and beta-catenin - insights into Alzheimers disease and cancer. Cancer and dementia are primarily afflictions of the aged and are increasingly important in an aging Australian population. 95% of all Alzheimer's disease is spontaneous (not inherited) but we know little about the molecular mechanisms underlying it. Our discovery that truncated presenilin proteins potently inhibit normal protein function suggests tha ....Truncating presenilin mutations and their effects on gamma-secretase activity, tau and beta-catenin - insights into Alzheimers disease and cancer. Cancer and dementia are primarily afflictions of the aged and are increasingly important in an aging Australian population. 95% of all Alzheimer's disease is spontaneous (not inherited) but we know little about the molecular mechanisms underlying it. Our discovery that truncated presenilin proteins potently inhibit normal protein function suggests that changes in presenilin function in aged cells might be a common molecular link between spontaneous and inherited Alzheimer's disease and could contribute to frontotemporal dementia and cancer. Our research will show whether this phenomenon might provide a breakthrough in our understanding of these diseases and be a productive area for research into their amelioration and/or prevention.Read moreRead less