p53R2 regulates thioredoxin reductase activity through interaction with TrxR2.

Ribonucleotide reductase small subunit p53R2 is a member of the ribonucleotide reductase family that supplies dNTPs for nuclear and mitochondrial DNA replication and repair. Here, we have identified a mitochondrial thioredoxin reductase 2 (TrxR2) as a novel p53R2-binding protein. We demonstrated a direct interaction between the two, and observed that p53R2 stimulated the enzymatic activity of TrxR in vitro. Moreover, TrxR2 activity was significantly lower in p53R2 knockdown cells, and increased when p53R2 was overexpressed, effects that were independent of p53. Furthermore, p53R2 knockdown suppressed UV-induced TrxR activity. These findings suggest that p53R2 acts as a positive regulator of TrxR2 activity in mitochondria both under normal physiological conditions and during the cellular response to DNA damage.

Preparation of nanoporous carbons via a grafting method for the application to electrochemical double layer capacitors.

Nanoporous carbon materials with a controlled pore size and surface area were prepared using grafting method. The use of 3-mercaptopropyltrimethoxysilane (MPTMS) as a grafting material played an important role in producing a porous structure by linking the silica to the polymer, with the subsequent formation of a silica-polymer composite. Importantly, the use of an organic solvent, compared to an aqueous solvent, has a positive effect in forming uniform and well-developed carbon structures, due to the high degree of dispersion with well-mixing of the carbon and silica precursors. The amounts of MPTMS and carbon precursor used determined the pore size and surface area of resulting carbon materials. The optimum ratio of MPTMS and carbon precursor for achieving a high surface area in excess of 2000 m2/g was determined. The use of a large amount of carbon precursor resulted in carbons with a relatively small surface area and an increase in MPTMS content led to an increase in the microporous structures. The capacitance value of the porous carbon prepared using the optimum ratio was determined to be 150 F/g.