Our research focuses on diverse cellular processes, including cancer dynamics, endocytic pathway, intracellular trafficking of proteins and membranes, membrane organization, nanomaterial traffic, and nanomaterial-mediated global gene expression pattern changes.
We test the effects of chemotherapeutic agents and engineered nanoparticles on cancer cells such as Hela and thyroid cancer cells. We routinely cultivate these cancer cells, performing cell viability/proliferation assays. The department has two flowcytometers with which we test apoptotic levels of cancer cells treated with foreign molecules. My lab houses a confocal fluorescence microscope and a fluorospectrometer, which are routinely used for visualization of cancer cell dynamics and for quantitating fluorescence.
These traffic pathways are imperative and dysregulation of these traffics are directly associated with multiple human disorders. It has been known that suboptimal endocytosis of LDL (Low Density Lipoprotein-bad cholesterol) or an inefficient recycling of LDL receptor is implicated in atherosclerosis. Inappropriate transport or trafficking of membrane components, including lipids and proteins, between membrane-bound organelles are associated with the onset of Alzheimer’s disease and other human diseases. Understanding these trafficking processes has been a major focus of cell biology for several decades. Accordingly, the Nobel Prize in Physiology and Medicine in 2014 was awarded to Dr. James E. Rothman, Dr. Randy W. Schekman and Dr. Thomas C. Südhof for their ground-breaking research concerning the regulation of inner cell protein/membrane traffic in eukaryotic cells.
The budding yeast, Saccharomyces cerevisiae, is a eukaryotic unicellular organism that harbors conserved traffic pathways. Its reproduction cycle is completed within 2 hours, and therefore many researchers have used yeast as their experimental organism for the study of intracellular trafficking. Results obtained from yeast are broadly applicable to higher eukaryotic systems.
Dynamin, which is a GTPase implicated in membrane-pinching off activity and is essential for membrane trafficking of endocytosis and secretory pathways. Our lab has found yeast dynamin-like protein Vps1 plays roles in those traffics, and recently we characterized that Vps1 physically interacts with a recycling factor and a late endosome marker, as well as with a membrane coat protein. We are currently working on the physiological significance of these interactions in recycling and endocytic degradation traffics. We will further elucidate a regulatory role of Vps1 on coat protein assembly at the Golgi.
Study of membrane fusion
We make artificial membranes made of phospholipids and process these to carry SNARE proteins. We study the roles of several proteins implicated in membrane fusion along with SNAREs.
Study of cytoskeletal motor proteins for intracellular trafficking
We are interested in identifying and characterizing motor proteins that carry protein cargo-laden vesicles, moving along the actin system.
Study of gene expression alteration using RNAseq
We have been testing the potential cytotoxicity of nanoparticles (carbon nanotubes, silver, cadmium, chitosan) on fungal, mammalian cancer cells. We have recently worked on the effects of these nanoparticles on gene expression pattern, using a high-end DNA sequencer. We plan to measure the relative abundance of mRNA sequences in nanoparticle-treated cells and validate the data with qPCR in the near future.