Pusan National University

About: Pusan National University is a education organization based out in Busan, South Korea. It is known for research contribution in the topics: Catalysis & Population. The organization has 24124 authors who have published 45054 publications receiving 819356 citations. The organization is also known as: Busan National University & Pusan University.

Role of ERK activation in cisplatin-induced apoptosis in OK renal epithelial cells.

Abstract: Cisplatin induces apoptosis in a variety of cell types. However, the signaling pathway of cisplatin-induced apoptosis in renal epithelial cells is poorly understood. The present study was undertaken to determine the role of the extracellular signal-regulated kinase (ERK) in cisplatin-induced apoptosis of renal epithelial cells using opossum kidney cells. Cisplatin at 50 microM induced apoptosis in a time-dependent manner. Cisplatin treatment caused sustained activation of ERK1/2, which was prevented by PD98059 and U0126, inhibitors of ERK1/2 upstream kinase MEK1/2. Transient transfection of cells with constitutive active MEK1 increased the cisplatin-induced apoptosis, whereas that with a dominant-negative mutant of MEK1 decreased it. Cisplatin induced an increase in Bax expression, mitochondrial membrane depolarization, mitochondrial cytochrome c release and caspase-3 activation, and these changes were prevented by the MEK inhibitor. These results suggested that (1) the ERK1/2 activation is required for the cisplatin-induced apoptosis of renal epithelial cells; and (2) ERK1/2 mediates the mitochondria-dependent apoptotic signaling by acting upstream of Bax expression.

Template Free Preparation of Heteroatoms Doped Carbon Spheres with Trace Fe for Efficient Oxygen Reduction Reaction and Supercapacitor

Abstract: Dithiooxamide (DTO), an organic ligand, is used to synthesize a ZnDTO framework, which acts as a precursor for self-doping of heteroatoms in the presence of hemoglobin via carbonization process for S and N doped carbon (SNC) and Fe-SNC. The sphere shaped porous carbon particles having a graphene network exhibit excellent performance for energy conversion and energy storage applications.

Pleiotropic Roles of Polyglycerolphosphate Synthase of Lipoteichoic Acid in Growth of Staphylococcus aureus Cells

Abstract: Lipoteichoic acid (LTA) is one of two anionic polymers on the surface of the gram-positive bacterium Staphylococcus aureus. LTA is critical for the bacterium-host cell interaction and has recently been shown to be required for cell growth and division. To determine additional biological roles of LTA, we found it necessary to identify permissive conditions for the growth of an LTA-deficient mutant. We found that an LTA-deficient S. aureus ΔltaS mutant could grow at 30°C but not at 37°C. Even at the permissive temperature, ΔltaS mutant cells had aberrant cell division and separation, decreased autolysis, and reduced levels of peptidoglycan hydrolases. Upshift of ΔltaS mutant cells to a nonpermissive temperature caused an inability to exclude Sytox green dye. A high-osmolarity growth medium remarkably rescued the colony-forming ability of the ΔltaS mutant at 37°C, indicating that LTA synthesis is required for growth under low-osmolarity conditions. In addition, the ΔltaS mutation was found to be synthetically lethal with the ΔtagO mutation, which disrupts the synthesis of the other anionic polymer, wall teichoic acid (WTA), at 30°C, suggesting that LTA and WTA compensate for one another in an essential function.