막생물학 연구실

Our research interests lie on targeting, processing and insertion of membrane proteins in eukaryotes. How membrane proteins are correctly targeted, membrane inserted, processed and folded are fundamental questions in cell biology. Yet, many unresolved questions of how diverse types of membrane and secretory proteins are recognized by the general translocation machinery, how membrane insertion, processing of membrane proteins are coordinated with spatiotemporal folding and translocation of soluble domains during early stages of their biogenesis, how these processes are regulated remain to be answered. Failed membrane protein biogenesis can lead to the development of various diseases. Viruses also exploit these pathways for the formation of viral packages and for hijacking the immune response in the eukaryotic hosts. Understanding of the secretory and membrane protein biogenesis will provide the basis for the mechanistic insights into the membrane protein folding related diseases and viral protein processing and maturation. Our current projects aim to elucidate the mechanisms of the signal peptidase-mediated processing of secretory and membrane proteins, membrane protein topogenesis in the endoplasmic reticulum (ER), and the characterization of the mitochondrial targeting sequences. The signal peptidase is an evolutionarily conserved membrane protease that cleaves the N-terminal signal peptide of secretory proteins. While prokaryotic signal peptidases function in a monomer, eukaryotic ones contain two non-catalytic subunits, Spc1 and Spc2. Recently, we have found that transmembrane segments of membrane proteins become susceptible to cleavage by signal peptidase when Spc1 is deleted. When Spc1 was overexpressed, membrane protein processing was reduced, indicating that it r