Dr. Julia Y. Lee
Assistant Professor
Department of Biology
Office:  Rm 227 Science Center
Research Lab:  Rm 216 Science Center
Phone:  610-660-3439
e-mail: jlee04@sju.edu

Education:

• BS (1994) West Chester University, West Chester, PA
• PhD (2002) University of Pennsylvania, Philadelphia, PA

Professional Experience:

• Post-doctoral Fellowship (2002-2006) Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine
• Assistant Professor (2006-) of Biology, St. Joseph’s University

Courses Taught:                

• Biology I: Cells (Fall)
• Immunology (Fall)
• Molecular Genetics (Spring)

Research Interests:
          Chromosomal DNA is not randomly distributed within the nucleus of eukaryotic cells.  There is evidence showing that DNA is orderly arranged into compartments by mechanisms that is yet fully elucidated.  This organization may play an important role in regulating gene expression when a DNA sequence is turned on or off to be transcribed for protein synthesis.  Eukaryotic genome contains regions of guanine-rich sequences, most interestingly at gene promoter regions where transcription initiation is intensely regulated.  Guanine (G)-rich DNA sequences have the capacity to form relatively stable G-quadruplexes that are four stranded DNA structures forming stacked layers of hydrogen-bonded planer G-quartet.  If G-quadruplexes are able to form with any four strands of DNA, intermolecularly and/or intramolecularly, these structures may be used to scaffold chromosomal DNA into ordered arrangements, especially between distal but related genes or those on separate chromosomes.  If this is the case, G-quadruplexes may have a direct role in regulating gene expression.

            My lab uses baker’s yeast, Saccharomyces cerevisiae, as a model system to address genetics questions.  By generating various mutations or overexpressing certain proteins, my students and I are able to ask how perturbing the natural chromosomal organization or disturbing the mechanisms to resolve unusual DNA structures, such as G-quadruplexes, may affect gene expression.  We are generating yeast mutants that are no longer able to anchor chromosomes to the nuclear membrane to ask if artificially stabilized G-quadruplexes might maintain chromosomal compartmentalization.  By overexpressing Spt4p, a protein shown to efficiently process transcription of GC-rich DNA, we are able to test if the inhibitory effects of G-quadruplexes on transcription can be overcome.  We are also interested to study if the so-called G-quadruplex scaffolds have the ability to bridge the promoter or control regions of two distal genes and essentially regulate the expression of both genes simultaneously.

Publications: 

• Lee, J. Y., J. D. Martin, E. Pennock, F. B. Johnson.  2007.  Evidence that a RecQ helicase slows senescence by resolving recombining telomeres.PLOS Biology. 5:1334-1344.

• Azam*, M., J. Y. Lee*, V. Abraham, R. Chanoux, K. A. Schoenly, F. B. Johnson.  2006.  Evidence that the S. cerevisiae Sgs1 protein facilitates recombinational repair of telomeres during senescence.  Nucl. Acid Res.  34:506-516.  * Authors contributed equally.

• Lee, J. Y., N. Kim, A. Sanford, K. E. Sullivan.  2003.  Histone acetylation and chromatin conformation are regulated separately at the TNFa promoter in monocytes and macrophages.  J. Leuk. Biol. 73: 862-871.

• Kilpatrick, L., J. Y. Lee, K. M. Haines, D. E. Campbell, K. E. Sullivan, and H. M. Korchak.  2002.  Role for d-PKC and PI 3-kinase in TNFa mediated anti-apoptotic signaling in the human neutrophil. Am. J. Physiol. Cell Physiol. 283: C48-57.

• Lee, J. Y., D. Goldman, L. M. Piliero, M. Petri, K. E. Sullivan.  2001.  Interferon-g polymorphisms in systemic lupus erythematosus.  Genes Imm. 2: 254-257.

• Lee, J. Y. and K. E. Sullivan.  2001.  IFN-g modulation of LPS-inducible TNF-a expression occurs at the level of gene transcription.  Infect. Imm., 69: 2847-2852.