Julia Maresca

Julia A. Maresca
Post-Doctoral Associate, Department of Civil and Environmental Engineering

Massachusetts Institute of Technology

Current Project
Carotenoid biosynthesis in a marine bacterium. Carotenoids are colored isoprenoid compounds made by all phototrophic organisms and a wide variety of non-phototrophic species. A fosmid library made from DNA collected at Station ALOHA, Hawaii, was screened in E. coli for development of color. In one orange-colored strain, the fosmid was found to encode an operon with the genes crtEIBYW, encoding several steps in carotenoid biosynthesis. Having this operon enables E. coli to make both canthaxanthin and echinenone, and insertional inactivation of each of these genes permitted identification of the intermediates in the pathway for canthaxanthin biosynthesis, which include phytoene, lycopene, gamma-carotene and beta-carotene.

Education
Ph.D., Biochemistry and Molecular Biology, The Pennsylvania State University, May 2007. Advisor: Donald A. Bryant.

B.A., Biology, University of Chicago, June 1999.

Publications
1. J.A. Maresca, J.C. Braff, and E.F. Delong. (2009) Characterization of canthaxanthin biosynthesis genes from an uncultured marine bacterium. Environmental Microbiology Reports. Available online

2. J.A. Maresca, S.P. Romberger, and D.A. Bryant. (2008) Isorenieratene biosynthesis in green sulfur bacteria requires the cooperative actions of two carotenoid cyclases. Journal of Bacteriology, 190: 6384-6391.

3. J.A. Maresca, J.E. Graham, and D.A. Bryant. (2008) The biochemical basis for structural diversity in the carotenoids of phototrophic bacteria. Photosynthesis Research, 97: 121-140. Available online

4. J.A. Maresca, J.E. Graham, M. Wu, J. Eisen, and D.A. Bryant. (2007) Identification of a new family of lycopene cyclases in photosynthetic bacteria. Proceedings of the National Academy of Sciences, 104: 11784-11789.

5. Bryant, D. A., A.M. Garcia Costas, J.A. Maresca, A. Gomez Maqueo Chew, C.G. Klatt, M.M. Bateson, L.J. Tallon, J. Hostetler, W.C. Nelson, J.F. Heidelberg, and D.M. Ward. (2007) "Chloracidobacterium thermophilum": an aerobic phototrophic acidobacterium. Science, 317: 523-526.

6. Kim H, H. Li, J.A. Maresca, D.A. Bryant, S. Savikhin. (2007) Triplet exciton formation as a novel photoprotection mechanism in chlorosomes of Chlorobium tepidum. Biophysical Journal 93: 192-201.

7.J.A. Maresca and D.A. Bryant. (2006) Identification of two genes encoding new carotenoid-modifying enzymes in the green sulfur bacterium Chlorobium tepidum. Journal of Bacteriology, 188: 6217-6223.

8. R.E. Ley, J.K. Harris, J. Wilcox, J.R .Spear, S.R. Miller, B.M. Bebout, J.A. Maresca, D.A. Bryant, N.R. Pace. (2006) Unprecedented bacterial community diversity and complexity in a hypersaline microbial mat. Applied and Environmental Microbiology, 72: 3685-3695.

9. Frigaard, N.-U., A. Gomez Maqueo Chew, J.A. Maresca, and D.A. Bryant. (2006) Bacteriochlorophyll biosynthesis in green bacteria. In: Advances in Photosynthesis and Respiration, Vol. 25, B. Grimm, R. Porra, W. Rüdiger, and H. Scheer (eds.), Chlorophylls and Bacteriochlorophylls: Biochemistry, Biophysics, Functions and Applications, pp. 201-221. Springer, Dordrecht, The Netherlands.

10. J.A. Maresca, N.-U. Frigaard, and D.A. Bryant (2005) Identification of a novel class of lycopene cyclases in photosynthetic bacteria. In: Photosynthesis: Fundamental Aspects to Global Perspectives, Proceedings of the XIIIth International Congress on Photosynthesis, Montreal, A. van der Est and D. Bruce, eds., pp. 884-886. Allen Press, Lawrence, KS, USA.

11. D.A. Bryant, N.-U. Frigaard, J.A. Maresca, A. Gomez Maqueo Chew and T. Li (2005) Chlorophyll and carotenoid biosynthesis in green sulfur bacteria: a genomic perspective. In: Photosynthesis: Fundamental Aspects to Global Perspectives, Proceedings of the XIIIth International Congress on Photosynthesis, Montreal, A. van der Est and D. Bruce, eds., pp. 866-869. Allen Press, Lawrence, KS, USA.

