Lee, Seung-Jae, Ph.D.

Assistant Professor
Division of Molecular and Life Sciences
Molecular Genetics

Publications Abstract
E-mail seungjaelee1@gmail.com
Phone +82-54-279-2351(office)
          +82-54-279-8066(lab.)
Laboratory Molecular Genetics of Aging Laboratory

Profile |  Research Interests  |  Selected Publications

Profile

Research Interests

Aging is a fundamental mystery in biology. Although a number of genetic and environmental factors that affect aging have been discovered, the mechanisms by which these factors influence aging are poorly understood. This is mainly due to the difficulty in studying complex aging processes at the organismal level. The roundworm C. elegans is an excellent model animal to overcome these complications because of its genetic tractability, ease of culture in controlled environments and very short lifespan. In our laboratory we plan to elucidate the molecular mechanisms by which these genetic and environmental factors regulate lifespan using C. elegans as a main model organism.
 

1. How can we dissect complex interactions between genetic and environmental factors that     affect aging?
We are working on how two important environmental factors, temperature and food, influence the lifespan of C. elegans. Our initial findings suggest that the effects on lifespan of both ambient temperature and a diet rich in glucose are under the control of endocrine signaling. Our discoveries represent novel departures from previously existing beliefs about how these two factors influence longevity. We plan to further investigate the interactions between each of these environmental factors and the endocrine signaling pathways that regulate lifespan.

2. What are the genes that regulate lifespan in response to environmental changes?
Despite the generally accepted notion that environmental factors can influence lifespan, only a handful of genes that mediate such effects are known. Therefore, the identification of additional genes will be crucial to gain mechanistic insights into how environmental changes affect aging. To this end, we are conducting large scale gene discovery efforts by employing DNA microarray analysis, RNAi screening and chemical mutagenesis screening. We plan to confirm the functional significance of the candidates from these experiments and to further characterize these genes.

3. Are our findings in C. elegans conserved in other organisms?
The ultimate goal of aging research using C. elegans is to provide more information to help understand general aging processes including those of human aging. Therefore, we plan to test whether our findings in C. elegans are conserved in other organisms such as Drosophila and mice. In particular, our laboratory has expertise in the molecular genetics of Drosophila as well as C. elegans. Our ability to utilize these two wonderful model animals in parallel will greatly aid our knowledge on how aging processes are conserved across phyla.

Since many findings on the regulation of aging in C. elegans have already been shown to be amazingly well conserved during evolution, we believe our research may eventually help us understand the secrets of human aging and improve the quality of old age.

Selected Publications 

1. Hwang, A.B., and Lee, S.J. (2011) Regulation of life span by mitochondrial respiration: the HIF-1 and ROS connection. Aging (Albany NY) 3:304-10
2. Lee, S.J.^*#, Hwang, A.B.^#, and Kenyon, C*. (2010) Inhibition of respiration extends C. elegans' life span via reactive oxygen species that activate HIF-1. Curr. Biol. 20:2131-6 (*corresponding authors, ^#co-first authors)
3. Yamawaki, T., Berman, J., McCormick, M., Gaglia, M.M., Lee, S.J., and Kenyon, C. (2010) The somatic reproductive tissues of C. elegans promote longevity through steroid hormone signaling. PLoS Biol. 8: e1000468
4. Henis-Korenblit, S., Zhang, P., Hansen, M., McCormick, M., Lee, S.J., Cary, M., and Kenyon, C. (2010) Insuling/IGF-1 signaling mutants reprogram ER stress response regulators to promote longevity. Proc. Natl. Acad. Sci. USA 107:9730-5
5. Kim, Y.I., Ryu, T., Lee, J., Heo, Y.S., Ahnn, J., Lee, S.J., Yoo, O. (2010) A genetic screen for modifiers of Drosophila caspase Dcp-1 reveals caspase involvement in autophagy and novel caspase-related genes. BMC Cell Biol. 11: 9
6. Lee, S.J., Murphy, C.T., and Kenyon, C. (2009) Glucose shortens the lifespan of Caenorhabditis elegans by down-regulating aquaporin gene expression. Cell Metab. 10: 379-391
7. Lee, S.J., and Kenyon, C. (2009) Regulation of longevity response to temperature by thermosensory neurons in Caenorhabditis elegans. Curr. Biol. 19: 715-722
8. Murphy, C.T.*, Lee S.J.*, and Kenyon C. (2007) Tissue entrainment by feedback regulation of insulin gene expression in the endoderm of Caenorhabditis elegans. Proc. Natl. Acad. Sci. USA 104: 19046-19050 (*co-first author)
9. Hansen, M., Taubert, S., Crawford, D., Libina, N., Lee, S.J., and Kenyon, C. (2007). Lifespan extension by conditions that inhibit translation in Caenorhabditis elegans. Aging Cell 6: 95-110.

Division of Molecular & Life Sciences| POSTECH