Inhwan Hwang 

    Professor Inhwan Hwang joined the Department of Life Science at POSTECH as an associate professor in 1999 from Gyeongsang National University where he taught for six years. He got his postdoctoral training at the Genetics Department of Harvard Medical School from 1988 to 1993 right after obtaining his doctoral degree in 1988 at the University of North Carolina-Chapel Hill. He earned his BS and MS degrees at Seoul National University in 1981 and 1983, respectively. Now he is the Director of the Creative Research Center for Plant Intracellular trafficking.
 

From understanding intracellular trafficking in plant cells to engineering of customer-designed cells

    Dr. Hwang focuses his research effort on elucidating and understanding the molecular mechanisms of 1) how a higher eukaryotic cell coordinates and maintains its multi-compartmental organization (subcellular organelles), 2) how a large number of proteins and lipids are transported between these compartments, 3) how a multi-cellular organism can be developed from a single cell. At the same time, he is actively pursuing the development of tools to improve or engineer plant cells as environmentally sound production systems.

    In eukaryotic systems such as the plant, the cell is composed of various subcellular compartments. Since the plant cell is composed of various compartments Dr. Hwang believes that the cell has an operating system to coordinate and regulate all these subcellular compartments to function as a single unit in a harmonious way and that a large number of molecules must be involved in these complex processes. Therefore, he is trying to isolate and characterize important molecular players of these processes by molecular, biochemical, and cellular approaches. To study intracellular trafficking and protein import into chloroplasts in plant cells in vivo, Dr. Hwang introduced completely new methods to the field of plant cell biology. He developed numerous marker proteins for all the known organelles in plant cells and used them to study intracellular trafficking in real time and more dynamic ways. By employing such novel systems, he has discovered and characterized many critical proteins such as five isoforms of ADL and their interacting proteins, many Rabs, Arf isoforms, actin, and lipid molecules involved in various steps of intracellular trafficking pathways and elucidated the molecular mechanisms of vacuolar trafficking of PtdIns3P and soluble cargo proteins from the Golgi apparatus. He also defined the molecular mechanism of protein trafficking from the ER to the storage vacuole. Endocytosis is another important area of his research. He discovered that molecules are internalized into the vacuole from the plasma membrane through the endosome and the prevacuolar compartment. His lab is also studying molecular mechanisms of protein imports into chloroplasts or protein targeting to the envelope membrane of chloroplasts in vivo and discovered a new organelle, named the prechloroplast compartment, that serves as an intermediate compartment for proteins destined to chloroplasts. In addition, he is trying to decipher targeting information encoded into various organellar proteins by dissecting them and re-assemblying these informations into new chimeric proteins. Through this process Dr. Hwang is trying to understand the underlying mechanism by which one could generate multi-functional proteins that can be targeted to the specific organelle by re-assemblying various functional modules and targeting information.

    "This study will provide valuable information on how a single cell orchestrates such a large number of proteins (cellular work force) to function as a single unit in a harmonious way. Furthermore, once we know how to create various multi-functional proteins and how to deploy these multi-functional and artificial proteins (new cellular work force) into various subcellular compartments of plant cells we will be able to engineer or improve plant cells to become environmentally sound production systems", he tells.