Control of transcription by the cardiac homeodomain protein Nkx2-5. The transcriptional regulatory protein Nkx2-5, a member of the homeodomain superfamily, is essential for heart development and mutations in the human gene cause congenital heart disease. We seek to define the molecular mechanisms that regulate the transcriptional activity of Nkx2-5. We have previously identified a transcriptional activation domain in the C-terminal region that is bipartite in nature and conserved among Nkx2-5 ....Control of transcription by the cardiac homeodomain protein Nkx2-5. The transcriptional regulatory protein Nkx2-5, a member of the homeodomain superfamily, is essential for heart development and mutations in the human gene cause congenital heart disease. We seek to define the molecular mechanisms that regulate the transcriptional activity of Nkx2-5. We have previously identified a transcriptional activation domain in the C-terminal region that is bipartite in nature and conserved among Nkx2-5 proteins from diverse species. We will characterise the consequences of mutations in this domain in mouse models and search for interacting proteins. Results will advance our understanding of gene regulation in the context of heart disease.Read moreRead less
Subunit stoichiometry and arrangement in the glycine receptor. Glycine receptors are important for nervous system function. These receptors comprise a mixture of 5 alpha and beta subunits arranged around a central ion-conducting pore. The subunit stoichiometry (i.e., numbers of alpha and beta subunits) and arrangement (i.e., subunit order) are unknown. The first aim of this project is to define these parameters using tethered subunits. The second aim is to use the tethered subunits to probe th ....Subunit stoichiometry and arrangement in the glycine receptor. Glycine receptors are important for nervous system function. These receptors comprise a mixture of 5 alpha and beta subunits arranged around a central ion-conducting pore. The subunit stoichiometry (i.e., numbers of alpha and beta subunits) and arrangement (i.e., subunit order) are unknown. The first aim of this project is to define these parameters using tethered subunits. The second aim is to use the tethered subunits to probe the structure and function of glycine and zinc binding sites at an unprecedented level of resolution. The results will provide crucial new information concerning glycine receptor structure and function.Read moreRead less
Metalloproteins and metalloenzymes. Most of the chemical reactions and physical movements in living systems are carried out by proteins. The information for producing proteins from amino acids is stored in the genes, but many biological processes depend on additional atoms or molecules ('cofactors') that are added to a protein after it is assembled. For example, more than 30% of all proteins contain metal atoms which are essential for their function. We are studying the structures of such meta ....Metalloproteins and metalloenzymes. Most of the chemical reactions and physical movements in living systems are carried out by proteins. The information for producing proteins from amino acids is stored in the genes, but many biological processes depend on additional atoms or molecules ('cofactors') that are added to a protein after it is assembled. For example, more than 30% of all proteins contain metal atoms which are essential for their function. We are studying the structures of such metalloproteins and metalloenzymes so that we can better understand their activities with long term aims of creating new molecules for biotechnology and/or drugs.Read moreRead less
Functional Genomics and Host Cell Specificity of Herpesviruses. Herpesviruses cause severe diseases in many species, but research on their large DNA genomes has been difficult due to the need to use animal cell cultures for the generation of virus mutants. The cloning of complete herpesvirus genomes as Bacterial Artificial Chromosomes (BACs) has revolutionized herpesvirus genomics, and it is now possible to examine herpesvirus gene functions in unprecedented detail using elegant new mutation tec ....Functional Genomics and Host Cell Specificity of Herpesviruses. Herpesviruses cause severe diseases in many species, but research on their large DNA genomes has been difficult due to the need to use animal cell cultures for the generation of virus mutants. The cloning of complete herpesvirus genomes as Bacterial Artificial Chromosomes (BACs) has revolutionized herpesvirus genomics, and it is now possible to examine herpesvirus gene functions in unprecedented detail using elegant new mutation techniques. The project, based on two related equine herpesviruses, will identify new targets for antiviral drugs or vaccines. These herpesvirus BAC systems represent frontier science that greatly facilitates the study of links between genome and phenome.Read moreRead less
Dissection of nodule and lateral root development in the model legume Lotus japonicus. We propose to isolate and decipher the function of plant genes involved in nodule development, with the view to extend and compare this knowledge to lateral root formation. While nodulation and lateral root formation are distinct processes, they appear to share anatomical and biochemical features. Working hypothesis is that nodule formation borrowed functions from lateral root development. Our approach impleme ....Dissection of nodule and lateral root development in the model legume Lotus japonicus. We propose to isolate and decipher the function of plant genes involved in nodule development, with the view to extend and compare this knowledge to lateral root formation. While nodulation and lateral root formation are distinct processes, they appear to share anatomical and biochemical features. Working hypothesis is that nodule formation borrowed functions from lateral root development. Our approach implements T-DNA and transposon insertional mutagenesis in the model legume Lotus japonicus. The success of this project will contribute significantly to the studies of plant-microbe interaction and plant morphogenesis.Read moreRead less
