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.

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 Laboratory for Integrated NanoDiagnostics (LIND) is developing innovative technologies for accurate, fast, compact, portable, manufacturable, low-cost diagnostics for a wide variety of applications. Our current focus is a large-scale collaboration with imec, a leading microelectronics company in Leuven, Belgium, where our silicon is designed and manufactured. With major funding from miDiagnostics we are inventing solutions that are opening new avenues.

The focus of the research in the Reddy Laboratory is to begin to understand how the nuclear periphery and other subcompartments contribute to general nuclear architecture and to specific gene regulation. Our research goals can be broken down into three complementary areas of research: understanding how genes are regulated at the nuclear periphery, deciphering how genes are localized (or ""addressed"") to specific nuclear compartments and how these processes are utilized in development and corrupted in disease.

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.

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.

HPTN (HIV Prevention Trials Network) Network Laboratory (NL) is responsible for collecting, testing and reporting results from biological samples; assisting in the development and quality assurance assessment of local laboratory capacity at the Clinical Trials Units (CTUs) participating in HPTN clinical trials (www.hptn.org); and identifying and implementing state-of-the-art assays and technologies to advance the scientific agenda of the Network.

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 Gould Laboratory studies vesicles, known as exosomes and microvesicles (EMVs), that can be taken up by neighboring cells, completing a pathway of intercellular vesicle traffic. Our laboratory studies the molecular mechanisms of EMV biogenesis and uptake, and their contributions to cell polarity, cell-to-cell interactions, and intercellular signaling. We also examine the ways in which HIV and other retroviruses use the exosome biogenesis pathway for the formation of infectious virions, and the consequences of their EMV origin.

Research in the Claypool Lab is focused on defining how lipids and membrane proteins interact to establish and maintain normal mitochondrial function and how derangements in this complex relationship result in pathophysiology. We have demonstrated that yeast lacking tafazzin recapitulates all of the phospholipid abnormalities observed in human patients and many of the mitochondrial defects. Another major project in our lab focuses on the mitochondrial ADP/ATP carrier that is required for oxidative phosphorylation. Researchers are studying how these novel interactions help establish normal mitochondrial function, the biochemical details of these associations, and whether disturbances in these assemblies can contribute to mitochondrial dysfunction.