Faculty
Wayne A Johnson Ph.D.
Somatosensory signaling is the process by which we become aware of external sensations such as touch, temperature or pain. Despite the importance of these sensory modalities to our everyday existence, we know relatively little about their molecular mechanisms. These sensations would appear to be quite different, however, recent work has shown that they may be separated by only a fine line at the molecular level. Two large ion channel families, the TRP channels and the ENaCs, appear to have been evolutionarily selected for a variety of physiological functions ranging from thermosensation and osmosensation to pain and touch. We have developed a genetic model system in Drosophila to examine the molecular components of somatosensory signal transduction in type II multiple dendritic(md) sensory neurons. We are applying a variety of techniques including electrophysiology, behavior, molecular biology and genetics to identify and characterize evolutionarily conserved signaling components.
Brad D Jones Ph.D.
The objective of the research in my laboratory is to elucidate the pathogenic mechanisms of Salmonella species. One important pathogenic attribute of Salmonella species is their ability to enter mammalian cells. The ability of these bacteria to invade host cells is controlled by a variety of environmental signals that control invasion gene expression. We have performed a variety of genetic screens to identify genes that control the expression of the Salmonella invasion machinery. Those experiments have revealed that the regulatory pathways use two-component signaling systems, known small DNA-binding proteins, and Salmonella-specific proteins. A variety of research projects are underway to characterize these pathways in detail and to explore how regulation of this particular virulence property is integrated into the control of the entire pathogenic strategy of the organism as well as to discover how virulence gene expression is managed within the context of bacterial physiology. This work as provided significant insights into the bacterial-host cell interactions that allow these bacteria to survive and grow within the lymphatic system of mammalian hosts. A second project in the laboratory, which has been recently funded, is a characterization of the virulence factors of Francisella tularensis. This potential bioweapon is a significant pathogen which causes a systemic infection similar to the \"plague\" caused by Yersinia pestis. Work is being initiated to characterize the adherence, invasive, and intracellular survival properties of this organism as well as to develop genetic tools for manipulation and study of the bacteria.