Engineering and expression of recombinant antibodies that interact with plant pathogenic phytoplasma membrane proteins - a model for phytoplasma disease management. . In Australia phytoplasmas are associated with serious diseases including papaya dieback and strawberry lethal yellows. Phytoplasmas cannot be cultured so there is a paucity of knowledge at the genomic level. We have identified the ABC Transporter and FtsH genes and expressed these phytoplasma membrane proteins (MP) in E. coli . We ....Engineering and expression of recombinant antibodies that interact with plant pathogenic phytoplasma membrane proteins - a model for phytoplasma disease management. . In Australia phytoplasmas are associated with serious diseases including papaya dieback and strawberry lethal yellows. Phytoplasmas cannot be cultured so there is a paucity of knowledge at the genomic level. We have identified the ABC Transporter and FtsH genes and expressed these phytoplasma membrane proteins (MP) in E. coli . We will generate antibody fragments that bind these MP and express them in tomato. We will analyse antibody expression in tomato and study their association with the phytoplasma membrane. Transgenic plants will be inoculated with phytoplasma and monitored for resistance. This work represents a major step towards engineering resistance to phytoplasmas.Read moreRead less
Understanding and changing the mechanism of an enzyme: converting a peptidase to a phosphotriesterase. Enzymes have the ability to catalyse biological reactions rapidly as a consequence of their unique three-dimensional structures. We seek to define the structures of a family of metalloenzymes that are required in most living organisms to activate hormones, degrade unwanted proteins or recycle the protein building blocks for further synthesis. We shall use this information to enhance a second ....Understanding and changing the mechanism of an enzyme: converting a peptidase to a phosphotriesterase. Enzymes have the ability to catalyse biological reactions rapidly as a consequence of their unique three-dimensional structures. We seek to define the structures of a family of metalloenzymes that are required in most living organisms to activate hormones, degrade unwanted proteins or recycle the protein building blocks for further synthesis. We shall use this information to enhance a second function of these enzymes, namely their ability to break down organophosphorus-containing insecticides and nerve agents. Ultimately, the structural information resulting from this project may be used in drug design to regulate blood pressure and in engineering proteins for bioremediation.Read moreRead less
Post-genomic investigation of the relict plastid and mitochondrion of malaria parasites. Malaria is a major global health problem. The malaria parasite has two substructures, a relict chloroplast and a mitochondrion, that are excellent targets for new and existing drugs. However, we do not know the key functions of these two compartments. The entire genetic blueprint (genome) is now available for the malaria parasite and I propose to determine exactly which parts of the genome service the rel ....Post-genomic investigation of the relict plastid and mitochondrion of malaria parasites. Malaria is a major global health problem. The malaria parasite has two substructures, a relict chloroplast and a mitochondrion, that are excellent targets for new and existing drugs. However, we do not know the key functions of these two compartments. The entire genetic blueprint (genome) is now available for the malaria parasite and I propose to determine exactly which parts of the genome service the relict chloroplast and mitochondria. This will sketch out a picture of their inner workings. Armed with this information we can take a rational approach to seeking an Achilles? Heel of malaria against which parasite-specific drugs can be developed.Read moreRead less
Gating and permeation in ClC channels. Chloride ion channels are essential proteins in all living cells but, compared to other channels, little is known of their structure or how this defines and controls chloride transport. We will produce both normal and structurally modified (mutant and known to cause disease) chloride channels in cultured cells by genetic engineering so that we can analyse channel function using a combination of electrophysiological and chemical methods. We expect to learn ....Gating and permeation in ClC channels. Chloride ion channels are essential proteins in all living cells but, compared to other channels, little is known of their structure or how this defines and controls chloride transport. We will produce both normal and structurally modified (mutant and known to cause disease) chloride channels in cultured cells by genetic engineering so that we can analyse channel function using a combination of electrophysiological and chemical methods. We expect to learn which channel parts are fundamental and how subtle changes in structure can alter the opening and closing of these channels and the way that chloride passes through them.Read moreRead less
A New Window into Transgene Silencing in Plants: mechanisms of copy-number independent, 5' sequence dependent, post-transcriptional silencing in a complex polyploid. Silencing of introduced genes is a major problem limiting plant molecular improvement. Sugarcane, a complex polyploid, shows the most efficient transgene silencing ever observed in plants. Silencing operates on the RNA, depends on the upstream sequence of the gene, and is independent of copy number. Other plant species develop endop ....A New Window into Transgene Silencing in Plants: mechanisms of copy-number independent, 5' sequence dependent, post-transcriptional silencing in a complex polyploid. Silencing of introduced genes is a major problem limiting plant molecular improvement. Sugarcane, a complex polyploid, shows the most efficient transgene silencing ever observed in plants. Silencing operates on the RNA, depends on the upstream sequence of the gene, and is independent of copy number. Other plant species develop endopolyploidy with age, and show unpredictable or patchy silencing. We speculate that differential silencing is a natural control mechanism in the exploitation of polyploidy in plants. The sugarcane system provides an exceptional opportunity to identify the sequences that trigger and protect from silencing, and to develop approaches to avoid the problem.Read moreRead less