Research Synopsis: Our laboratory is interested in two areas of cellular regulation that play critical roles in normal growth and development, and have important ramifications for disease states.

Stressful conditions result in changes in cell proliferation, the reprogramming of cellular metabolism, accumulation of unfolded and aggregated proteins and other conditions associated with cardiovascular and neurodegenerative disease and other pathophysiological states. Our lab focuses on understanding how cells sense and respond to stress through the activation of a class of transcription factors called Heat Shock Transcription Factors (HSF). Using yeast and mammalian cells our laboratory is interested in dissecting the biochemical mechanisms by which HSFs are activated in response to a wide array of stressful conditions that include high temperatures, infection, inflammation, the presence of unfolded proteins and pharmacological agents. Furthermore, using powerful genetic and genomic approaches we are interested in understanding genome-wide stress responses, and their biological implications in health and disease.

The micronutrients copper (Cu) and iron (Fe) are essential catalytic co-factors for a wide variety of enzymes important for energy generation, DNA replication, lipid metabolism, the maturation of neuropeptides, protection from reactive oxygen species, connective tissue maturation and many other important processes in growth and development. Our lab is interested in understanding how organisms acquire and distribute Cu through studies of the Ctr family of high affinity Cu transporters, integral membrane proteins that are located on the plasma membrane, as well as on intracellular vesicular membranes. The importance of the mammalian Ctr1 Cu transporter is evident from our observation that mice lacking both genes encoding Ctr1 die midway through gestation, with severe growth and developmental abnormalities. Furthermore, our recent observation that yeast and mammalian Ctr1 proteins function in the acquisition and resistance to the anti-cancer drug cisplatin, suggests a broader role for these proteins. We use genetics, biochemistry, cell and molecular biology to understand the structure, function, regulation and physiological roles of the Ctr family of proteins in yeast, flies and mice. These studies are aimed at ultimately understanding the role of Cu homeostasis in normal growth and development, and in disease. Furthermore, we are deciphering how Fe deficiency leads to cellular metabolic reprogramming through targeted mRNA degradation.

Nose, Y., Kim, B. and Thiele, D.J. (2006) Ctr1 Drives Intestinal Copper Absorption and is Essential for Growth, Iron Metabolism and Neonatal Cardiac Function. Cell Metabolism 4: 235-244.

Hahn, J.-S., Neef, D. and Thiele, D. J. (2006) A Stress Regulatory Network for Coordinated Activation of Proteasome Expression Mediated by Heat Shock Transcription Factor. Molecular Microbiology 60: 240-251.

Park, K.-W., Hahn, J.S., Fan, Q., Thiele, D.J. and Li, L. (2006) De Novo Appearance and "Strain" Formation of Yeast Prion [PSI+] Are Regulated By the Heat Shock Transcription Factor. Genetics 173: 35-47.

Selvaraj, A., Balamurugan, K., Yepiskoposyan, H., Zhou, H., Egli, D., Georgiev, O., Thiele, D. J. and Schaffner, W. (2005). Metal-responsive transcription factor (MTF-1) handles both extremes, copper load and copper starvation, by activating different genes. Genes and Development 19: 891-889.

Puig, S., Askeland, E. and Thiele, D.J. (2005) Coordinated remodeling of cellular metabolism during iron deficiency through targeted mRNA degradation. Cell 120: 99-110.

Rees, E., Lee, J. and Thiele, D.J. (2004) Mobilization of Intracellular Copper Stores by the Ctr2 Vacuolar Copper Transporter. Journal of Biological Chemistry 279: 54221 - 54229.

Hahn, J.-S., Hu, Z., Thiele, D.J. and Iyer, V. (2004) Genome wide analysis of the biology of stress responses through heat shock transcription factor. Molecular and Cellular Biology 24: 5249-5256.

Petris, M.J., Smith, K., Lee, J. and Thiele, D.J. 2003. Copper stimulated endocytosis and degradation of the human copper transporter hCtr1. Journal of Biological Chemistry 278: 9639-9646

Ahn, S.-G. and Thiele, D.J. 2003. Redox regulation of mammalian Heat Shock Factor 1 is essential for Hsp gene activation and protection from stress. Genes and Development 17: 516-528.

Ishida, S., Lee, J., Thiele, D.J., and Herskowitz, I. 2002. Uptake of the anticancer drug cisplatin mediated by the copper transporter Ctr1 in yeast and mammals. Proc. Natl. Acad. Sci. USA 99: 14298-14302.

Lee, J., Petris, M. and Thiele, D.J. 2002. Characterization of Mouse Embryonic Cells Deficient in the Ctr1 High Affinity Copper Transporter: Identification of a Ctr1-indepedent Copper Transport System. Journal of Biological Chemistry 277: 40253-40259.

Puig, S., Lee, J., Lau, M. and Thiele, D.J. 2002. Biochemical and genetic analyses of yeast and human high affinity copper transporters suggest a conserved mechanism for copper uptake. Journal of Biological Chemistry 277: 26021-26030.

Ahn, S-G., Liu, P.C.C., Klyachko, K., Morimoto, R., and Thiele, D.J. 2001. The Loop Domain of Heat Shock Transcription Factor 1 Dictates DNA Bindng Specificity and Responses to Heat Stress. Genes and Development 15: 2134-2145.

Lee, J. Prohaska, J.R., and Thiele, D.J. 2001. Essential Role for Mammalian Copper Transporter Ctr1 in Copper Homeostasis and Embryonic Development. Proc. Natl. Acad. Sci., USA 98: 6842-6847.