Flaviviruses are the agents of many mosquito-transmitted infections such as encephalitis and dengue. Hepatitis C virus is a member of the same virus family. Using Australian flavivirus Kunjin as a model and advanced techniques in molecular biology, biochemistry and electron micriscopy, the research at SASVRC has established international leadership in the area of flavivirus RNA replication and ultrastructure of virus-infected cells. The objectives of this application are to advance further our u ....Flaviviruses are the agents of many mosquito-transmitted infections such as encephalitis and dengue. Hepatitis C virus is a member of the same virus family. Using Australian flavivirus Kunjin as a model and advanced techniques in molecular biology, biochemistry and electron micriscopy, the research at SASVRC has established international leadership in the area of flavivirus RNA replication and ultrastructure of virus-infected cells. The objectives of this application are to advance further our understanding of how the flavivirus RNA replication complex synthesizes RNA and how this RNA is specifically packaged to produce infectious virus. To achieve these goals we will employ state-of-the-art molecular biology techniques based on manipulations with infectious complementary DNA copy of Kunjin virus RNA. The intimate understanding of these mechanisms in flavivirus replication should facilitate the design of efficient antiviral drugs by specifically targeting unique events in RNA replication and-or packaging. This may assist in the development of antiviral drugs for treatment of infections caused by other higly pathogenic flaviviruses in Australia, such as dengue, Japanese encephalitis and Murray Valley encephalitis, and in the rest of the wirld such as New York strain of West Nile virus as well as the related heptitis C virus. Understanding the mechanisms of Kunjin virus replication and assembly will also aid in the further development of this virus as a safe vaccine vector against other viruses, e.g. HIV, and diseases such as cancer.Read moreRead less
Title: Structure of hepadnaviral pre-genomic RNA. We aim to study the replication strategy of human hepatitis B virus (HBV), a member of the hepadnavirus family. Hepadnaviruses infect hepatocytes in the liver and are released in high numbers into the bloodstream. Infection is transmitted by blood or sexual contact. Hepadnaviruses cause acute and chronic infection with varying degrees of liver disease. The HBV DNA genome is formed by copying of a viral pre-genome made of RNA, into DNA. This proce ....Title: Structure of hepadnaviral pre-genomic RNA. We aim to study the replication strategy of human hepatitis B virus (HBV), a member of the hepadnavirus family. Hepadnaviruses infect hepatocytes in the liver and are released in high numbers into the bloodstream. Infection is transmitted by blood or sexual contact. Hepadnaviruses cause acute and chronic infection with varying degrees of liver disease. The HBV DNA genome is formed by copying of a viral pre-genome made of RNA, into DNA. This process is called reverse transcription and is performed by the viral polymerase. Reverse transcription occurs within viral nucleocapsids made of core antigen. After formation of the new viral DNA genome, nucleocapsids are enveloped in surface antigen and are released from the cell. It is assumed that 1 copy of HBV pre-genomic RNA is packaged within each viral nucleocapsid. However, members of the retrovirus family that have common evolutionary origins to hepadnaviruses and also replicate via reverse transcription, contain 2 copies of RNA. The human immunodeficiency virus (HIV), the AIDS virus, is a well-studied example. In HIV infection 2 RNA genomes are packaged into each nucleocapsid and form a dimeric RNA genome. The HIV RNA is able to fold into a series of stem loops that promote formation of dimers. During the reverse transcription step in HIV replication, the polymerase switches templates and forms new combined strains of virus. The project aims to determine if 2 copies of pre-genomic RNA are packaged into HBV nucleocapsids. HBV pre-genomic RNA is able to form stem loop structures similar to those in HIV and has the potential to form dimeric RNA. If 2 copies of HBV pre-genomic RNA are packaged this will allow us to redefine the viral replication strategy and to develop a greater understanding of the relationships between hepadnaviruses and retroviruses. The formation of dimers will also provide a mechanism for recombination between HBV strains.Read moreRead less
Molecular Analyses Of Flavivirus RNA Replication, Encapsidation, And Complementation
Funder
National Health and Medical Research Council
Funding Amount
$602,545.00
Summary
