Since 1996, my laboratory has also initiated a project to map the global structure of chromatin in situ using autofluorescent proteins as DNA markers. This approach open for the first time a window to the subnuclear architecture in live cells and should provide new understandings on the organization and dynamics of the biological information contained within chromosomes. We are also applying a fluorescent protein fusion tagging approach at a whole genome level with the aim of producing a collection of transgenic plant lines that will have most of the proteins in the genome tagged with a visible marker. These resources and novel technologies should provide an exciting opportunity to study subcellular organization of DNA and proteins at a global scale.
My research interests are in the area of programmed cell death, in terms of its mechanism of activation as well as its role in disease resistance. Programmed cell death (pcd) is a fundamental process that is recognized to occur in higher eukaryotes. Thus, during development of a multicellular organism, certain cells are destined to turnover in relatively predictable times and places. In addition, environmental and hormonal signals can also activate a cellular suicide program. Although pcd has been intensely studied in the past several years, particularly in mammalian cells and C. elegans, the actual mechanism through which eukaryotic cells commit suicide remains enigmatic. The current working hypothesis in this field is that the cellular machinery for pcd is present all the time in eukaryotic cells and is actively suppressed by certain proteins. Recently, we obtained evidence through inhibitor studies that caspases, a family of proteases that are conserved in animals as key regulators of pcd, are also likely to be involved in at least some cases of pcd in plants. This exciting finding suggests that the underlying mechanism for pcd may be conserved across plant and animal kingdoms. At the present time, my research focus in this area is directed at the elucidation of the molecular mechanisms involved in pcd and how this process can be regulated in vivo and are currently engaged in the characterization of plant caspases. To this end, we have designed a novel detection technology for visualizing and tracking specific protease activities in living cells. This technology is currently being deployed to functionally clone the plant proteases that may be involved in controlling pcd. Ultimately, we would like to define the regulatory pathways through which caspases involved in HR-pcd are controlled. This work should have broad impact on our understanding of how control of cellular suicide can be regulated to counter diseases as diverse as viruses and neurodegenerative disorders.