The environmentally prevalent arsenate (AsV) is reduced in the body to the much more toxic arsenite (AsIII). Recently, we have demonstrated that the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) catalyzes the reduction of AsV in the presence of glutathione, yet the role of GAPDH in AsV reduction in vivo is unknown. Therefore, we examined the effect of (S)-alpha-cholorhydrin...

“Oscillations and Dynamic Instabilities in Chemical Systems” is the title of the Gordon Research Conference inaugurated in 1982 by Irving R. Epstein, whom we honor with this Focus Issue. Oscillations and dynamic instabilities in chemical systems comprise the study of dynamical phenomena in chemically reacting systems far from equilibrium. Systematic exploration of this area began with investiga...

Along the gastrointestinal tract a number of epithelia contribute with acid or basic secretions in order to aid digestive processes. The stomach and pancreas are the most extreme examples of acid (H(+)) and base (HCO(-) 3) transporters, respectively. Nevertheless, they share the same challenges of transporting acid and bases across epithelia and effectively regulating their intracellular pH. In...

Sudden temperature changes in soil can induce stress in soil-dwelling invertebrates. Hyperthermic conditions have an impact on gene expression as one of the first steps. We use a transcriptomics approach using microarrays to identify expression changes in response to heat in the springtail Folsomia candida. An elevation of temperature (Delta 10 degrees C) altered the expression of 142 genes (11...

The ParA family of ATPases is responsible for transporting bacterial chromosomes, plasmids and large protein machineries. ParAs pattern the nucleoid in vivo, but how patterning functions or is exploited in transport is of considerable debate. Here we discuss the process of self-organization into patterns on the bacterial nucleoid and explore how it relates to the molecular mechanism of ParA act...

Ethylene is an important regulator of plant growth. We identified an Arabidopsis mutant, responsive-to-antagonist1 (ran1), that shows ethylene phenotypes in response to treatment with trans-cyclooctene, a potent receptor antagonist. Genetic epistasis studies revealed an early requirement for RAN1 in the ethylene pathway. RAN1 was cloned and found to encode a protein with similarity to copper-tr...

Copper is an essential micronutrient that is necessary for healthy immune function. This requirement is underscored by an increased susceptibility to bacterial infection in copper-deficient animals; however, a molecular understanding of its importance in immune defense is unknown. In this study, we investigated the effect of proinflammatory agents on copper homeostasis in RAW264.7 macrophages. ...

Although the mechanisms underlying selective targeting of tail-anchored (TA) membrane proteins are well established in mammalian and yeast cells, little is known about their role in mediating intracellular membrane trafficking in plant cells. However, a recent study suggested that, in green algae, arsenite transporters located in the cytosol (ArsA1 and ArsA2) control the insertion of TA protein...

BACKGROUND Arsenic is both a human carcinogen and a chemotherapeutic agent, but the mechanism of neither arsenic-induced carcinogenesis nor tumor selective cytotoxicity is clear. Using a model cell line in which p53 expression is regulated exogenously in a tetracycline-off system (TR9-7 cells) , our laboratory has shown that arsenite disrupts mitosis and that p53-deficient cells [p53(-)], in co...