Laboratory of Structural Biology

Structural biology is the essential part of modern biology for understanding the fascinating molecular events within the cell and for developing novel therapeutics. We are particularly interested in the structure-function relationship of the protein complexes involved in protein degradation and autophagy pathways. A myriad of proteins and organelles in cell have their own life-span. Problems in protein and/or organelle turn-over cause defects in cellular processes and subsequently numerous diseases in general. Accordingly, to understand structure-function relationship on the target proteins and related molecule diseases, it is important to recognize protein degradation signals, activation mechanism of proteases, and molecular events in the autophagic pathways. The below three sections sketch our key research activities. 1. Autophagic molecules Autophagy, a bulk degradation process of cell’s own proteins or oranelles by lysosomes (or vacuoles in fungi), is tightly regulated to maintain a balance between synthesis and degradation of cellular products. It is an important mechanism for recycling cellular building blocks under metabolically stressful conditions. We have expanded our research to whole autophagic pathways including several selective autophagy pathways (including xenophagy [autophagy for bacterial clearance] and aggrephagy [autophagy for protein aggregates]), ubiquitylation-like enzymatic mechanism, and autophagosome maturation. 2. Ubiquitin Biology Ubiquitin (Ub) is a small protein composed of 76 amino acids found only in eukaryotes. It plays as a key signal for proteasome-dependent protein degradation pathway by a covalent modification of target proteins. Ub-dependent degradation regulates diverse cellular processes including cell cycle progression, muscle di