Tracey Freitas
2538 McCarthy Mall, Snyder Hall 111
Honolulu, HI 96822
(808) 956-6945 (phone)
(808) 956-5339 (fax)
traceyf@hawaii.edu

Education

Research Summary

Streptococcus pyogenes, the sole member of the Group A Streptococci (GAS), is a common cause of human infections, from superficial infections of the skin to more life-threatening infections leading to rheumatic fever, a disease observed commonly in children. Various GAS strains exist and may be grouped according to the order of specific virulence genes in a pathogenic island of their genome, known as the fibronectin-binding, collagen-binding T antigen (FCT) region.  Polynesian children are known to become infected with rheumatic fever-causing GAS strains that their mainland US counterparts do not. My research focuses on the identification of those factors leading to colonization, invasion, and ultimately, the development of rheumatic fever in these susceptible Polynesian individuals. Currently, we are sequencing and assembling the genome of two GAS strains, one of which exhibits a predisposition to the infection of Polynesian children. This research, coupled with the bioinformatic tools developed within our lab, we aim to identify the roles of the FCT virulence genes and phage particles in the development of rheumatic fever.

Publications

Saito, J.A., Freitas, T.A.K., & Alam, M. 2008. Cloning, expression, and purification of the N-terminal heme-binding domain of globin-coupled sensors.  Methods in Enzymology.  437: 163-172.

Freitas, T.A.K., Saito, J.A., Wan, X., Hou, S., & Alam, M.  2007.  Protoglobin and globin-coupled sensors.  In Ghosh, A. (Ed.)  The smallest biomolecules: diatomics and their interactions with heme proteins.  pp. 175-202.

Park, D.J., Freitas, T.A., Guyette, C.V., Wallick, C.J., Jin, C., Lau, A.F., & Warn-Cramer, B.J.  2006.  Connexin43 Interacts with the 14-3-3 Scaffolding Protein.  Protein Science.  15(10):2344-2355.

Hou, S., Saw, J.H., Lee, K.S., Freitas, T.A., Belisle, C., Kawarabayasi, Y., Donachie, S.P., Galperin, M.Y., Koonin, E.V., Makarova, K.S., Omelchenko, M.V., Sorokin, A., Wolf, Y.I., Li, Q., Keum, Y.S., Campbell, S., Denery, J., Aizawa, S.-I., Shibata, S., Malahoff, A., & Alam, M.  2004.  Genome Sequence of the deep-sea γ-proteobacterium Idiomarina loihiensis reveals amino acid fermentation as a source of carbon and energy.  Pro Natl Acad Sci USA.  101(52):18036-18041.

Freitas, T.A.K., Saito, J.A., Hou, S., & Alam, M.  2005.  Globin-coupled sensors, protoglobins, and the last universal common ancestor.  Journal of Inorganic Biochemistry.  99:23-33.

Freitas, T.A.K., Hou, S., Dioum, E.M., Saito, J.A., Newhouse, J., Gonzalez, G., Gilles-Gonzalez, M.A., & Alam, M.  2004.  Ancestral hemoglobins in Archaea.  Proceedings of the National Academy of Sciences, USA.  101:6675-6680.

Freitas, T.A., Hou, S., & Alam, M.  2003.  The Diversity of Globin-Coupled Sensors. FEBS Lett.  552(2-3):99-104.

Hou, S., Freitas, T., Larsen, R.W., Piatibratov, M., Sivozhelezov, V., Yamamoto, A., Meleshkevitch, E.A., Zimmer, M., Ordal, G.W., & Alam, M.  2001.  Globin-coupled sensors: a class of heme-containing sensors in Archaea and Bacteria.  Proc Natl Acad Sci USA.  98(16):9353-9358.

Wailap Victor Ng et al. 2000. Genome sequence of Halobacterium species NRC-1.  Proc Natl Acad Sci USA.  24;97(22):12176-12181.

Brooun, A., Bell, J., Freitas, T., Larsen, R.W., & Alam, M.  1998.  An archaeal aerotaxis transducer combines subunit I core structures of eukaryotic cytochrome c oxidase and eubacterial methyl-accepting chemotaxis proteins.  J Bacteriol.  180(7):1642-1646.

Hou, S., Brooun, A., Yu, H.S., Freitas, T., & Alam, M.  1998.  Sensory rhodopsin II transducer HtrII is also responsible for serine chemotaxis in the archaeon Halobacterium salinarum.  J Bacteriol.  180(6):1600-1602.