Escalante-Semerena Our laboratory is interested in bacterial metabolism and physiology. Much of the work we do is performed in Salmonella enterica because we can do sophisticated genetic analyses of strains. We are currently focused on three areas of research. First, we study metabolic pathway integration. We identified the cobB gene of Salmonella enterica as a new member of the SIR2 family regulatory proteins in eukaryotes whose activities are needed for gene silencing and cell aging. Our report was an important contribution to this field of research and led to the identification of two enzymatic activities associated with these proteins. Lab site: http://escalab.com/ Read more about Escalante-Semerena
Elizabeth Ottesen Associate Professor, Graduate Coordinator- Advising Work in the Ottesen lab seeks to understand the structure and function of complex microbial communities, and the ways in which microbes interact with and perceive complex environments. A major focus is the use of molecular ecological tools to observe microbial behavior in the environment. This includes not only observing and tracking changes in which microbes are present in an environment, but also using community transcriptomics to observe changes in microbial gene expression over time. By studying microbial behavior “in the wild”, we hope to gain a better understanding of the roles and significance of diverse members of the uncultured microbial majority. Education: Ph.D. in Biology, California Institute of Technology (2008) Research Research Areas: Microbial Ecology Bioinformatics and -omics/Computational Biology Microbe-Host Interactions Labs (via personnel): Elizabeth Ottesen Labs: Ottesen Read more about Elizabeth Ottesen
Diana Downs Professor The goal of the research in my laboratory is to understand the integration of metabolic pathways that results in the robust physiology associated with microbes. In this effort we emphasize a biochemical genetic approach that utilizes in vivo analyses to inform the design of in vitro experiments. Currently the work in the lab is in two general areas. 1) Understanding the Rid system of endogenous metabolite stress. My laboratory identified a new stress system that is conserved across all domains. We showed that enamine metabolites, which are necessary intermediates in some PLP-dependent reactions, are able to damage cellular components. The RidA protein family is responsible for deaminating the enamines to generate stable keto acid products. These findings have opened an exciting new field of study in the lab. Immediate questions include; which enzymes generate enamine stressors? Which enzymes are targets of the damage? What is the specificity of RidA homologs? What are the biochemical consequences of lacking RidA in various organisms. This project has not only defined a new stress and cellular response to it, but has implications for our understanding of the composition and characteristics of the cellular milieu. 2) Exploring metabolic integration and redundancy. By virtue of the selective pressure exerted through millions of years of evolution, a living cell is likely to be the most well tuned and complex system in existence. The research in the laboratory takes advantage of the emerging technologies to better understand molecular details of metabolic processes and identify the mechanisms used to integrate these processes into a productive physiology. In our study of metabolic integration, we use a well-characterized biosynthetic pathway as a “nucleation point” from which to build and expand a model system. Our strategy has been to utilize genetic techniques to identify metabolic connections to this central pathway and thus build a defined network that we can then dissect on the molecular level. A solid understanding of metabolic integration is critical for the advancement of many fields including; metabolic diseases, drug discovery, synthetic biology, successful manipulation of microbes for societal uses, etc. Students from my laboratory have strong training in classical and molecular genetics particularly as applied to metabolic questions. In addition they are exposed to, and utilize, standard biochemical and molecular biological approaches. The students are encouraged to think logically about big biological questions and how to tease them apart. I strive to train students to think beyond linear pathways and transcriptional regulation to appreciate the integrated nature of metabolism and the inherent chemistry. Education: B.S. Biology, University of Utah (1981) Ph.D. Biology (Bacterial Genetics), University of Utah (1987) Research Research Areas: Bioinformatics and -omics/Computational Biology Microbial Physiology Molecular Microbiology Labs: Downs Selected Publications Selected Publications: http://www.ncbi.nlm.nih.gov/sites/myncbi/diana.downs.1/bibliography/40453984/public/?sort=date&direction=ascending Read more about Diana Downs
Molecular Microbiology Molecular approaches to studying microbial structures, cell biology, gene regulation, genomic stability, development, etc. Read more about Molecular Microbiology