12. A.R. Brannon, J.A. Maresca, J.D. Boeke, M.A. Basrai, and A.A. McBride (2005) Reconstitution of BPV E2-mediated plasmid segregation in yeast by the Brd4 bromo-domain protein. Proceedings of the National Academy of Sciences 102 (8): 2998-3003.

13. N.-U. Frigaard, J.A. Maresca, C.E. Yunker, A.D. Jones, and D.A. Bryant (2004) Genetic manipulation of carotenoid biosynthesis in the green sulfur bacterium Chlorobium tepidum. Journal of Bacteriology 186: 5210-5220.

14. J.A. Maresca, A. Gomez Maqueo Chew, M. Ros Ponsatí, N-U. Frigaard, J.G. Ormerod, and D.A. Bryant (2004) The bchU gene of Chlorobium tepidum encodes the C-20 methyltransferase in bacteriochlorophyll c biosynthesis. Journal of Bacteriology 186 (9): 2558-2566.

15. N.-U. Frigaard, A. Gomez Maqueo Chew, H. Li, J.A. Maresca, D.A. Bryant (2003) Chlorobium tepidum: insights into the structure, physiology, and metabolism of a green sulfur bacterium derived from the complete genome sequence. Photosynthesis Research 78: 93-117.

16. E.K. Dimitriadis, F. Horkay, J. Maresca, B. Kachar, RS Chadwick (2002) Determination of elastic moduli of soft, thin samples using the atomic force microscope. Biophysical Journal 82(5): 2798-810.

17. A. Krol, J. Maresca, M. Dewhirst, F. Yuan (1999) Available volume fraction of macromolecules in the extravascular space of a fibrosarcoma: Implications for drug delivery. Cancer Research 59: 4136-4141.

Research Experience
2007-present: Post-doctoral fellow, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology. Advisor: Dr. Edward F. Delong.

2001-2007: Graduate Research Assistant, Department of Biochemistry and Molecular Biology, The Pennsylvania State University. Advisor: Dr. Donald A. Bryant.

2000-2001: IRTA Post-Baccalaureate Fellow, Lab of Viral Diseases, National Institute on Allergy and Infectious Disease. Advisor: Dr. Alison McBride.

1999–2000: IRTA Post-Baccalaureate Fellow, Lab of Auditory Mechanics, National Institute on Deafness and Communicative Diseases. Advisor: Dr. Richard Chadwick.

1998-1999: Undergraduate researcher, Department of Organismal Biology and Anatomy, University of Chicago. Advisor: Dr. Martin Feder.

1998: NSF-REU Summer Student, Biomedical Engineering, Duke University. Advisor: Dr. Fan Yuan.

Fellowships and Awards
2007. Graduate School Alumni Association Dissertation Award, The Pennsylvania State University, for “The genetic basis for pigment variation in green sulfur bacteria.”

2005. International Travel Award, Biogeochemical Research Initiative for Education (NSF-IGERT). Travel to work in Jorg Overmann's lab, Ludwig-Maximilians University, Munich, Germany.

2002-2006. NASA Space Grant Fellowship, Pennsylvania Space Grant Consortium.

2004. Summer Research Fellowship, Center for Environmental Chemistry and Geochemistry, The Pennsylvania State University, for “Nutrient cycling in a stratified lake.”

2003. Research Award, Biogeochemical Research Initiative for Education (NSF-IGERT) for “Breakdown of bacterial homoserine lactone signals by archaea.” (Research supplies only)

2001-2002. University Graduate Fellowship, The Pennsylvania State University.

Outreach Activities
2004, 2005. Volunteer Coordinator, BioDays at Penn State. Organized volunteers to present their current research and staff demos presenting biological sciences to the general public. 2004, 2005.

2004. Demonstration for BioDays: “Glowing bacteria: how bacteria count without counting.”

2003. Expanding Your Horizons Conference, Women in Science and Engineering Institute, The Pennsylvania State University. Workshop for middle-school girls: “Who’s on the sunshine diet? Colored bacteria and how they use sunlight.”

2002. MathFest Conference, Women in Science and Engineering Institute, The Pennsylvania State University. Workshop for middle-school girls: “What lives in pond scum?”