I graduated from Seoul National University and Korea Advanced Institute of Science and Technology. Then I was affiliated in Department of Biochemistry, Hallym University College of Medicine. I worked in Howard Hughes Medical Institute in University of Washington as a postdoctoral fellow and associate researcher. I initiated the research about Rab3A, Ras-related small GTPase in HHMI. We found that Ca2+/calmodulin binds to Rab3A in synaptic vesicle, releasing Rab3A from synaptic vesicle (JBC 272:20857-20865, 1997). The protein interaction was demonstrated to be essential for exocytosis for neurotransmitter secretion (EMBO J. 18:5885-5891, 1999). Then, I have been interested in Rho GTPases, because they critically regulate a lot of cellular functions. In particular, I am recently working in RhoA-mediated tumorigenesis. We found that cysteine16/20 oxidation and tyrosine42 phosphorylation of RhoA are critical for tumorigenesis. Recently, we submitted a manuscript that pyruvate dehydrogenase (PDH) and pyruvate kinase M2 (PKM2) are important for cancer cell proliferation. Now we are working on tumor-associated macrophages (TAMs) and metabolic enzymes, which are relevant to tumorigenesis.

Regulatory Functions of Small GTP-binding proteins in the following areas: 1. Tumorigenesis through RhoA GTPase, NF-κB and β-catenin in response to ROS, EGF and Wnt. 2. Insulin signaling and insulin resistance and metabolic enzymes (PKM2, PDH) related to cancer. 3. Macrophage functions: phagocytosis, ROS formation, and tumor associated macrophage (TAM). 4. Regulation of neurite outgrowth from PC12 cells upon NGF, FGF, cAMP, and Aβ peptide.