Starai Research Interests: Upon invasion of a host cell, intracellular pathogens must actively ensure their survival in an immediately hostile environment. One such survival tactic of some pathogenic bacteria is through the subversion of host membrane fusion machinery, thereby inhibiting phagolysosomal fusion and subsequent delivery of the bacterium to the host degradative lysosome. The foodborne pathogen, Salmonella enterica, and the causative agent of Legionnaire’s disease, Legionella pneumophila, are examples of such bacterial pathogens that utilize this particular survival tactic. While evading host cell defenses in this manner is key to the organism’s ability to cause infection and disease, the mechanisms underlying these evasion pathways remain poorly understood. Many studies have tentatively identified bacterial factors thought to be important for the disruption of normal host membrane dynamics, but the biochemical analysis of these factors remains lacking. By employing a powerful in vivo and in vitro model system of eukaryotic membrane fusion, my laboratory will investigate the biochemistry of eukaryotic membrane fusion, identify and biochemically characterize bacterial effectors capable of modulating membrane fusion, and finally analyze these activities within the context of pathogenesis. Vacuoles of the budding yeast Saccharomyces cerevisiae serve the equivalent physiological function of the mammalian lysosome, and undergo constant rounds of fission and homotypic (self) fusion in response to cellular growth conditions. Isolation of these fusogenic organelles from yeast is now a straightforward task, and robust colorimetric assays have been developed to assay the multi-stage process of their fusion in vitro. As an excellent model of general eukaryotic SNARE-, Rab GTPase-, and SM protein-dependent intracellular membrane fusion, the yeast homotypic vacuole fusion system will comprise the backbone of our genetic, molecular, and biochemical approaches. Initial studies in the lab will characterize factors that allow an organism to drive a given membrane fusion event with a specific set of fusion machinery. The recent discovery that a yeast protein complex (the so-called HOPS complex) provides a proofreading activity to ensure proper homotypic vacuole fusion will be further studied. In addition, we will conduct genetic and biochemical screens of the intracellular pathogens Salmonella and Legionella to identify bacterially-produced inhibitors of vacuole fusion in vivo and in vitro. Mechanistic information gleaned from these studies will open new avenues towards the detailed study of basic bacterial pathogenesis. Read more about Starai
What They Are Doing Now: Jeff Bose Congratulations to Jeff Bose, who graduated with a PhD in Microbiology in 2007. He was awarded a National Research Service Award from the NIH for his postdoctoral project with Dr. Ken Bayles at the University of Nebraska Medical Center. The title of the project is "The Molecular Control of Cell Death in Staphylococcus aureus". Read more about What They Are Doing Now: Jeff Bose
What They Are Doing Now: Dawn Adin Dawn Adin (Ph.D. 2008) earned her B.S. at Jacksonville University in 2001. She then entered the Microbiology Graduate Program and joined Eric Stabb’s laboratory. Read more about What They Are Doing Now: Dawn Adin
What They Are Doing Now: Emily DeCrescenzo Henriksen Emily DeCrescenzo Henriksen (Ph.D. 2008) obtained her PhD from the Department of Microbiology in 2008 with Dr. Joy Doran-Peterson and is currently working at the Idaho National Laboratory. After completing a two-year postdoctoral position, Emily will transition to a staff scientist position at INL in August 2010. Emily continues to work on biofuels, studying extremophilic enzymes and their applications in bioethanol production. Read more about What They Are Doing Now: Emily DeCrescenzo Henriksen
What They Are Doing Now: Kate Brandon Kate Brandon (M.S. 2008). After graduating with her Masters in December 2008, Kate Brandon started working at Novozymes, the world's leading enzyme supplier (located outside Raleigh, NC). As an associate scientist in the Enzyme Application R&D department, she has continued to work on enabling the biomass to ethanol industry, research she started in Dr. Joy Doran Peterson's lab. In early 2010, Novozymes launched Cellic CTec 2, the first commerically viable enzyme solution for second generation biofuels, a product she helped to develop and qualify. Read more about What They Are Doing Now: Kate Brandon
What They Are Doing Now: Andrea Zbell Andrea Zbell (Ph.D, 2008) is currently a postdoctoral associate in Dr. Phil Rather’s lab at Emory University (Atlanta, GA), where she has been studying biofilm formation by Acinetobacter baumannii. Indeed Dr. Rather recently presented a seminar to our (UGA) Microbiology Department, and a portion of the presented work was Andrea’s. Andrea is currently writing a manuscript about this work. While conducting the postdoctoral research in Atlanta, Andrea also taught as an adjunct faculty member at Southern Catholic College, in Dawsonville, GA. Read more about What They Are Doing Now: Andrea Zbell