A Structural And Functional Basis For The Regulation Of Gene Expression By Nuclear Retention Of RNA
Funder
National Health and Medical Research Council
Funding Amount
$504,097.00
Summary
The nuclear retention mechanism is a novel way used by cells to control which genes are made into proteins - a fundamental process for all diseases, particularly cancers. This project will employ cutting edge structural and proteomic techniques to determine the molecular details underpinning nuclear retention. These insights will be important for the development of new tissue-restricted gene therapy applications and drugs targeting the cancers that rely on this mechanism.
Structure-function Analysis Of Nuclear Receptor And Cofactor Action: Evidence For A Role In Muscle.
Funder
National Health and Medical Research Council
Funding Amount
$692,040.00
Summary
Hormone receptors have critical roles in almost all aspects of physiology by transducing the effects of hormones into metabolic responses. There are ~45 orphan hormone receptors encoded by distinct genes in humans, since all receptors are important in the treatment of human disease, the plethora of orphan receptors has been the catalyst for the development of a new paradigm, reverse endocrinology. Reverse endocrinology is the process whereby the orphan hormone receptor is used to search for a pr ....Hormone receptors have critical roles in almost all aspects of physiology by transducing the effects of hormones into metabolic responses. There are ~45 orphan hormone receptors encoded by distinct genes in humans, since all receptors are important in the treatment of human disease, the plethora of orphan receptors has been the catalyst for the development of a new paradigm, reverse endocrinology. Reverse endocrinology is the process whereby the orphan hormone receptor is used to search for a previously unknown hormone, and metabolic pathway. We are interested in the orphan hormone receptors, Rev-erbA and RVR, orphan members of the receptor superfamily. Rev-erb alpha expression is regulated by fibrates, widely used hypolipidemic drugs, and the circadian cycle. Rev-erbs mediate the regulation of lipid metabolism and peroxisomal beta oxidation. Furthermore, Rev-erbs are acutely induced during brain seizures, postulated to regulate cerebellar plasticity, and involved in growth control. In view of these critical regulatory roles, and the success of reverse endocrinology to date, we intend to complete the structural analysis of the Rev-erb and RVR as a tool to identify the hormone that binds this receptor. Hormone receptors recruit proteins called nuclear receptor cofactors, that function as regulators of gene expression. The cofactors regulate gene expression and development. Furthermore these cofactors, when misregulated result in the onset of disease and carcinogenesis, which underscores the need for achieving a high resolution view of their function in many tissues. Along these lines, we are interested in exmining the function of these cofactors in muscle. Understanding the molecular role of the NR cofactors during muscle differentiation will be a critical step toward elucidating the dysregulation-function of these proteins in muscle diseases, such as rhabdomyosarcoma and inflammatory myopathy that have cofactor deficiency.Read moreRead less
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
Mechanisms By Which Chromatin Modulates Gene Expression.
Funder
National Health and Medical Research Council
Funding Amount
$267,750.00
Summary
Gene expression in a cell occurs in the nucleus where genes are stored. In the nucleus, DNA is not in a free form but is covered with an equivalent weight of protein to form a structure known as chromatin. Chromatin is a periodic structure made up of repeating, regularly spaced subunits, the subunit being the nucleosome. A nucleosome consists of a group of proteins (histones) wrapped around with DNA. A nucleosome is both capable of blocking and activating gene expression. Therefore one important ....Gene expression in a cell occurs in the nucleus where genes are stored. In the nucleus, DNA is not in a free form but is covered with an equivalent weight of protein to form a structure known as chromatin. Chromatin is a periodic structure made up of repeating, regularly spaced subunits, the subunit being the nucleosome. A nucleosome consists of a group of proteins (histones) wrapped around with DNA. A nucleosome is both capable of blocking and activating gene expression. Therefore one important function of chromatin is to tightly regulate gene expression which is essential to allow an organism to develop properly. When gene expression is not accurately controlled by chromatin developmental defects or cancer can result from the production of incorrect proteins. To control correct gene expression, highly specific mechanisms must operate in the cell to remove, or modify, nucleosomes at certain genes at a precise time during development. One mechanism that we believe to be important is changing the make-up of a nucleosome. This can be achieved in the cell by the replacement of histones with different specialized forms of these histones (variants). We believe that these histone variants can specifically generate chromosomal domains which could in some cases expose or in other cases hide certain genes and thereby turn them on or off. Employing a new approach, we will study one of these histone variants to discover the role it plays in determining the type of chromosomal domain made and the role of this domain has in turning genes on or off at precise times in early development during the formation of different specialized cell types. This new information may define targets for the prevention of incorrect gene expression during cancer progression or abnormal development.Read moreRead less
Investigation Of The Influence Preterm Birth On Lung Structure And Function In School Age Children.
Funder
National Health and Medical Research Council
Funding Amount
$204,482.00
Summary
Bronchopulmonary dysplasia (BPD) remains the most significant chronic lung complication of premature birth. While some information on the long term respiratory outcomes in BPD exist there are no comprehensive studies linking lung structure, function and respiratory symptoms and relating these changes to neonatal history. Studies of this kind are essential to ensure future healthcare for these children can be planned accordingly.