Sun Sun


Department of Chemistry & Biochemistry
The University of Texas at Austin
1 University Station A5300
Austin, TX 78712-0165





















Contact Information


Office: WEL: 4.230D
Phone: 471-5842

Lab


Office: WEL 4.244
Phone: 471-6836
Fax:

Dean R. Appling


dappling@mail.utexas.edu
Professor, Faculty
Lester J. Reed Professorship in Biochemistry

Research Group


Appling Lab

Education


BS Biology, Texas A&M University, 1977
PhD Biochemistry, Vanderbilt University, 1981
Postdoctorate, University of California - Berkeley, 1981-85


Affiliations


Institute for Cellular and Molecular Biology;

Regulation and organization of metabolic pathways


Eukaryotic cells are composed of many different compartments, such as mitochondria and nuclei. Although each of these compartments exhibits a distinct set of metabolic processes, they must all communicate with each other for the cell to function properly. Understanding how these processes are organized and controlled represents the next frontier in the study of metabolism. We have focused our efforts on folate-mediated one-carbon metabolism. This set of pathways is found in all cells and organisms, is central to fundamental processes such as nucleic acid and protein synthesis, and occurs in multiple compartments. We utilize a wide variety of biochemical and molecular genetic techniques, as well as nuclear magnetic resonance, to study the organization of these pathways in both mammalian and yeast systems. The use of noninvasive techniques such as NMR has revealed metabolic relationships and interactions that were overlooked in traditional in vitro systems.

The molecular organization of a metabolic pathway is ultimately dependent on the unique three-dimensional structures of the individual enzyme components. Thus, we have several protein structure projects ongoing in the laboratory. Techniques include kinetic analysis, site-directed mutagenesis, and X-ray crystallography (in collaboration with Dr. Robertus). Our goal is to understand how these enzymes function and interact with one another in the cell.



Representative Publications



Prasannan, Priya and Appling, Dean R. "Human mitochondrial C1-tetrahydrofolate synthase: Submitochondrial localization of the full-length enzyme and characterization of a short isoform" Arch. Biochem. Biophys. 481 (2009): 86-93. http://dx.doi.org/10.1016/j.abb.2008.10.028

Lee, C., Kramer, G., Graham, D. E., and Appling, D. R. "Yeast Mitochondrial Initiator tRNA Is Methylated at Guanosine 37 by the Trm5-encoded tRNA (Guanine-N1-)-methyltransferase" J. Biol. Chem. 282 (2007): 27744-27753. http://www.jbc.org/cgi/content/full/282/38/27744

Lu, P., Rangan, A., Chan, S.Y., Appling, D.R., Hoffman, D.W., and Marcotte, E.M. "Global metabolic changes following loss of a feedback loop reveal dynamic steady states of the yeast metabolome" Metab Eng. 9 (2007): 8-20. http://dx.doi.org/10.1016/j.ymben.2006.06.003

Suliman, H.S., Appling. D.R., and Robertus, J. "The gene for cobalamin-independent methionine synthase is essential in Candida albicans: A potential antifungal target" Arch Biochem Biophys 467 (2007): 218-226. http://dx.doi.org/10.1016/j.abb.2007.09.003

Wagner, W., Breksa, A.P. III, Monzingo, A.F., Appling, D.R. and Robertus, J.D. "Kinetic and Structural Analysis of Active Site Mutants of Monofunctional NAD-Dependent 5,10-Methylenetetrahydrofolate Dehydrogenase from Saccharomyces cerevisiae" Biochemistry 44 (2005): 13163-13171. http://dx.doi.org/10.1021/bi051038x