Flaviviruses are the agents of many mosquito-transmitted infections such as encephalitis and dengue. Hepatitis C virus is a member of the same virus family. Using Australian flavivirus Kunjin as a model and advanced techniques in molecular biology, biochemistry and electron micriscopy, the Flavivirus Research Unit at SASVRC has established itself as an international leader in the area of flavivirus RNA replication and ultrastructure of virus-infected cells. The objectives of this application are ....Flaviviruses are the agents of many mosquito-transmitted infections such as encephalitis and dengue. Hepatitis C virus is a member of the same virus family. Using Australian flavivirus Kunjin as a model and advanced techniques in molecular biology, biochemistry and electron micriscopy, the Flavivirus Research Unit at SASVRC has established itself as an international leader in the area of flavivirus RNA replication and ultrastructure of virus-infected cells. The objectives of this application are to advance further our understanding of how the flavivirus RNA replication complex is assembled, how it synthesizes RNA and how this RNA is specifically packaged to produce infectious virus. To achieve these goals we will employ state-of-the-art molecular biology techniques based on manipulations with infectious complementary DNA copy of Kunjin virus RNA. The intimate understanding of these mechanisms in flavivirus replication should facilitate the design of efficient antiviral drugs by specifically targeting unique events in RNA replication and-or packaging. This may assist in the development of antiviral drugs for treatment of infections caused by other higly pathogenic flaviviruses in Australia, such as dengue, Japanese encephalitis and Murray Valley encephalitis, as well as of the related heptitis C virus.Read moreRead less
Pathways That Regulate Nuclear Export Of Circular RNA
Funder
National Health and Medical Research Council
Funding Amount
$933,327.00
Summary
An emerging and unusual class of RNA molecules, circular RNAs (circRNAs), is widespread and plays important roles in cancer initiation and progression. However, the pathways responsible for nuclear export of circRNAs are unknown. We propose here to systematically determine how circRNAs are exported from the nucleus and characterise the effect of modulating circRNA export pathways in cancer. This will enable us to determine whether circRNAs can function as a biomarker of patient response.
Understanding The Role Of Circular RNAs In Neuronal Biology Using RNA-targeting CRISPR/Cas9
Funder
National Health and Medical Research Council
Funding Amount
$398,097.00
Summary
The regulation of gene expression through a process known as RNA splicing has been shown to be at the heart of a number of processes required for brain development, memory and learning, and is often dysregulated in a number of neurological diseases. Circular RNAs (circRNAs) have been recently shown to be a relatively abundant class of spliced RNA that are specifically enriched in brain tissue. In this project, I aim to understand the roles of circRNAs in neuronal development.
Mechanisms And Patterns Of Post-Transcriptional Gene Control
Funder
National Health and Medical Research Council
Funding Amount
$707,370.00
Summary
Genetic information resides in the DNA of our genome; however, to use this information it must be transcribed into chemically related RNA molecules, collectively known as the transcriptome. While different body cells carry the same genome, they differ widely in their transcriptome composition. To understand how cells properly utilise their transcriptomes we will characterise the marks and binding partners found on RNA in the context of cardiac and cancer biology.
Molecular Basis For RIG-I Like Receptor Activation Of The Innate Immune Pathway.
Funder
National Health and Medical Research Council
Funding Amount
$564,770.00
Summary
This project is to understand how proteins in the cell detect the presence of invading viruses, and pass on the message for the cell to produce defence molecules. The overproduction of these defence molecules can lead to inflammatory diseases. This research will help us to understand the process of the innate immune response in cells and how we might control it in disease states.
MRNA Surveillance In Human Genetic Disease: Molecular Determinants Of Nonsense-mediated MRNA Decay
Funder
National Health and Medical Research Council
Funding Amount
$371,275.00
Summary
In about 1/3 of inherited disorders the mutations introduce an abnormal stop signal into the gene so that cells risk producing truncated or erroneous proteins. To prevent this cells have developed control surveillance mechanisms called Nonsense Mediated mRNA Decay (NMD). We have found a new form of NMD and our studies are directed determining how this works in cells, which genes use this pathway, and the consequences of this for human genetic disease.
An unusual type of molecule, circular RNA, was recently discovered to be present in human cells, and to potentially affect the ability of cancer cells in invade and metastasise. We will investigate the interactions these circular RNA molecules have with other molecules, what functions they have, and how they affect cancer cell invasion and metastasis. This could potentially reveal new ways of intervening in cancer metastasis, leading to new therapeutic modalities for cancer patients.
Investigation Of 5-methylcytosine And MicroRNA Function In Eukaryotic RNA
Funder
National Health and Medical Research Council
Funding Amount
$311,991.00
Summary
It is hypothesised that 5-methylcytosine in RNA represents a novel regulatory code affecting transcriptome utilisation in ways currently hidden from view. To unravel this code and its (patho)- physiological role(s), this study proposes to generate and interpret comprehensive transcriptome-scale maps of 5-methylcytosine in a range of cellular contexts chosen to reveal links to cellular differentiation, growth, and malignant transformation.