In this study, Bax inhibitor-1 (BI-1release from ER microsomes from BI-1-overexpressing cells and BI-1-reconsituted liposomes. Acidic conditions also induced BI-1 protein oligomerization. Interestingly subjecting BI-1-overexpressing cells to acidic conditions induced more Bax recruitment to mitochondria, more cytochrome c release from mitochondria, and more cell death. These findings suggest that BI-1 increases Ca 2؉ leak rates from the ER through a mechanism that is dependent on pH and on the carboxyl-terminal cytosolic region of the BI-1 protein. The findings also reveal a cell death-promoting phenotype for BI-1 that is manifested under low pH conditions. The endoplasmic reticulum (ER)3 contains the largest calcium reserve in the cell (1, 2). Agonist-induced ER calcium release occurs through Ca 2ϩ channels such as inositol trisphosphate (IP 3 ) and ryanodine receptors (3). Calcium uptake into the ER occurs when the calcium release channels are closed (i.e. negative feedback to the IP 3 receptor) (4) and is performed by sarcoplasmic reticulum/ER-associated calcium-activated ATPase pumps (5). In the resting state, the Ca 2ϩ content of the ER reflects a balance between active uptake by sarcoplasmic reticulum/ER-associated calcium-activated ATPase and passive efflux or basal leakage through other Ca 2ϩ channels. This leakage is revealed when sarcoplasmic reticulum/ER-associated calcium-activated ATPase pumps are inhibited by agents such as thapsigargin (6), causing Ca 2ϩ to leak out of the ER into the cytosol.The Bax inhibitor-1 (BI-1) (also known as "testis enhanced gene transcript" (TEGT)) is an antiapoptotic protein capable of inhibiting Bax activation and translocation to mitochondria (7). This ubiquitously expressed protein contains several transmembrane domains and localizes to the ER. The homology of BI-1 sequences among species is striking, and the characteristic hydrophobicity and ER membrane localization are evolutionarily conserved (8). BI-1 affects calcium leakage from the ER as measured with Ca 2ϩ -sensitive, ER-targeted fluorescent proteins and Ca 2ϩ -sensitive dyes (9). However, the mechanism by which BI-1 regulates ER Ca 2ϩ fluxes remains unclear. Here we have provided additional evidence that BI-1 induces passive Ca 2ϩ leakage from the ER and also show that BI-1 activity is regulated by pH in a manner dependent on the carboxyl-terminal cytosolic domain of this protein.* This work was supported, in whole or in part, by National Institutes of Health Grant AG15393 (to J. C. R.). This work was also supported by Korea Research Foundation Grants KRF-2005-070-C00095, E00021, and 2005-015-E00210 and Korea Science and Engineering Foundation Grants R01-2006-000-10422-0 and R01-2007-000-20275-0. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

This study aims to develop and apply self-healing concrete as a new method for crack control and enhanced service life in concrete structure. This concept is one of the maintenance-free methods which, apart from saving direct costs for maintenance and repair, reduces the indirect costs -a saving generally welcomed by contractors. In this research, the self-healing phenomenon of autogenous healing concrete using geo-materials for practical industrial application was investigated. Moreover, a self-healing concrete was fabricated by ready-mixed car in a ready-mixed concrete factory, then used for the construction of artificial water-retaining structures and actual tunnel structures. The results show that the crack of concrete was significantly self-healed up to 28 days re-curing. Crack-width of 0.15mm was self-healed after re-curing for 3 days and the crack width decreased from 0.22 mm to 0.16 mm after re-curing for 7 days. Furthermore, it was almost completely self-healed at 33 days. It was founded that this phenomenon occurred mainly due to the swelling effect, expansion effect and re-crystallization. From these results, it is considered that the utilization of appropriate dosages of geo-materials has a high potential for one of new repairing methods of cracked concrete under the water leakage of underground civil infrastructure such as tunnels.

It has been suggested that plant phytochromes are autophosphorylating serine/threonine kinases. However, the biochemical properties and functional roles of putative phytochrome kinase activity in plant light signalling are largely unknown. Here, we describe the biochemical and functional characterization of Avena sativa phytochrome A (AsphyA) as a potential protein kinase. We provide evidence that phytochrome-interacting factors (PIFs) are phosphorylated by phytochromes in vitro. Domain mapping of AsphyA shows that the photosensory core region consisting of PAS-GAF-PHY domains in the N-terminal is required for the observed kinase activity. Moreover, we demonstrate that transgenic plants expressing mutant versions of AsphyA, which display reduced activity in in vitro kinase assays, show hyposensitive responses to far-red light. Further analysis reveals that far-red light-induced phosphorylation and degradation of PIF3 are significantly reduced in these transgenic plants. Collectively, these results suggest a positive relationship between phytochrome kinase activity and photoresponses in plants.

This study investigated the molecular mechanism by which Bax inhibitor 1 (BI1) abrogates the accumulation of reactive oxygen species (ROS) in the endoplasmic reticulum (ER). Electron uncoupling between NADPH-dependent cytochrome P450 reductase (NPR) and cytochrome P450 2E1 (P450 2E1) is a major source of ROS on the ER membrane. ER stress produced ROS accumulation and lipid peroxidation of the ER membrane, but BI1 reduced this accumulation. Under ER stress, expression of P450 2E1 in control cells was upregulated more than in BI1-overexpressing cells. In control cells, inhibiting P450 2E1 through chemical or siRNA approaches suppressed ROS accumulation, ER membrane lipid peroxidation and the resultant cell death after ER stress. However, it had little effect in BI1-overexpressing cells. In addition, BI1 knock down also increased ROS accumulation and expression of P450 2E1. In a reconstituted phospholipid membrane containing purified BI1, NPR and P450 2E1, BI1 dose-dependently decreased the production of ROS. BI1 bound to NPR with higher affinity than P450 2E1. Furthermore, BI1 overexpression reduced the interaction of NPR and P450 2E1, and decreased the catalytic activity of P450 2E1, suggesting that the flow of electrons from NPR to P450 2E1 can be modulated by BI1. In summary, BI1 reduces the accumulation of ROS and the resultant cell death through regulating P450 2E1.

An extreme diversity of substrates and catalytic reactions of cytochrome P450 (P450) enzymes is considered to be the consequence of evolutionary adaptation driven by different metabolic or environmental demands. Here we report the presence of numerous natural variants of P450 BM3 (CYP102A1) within a species of Bacillus megaterium. Extensive amino acid substitutions (up to 5% of the total 1049 amino acid residues) were identified from the variants. Phylogenetic analyses suggest that this P450 gene evolve more rapidly than the rRNA gene locus. It was found that key catalytic residues in the substrate channel and active site are retained. Although there were no apparent variations in hydroxylation activity towards myristic acid (C14) and palmitic acid (C16), the hydroxylation rates of lauric acid (C12) by the variants varied in the range of >25-fold. Interestingly, catalytic activities of the variants are promiscuous towards non-natural substrates including human P450 substrates. It can be suggested that CYP102A1 variants can acquire new catalytic activities through site-specific mutations distal to the active site.