The Greider lab uses biochemistry to study telomerase and cellular and organismal consequences of telomere dysfunction. Telomeres protect chromosome ends from being recognized as DNA damage and chromosomal rearrangements. Conventional replication leads to telomere shortening, but telomere length is maintained by the enzyme telomerase. Telomerase is required for cells that undergo many rounds of divisions, especially tumor cells and some stem cells. The lab has generated telomerase null mice that are viable and show progressive telomere shortening for up to six generations. In the later generations, when telomeres are short, cells die via apoptosis or senescence. Crosses of these telomerase null mice to other tumor prone mice show that tumor formation can be greatly reduced by short telomeres. The lab also is using the telomerase null mice to explore the essential role of telomerase stem cell viability. Telomerase mutations cause autosomal dominant dyskeratosis congenita. People with this disease die of bone marrow failure, likely due to stem cell loss. The lab has developed a mouse model to study this disease. Future work in the lab will focus on identifying genes that induce DNA damage in response to short telomeres, identifying how telomeres are processed and how telomere elongation is regulated.

The George Rose Lab investigates protein folding, the spontaneous disorder transition that takes place under physiological conditions. The protein polymer is flexible in its unfolded state but takes on a unique native, three-dimensional form when folded. We propose that the folded state is selected from a set number of structural possibilities, each corresponding to either a distinct hydrogen-bonded arrangement of ??helices or a strand of ??sheet.

The Berger Lab's research is focused on understanding how multi-subunit assemblies use ATP for overcoming topological challenges within the chromosome and controlling the flow of genetic information. A long-term goal is to develop mechanistic models that explain in atomic level detail how macromolecular machines transduce chemical energy into force and motion, and to determine how cells exploit and control these complexes and their activities for initiating DNA replication, shaping chromosome superstructure and executing myriad other essential nucleic-acid transactions. Our principal approaches include a blend of structural (X-ray crystallography, single-particle EM, SAXS) and solution biochemical methods to define the architecture, function, evolution and regulation of biological complexes. We also have extensive interests in mechanistic enzymology and the study of small-molecule inhibitors of therapeutic potential, the development of chemical approaches to trapping weak protein/protein and protein/nucleic acid interactions, and in using microfluidics and single-molecule approaches for biochemical investigations of protein dynamics.

Research in the Bradley Undem Lab centers around the hypothesis that the peripheral nervous system is directly involved in the processes of inflammation. This hypothesis is being studied primarily in the central airways and sympathetic ganglia. We are addressing this in a multidisciplinary fashion, using pharmacological, electrophysiological, biochemical and anatomical methodologies.

The objective of the Xiao Group's research is to study the dynamics of cellular processes as they occur in real time at the single-molecule and single-cell level. The depth and breadth of our research requires an interdisciplinary approach, combining biological, biochemical and biophysical methods to address compelling biological problems quantitatively. We currently are focused on dynamics of the E. coli cell division complex assembly and the molecular mechanism in gene regulation.

The Devreotes Laboratory is engaged in genetic analysis of chemotaxis in eukaryotic cells. Our long-term goal is a complete description of the network controlling chemotactic behavior. We are analyzing combinations of deficiencies to understand interactions among network components and carrying out additional genetic screens to identify new pathways involved in chemotaxis. A comprehensive understanding of this fascinating process should lead to control of pathological conditions such as inflammation and cancer metastasis.

Our research focuses on the biology of the peptidoglycan of Mycobacterium tuberculosis, the organism that causes tuberculosis, and Mycobacteroides abscessus, a related bacterium that causes opportunistic infections. We study basic mechanisms associated with peptidoglycan physiology but with an intent to leverage our findings to develop tools that will be useful in the clinic to treat mycobacterial infections. Peptidoglycan is the exoskeleton of bacteria that not only provides structural rigidity and cell shape but also several vital physiological functions. Breaching this structure is often lethal to bacteria. We are exploring fundamental mechanisms by which bacteria synthesize and preserve their peptidoglycan. Although our lab uses genetic, biochemical and biophysical approaches to study the peptidoglycan, we pursue questions irrespective of the expertise required to answer those questions. It is through these studies that we identified synergy between two beta-lactam antibiotics against select mycobacteria.

The Nicholas Flavahan Lab primarily researches the cellular interactions and subcellular signaling pathways that control normal vascular function and regulate the initiation of vascular disease. We use biochemical and molecular analyses of cellular mediators and cell signaling mechanisms in cultured vascular cells, while also conducting physiological assessments and fluorescent microscopic imaging of signaling systems in isolated blood vessels. A major component of our research involves aterioles, tiny blood vessles that are responsible for controlling the peripheral resistance of the cardiovascular system, which help determine organ blood flow.

Complexity in signaling networks is often derived from co-opting one set of molecules for multiple operations. Understanding how cells achieve such sophisticated processing using a finite set of molecules within a confined space--what we call the ""signaling paradox""--is critical to biology and engineering as well as the emerging field of synthetic biology. In the Inoue Lab, we have recently developed a series of chemical-molecular tools that allow for inducible, quick-onset and specific perturbation of various signaling molecules. Using this novel technique in conjunction with fluorescence imaging, microfabricated devices, quantitative analysis and computational modeling, we are dissecting intricate signaling networks. In particular, we investigate positive-feedback mechanisms underlying the initiation of neutrophil chemotaxis (known as symmetry breaking), as well as spatio-temporally compartmentalized signaling of Ras and membrane lipids such as phosphoinositides. In parallel, we also try to understand how cell morphology affects biochemical pathways inside cells. Ultimately, we will generate completely orthogonal machinery in cells to achieve existing, as well as novel, cellular functions. Our synthetic, multidisciplinary approach will elucidate the signaling paradox created by nature.

The Hey-Kyoung Lee Lab is interested in exploring the cellular and molecular changes that happen at synapses to allow memory storage. We use various techniques, including electrophysiological recording, biochemical and molecular analysis, and imaging, to understand the cellular and molecular changes that happen during synaptic plasticity. Currently, we are examining the molecular and cellular mechanisms of global homeostatic synaptic plasticity using sensory cortices as model systems. In particular, we found that loss of vision elicits global changes in excitatory synaptic transmission in the primary visual cortex. Vision loss also triggers specific synaptic changes in other primary sensory cortices, which we postulate underlies sensory compensation in the blind. One of our main research goals is to understand the mechanisms underlying such cross-modal synaptic plasticity. We are also interested in elucidating the events that occur in diseased brains. In collaboration with other researchers, we are analyzing various mouse models of Alzheimer's disease, especially focusing on the possible alterations in synaptic plasticity mechanisms.