Determining The Pathobiology Of Human Sarcomeric Myopathies Using Zebrafish
Funder
National Health and Medical Research Council
Funding Amount
$509,541.00
Summary
Laing muscular dystrophy and ACTA1 congenital muscular dystrophy are severe muscle diseases with high morbidity. We will create zebrafish strains that carry these diseases and use these to understand the causes of muscle failure and investigate possible areas of treatment for these conditions.
Molecular Genetic Characterisation Of A Novel X-linked Skeletal Myopathy
Funder
National Health and Medical Research Council
Funding Amount
$158,104.00
Summary
This project aims to identify the genetic basis of a new disease that is characterised by episodes of muscular weakness. This disease only affects males. The signficance of the project is that this is the first description of such a disorder and gives us an opportunity to study a previously unsuspected aspect of human muscle function.
Targeting To Mitochondria Of Tail-Anchored Proteins. Defining The Molecular Apparatus Of Targeting.
Funder
National Health and Medical Research Council
Funding Amount
$254,751.00
Summary
The cells of the body have an intricate and dynamic internal architecture, with the components (proteins, lipids, and nucleic acids) of the cell carefully arranged. It is widely viewed that just how each component finds its place in the cell, the cellular adressing system, is of critical importance. This was recognized this year by the award of the Nobel Prize in Medicine to Dr. Gunter Blobel for his work on the signals that direct different proteins to their correct destination. One such destin ....The cells of the body have an intricate and dynamic internal architecture, with the components (proteins, lipids, and nucleic acids) of the cell carefully arranged. It is widely viewed that just how each component finds its place in the cell, the cellular adressing system, is of critical importance. This was recognized this year by the award of the Nobel Prize in Medicine to Dr. Gunter Blobel for his work on the signals that direct different proteins to their correct destination. One such destination is the mitochnondria, the particles in the cell that produce chemical energy. The work in this proposal is designed to define precisely the molecular apparatus that targets a group of proteins to mitochondria. This group, proteins that are inserted into the mitochondria at one end of the protein, includes a variety of critical proteins, including those that determine the life or death of a cell. We will define both the address contained within those proteins, and the machinery on the mitochondria that recognizes that address, and ensures that those proteins will become part of the mitochondria. This research has two applications. By understanding the address, we will be able to decode the vast amount genomic data that is being produced, to predict exactly which proteins are delivered to mitochondria. Secondly, by understanding the targeting machinery, we may begin to design molecules that can inhibit its function, and thus manipulate the delivery of those proteins that affect cell life and death.Read moreRead less
Regulation Of Myotubularin Function By The Novel 3-phosphatase Adapter Protein (3-PAP)
Funder
National Health and Medical Research Council
Funding Amount
$488,273.00
Summary
Phospholipids are important components of cell membranes. Phospholipids are turned-on by enzymes called kinases and these phospholipids stimulate a variety of critical functions within the cells. Phospholipids are turned-off by another type of enzymes classed as phosphatases, thereby switching off a broad range of cell functions. Myotubularin is an enzyme, which neutralizes particular type of phospholipids that are involved in the shuttling of proteins between compartments within the cell. Loss ....Phospholipids are important components of cell membranes. Phospholipids are turned-on by enzymes called kinases and these phospholipids stimulate a variety of critical functions within the cells. Phospholipids are turned-off by another type of enzymes classed as phosphatases, thereby switching off a broad range of cell functions. Myotubularin is an enzyme, which neutralizes particular type of phospholipids that are involved in the shuttling of proteins between compartments within the cell. Loss of function of myotubularin, due to inherited genetic changes (mutations), leads to abnormal muscle development manifesting as weakness since birth, and this particular disease is known as 'X-linked myotubular myopathy'. However, there is yet no information on the mechanisms by which failure of protein shuttling (transport) causes myopathy. We have discovered a new protein, 3-phosphatase adapter protein (3-PAP) that links with myotubularin and plays an important role in the function of myotubularin. Our research proposal seeks to clarify the important role of 3-PAP in the development of muscle cells. We propose to study the location of 3-PAP within cells and analyse the influence of 3-PAP on protein shuttling. We have created mice that are deficient in the 3-PAP gene. These special mice will help us understand the importance of 3-PAP in the development and function of nerve and muscle tissue.Read moreRead less
Novel Transcriptional Regulation In Skeletal Muscle Development And Disease
Funder
National Health and Medical Research Council
Funding Amount
$344,592.00
Summary
It has been assumed that once genes are activated in a particular type of cell, they remain 'on'. From work described in this laboratory, we now know that gene activity may come and go. Instead of the analogy of a light switch that has been turned on and stays on, it appears that at least in muscle, gene activity is more like blinking lights. If you take an image of muscle tissue, which is just a snapshot in time, a gene may not appear to be activated if it was temporarily 'flashing off' at the ....It has been assumed that once genes are activated in a particular type of cell, they remain 'on'. From work described in this laboratory, we now know that gene activity may come and go. Instead of the analogy of a light switch that has been turned on and stays on, it appears that at least in muscle, gene activity is more like blinking lights. If you take an image of muscle tissue, which is just a snapshot in time, a gene may not appear to be activated if it was temporarily 'flashing off' at the time of viewing. This may occur in all tissue types, but it is more easily detected in muscle because the cell is large with many nuclei, rather than small with a single nucleus. Another reason why this phenomenon is more readily detectable in muscle cells is that they are very dynamic cells that can undergo fairly radical changes in shape. An actively growing or hypertrophying muscle cell may have all of its genes at a high pitch of transcriptional activity to support rapid growth. However, once a muscle cell has reached its appropriate size, then muscle genes switch to a flashing mode of transcription to maintain rather than build structures. SIGNIFICANCE: (1) This may be a fundamental mechanism of gene regulation that occurs in virtually all cell types. As such, our finding will open an area of research into the types of molecules involved in this novel mechanism. (2) Our studies will result in a better understanding of the mechanisms of muscle cell hypertrophy in response to excercise and drugs, as well as atrophy due to nerve damage or inherited muscle disease. (3) This mechanism may explain the expression of foreign DNA in muscle cells delivered via gene therapy approaches. Our findings could result in a more efficacious means of expressing the introduced gene that might require tricking the muscle fibre into believing that it is in a perpetual growth mode.Read moreRead less
Identification Of The Molecular Mechanisms By Which Mutations In FHL1 Lead To Protein Misfolding And Skeletal Muscle Disease
Funder
National Health and Medical Research Council
Funding Amount
$609,424.00
Summary
Skeletal muscle diseases result in debilitating muscle loss and may result from an error (mutation) within a gene. Mutations in FHL1 were identified as the cause of four different muscle diseases. Using purified FHL1, skeletal muscle cells and animal models we will investigate how FHL1 mutations cause muscle wasting, and loss of muscle strength.