4550A Thomas Hall
North Carolina State University
Raleigh, NC 27695-7615
Amy M. Grunden
Amy Grunden was born in Lakeland, Florida. As the daughter of an active-duty serviceman, she lived in a number of places during her childhood including El Paso (Texas), Omaha (Nebraska), Leominster (Massachusetts), Sierra Vista (Arizona), Fort Meade (Maryland) and Munich (Germany). Even as a child in grammar school, Amy had a keen interest in the biological sciences. She went on to pursue this interest in college, majoring in microbiology and cell sciences at the University of Florida. As an undergraduate, Amy became interested in academic research and undertook undergraduate research studies on the genetic and biochemical characterization of the regulation molybdate uptake by the bacterium Escherichia coli. After graduating with her B.S. in 1993, she continued her former undergraduate research project at the University of Florida, and eventually graduated with a Ph.D. in 1996. Amy next served as a post-doctoral research associate in the Department of Biochemistry and Molecular Biology at the University of Georgia. While at Georgia, she began working with microorganisms known as hyperthermophiles, which grow at temperatures ranging from 80C to 113C and became very interested in the mechanisms and adaptations which allow these unique organisms to thrive at such high temperatures. In July, 2000, Amy joined the faculty in the Department of Microbiology at North Carolina State University as an assistant professor and she is currently developing a research program to further investigate the physiology of hyperthermophilic microorganisms using a thermal-vent archaeon Pyrococcus furiosus as the primary research organism.
Hyperthermophiles, which are microorganisms that have an optimum growth temperature of at least 80C and a maximum growth temperature of 90C or above, were first isolated from hydrothermal vents (image at left) in the early 1980s. At present, more than 20 different genera of hyperthermophiles are known with two of these classified as bacteria and the rest as archaea. Archaea, which are known to constitute a third domain of life based on 16S rRNA analysis, are prokaryotes that have some eukaryotic features such as a similar mechanism of transcription. The discovery of hyperthermophilic archaea immediately engendered a great deal of research interest in several areas such as the potential biotechnological applications of purified thermostable enzymes, the identification of thermoprotection mechanisms that enable growth at high temperatures, and the characterization of the basic biochemistry and physiology of hyperthermophiles. Additionally, their discovery prompted studies focusing on the evolutionary significance of hyperthermophilic archaea, which are considered the extant microbes most closely related to the universal common ancestor from which both prokaryotic and eukaryotic cells arose.
While much progress has been made in these areas, especially with regard to the biochemistry and physiology of these organisms, very little is known about the actual regulation of their metabolic processes. My primary research interest is to investigate the mechanisms of metabolic regulation, particularly transcriptional regulatory mechanisms, utilized by hyperthermophilic archaea. The hyperthermophilic archaeon, Pyrococcus furiosus, an obligately anaerobic, fermentative heterotroph, growing optimally at 98C, serves as the primary research organism for these studies since its genome has been recently sequenced and because there already exists a sizeable body of literature describing the biochemistry and physiology of P. furiosus (image at right).
Currently my laboratory is investigating the regulation of two different critical metabolic systems in P. furiosus: the regulation of the utilization of phosphate and the regulation of the uptake and processing of tungsten. The methods that we are using to characterize the regulation of these two systems are DNA array analysis (below, left) and differential proteomic analysis (below, right). By using these methods, we will be able to determine how P. furiosus genes are regulated in response to a host of different growth conditions including growth with varying phosphate and tungsten availability, growth on different carbon and nitrogen sources, and growth under conditions of heat and cold shock. From the analysis of regulated genes, regulatory DNA-binding motifs can be identified which will ultimately enable the identification of the responsible transcriptional regulatory genes. The subsequent biochemical and genomic analysis of identified transcriptional regulators will substantially expand our currently limited understanding of transcriptional regulation of metabolic pathways in hyperthermophilic archaea.